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myisamchk
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The myisamchk utility gets information about your database tables or checks, repairs, or optimizes them. myisamchk works with MyISAM tables (tables that have .MYD and .MYI files for storing data and indexes). You can also use the CHECK TABLE and REPAIR TABLE statements to check and repair MyISAM tables. See Section 13.7.3.2, “CHECK TABLE Statement”, and Section 13.7.3.5, “REPAIR TABLE Statement”. The use of myisamchk with partitioned tables is not supported. Caution It is best to make a backup of a table before performing a table repair operation; under some circumstances the operation might cause data loss. Possible causes include but are not limited to file system errors. Invoke myisamchk like this: myisamchk [options] tbl_name ... The options specify what you want myisamchk to do. They are described in the following sections. You can also get a list of options by invoking myisamchk --help. With no options, myisamchk simply checks your table as the default operation. To get more information or to tell myisamchk to take corrective action, specify options as described in the following discussion. tbl_name is the database table you want to check or repair. If you run myisamchk somewhere other than in the database directory, you must specify the path to the database directory, because myisamchk has no idea where the database is located. In fact, myisamchk does not actually care whether the files you are working on are located in a database directory. You can copy the files that correspond to a database table into some other location and perform recovery operations on them there. You can name several tables on the myisamchk command line if you wish. You can also specify a table by naming its index file (the file with the .MYI suffix). This enables you to specify all tables in a directory by using the pattern *.MYI. For example, if you are in a database directory, you can check all the MyISAM tables in that directory like this: myisamchk *.MYI If you are not in the database directory, you can check all the tables there by specifying the path to the directory: myisamchk /path/to/database_dir/*.MYI You can even check all tables in all databases by specifying a wildcard with the path to the MySQL data directory: myisamchk /path/to/datadir/*/*.MYI The recommended way to quickly check all MyISAM tables is: myisamchk --silent --fast /path/to/datadir/*/*.MYI If you want to check all MyISAM tables and repair any that are corrupted, you can use the following command: myisamchk --silent --force --fast --update-state \ --key_buffer_size=64M --myisam_sort_buffer_size=64M \ --read_buffer_size=1M --write_buffer_size=1M \ /path/to/datadir/*/*.MYI This command assumes that you have more than 64MB free. For more information about memory allocation with myisamchk, see the section called “MYISAMCHK MEMORY USAGE”. For additional information about using myisamchk, see Section 7.6, “MyISAM Table Maintenance and Crash Recovery”. Important You must ensure that no other program is using the tables while you are running myisamchk. The most effective means of doing so is to shut down the MySQL server while running myisamchk, or to lock all tables that myisamchk is being used on. Otherwise, when you run myisamchk, it may display the following error message: warning: clients are using or haven't closed the table properly This means that you are trying to check a table that has been updated by another program (such as the mysqld server) that hasn't yet closed the file or that has died without closing the file properly, which can sometimes lead to the corruption of one or more MyISAM tables. If mysqld is running, you must force it to flush any table modifications that are still buffered in memory by using FLUSH TABLES. You should then ensure that no one is using the tables while you are running myisamchk However, the easiest way to avoid this problem is to use CHECK TABLE instead of myisamchk to check tables. See Section 13.7.3.2, “CHECK TABLE Statement”. myisamchk supports the following options, which can be specified on the command line or in the [myisamchk] group of an option file. For information about option files used by MySQL programs, see Section 4.2.2.2, “Using Option Files”. MYISAMCHK GENERAL OPTIONS The options described in this section can be used for any type of table maintenance operation performed by myisamchk. The sections following this one describe options that pertain only to specific operations, such as table checking or repairing. • --help, -? ┌────────────────────┬────────┐ │Command-Line Format │ --help │ └────────────────────┴────────┘ Display a help message and exit. Options are grouped by type of operation. • --HELP, -H ┌────────────────────┬────────┐ │Command-Line Format │ --HELP │ └────────────────────┴────────┘ Display a help message and exit. Options are presented in a single list. • --debug=debug_options, -# debug_options ┌────────────────────┬────────────────────────────┐ │Command-Line Format │ --debug[=debug_options] │ ├────────────────────┼────────────────────────────┤ │Type │ String │ ├────────────────────┼────────────────────────────┤ │Default Value │ d:t:o,/tmp/myisamchk.trace │ └────────────────────┴────────────────────────────┘ Write a debugging log. A typical debug_options string is d:t:o,file_name. The default is d:t:o,/tmp/myisamchk.trace. This option is available only if MySQL was built using WITH_DEBUG. MySQL release binaries provided by Oracle are not built using this option. • --defaults-extra-file=file_name ┌────────────────────┬─────────────────────────────────┐ │Command-Line Format │ --defaults-extra-file=file_name │ ├────────────────────┼─────────────────────────────────┤ │Type │ File name │ └────────────────────┴─────────────────────────────────┘ Read this option file after the global option file but (on Unix) before the user option file. If the file does not exist or is otherwise inaccessible, an error occurs. If file_name is not an absolute path name, it is interpreted relative to the current directory. For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”. • --defaults-file=file_name ┌────────────────────┬───────────────────────────┐ │Command-Line Format │ --defaults-file=file_name │ ├────────────────────┼───────────────────────────┤ │Type │ File name │ └────────────────────┴───────────────────────────┘ Use only the given option file. If the file does not exist or is otherwise inaccessible, an error occurs. If file_name is not an absolute path name, it is interpreted relative to the current directory. For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”. • --defaults-group-suffix=str ┌────────────────────┬─────────────────────────────┐ │Command-Line Format │ --defaults-group-suffix=str │ ├────────────────────┼─────────────────────────────┤ │Type │ String │ └────────────────────┴─────────────────────────────┘ Read not only the usual option groups, but also groups with the usual names and a suffix of str. For example, myisamchk normally reads the [myisamchk] group. If this option is given as --defaults-group-suffix=_other, myisamchk also reads the [myisamchk_other] group. For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”. • --no-defaults ┌────────────────────┬───────────────┐ │Command-Line Format │ --no-defaults │ └────────────────────┴───────────────┘ Do not read any option files. If program startup fails due to reading unknown options from an option file, --no-defaults can be used to prevent them from being read. The exception is that the .mylogin.cnf file is read in all cases, if it exists. This permits passwords to be specified in a safer way than on the command line even when --no-defaults is used. To create .mylogin.cnf, use the mysql_config_editor utility. See mysql_config_editor(1). For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”. • --print-defaults ┌────────────────────┬──────────────────┐ │Command-Line Format │ --print-defaults │ └────────────────────┴──────────────────┘ Print the program name and all options that it gets from option files. For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”. • --silent, -s ┌────────────────────┬──────────┐ │Command-Line Format │ --silent │ └────────────────────┴──────────┘ Silent mode. Write output only when errors occur. You can use -s twice (-ss) to make myisamchk very silent. • --verbose, -v ┌────────────────────┬───────────┐ │Command-Line Format │ --verbose │ └────────────────────┴───────────┘ Verbose mode. Print more information about what the program does. This can be used with -d and -e. Use -v multiple times (-vv, -vvv) for even more output. • --version, -V ┌────────────────────┬───────────┐ │Command-Line Format │ --version │ └────────────────────┴───────────┘ Display version information and exit. • --wait, -w ┌────────────────────┬─────────┐ │Command-Line Format │ --wait │ ├────────────────────┼─────────┤ │Type │ Boolean │ ├────────────────────┼─────────┤ │Default Value │ false │ └────────────────────┴─────────┘ Instead of terminating with an error if the table is locked, wait until the table is unlocked before continuing. If you are running mysqld with external locking disabled, the table can be locked only by another myisamchk command. You can also set the following variables by using --var_name=value syntax: ┌───────────────────────┬───────────────────┐ │Variable │ Default Value │ ├───────────────────────┼───────────────────┤ │decode_bits │ 9 │ ├───────────────────────┼───────────────────┤ │ft_max_word_len │ version-dependent │ ├───────────────────────┼───────────────────┤ │ft_min_word_len │ 4 │ ├───────────────────────┼───────────────────┤ │ft_stopword_file │ built-in list │ ├───────────────────────┼───────────────────┤ │key_buffer_size │ 523264 │ ├───────────────────────┼───────────────────┤ │myisam_block_size │ 1024 │ ├───────────────────────┼───────────────────┤ │myisam_sort_key_blocks │ 16 │ ├───────────────────────┼───────────────────┤ │read_buffer_size │ 262136 │ ├───────────────────────┼───────────────────┤ │sort_buffer_size │ 2097144 │ ├───────────────────────┼───────────────────┤ │sort_key_blocks │ 16 │ ├───────────────────────┼───────────────────┤ │stats_method │ nulls_unequal │ ├───────────────────────┼───────────────────┤ │write_buffer_size │ 262136 │ └───────────────────────┴───────────────────┘ The possible myisamchk variables and their default values can be examined with myisamchk --help: myisam_sort_buffer_size is used when the keys are repaired by sorting keys, which is the normal case when you use --recover. sort_buffer_size is a deprecated synonym for myisam_sort_buffer_size. key_buffer_size is used when you are checking the table with --extend-check or when the keys are repaired by inserting keys row by row into the table (like when doing normal inserts). Repairing through the key buffer is used in the following cases: • You use --safe-recover. • The temporary files needed to sort the keys would be more than twice as big as when creating the key file directly. This is often the case when you have large key values for CHAR, VARCHAR, or TEXT columns, because the sort operation needs to store the complete key values as it proceeds. If you have lots of temporary space and you can force myisamchk to repair by sorting, you can use the --sort-recover option. Repairing through the key buffer takes much less disk space than using sorting, but is also much slower. If you want a faster repair, set the key_buffer_size and myisam_sort_buffer_size variables to about 25% of your available memory. You can set both variables to large values, because only one of them is used at a time. myisam_block_size is the size used for index blocks. stats_method influences how NULL values are treated for index statistics collection when the --analyze option is given. It acts like the myisam_stats_method system variable. For more information, see the description of myisam_stats_method in Section 5.1.8, “Server System Variables”, and Section 8.3.8, “InnoDB and MyISAM Index Statistics Collection”. ft_min_word_len and ft_max_word_len indicate the minimum and maximum word length for FULLTEXT indexes on MyISAM tables. ft_stopword_file names the stopword file. These need to be set under the following circumstances. If you use myisamchk to perform an operation that modifies table indexes (such as repair or analyze), the FULLTEXT indexes are rebuilt using the default full-text parameter values for minimum and maximum word length and the stopword file unless you specify otherwise. This can result in queries failing. The problem occurs because these parameters are known only by the server. They are not stored in MyISAM index files. To avoid the problem if you have modified the minimum or maximum word length or the stopword file in the server, specify the same ft_min_word_len, ft_max_word_len, and ft_stopword_file values to myisamchk that you use for mysqld. For example, if you have set the minimum word length to 3, you can repair a table with myisamchk like this: myisamchk --recover --ft_min_word_len=3 tbl_name.MYI To ensure that myisamchk and the server use the same values for full-text parameters, you can place each one in both the [mysqld] and [myisamchk] sections of an option file: [mysqld] ft_min_word_len=3 [myisamchk] ft_min_word_len=3 An alternative to using myisamchk is to use the REPAIR TABLE, ANALYZE TABLE, OPTIMIZE TABLE, or ALTER TABLE. These statements are performed by the server, which knows the proper full-text parameter values to use. MYISAMCHK CHECK OPTIONS myisamchk supports the following options for table checking operations: • --check, -c ┌────────────────────┬─────────┐ │Command-Line Format │ --check │ └────────────────────┴─────────┘ Check the table for errors. This is the default operation if you specify no option that selects an operation type explicitly. • --check-only-changed, -C ┌────────────────────┬──────────────────────┐ │Command-Line Format │ --check-only-changed │ └────────────────────┴──────────────────────┘ Check only tables that have changed since the last check. • --extend-check, -e ┌────────────────────┬────────────────┐ │Command-Line Format │ --extend-check │ └────────────────────┴────────────────┘ Check the table very thoroughly. This is quite slow if the table has many indexes. This option should only be used in extreme cases. Normally, myisamchk or myisamchk --medium-check should be able to determine whether there are any errors in the table. If you are using --extend-check and have plenty of memory, setting the key_buffer_size variable to a large value helps the repair operation run faster. See also the description of this option under table repair options. For a description of the output format, see the section called “OBTAINING TABLE INFORMATION WITH MYISAMCHK”. • --fast, -F ┌────────────────────┬────────┐ │Command-Line Format │ --fast │ └────────────────────┴────────┘ Check only tables that haven't been closed properly. • --force, -f ┌────────────────────┬─────────┐ │Command-Line Format │ --force │ └────────────────────┴─────────┘ Do a repair operation automatically if myisamchk finds any errors in the table. The repair type is the same as that specified with the --recover or -r option. • --information, -i ┌────────────────────┬───────────────┐ │Command-Line Format │ --information │ └────────────────────┴───────────────┘ Print informational statistics about the table that is checked. • --medium-check, -m ┌────────────────────┬────────────────┐ │Command-Line Format │ --medium-check │ └────────────────────┴────────────────┘ Do a check that is faster than an --extend-check operation. This finds only 99.99% of all errors, which should be good enough in most cases. • --read-only, -T ┌────────────────────┬─────────────┐ │Command-Line Format │ --read-only │ └────────────────────┴─────────────┘ Do not mark the table as checked. This is useful if you use myisamchk to check a table that is in use by some other application that does not use locking, such as mysqld when run with external locking disabled. • --update-state, -U ┌────────────────────┬────────────────┐ │Command-Line Format │ --update-state │ └────────────────────┴────────────────┘ Store information in the .MYI file to indicate when the table was checked and whether the table crashed. This should be used to get full benefit of the --check-only-changed option, but you shouldn't use this option if the mysqld server is using the table and you are running it with external locking disabled. MYISAMCHK REPAIR OPTIONS myisamchk supports the following options for table repair operations (operations performed when an option such as --recover or --safe-recover is given): • --backup, -B ┌────────────────────┬──────────┐ │Command-Line Format │ --backup │ └────────────────────┴──────────┘ Make a backup of the .MYD file as file_name-time.BAK • --character-sets-dir=dir_name ┌────────────────────┬───────────────────────────┐ │Command-Line Format │ --character-sets-dir=path │ ├────────────────────┼───────────────────────────┤ │Type │ String │ ├────────────────────┼───────────────────────────┤ │Default Value │ [none] │ └────────────────────┴───────────────────────────┘ The directory where character sets are installed. See Section 10.15, “Character Set Configuration”. • --correct-checksum ┌────────────────────┬────────────────────┐ │Command-Line Format │ --correct-checksum │ └────────────────────┴────────────────────┘ Correct the checksum information for the table. • --data-file-length=len, -D len ┌────────────────────┬────────────────────────┐ │Command-Line Format │ --data-file-length=len │ ├────────────────────┼────────────────────────┤ │Type │ Numeric │ └────────────────────┴────────────────────────┘ The maximum length of the data file (when re-creating data file when it is “full”). • --extend-check, -e ┌────────────────────┬────────────────┐ │Command-Line Format │ --extend-check │ └────────────────────┴────────────────┘ Do a repair that tries to recover every possible row from the data file. Normally, this also finds a lot of garbage rows. Do not use this option unless you are desperate. See also the description of this option under table checking options. For a description of the output format, see the section called “OBTAINING TABLE INFORMATION WITH MYISAMCHK”. • --force, -f ┌────────────────────┬─────────┐ │Command-Line Format │ --force │ └────────────────────┴─────────┘ Overwrite old intermediate files (files with names like tbl_name.TMD) instead of aborting. • --keys-used=val, -k val ┌────────────────────┬─────────────────┐ │Command-Line Format │ --keys-used=val │ ├────────────────────┼─────────────────┤ │Type │ Numeric │ └────────────────────┴─────────────────┘ For myisamchk, the option value is a bit value that indicates which indexes to update. Each binary bit of the option value corresponds to a table index, where the first index is bit 0. An option value of 0 disables updates to all indexes, which can be used to get faster inserts. Deactivated indexes can be reactivated by using myisamchk -r. • --max-record-length=len ┌────────────────────┬─────────────────────────┐ │Command-Line Format │ --max-record-length=len │ ├────────────────────┼─────────────────────────┤ │Type │ Numeric │ └────────────────────┴─────────────────────────┘ Skip rows larger than the given length if myisamchk cannot allocate memory to hold them. • --parallel-recover, -p ┌────────────────────┬────────────────────┐ │Command-Line Format │ --parallel-recover │ └────────────────────┴────────────────────┘ Note This option is deprecated in MySQL 8.0.28 and removed in MySQL 8.0.30. Use the same technique as -r and -n, but create all the keys in parallel, using different threads. This is beta-quality code. Use at your own risk! • --quick, -q ┌────────────────────┬─────────┐ │Command-Line Format │ --quick │ └────────────────────┴─────────┘ Achieve a faster repair by modifying only the index file, not the data file. You can specify this option twice to force myisamchk to modify the original data file in case of duplicate keys. • --recover, -r ┌────────────────────┬───────────┐ │Command-Line Format │ --recover │ └────────────────────┴───────────┘ Do a repair that can fix almost any problem except unique keys that are not unique (which is an extremely unlikely error with MyISAM tables). If you want to recover a table, this is the option to try first. You should try --safe-recover only if myisamchk reports that the table cannot be recovered using --recover. (In the unlikely case that --recover fails, the data file remains intact.) If you have lots of memory, you should increase the value of myisam_sort_buffer_size. • --safe-recover, -o ┌────────────────────┬────────────────┐ │Command-Line Format │ --safe-recover │ └────────────────────┴────────────────┘ Do a repair using an old recovery method that reads through all rows in order and updates all index trees based on the rows found. This is an order of magnitude slower than --recover, but can handle a couple of very unlikely cases that --recover cannot. This recovery method also uses much less disk space than --recover. Normally, you should repair first using --recover, and then with --safe-recover only if --recover fails. If you have lots of memory, you should increase the value of key_buffer_size. • --set-collation=name ┌────────────────────┬──────────────────────┐ │Command-Line Format │ --set-collation=name │ ├────────────────────┼──────────────────────┤ │Type │ String │ └────────────────────┴──────────────────────┘ Specify the collation to use for sorting table indexes. The character set name is implied by the first part of the collation name. • --sort-recover, -n ┌────────────────────┬────────────────┐ │Command-Line Format │ --sort-recover │ └────────────────────┴────────────────┘ Force myisamchk to use sorting to resolve the keys even if the temporary files would be very large. • --tmpdir=dir_name, -t dir_name ┌────────────────────┬───────────────────┐ │Command-Line Format │ --tmpdir=dir_name │ ├────────────────────┼───────────────────┤ │Type │ Directory name │ └────────────────────┴───────────────────┘ The path of the directory to be used for storing temporary files. If this is not set, myisamchk uses the value of the TMPDIR environment variable. --tmpdir can be set to a list of directory paths that are used successively in round-robin fashion for creating temporary files. The separator character between directory names is the colon (:) on Unix and the semicolon (;) on Windows. • --unpack, -u ┌────────────────────┬──────────┐ │Command-Line Format │ --unpack │ └────────────────────┴──────────┘ Unpack a table that was packed with myisampack. OTHER MYISAMCHK OPTIONS myisamchk supports the following options for actions other than table checks and repairs: • --analyze, -a ┌────────────────────┬───────────┐ │Command-Line Format │ --analyze │ └────────────────────┴───────────┘ Analyze the distribution of key values. This improves join performance by enabling the join optimizer to better choose the order in which to join the tables and which indexes it should use. To obtain information about the key distribution, use a myisamchk --description --verbose tbl_name command or the SHOW INDEX FROM tbl_name statement. • --block-search=offset, -b offset ┌────────────────────┬───────────────────────┐ │Command-Line Format │ --block-search=offset │ ├────────────────────┼───────────────────────┤ │Type │ Numeric │ └────────────────────┴───────────────────────┘ Find the record that a block at the given offset belongs to. • --description, -d ┌────────────────────┬───────────────┐ │Command-Line Format │ --description │ └────────────────────┴───────────────┘ Print some descriptive information about the table. Specifying the --verbose option once or twice produces additional information. See the section called “OBTAINING TABLE INFORMATION WITH MYISAMCHK”. • --set-auto-increment[=value], -A[value] Force AUTO_INCREMENT numbering for new records to start at the given value (or higher, if there are existing records with AUTO_INCREMENT values this large). If value is not specified, AUTO_INCREMENT numbers for new records begin with the largest value currently in the table, plus one. • --sort-index, -S ┌────────────────────┬──────────────┐ │Command-Line Format │ --sort-index │ └────────────────────┴──────────────┘ Sort the index tree blocks in high-low order. This optimizes seeks and makes table scans that use indexes faster. • --sort-records=N, -R N ┌────────────────────┬──────────────────┐ │Command-Line Format │ --sort-records=# │ ├────────────────────┼──────────────────┤ │Type │ Numeric │ └────────────────────┴──────────────────┘ Sort records according to a particular index. This makes your data much more localized and may speed up range-based SELECT and ORDER BY operations that use this index. (The first time you use this option to sort a table, it may be very slow.) To determine a table's index numbers, use SHOW INDEX, which displays a table's indexes in the same order that myisamchk sees them. Indexes are numbered beginning with 1. If keys are not packed (PACK_KEYS=0), they have the same length, so when myisamchk sorts and moves records, it just overwrites record offsets in the index. If keys are packed (PACK_KEYS=1), myisamchk must unpack key blocks first, then re-create indexes and pack the key blocks again. (In this case, re-creating indexes is faster than updating offsets for each index.) OBTAINING TABLE INFORMATION WITH MYISAMCHK To obtain a description of a MyISAM table or statistics about it, use the commands shown here. The output from these commands is explained later in this section. • myisamchk -d tbl_name Runs myisamchk in “describe mode” to produce a description of your table. If you start the MySQL server with external locking disabled, myisamchk may report an error for a table that is updated while it runs. However, because myisamchk does not change the table in describe mode, there is no risk of destroying data. • myisamchk -dv tbl_name Adding -v runs myisamchk in verbose mode so that it produces more information about the table. Adding -v a second time produces even more information. • myisamchk -eis tbl_name Shows only the most important information from a table. This operation is slow because it must read the entire table. • myisamchk -eiv tbl_name This is like -eis, but tells you what is being done. The tbl_name argument can be either the name of a MyISAM table or the name of its index file, as described in myisamchk(1). Multiple tbl_name arguments can be given. Suppose that a table named person has the following structure. (The MAX_ROWS table option is included so that in the example output from myisamchk shown later, some values are smaller and fit the output format more easily.) CREATE TABLE person ( id INT NOT NULL AUTO_INCREMENT, last_name VARCHAR(20) NOT NULL, first_name VARCHAR(20) NOT NULL, birth DATE, death DATE, PRIMARY KEY (id), INDEX (last_name, first_name), INDEX (birth) ) MAX_ROWS = 1000000 ENGINE=MYISAM; Suppose also that the table has these data and index file sizes: -rw-rw---- 1 mysql mysql 9347072 Aug 19 11:47 person.MYD -rw-rw---- 1 mysql mysql 6066176 Aug 19 11:47 person.MYI Example of myisamchk -dvv output: MyISAM file: person Record format: Packed Character set: utf8mb4_0900_ai_ci (255) File-version: 1 Creation time: 2017-03-30 21:21:30 Status: checked,analyzed,optimized keys,sorted index pages Auto increment key: 1 Last value: 306688 Data records: 306688 Deleted blocks: 0 Datafile parts: 306688 Deleted data: 0 Datafile pointer (bytes): 4 Keyfile pointer (bytes): 3 Datafile length: 9347072 Keyfile length: 6066176 Max datafile length: 4294967294 Max keyfile length: 17179868159 Recordlength: 54 table description: Key Start Len Index Type Rec/key Root Blocksize 1 2 4 unique long 1 1024 2 6 80 multip. varchar prefix 0 1024 87 80 varchar 0 3 168 3 multip. uint24 NULL 0 1024 Field Start Length Nullpos Nullbit Type 1 1 1 2 2 4 no zeros 3 6 81 varchar 4 87 81 varchar 5 168 3 1 1 no zeros 6 171 3 1 2 no zeros Explanations for the types of information myisamchk produces are given here. “Keyfile” refers to the index file. “Record” and “row” are synonymous, as are “field” and “column.” The initial part of the table description contains these values: • MyISAM file Name of the MyISAM (index) file. • Record format The format used to store table rows. The preceding examples use Fixed length. Other possible values are Compressed and Packed. (Packed corresponds to what SHOW TABLE STATUS reports as Dynamic.) • Chararacter set The table default character set. • File-version Version of MyISAM format. Always 1. • Creation time When the data file was created. • Recover time When the index/data file was last reconstructed. • Status Table status flags. Possible values are crashed, open, changed, analyzed, optimized keys, and sorted index pages. • Auto increment key, Last value The key number associated the table's AUTO_INCREMENT column, and the most recently generated value for this column. These fields do not appear if there is no such column. • Data records The number of rows in the table. • Deleted blocks How many deleted blocks still have reserved space. You can optimize your table to minimize this space. See Section 7.6.4, “MyISAM Table Optimization”. • Datafile parts For dynamic-row format, this indicates how many data blocks there are. For an optimized table without fragmented rows, this is the same as Data records. • Deleted data How many bytes of unreclaimed deleted data there are. You can optimize your table to minimize this space. See Section 7.6.4, “MyISAM Table Optimization”. • Datafile pointer The size of the data file pointer, in bytes. It is usually 2, 3, 4, or 5 bytes. Most tables manage with 2 bytes, but this cannot be controlled from MySQL yet. For fixed tables, this is a row address. For dynamic tables, this is a byte address. • Keyfile pointer The size of the index file pointer, in bytes. It is usually 1, 2, or 3 bytes. Most tables manage with 2 bytes, but this is calculated automatically by MySQL. It is always a block address. • Max datafile length How long the table data file can become, in bytes. • Max keyfile length How long the table index file can become, in bytes. • Recordlength How much space each row takes, in bytes. The table description part of the output includes a list of all keys in the table. For each key, myisamchk displays some low-level information: • Key This key's number. This value is shown only for the first column of the key. If this value is missing, the line corresponds to the second or later column of a multiple-column key. For the table shown in the example, there are two table description lines for the second index. This indicates that it is a multiple-part index with two parts. • Start Where in the row this portion of the index starts. • Len How long this portion of the index is. For packed numbers, this should always be the full length of the column. For strings, it may be shorter than the full length of the indexed column, because you can index a prefix of a string column. The total length of a multiple-part key is the sum of the Len values for all key parts. • Index Whether a key value can exist multiple times in the index. Possible values are unique or multip. (multiple). • Type What data type this portion of the index has. This is a MyISAM data type with the possible values packed, stripped, or empty. • Root Address of the root index block. • Blocksize The size of each index block. By default this is 1024, but the value may be changed at compile time when MySQL is built from source. • Rec/key This is a statistical value used by the optimizer. It tells how many rows there are per value for this index. A unique index always has a value of 1. This may be updated after a table is loaded (or greatly changed) with myisamchk -a. If this is not updated at all, a default value of 30 is given. The last part of the output provides information about each column: • Field The column number. • Start The byte position of the column within table rows. • Length The length of the column in bytes. • Nullpos, Nullbit For columns that can be NULL, MyISAM stores NULL values as a flag in a byte. Depending on how many nullable columns there are, there can be one or more bytes used for this purpose. The Nullpos and Nullbit values, if nonempty, indicate which byte and bit contains that flag indicating whether the column is NULL. The position and number of bytes used to store NULL flags is shown in the line for field 1. This is why there are six Field lines for the person table even though it has only five columns. • Type The data type. The value may contain any of the following descriptors: • constant All rows have the same value. • no endspace Do not store endspace. • no endspace, not_always Do not store endspace and do not do endspace compression for all values. • no endspace, no empty Do not store endspace. Do not store empty values. • table-lookup The column was converted to an ENUM. • zerofill(N) The most significant N bytes in the value are always 0 and are not stored. • no zeros Do not store zeros. • always zero Zero values are stored using one bit. • Huff tree The number of the Huffman tree associated with the column. • Bits The number of bits used in the Huffman tree. The Huff tree and Bits fields are displayed if the table has been compressed with myisampack. See myisampack(1), for an example of this information. Example of myisamchk -eiv output: Checking MyISAM file: person Data records: 306688 Deleted blocks: 0 - check file-size - check record delete-chain No recordlinks - check key delete-chain block_size 1024: - check index reference - check data record references index: 1 Key: 1: Keyblocks used: 98% Packed: 0% Max levels: 3 - check data record references index: 2 Key: 2: Keyblocks used: 99% Packed: 97% Max levels: 3 - check data record references index: 3 Key: 3: Keyblocks used: 98% Packed: -14% Max levels: 3 Total: Keyblocks used: 98% Packed: 89% - check records and index references *** LOTS OF ROW NUMBERS DELETED *** Records: 306688 M.recordlength: 25 Packed: 83% Recordspace used: 97% Empty space: 2% Blocks/Record: 1.00 Record blocks: 306688 Delete blocks: 0 Record data: 7934464 Deleted data: 0 Lost space: 256512 Linkdata: 1156096 User time 43.08, System time 1.68 Maximum resident set size 0, Integral resident set size 0 Non-physical pagefaults 0, Physical pagefaults 0, Swaps 0 Blocks in 0 out 7, Messages in 0 out 0, Signals 0 Voluntary context switches 0, Involuntary context switches 0 Maximum memory usage: 1046926 bytes (1023k) myisamchk -eiv output includes the following information: • Data records The number of rows in the table. • Deleted blocks How many deleted blocks still have reserved space. You can optimize your table to minimize this space. See Section 7.6.4, “MyISAM Table Optimization”. • Key The key number. • Keyblocks used What percentage of the keyblocks are used. When a table has just been reorganized with myisamchk, the values are very high (very near theoretical maximum). • Packed MySQL tries to pack key values that have a common suffix. This can only be used for indexes on CHAR and VARCHAR columns. For long indexed strings that have similar leftmost parts, this can significantly reduce the space used. In the preceding example, the second key is 40 bytes long and a 97% reduction in space is achieved. • Max levels How deep the B-tree for this key is. Large tables with long key values get high values. • Records How many rows are in the table. • M.recordlength The average row length. This is the exact row length for tables with fixed-length rows, because all rows have the same length. • Packed MySQL strips spaces from the end of strings. The Packed value indicates the percentage of savings achieved by doing this. • Recordspace used What percentage of the data file is used. • Empty space What percentage of the data file is unused. • Blocks/Record Average number of blocks per row (that is, how many links a fragmented row is composed of). This is always 1.0 for fixed-format tables. This value should stay as close to 1.0 as possible. If it gets too large, you can reorganize the table. See Section 7.6.4, “MyISAM Table Optimization”. • Recordblocks How many blocks (links) are used. For fixed-format tables, this is the same as the number of rows. • Deleteblocks How many blocks (links) are deleted. • Recorddata How many bytes in the data file are used. • Deleted data How many bytes in the data file are deleted (unused). • Lost space If a row is updated to a shorter length, some space is lost. This is the sum of all such losses, in bytes. • Linkdata When the dynamic table format is used, row fragments are linked with pointers (4 to 7 bytes each). Linkdata is the sum of the amount of storage used by all such pointers. MYISAMCHK MEMORY USAGE Memory allocation is important when you run myisamchk. myisamchk uses no more memory than its memory-related variables are set to. If you are going to use myisamchk on very large tables, you should first decide how much memory you want it to use. The default is to use only about 3MB to perform repairs. By using larger values, you can get myisamchk to operate faster. For example, if you have more than 512MB RAM available, you could use options such as these (in addition to any other options you might specify): myisamchk --myisam_sort_buffer_size=256M \ --key_buffer_size=512M \ --read_buffer_size=64M \ --write_buffer_size=64M ... Using --myisam_sort_buffer_size=16M is probably enough for most cases. Be aware that myisamchk uses temporary files in TMPDIR. If TMPDIR points to a memory file system, out of memory errors can easily occur. If this happens, run myisamchk with the --tmpdir=dir_name option to specify a directory located on a file system that has more space. When performing repair operations, myisamchk also needs a lot of disk space: • Twice the size of the data file (the original file and a copy). This space is not needed if you do a repair with --quick; in this case, only the index file is re-created. This space must be available on the same file system as the original data file, as the copy is created in the same directory as the original. • Space for the new index file that replaces the old one. The old index file is truncated at the start of the repair operation, so you usually ignore this space. This space must be available on the same file system as the original data file. • When using --recover or --sort-recover (but not when using --safe-recover), you need space on disk for sorting. This space is allocated in the temporary directory (specified by TMPDIR or --tmpdir=dir_name). The following formula yields the amount of space required: (largest_key + row_pointer_length) * number_of_rows * 2 You can check the length of the keys and the row_pointer_length with myisamchk -dv tbl_name (see the section called “OBTAINING TABLE INFORMATION WITH MYISAMCHK”). The row_pointer_length and number_of_rows values are the Datafile pointer and Data records values in the table description. To determine the largest_key value, check the Key lines in the table description. The Len column indicates the number of bytes for each key part. For a multiple-column index, the key size is the sum of the Len values for all key parts. If you have a problem with disk space during repair, you can try --safe-recover instead of --recover. COPYRIGHT Copyright © 1997, 2023, Oracle and/or its affiliates. This documentation is free software; you can redistribute it and/or modify it only under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This documentation is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with the program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or see http://www.gnu.org/licenses/. SEE ALSO For more information, please refer to the MySQL Reference Manual, which may already be installed locally and which is also available online at http://dev.mysql.com/doc/. AUTHOR Oracle Corporation (http://dev.mysql.com/). MySQL 8.3 11/23/2023 MYISAMCHK(1)
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myisamchk - MyISAM table-maintenance utility
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myisamchk [options] tbl_name ...
| null | null |
xxhsum
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Print or check xxHash (32, 64 or 128 bits) checksums. When no FILE, read standard input, except if it´s the console. When FILE is -, read standard input even if it´s the console. xxhsum supports a command line syntax similar but not identical to md5sum(1). Differences are: xxhsum doesn´t have text/binary mode switch (-b, -t); xxhsum always treats files as binary file; xxhsum has a hash bit width switch (-H); As xxHash is a fast non-cryptographic checksum algorithm, xxhsum should not be used for security related purposes. xxhsum -b invokes benchmark mode. See OPTIONS and EXAMPLES for details.
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xxhsum - print or check xxHash non-cryptographic checksums
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xxhsum [<OPTION>] ... [<FILE>] ... xxhsum -b [<OPTION>] ... xxh32sum is equivalent to xxhsum -H0 xxh64sum is equivalent to xxhsum -H1 xxh128sum is equivalent to xxhsum -H2
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-V, --version Displays xxhsum version and exits -HHASHTYPE Hash selection. HASHTYPE means 0=32bits, 1=64bits, 2=128bits. Alternatively, HASHTYPE 32=32bits, 64=64bits, 128=128bits. Default value is 1 (64bits) --tag Output in the BSD style. --little-endian Set output hexadecimal checksum value as little endian convention. By default, value is displayed as big endian. -h, --help Displays help and exits The following four options are useful only when verifying checksums (-c) -c, --check FILE Read xxHash sums from FILE and check them -q, --quiet Don´t print OK for each successfully verified file --strict Return an error code if any line in the file is invalid, not just if some checksums are wrong. This policy is disabled by default, though UI will prompt an informational message if any line in the file is detected invalid. --status Don´t output anything. Status code shows success. -w, --warn Emit a warning message about each improperly formatted checksum line. The following options are useful only benchmark purpose -b Benchmark mode. See EXAMPLES for details. -b# Specify ID of variant to be tested. Multiple variants can be selected, separated by a ´,´ comma. -BBLOCKSIZE Only useful for benchmark mode (-b). See EXAMPLES for details. BLOCKSIZE specifies benchmark mode´s test data block size in bytes. Default value is 102400 -iITERATIONS Only useful for benchmark mode (-b). See EXAMPLES for details. ITERATIONS specifies number of iterations in benchmark. Single iteration lasts approximately 1000 milliseconds. Default value is 3 EXIT STATUS xxhsum exit 0 on success, 1 if at least one file couldn´t be read or doesn´t have the same checksum as the -c option.
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Output xxHash (64bit) checksum values of specific files to standard output $ xxhsum -H1 foo bar baz Output xxHash (32bit and 64bit) checksum values of specific files to standard output, and redirect it to xyz.xxh32 and qux.xxh64 $ xxhsum -H0 foo bar baz > xyz.xxh32 $ xxhsum -H1 foo bar baz > qux.xxh64 Read xxHash sums from specific files and check them $ xxhsum -c xyz.xxh32 qux.xxh64 Benchmark xxHash algorithm. By default, xxhsum benchmarks xxHash main variants on a synthetic sample of 100 KB, and print results into standard output. The first column is the algorithm, the second column is the source data size in bytes, the third column is the number of hashes generated per second (throughput), and finally the last column translates speed in megabytes per second. $ xxhsum -b In the following example, the sample to hash is set to 16384 bytes, the variants to be benched are selected by their IDs, and each benchmark test is repeated 10 times, for increased accuracy. $ xxhsum -b1,2,3 -i10 -B16384 BUGS Report bugs at: https://github.com/Cyan4973/xxHash/issues/ AUTHOR Yann Collet SEE ALSO md5sum(1) xxhsum 0.7.4 July 2020 XXHSUM(1)
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orc-contents
| null | null | null | null | null |
gss-client
| null | null | null | null | null |
datashader
| null | null | null | null | null |
2to3-3.11
| null | null | null | null | null |
pyrsa-decrypt
| null | null | null | null | null |
wsdump
| null | null | null | null | null |
imageio_download_bin
| null | null | null | null | null |
mysql_secure_installation
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This program enables you to improve the security of your MySQL installation in the following ways: • You can set a password for root accounts. • You can remove root accounts that are accessible from outside the local host. • You can remove anonymous-user accounts. • You can remove the test database (which by default can be accessed by all users, even anonymous users), and privileges that permit anyone to access databases with names that start with test_. mysql_secure_installation helps you implement security recommendations similar to those described at Section 2.9.4, “Securing the Initial MySQL Account”. Normal usage is to connect to the local MySQL server; invoke mysql_secure_installation without arguments: mysql_secure_installation When executed, mysql_secure_installation prompts you to determine which actions to perform. The validate_password component can be used for password strength checking. If the plugin is not installed, mysql_secure_installation prompts the user whether to install it. Any passwords entered later are checked using the plugin if it is enabled. Most of the usual MySQL client options such as --host and --port can be used on the command line and in option files. For example, to connect to the local server over IPv6 using port 3307, use this command: mysql_secure_installation --host=::1 --port=3307 mysql_secure_installation supports the following options, which can be specified on the command line or in the [mysql_secure_installation] and [client] groups of an option file. For information about option files used by MySQL programs, see Section 4.2.2.2, “Using Option Files”. • --help, -? ┌────────────────────┬────────┐ │Command-Line Format │ --help │ └────────────────────┴────────┘ Display a help message and exit. • --defaults-extra-file=file_name ┌────────────────────┬─────────────────────────────────┐ │Command-Line Format │ --defaults-extra-file=file_name │ ├────────────────────┼─────────────────────────────────┤ │Type │ File name │ └────────────────────┴─────────────────────────────────┘ Read this option file after the global option file but (on Unix) before the user option file. If the file does not exist or is otherwise inaccessible, an error occurs. If file_name is not an absolute path name, it is interpreted relative to the current directory. For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”. • --defaults-file=file_name ┌────────────────────┬───────────────────────────┐ │Command-Line Format │ --defaults-file=file_name │ ├────────────────────┼───────────────────────────┤ │Type │ File name │ └────────────────────┴───────────────────────────┘ Use only the given option file. If the file does not exist or is otherwise inaccessible, an error occurs. If file_name is not an absolute path name, it is interpreted relative to the current directory. For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”. • --defaults-group-suffix=str ┌────────────────────┬─────────────────────────────┐ │Command-Line Format │ --defaults-group-suffix=str │ ├────────────────────┼─────────────────────────────┤ │Type │ String │ └────────────────────┴─────────────────────────────┘ Read not only the usual option groups, but also groups with the usual names and a suffix of str. For example, mysql_secure_installation normally reads the [client] and [mysql_secure_installation] groups. If this option is given as --defaults-group-suffix=_other, mysql_secure_installation also reads the [client_other] and [mysql_secure_installation_other] groups. For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”. • --host=host_name, -h host_name ┌────────────────────┬────────┐ │Command-Line Format │ --host │ └────────────────────┴────────┘ Connect to the MySQL server on the given host. • --no-defaults ┌────────────────────┬───────────────┐ │Command-Line Format │ --no-defaults │ └────────────────────┴───────────────┘ Do not read any option files. If program startup fails due to reading unknown options from an option file, --no-defaults can be used to prevent them from being read. The exception is that the .mylogin.cnf file is read in all cases, if it exists. This permits passwords to be specified in a safer way than on the command line even when --no-defaults is used. To create .mylogin.cnf, use the mysql_config_editor utility. See mysql_config_editor(1). For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”. • --password=password, -p password ┌────────────────────┬─────────────────────┐ │Command-Line Format │ --password=password │ ├────────────────────┼─────────────────────┤ │Type │ String │ ├────────────────────┼─────────────────────┤ │Default Value │ [none] │ └────────────────────┴─────────────────────┘ This option is accepted but ignored. Whether or not this option is used, mysql_secure_installation always prompts the user for a password. • --port=port_num, -P port_num ┌────────────────────┬─────────────────┐ │Command-Line Format │ --port=port_num │ ├────────────────────┼─────────────────┤ │Type │ Numeric │ ├────────────────────┼─────────────────┤ │Default Value │ 3306 │ └────────────────────┴─────────────────┘ For TCP/IP connections, the port number to use. • --print-defaults ┌────────────────────┬──────────────────┐ │Command-Line Format │ --print-defaults │ └────────────────────┴──────────────────┘ Print the program name and all options that it gets from option files. For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”. • --protocol={TCP|SOCKET|PIPE|MEMORY} ┌────────────────────┬────────────────────────┐ │Command-Line Format │ --protocol=type │ ├────────────────────┼────────────────────────┤ │Type │ String │ ├────────────────────┼────────────────────────┤ │Default Value │ [see text] │ ├────────────────────┼────────────────────────┤ │Valid Values │ TCP SOCKET PIPE │ │ │ MEMORY │ └────────────────────┴────────────────────────┘ The transport protocol to use for connecting to the server. It is useful when the other connection parameters normally result in use of a protocol other than the one you want. For details on the permissible values, see Section 4.2.7, “Connection Transport Protocols”. • --socket=path, -S path ┌────────────────────┬────────────────────────────────┐ │Command-Line Format │ --socket={file_name|pipe_name} │ ├────────────────────┼────────────────────────────────┤ │Type │ String │ └────────────────────┴────────────────────────────────┘ For connections to localhost, the Unix socket file to use, or, on Windows, the name of the named pipe to use. On Windows, this option applies only if the server was started with the named_pipe system variable enabled to support named-pipe connections. In addition, the connection must be a member of the Windows group specified by the named_pipe_full_access_group system variable. • --ssl* Options that begin with --ssl specify whether to connect to the server using encryption and indicate where to find SSL keys and certificates. See the section called “Command Options for Encrypted Connections”. • --ssl-fips-mode={OFF|ON|STRICT} ┌────────────────────┬─────────────────────────────────┐ │Command-Line Format │ --ssl-fips-mode={OFF|ON|STRICT} │ ├────────────────────┼─────────────────────────────────┤ │Deprecated │ Yes │ ├────────────────────┼─────────────────────────────────┤ │Type │ Enumeration │ ├────────────────────┼─────────────────────────────────┤ │Default Value │ OFF │ ├────────────────────┼─────────────────────────────────┤ │Valid Values │ OFF ON STRICT │ └────────────────────┴─────────────────────────────────┘ Controls whether to enable FIPS mode on the client side. The --ssl-fips-mode option differs from other --ssl-xxx options in that it is not used to establish encrypted connections, but rather to affect which cryptographic operations to permit. See Section 6.8, “FIPS Support”. These --ssl-fips-mode values are permitted: • OFF: Disable FIPS mode. • ON: Enable FIPS mode. • STRICT: Enable “strict” FIPS mode. Note If the OpenSSL FIPS Object Module is not available, the only permitted value for --ssl-fips-mode is OFF. In this case, setting --ssl-fips-mode to ON or STRICT causes the client to produce a warning at startup and to operate in non-FIPS mode. This option is deprecated. Expect it to be removed in a future version of MySQL. • --tls-ciphersuites=ciphersuite_list ┌────────────────────┬─────────────────────────────────────┐ │Command-Line Format │ --tls-ciphersuites=ciphersuite_list │ ├────────────────────┼─────────────────────────────────────┤ │Type │ String │ └────────────────────┴─────────────────────────────────────┘ The permissible ciphersuites for encrypted connections that use TLSv1.3. The value is a list of one or more colon-separated ciphersuite names. The ciphersuites that can be named for this option depend on the SSL library used to compile MySQL. For details, see Section 6.3.2, “Encrypted Connection TLS Protocols and Ciphers”. • --tls-sni-servername=server_name ┌────────────────────┬──────────────────────────────────┐ │Command-Line Format │ --tls-sni-servername=server_name │ ├────────────────────┼──────────────────────────────────┤ │Type │ String │ └────────────────────┴──────────────────────────────────┘ When specified, the name is passed to the libmysqlclient C API library using the MYSQL_OPT_TLS_SNI_SERVERNAME option of mysql_options(). The server name is not case-sensitive. To show which server name the client specified for the current session, if any, check the Tls_sni_server_name status variable. Server Name Indication (SNI) is an extension to the TLS protocol (OpenSSL must be compiled using TLS extensions for this option to function). The MySQL implementation of SNI represents the client-side only. • --tls-version=protocol_list ┌────────────────────┬───────────────────────────────┐ │Command-Line Format │ --tls-version=protocol_list │ ├────────────────────┼───────────────────────────────┤ │Type │ String │ ├────────────────────┼───────────────────────────────┤ │Default Value │ TLSv1,TLSv1.1,TLSv1.2,TLSv1.3 │ │ │ (OpenSSL 1.1.1 or higher) │ │ │ TLSv1,TLSv1.1,TLSv1.2 │ │ │ (otherwise) │ └────────────────────┴───────────────────────────────┘ The permissible TLS protocols for encrypted connections. The value is a list of one or more comma-separated protocol names. The protocols that can be named for this option depend on the SSL library used to compile MySQL. For details, see Section 6.3.2, “Encrypted Connection TLS Protocols and Ciphers”. • --use-default ┌────────────────────┬───────────────┐ │Command-Line Format │ --use-default │ ├────────────────────┼───────────────┤ │Type │ Boolean │ └────────────────────┴───────────────┘ Execute noninteractively. This option can be used for unattended installation operations. • --user=user_name, -u user_name ┌────────────────────┬──────────────────┐ │Command-Line Format │ --user=user_name │ ├────────────────────┼──────────────────┤ │Type │ String │ └────────────────────┴──────────────────┘ The user name of the MySQL account to use for connecting to the server. COPYRIGHT Copyright © 1997, 2023, Oracle and/or its affiliates. This documentation is free software; you can redistribute it and/or modify it only under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This documentation is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with the program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or see http://www.gnu.org/licenses/. SEE ALSO For more information, please refer to the MySQL Reference Manual, which may already be installed locally and which is also available online at http://dev.mysql.com/doc/. AUTHOR Oracle Corporation (http://dev.mysql.com/). MySQL 8.3 11/23/2023 MYSQL_SECURE_INSTALLATION(1)
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mysql_secure_installation - improve MySQL installation security
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mysql_secure_installation
| null | null |
tqdm
| null | null | null | null | null |
xxh128sum
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Print or check xxHash (32, 64 or 128 bits) checksums. When no FILE, read standard input, except if it´s the console. When FILE is -, read standard input even if it´s the console. xxhsum supports a command line syntax similar but not identical to md5sum(1). Differences are: xxhsum doesn´t have text/binary mode switch (-b, -t); xxhsum always treats files as binary file; xxhsum has a hash bit width switch (-H); As xxHash is a fast non-cryptographic checksum algorithm, xxhsum should not be used for security related purposes. xxhsum -b invokes benchmark mode. See OPTIONS and EXAMPLES for details.
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xxhsum - print or check xxHash non-cryptographic checksums
|
xxhsum [<OPTION>] ... [<FILE>] ... xxhsum -b [<OPTION>] ... xxh32sum is equivalent to xxhsum -H0 xxh64sum is equivalent to xxhsum -H1 xxh128sum is equivalent to xxhsum -H2
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-V, --version Displays xxhsum version and exits -HHASHTYPE Hash selection. HASHTYPE means 0=32bits, 1=64bits, 2=128bits. Alternatively, HASHTYPE 32=32bits, 64=64bits, 128=128bits. Default value is 1 (64bits) --tag Output in the BSD style. --little-endian Set output hexadecimal checksum value as little endian convention. By default, value is displayed as big endian. -h, --help Displays help and exits The following four options are useful only when verifying checksums (-c) -c, --check FILE Read xxHash sums from FILE and check them -q, --quiet Don´t print OK for each successfully verified file --strict Return an error code if any line in the file is invalid, not just if some checksums are wrong. This policy is disabled by default, though UI will prompt an informational message if any line in the file is detected invalid. --status Don´t output anything. Status code shows success. -w, --warn Emit a warning message about each improperly formatted checksum line. The following options are useful only benchmark purpose -b Benchmark mode. See EXAMPLES for details. -b# Specify ID of variant to be tested. Multiple variants can be selected, separated by a ´,´ comma. -BBLOCKSIZE Only useful for benchmark mode (-b). See EXAMPLES for details. BLOCKSIZE specifies benchmark mode´s test data block size in bytes. Default value is 102400 -iITERATIONS Only useful for benchmark mode (-b). See EXAMPLES for details. ITERATIONS specifies number of iterations in benchmark. Single iteration lasts approximately 1000 milliseconds. Default value is 3 EXIT STATUS xxhsum exit 0 on success, 1 if at least one file couldn´t be read or doesn´t have the same checksum as the -c option.
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Output xxHash (64bit) checksum values of specific files to standard output $ xxhsum -H1 foo bar baz Output xxHash (32bit and 64bit) checksum values of specific files to standard output, and redirect it to xyz.xxh32 and qux.xxh64 $ xxhsum -H0 foo bar baz > xyz.xxh32 $ xxhsum -H1 foo bar baz > qux.xxh64 Read xxHash sums from specific files and check them $ xxhsum -c xyz.xxh32 qux.xxh64 Benchmark xxHash algorithm. By default, xxhsum benchmarks xxHash main variants on a synthetic sample of 100 KB, and print results into standard output. The first column is the algorithm, the second column is the source data size in bytes, the third column is the number of hashes generated per second (throughput), and finally the last column translates speed in megabytes per second. $ xxhsum -b In the following example, the sample to hash is set to 16384 bytes, the variants to be benched are selected by their IDs, and each benchmark test is repeated 10 times, for increased accuracy. $ xxhsum -b1,2,3 -i10 -B16384 BUGS Report bugs at: https://github.com/Cyan4973/xxHash/issues/ AUTHOR Yann Collet SEE ALSO md5sum(1) xxhsum 0.7.4 July 2020 XXHSUM(1)
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keyring
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ahost
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Look up the DNS A or AAAA record associated with HOST (a hostname or an IP address). This utility comes with the c-ares asynchronous resolver library.
|
ahost - print the A or AAAA record associated with a hostname or IP address
|
ahost [OPTION]... HOST...
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-d Print some extra debugging output. -h, -? Display this help and exit. -t type If type is "a", print the A record. If type is "aaaa", print the AAAA record. If type is "u", look for both AAAA and A records (default). -s server Set the server list to use for DNS lookups. -D domain Specify the domain to search instead of using the default values from /etc/resolv.conf. This option only has an effect on platforms that use /etc/resolv.conf for DNS configuration; it has no effect on other platforms (such as Win32 or Android). REPORTING BUGS Report bugs to the c-ares mailing list: https://lists.haxx.se/listinfo/c-ares SEE ALSO adig(1) c-ares utilities April 2011 AHOST(1)
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cbrunsli
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gettext
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The gettext program translates a natural language message into the user's language, by looking up the translation in a message catalog. Display native language translation of a textual message. -d, --domain=TEXTDOMAIN retrieve translated messages from TEXTDOMAIN -c, --context=CONTEXT specify context for MSGID -e enable expansion of some escape sequences -n suppress trailing newline -E (ignored for compatibility) [TEXTDOMAIN] MSGID retrieve translated message corresponding to MSGID from TEXTDOMAIN Informative output: -h, --help display this help and exit -V, --version display version information and exit If the TEXTDOMAIN parameter is not given, the domain is determined from the environment variable TEXTDOMAIN. If the message catalog is not found in the regular directory, another location can be specified with the environment variable TEXTDOMAINDIR. When used with the -s option the program behaves like the 'echo' command. But it does not simply copy its arguments to stdout. Instead those messages found in the selected catalog are translated. Standard search directory: /opt/homebrew/Cellar/gettext/0.22.5/share/locale AUTHOR Written by Ulrich Drepper. REPORTING BUGS Report bugs in the bug tracker at <https://savannah.gnu.org/projects/gettext> or by email to <bug-gettext@gnu.org>. COPYRIGHT Copyright © 1995-2023 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. SEE ALSO The full documentation for gettext is maintained as a Texinfo manual. If the info and gettext programs are properly installed at your site, the command info gettext should give you access to the complete manual. GNU gettext-runtime 0.22.5 February 2024 GETTEXT(1)
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gettext - translate message
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gettext [OPTION] [[TEXTDOMAIN] MSGID] gettext [OPTION] -s [MSGID]...
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gtester-report
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sqlite3
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To start a sqlite3 interactive session, invoke the sqlite3 command and optionally provide the name of a database file. If the database file does not exist, it will be created. If the database file does exist, it will be opened. For example, to create a new database file named "mydata.db", create a table named "memos" and insert a couple of records into that table: $ sqlite3 mydata.db SQLite version 3.8.8 Enter ".help" for instructions sqlite> create table memos(text, priority INTEGER); sqlite> insert into memos values('deliver project description', 10); sqlite> insert into memos values('lunch with Christine', 100); sqlite> select * from memos; deliver project description|10 lunch with Christine|100 sqlite> If no database name is supplied, the ATTACH sql command can be used to attach to existing or create new database files. ATTACH can also be used to attach to multiple databases within the same interactive session. This is useful for migrating data between databases, possibly changing the schema along the way. Optionally, a SQL statement or set of SQL statements can be supplied as a single argument. Multiple statements should be separated by semi- colons. For example: $ sqlite3 -line mydata.db 'select * from memos where priority > 20;' text = lunch with Christine priority = 100 SQLITE META-COMMANDS The interactive interpreter offers a set of meta-commands that can be used to control the output format, examine the currently attached database files, or perform administrative operations upon the attached databases (such as rebuilding indices). Meta-commands are always prefixed with a dot (.). A list of available meta-commands can be viewed at any time by issuing the '.help' command. For example: sqlite> .help .backup ?DB? FILE Backup DB (default "main") to FILE .bail on|off Stop after hitting an error. Default OFF .clone NEWDB Clone data into NEWDB from the existing database .databases List names and files of attached databases .dump ?TABLE? ... Dump the database in an SQL text format If TABLE specified, only dump tables matching LIKE pattern TABLE. .echo on|off Turn command echo on or off .eqp on|off Enable or disable automatic EXPLAIN QUERY PLAN .exit Exit this program .explain ?on|off? Turn output mode suitable for EXPLAIN on or off. With no args, it turns EXPLAIN on. .fullschema Show schema and the content of sqlite_stat tables .headers on|off Turn display of headers on or off .help Show this message .import FILE TABLE Import data from FILE into TABLE .indices ?TABLE? Show names of all indices If TABLE specified, only show indices for tables matching LIKE pattern TABLE. .load FILE ?ENTRY? Load an extension library .log FILE|off Turn logging on or off. FILE can be stderr/stdout .mode MODE ?TABLE? Set output mode where MODE is one of: csv Comma-separated values column Left-aligned columns. (See .width) html HTML <table> code insert SQL insert statements for TABLE line One value per line list Values delimited by .separator string tabs Tab-separated values tcl TCL list elements .nullvalue STRING Use STRING in place of NULL values .once FILENAME Output for the next SQL command only to FILENAME .open ?FILENAME? Close existing database and reopen FILENAME .output ?FILENAME? Send output to FILENAME or stdout .print STRING... Print literal STRING .prompt MAIN CONTINUE Replace the standard prompts .quit Exit this program .read FILENAME Execute SQL in FILENAME .restore ?DB? FILE Restore content of DB (default "main") from FILE .save FILE Write in-memory database into FILE .schema ?TABLE? Show the CREATE statements If TABLE specified, only show tables matching LIKE pattern TABLE. .separator STRING ?NL? Change separator used by output mode and .import NL is the end-of-line mark for CSV .shell CMD ARGS... Run CMD ARGS... in a system shell .show Show the current values for various settings .stats on|off Turn stats on or off .system CMD ARGS... Run CMD ARGS... in a system shell .tables ?TABLE? List names of tables If TABLE specified, only list tables matching LIKE pattern TABLE. .timeout MS Try opening locked tables for MS milliseconds .timer on|off Turn SQL timer on or off .trace FILE|off Output each SQL statement as it is run .vfsname ?AUX? Print the name of the VFS stack .width NUM1 NUM2 ... Set column widths for "column" mode Negative values right-justify sqlite>
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sqlite3 - A command line interface for SQLite version 3
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sqlite3 [options] [databasefile] [SQL] SUMMARY sqlite3 is a terminal-based front-end to the SQLite library that can evaluate queries interactively and display the results in multiple formats. sqlite3 can also be used within shell scripts and other applications to provide batch processing features.
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sqlite3 has the following options: -bail Stop after hitting an error. -batch Force batch I/O. -column Query results will be displayed in a table like form, using whitespace characters to separate the columns and align the output. -cmd command run command before reading stdin -csv Set output mode to CSV (comma separated values). -echo Print commands before execution. -init file Read and execute commands from file , which can contain a mix of SQL statements and meta-commands. -[no]header Turn headers on or off. -help Show help on options and exit. -html Query results will be output as simple HTML tables. -interactive Force interactive I/O. -line Query results will be displayed with one value per line, rows separated by a blank line. Designed to be easily parsed by scripts or other programs -list Query results will be displayed with the separator (|, by default) character between each field value. The default. -mmap N Set default mmap size to N -nullvalue string Set string used to represent NULL values. Default is '' (empty string). -separator separator Set output field separator. Default is '|'. -stats Print memory stats before each finalize. -version Show SQLite version. -vfs name Use name as the default VFS. INIT FILE sqlite3 reads an initialization file to set the configuration of the interactive environment. Throughout initialization, any previously specified setting can be overridden. The sequence of initialization is as follows: o The default configuration is established as follows: mode = LIST separator = "|" main prompt = "sqlite> " continue prompt = " ...> " o If the file ~/.sqliterc exists, it is processed first. can be found in the user's home directory, it is read and processed. It should generally only contain meta-commands. o If the -init option is present, the specified file is processed. o All other command line options are processed. SEE ALSO http://www.sqlite.org/cli.html The sqlite3-doc package. AUTHOR This manual page was originally written by Andreas Rottmann <rotty@debian.org>, for the Debian GNU/Linux system (but may be used by others). It was subsequently revised by Bill Bumgarner <bbum@mac.com> and further updated by Laszlo Boszormenyi <gcs@debian.hu> . Fri Oct 31 10:41:31 EDT 2014 SQLITE3(1)
| null |
markdown-it
| null | null | null | null | null |
infocmp
|
infocmp can be used to compare a binary terminfo entry with other terminfo entries, rewrite a terminfo description to take advantage of the use= terminfo field, or print out a terminfo description from the binary file (term) in a variety of formats. In all cases, the boolean fields will be printed first, followed by the numeric fields, followed by the string fields. Default Options If no options are specified and zero or one termnames are specified, the -I option will be assumed. If more than one termname is specified, the -d option will be assumed. Comparison Options [-d] [-c] [-n] infocmp compares the terminfo description of the first terminal termname with each of the descriptions given by the entries for the other terminal's termnames. If a capability is defined for only one of the terminals, the value returned will depend on the type of the capability: F for boolean variables, -1 for integer variables, and NULL for string variables. The -d option produces a list of each capability that is different between two entries. This option is useful to show the difference between two entries, created by different people, for the same or similar terminals. The -c option produces a list of each capability that is common between two or more entries. Capabilities that are not set are ignored. This option can be used as a quick check to see if the -u option is worth using. The -n option produces a list of each capability that is in none of the given entries. If no termnames are given, the environment variable TERM will be used for both of the termnames. This can be used as a quick check to see if anything was left out of a description. Source Listing Options [-I] [-L] [-C] [-r] The -I, -L, and -C options will produce a source listing for each terminal named. -I use the terminfo names -L use the long C variable name listed in <term.h> -C use the termcap names -r when using -C, put out all capabilities in termcap form -K modifies the -C option, improving BSD-compatibility. If no termnames are given, the environment variable TERM will be used for the terminal name. The source produced by the -C option may be used directly as a termcap entry, but not all parameterized strings can be changed to the termcap format. infocmp will attempt to convert most of the parameterized information, and anything not converted will be plainly marked in the output and commented out. These should be edited by hand. For best results when converting to termcap format, you should use both -C and -r. Normally a termcap description is limited to 1023 bytes. infocmp trims away less essential parts to make it fit. If you are converting to one of the (rare) termcap implementations which accept an unlimited size of termcap, you may want to add the -T option. More often however, you must help the termcap implementation, and trim excess whitespace (use the -0 option for that). All padding information for strings will be collected together and placed at the beginning of the string where termcap expects it. Mandatory padding (padding information with a trailing '/') will become optional. All termcap variables no longer supported by terminfo, but which are derivable from other terminfo variables, will be output. Not all terminfo capabilities will be translated; only those variables which were part of termcap will normally be output. Specifying the -r option will take off this restriction, allowing all capabilities to be output in termcap form. Normally you would use both the -C and -r options. The actual format used incorporates some improvements for escaped characters from terminfo format. For a stricter BSD-compatible translation, use the -K option rather than -C. Note that because padding is collected to the beginning of the capability, not all capabilities are output. Mandatory padding is not supported. Because termcap strings are not as flexible, it is not always possible to convert a terminfo string capability into an equivalent termcap format. A subsequent conversion of the termcap file back into terminfo format will not necessarily reproduce the original terminfo source. Some common terminfo parameter sequences, their termcap equivalents, and some terminal types which commonly have such sequences, are: terminfo termcap Representative Terminals ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ %p1%c %. adm %p1%d %d hp, ANSI standard, vt100 %p1%'x'%+%c %+x concept %i %iq ANSI standard, vt100 %p1%?%'x'%>%t%p1%'y'%+%; %>xy concept %p2 is printed before %p1 %r hp Use= Option [-u] The -u option produces a terminfo source description of the first terminal termname which is relative to the sum of the descriptions given by the entries for the other terminals termnames. It does this by analyzing the differences between the first termname and the other termnames and producing a description with use= fields for the other terminals. In this manner, it is possible to retrofit generic terminfo entries into a terminal's description. Or, if two similar terminals exist, but were coded at different times or by different people so that each description is a full description, using infocmp will show what can be done to change one description to be relative to the other. A capability will get printed with an at-sign (@) if it no longer exists in the first termname, but one of the other termname entries contains a value for it. A capability's value gets printed if the value in the first termname is not found in any of the other termname entries, or if the first of the other termname entries that has this capability gives a different value for the capability than that in the first termname. The order of the other termname entries is significant. Since the terminfo compiler tic does a left-to-right scan of the capabilities, specifying two use= entries that contain differing entries for the same capabilities will produce different results depending on the order that the entries are given in. infocmp will flag any such inconsistencies between the other termname entries as they are found. Alternatively, specifying a capability after a use= entry that contains that capability will cause the second specification to be ignored. Using infocmp to recreate a description can be a useful check to make sure that everything was specified correctly in the original source description. Another error that does not cause incorrect compiled files, but will slow down the compilation time, is specifying extra use= fields that are superfluous. infocmp will flag any other termname use= fields that were not needed. Changing Databases [-A directory] [-B directory] Like other ncurses utilities, infocmp looks for the terminal descriptions in several places. You can use the TERMINFO and TERMINFO_DIRS environment variables to override the compiled-in default list of places to search (see curses(3X) for details). You can also use the options -A and -B to override the list of places to search when comparing terminal descriptions: • The -A option sets the location for the first termname • The -B option sets the location for the other termnames. Using these options, it is possible to compare descriptions for a terminal with the same name located in two different databases. For instance, you can use this feature for comparing descriptions for the same terminal created by different people. Other Options -0 causes the fields to be printed on one line, without wrapping. -1 causes the fields to be printed out one to a line. Otherwise, the fields will be printed several to a line to a maximum width of 60 characters. -a tells infocmp to retain commented-out capabilities rather than discarding them. Capabilities are commented by prefixing them with a period. -D tells infocmp to print the database locations that it knows about, and exit. -E Dump the capabilities of the given terminal as tables, needed in the C initializer for a TERMTYPE structure (the terminal capability structure in the <term.h>). This option is useful for preparing versions of the curses library hardwired for a given terminal type. The tables are all declared static, and are named according to the type and the name of the corresponding terminal entry. Before ncurses 5.0, the split between the -e and -E options was not needed; but support for extended names required making the arrays of terminal capabilities separate from the TERMTYPE structure. -e Dump the capabilities of the given terminal as a C initializer for a TERMTYPE structure (the terminal capability structure in the <term.h>). This option is useful for preparing versions of the curses library hardwired for a given terminal type. -F compare terminfo files. This assumes that two following arguments are filenames. The files are searched for pairwise matches between entries, with two entries considered to match if any of their names do. The report printed to standard output lists entries with no matches in the other file, and entries with more than one match. For entries with exactly one match it includes a difference report. Normally, to reduce the volume of the report, use references are not resolved before looking for differences, but resolution can be forced by also specifying -r. -f Display complex terminfo strings which contain if/then/else/endif expressions indented for readability. -G Display constant literals in decimal form rather than their character equivalents. -g Display constant character literals in quoted form rather than their decimal equivalents. -i Analyze the initialization (is1, is2, is3), and reset (rs1, rs2, rs3), strings in the entry, as well as those used for starting/stopping cursor-positioning mode (smcup, rmcup) as well as starting/stopping keymap mode (smkx, rmkx). For each string, the code tries to analyze it into actions in terms of the other capabilities in the entry, certain X3.64/ISO 6429/ECMA-48 capabilities, and certain DEC VT-series private modes (the set of recognized special sequences has been selected for completeness over the existing terminfo database). Each report line consists of the capability name, followed by a colon and space, followed by a printable expansion of the capability string with sections matching recognized actions translated into {}-bracketed descriptions. Here is a list of the DEC/ANSI special sequences recognized: Action Meaning ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ RIS full reset SC save cursor RC restore cursor LL home-down RSR reset scroll region ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ DECSTR soft reset (VT320) S7C1T 7-bit controls (VT220) ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ISO DEC G0 enable DEC graphics for G0 ISO UK G0 enable UK chars for G0 ISO US G0 enable US chars for G0 ISO DEC G1 enable DEC graphics for G1 ISO UK G1 enable UK chars for G1 ISO US G1 enable US chars for G1 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ DECPAM application keypad mode DECPNM normal keypad mode DECANSI enter ANSI mode ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ECMA[+-]AM keyboard action mode ECMA[+-]IRM insert replace mode ECMA[+-]SRM send receive mode ECMA[+-]LNM linefeed mode ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ DEC[+-]CKM application cursor keys DEC[+-]ANM set VT52 mode DEC[+-]COLM 132-column mode DEC[+-]SCLM smooth scroll DEC[+-]SCNM reverse video mode DEC[+-]OM origin mode DEC[+-]AWM wraparound mode DEC[+-]ARM auto-repeat mode It also recognizes a SGR action corresponding to ANSI/ISO 6429/ECMA Set Graphics Rendition, with the values NORMAL, BOLD, UNDERLINE, BLINK, and REVERSE. All but NORMAL may be prefixed with `+' (turn on) or `-' (turn off). An SGR0 designates an empty highlight sequence (equivalent to {SGR:NORMAL}). -l Set output format to terminfo. -p Ignore padding specifications when comparing strings. -q Make the comparison listing shorter by omitting subheadings, and using "-" for absent capabilities, "@" for canceled rather than "NULL". -Rsubset Restrict output to a given subset. This option is for use with archaic versions of terminfo like those on SVr1, Ultrix, or HP/UX that do not support the full set of SVR4/XSI Curses terminfo; and variants such as AIX that have their own extensions incompatible with SVr4/XSI. Available terminfo subsets are "SVr1", "Ultrix", "HP", and "AIX"; see terminfo(5) for details. You can also choose the subset "BSD" which selects only capabilities with termcap equivalents recognized by 4.4BSD. -s [d|i|l|c] The -s option sorts the fields within each type according to the argument below: d leave fields in the order that they are stored in the terminfo database. i sort by terminfo name. l sort by the long C variable name. c sort by the termcap name. If the -s option is not given, the fields printed out will be sorted alphabetically by the terminfo name within each type, except in the case of the -C or the -L options, which cause the sorting to be done by the termcap name or the long C variable name, respectively. -T eliminates size-restrictions on the generated text. This is mainly useful for testing and analysis, since the compiled descriptions are limited (e.g., 1023 for termcap, 4096 for terminfo). -t tells tic to discard commented-out capabilities. Normally when translating from terminfo to termcap, untranslatable capabilities are commented-out. -U tells infocmp to not post-process the data after parsing the source file. This feature helps when comparing the actual contents of two source files, since it excludes the inferences that infocmp makes to fill in missing data. -V reports the version of ncurses which was used in this program, and exits. -v n prints out tracing information on standard error as the program runs. Higher values of n induce greater verbosity. -w width changes the output to width characters. -x print information for user-defined capabilities. These are extensions to the terminfo repertoire which can be loaded using the -x option of tic. FILES /usr/share/terminfo Compiled terminal description database. EXTENSIONS The -0, -1, -E, -F, -G, -R, -T, -V, -a, -e, -f, -g, -i, -l, -p, -q and -t options are not supported in SVr4 curses. The -r option's notion of `termcap' capabilities is System V Release 4's. Actual BSD curses versions will have a more restricted set. To see only the 4.4BSD set, use -r -RBSD. BUGS The -F option of infocmp(1M) should be a toe(1M) mode. SEE ALSO captoinfo(1M), infotocap(1M), tic(1M), toe(1M), curses(3X), terminfo(5). http://invisible-island.net/ncurses/tctest.html This describes ncurses version 5.7 (patch 20081102). AUTHOR Eric S. Raymond <esr@snark.thyrsus.com> and Thomas E. Dickey <dickey@invisible-island.net> infocmp(1M)
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infocmp - compare or print out terminfo descriptions
|
infocmp [-1CDEFGIKLTUVcdegilnpqrtux] [-v n] [-s d| i| l| c] [-R subset] [-w width] [-A directory] [-B directory] [termname...]
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arm64-apple-darwin20.0.0-ar
| null | null | null | null | null |
huggingface-cli
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nm
|
As of Xcode 8.0 the default nm(1) tool is llvm-nm(1). For the most part nm(1) and llvm-nm(1) have the same options; notable exceptions include -f, -s, and -L as described below. This document explains options common between the two commands as well as some historically relevant options supported by nm-classic(1). More help on options for llvm-nm(1) is provided when running it with the --help option. nm displays the name list (symbol table of nlist structures) of each object file in the argument list. In some cases, as with an object that has had strip(1) with its -T option used on the object, that can be different than the dyld information. For that information use dyldinfo(1). If an argument is an archive, a listing for each object file in the archive will be produced. File can be of the form libx.a(x.o), in which case only symbols from that member of the object file are listed. (The parentheses have to be quoted to get by the shell.) If no file is given, the symbols in a.out are listed. Each symbol name is preceded by its value (blanks if undefined). Unless the -m option is specified, this value is followed by one of the following characters, representing the symbol type: U (undefined), A (absolute), T (text section symbol), D (data section symbol), B (bss section symbol), C (common symbol), - (for debugger symbol table entries; see -a below), S (symbol in a section other than those above), or I (indirect symbol). If the symbol is local (non-external), the symbol's type is instead represented by the corresponding lowercase letter. A lower case u in a dynamic shared library indicates a undefined reference to a private external in another module in the same library. If the symbol is a Objective-C method, the symbol name is ±[Class_name(category_name) method:name:], where `+' is for class methods, `-' is for instance methods, and (category_name) is present only when the method is in a category. The output is sorted alphabetically by default. Options are: -a Display all symbol table entries, including those inserted for use by debuggers. -g Display only global (external) symbols. -n Sort numerically rather than alphabetically. -o Prepend file or archive element name to each output line, rather than only once. -p Don't sort; display in symbol-table order. -r Sort in reverse order. -u Display only undefined symbols. -U Don't display undefined symbols. -m Display the N_SECT type symbols (Mach-O symbols) as (segment_name, section_name) followed by either external or non-external and then the symbol name. Undefined, common, absolute and indirect symbols get displayed as (undefined), (common), (absolute), and (indirect), respectively. Other symbol details are displayed in a human-friendly manner, such as "[no dead strip]". nm will display the referenced symbol for indirect symbols and will display the name of the library expected to provide an undefined symbol. See nlist(3) and <mach- o/nlist.h> for more information on the nlist structure. -x Display the symbol table entry's fields in hexadecimal, along with the name as a string. -j Just display the symbol names (no value or type). -s segname sectname List only those symbols in the section (segname,sectname). For llvm-nm(1) this option must be last on the command line, and after the files. -l List a pseudo symbol .section_start if no symbol has as its value the starting address of the section. (This is used with the -s option above.) -arch arch_type Specifies the architecture, arch_type, of the file for nm(1) to operate on when the file is a universal file (see arch(3) for the currently known arch_types). The arch_type can be "all" to operate on all architectures in the file. The default is to display the symbols from only the host architecture, if the file contains it; otherwise, symbols for all architectures in the file are displayed. -f format For llvm-nm(1) this specifies the output format. Where format can be bsd, sysv, posix or darwin. -f For nm-classic(1) this displays the symbol table of a dynamic library flat (as one file not separate modules). This is obsolete and not supported with llvm-nm(1). -A Write the pathname or library name of an object on each line. -P Write information in a portable output format. -t format For the -P output, write the numeric value in the specified format. The format shall be dependent on the single character used as the format option-argument: d The value shall be written in decimal (default). o The value shall be written in octal. x The value shall be written in hexadecimal. -L Display the symbols in the bitcode files in the (__LLVM,__bundle) section if present instead of the object's symbol table. For nm-classic(1) this is the default if the object has no symbol table and an (__LLVM,__bundle) section exists. This option is not supported by llvm-nm(1) where displaying llvm bitcode symbols is the default behavior. SEE ALSO ar(1), ar(5), Mach-O(5), stab(5), nlist(3), dyldinfo(1) BUGS Displaying Mach-O symbols with -m is too verbose. Without the -m, symbols in the Objective-C sections get displayed as an `s'. Apple, Inc. December 13, 2018 NM(1)
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nm - display name list (symbol table)
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llvm-nm [ -agnoprumxjlPA ] [ - ] [ -t format ] [[ -arch arch_flag ]...] [ file ... ] [ -s segname sectname ] nm-classic [ -agnoprumxjlfPA [ s segname sectname ]] [ - ] [ -t format ] [[ -arch arch_flag ]...] [ file ... ]
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gettext.sh
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jupyter-troubleshoot
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xzless
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xzless is a filter that displays text from compressed files to a terminal. Files supported by xz(1) are decompressed; other files are assumed to be in uncompressed form already. If no files are given, xzless reads from standard input. xzless uses less(1) to present its output. Unlike xzmore, its choice of pager cannot be altered by setting an environment variable. Commands are based on both more(1) and vi(1) and allow back and forth movement and searching. See the less(1) manual for more information. The command named lzless is provided for backward compatibility with LZMA Utils. ENVIRONMENT LESSMETACHARS A list of characters special to the shell. Set by xzless unless it is already set in the environment. LESSOPEN Set to a command line to invoke the xz(1) decompressor for preprocessing the input files to less(1). SEE ALSO less(1), xz(1), xzmore(1), zless(1) Tukaani 2024-02-12 XZLESS(1)
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xzless, lzless - view xz or lzma compressed (text) files
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xzless [file...] lzless [file...]
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pal2rgb
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arm64-apple-darwin20.0.0-install_name_tool
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Install_name_tool changes the dynamic shared library install names and or adds, changes or deletes the rpaths recorded in a Mach-O binary. For this tool to work when the install names or rpaths are larger the binary should be built with the ld(1) -headerpad_max_install_names option. -change old new Changes the dependent shared library install name old to new in the specified Mach-O binary. More than one of these options can be specified. If the Mach-O binary does not contain the old install name in a specified -change option the option is ignored. -id name Changes the shared library identification name of a dynamic shared library to name. If the Mach-O binary is not a dynamic shared library and the -id option is specified it is ignored. -rpath old new Changes the rpath path name old to new in the specified Mach-O binary. More than one of these options can be specified. If the Mach-O binary does not contain the old rpath path name in a specified -rpath it is an error. -add_rpath new Adds the rpath path name new in the specified Mach-O binary. More than one of these options can be specified. If the Mach-O binary already contains the new rpath path name specified in -add_rpath it is an error. -delete_rpath old deletes the rpath path name old in the specified Mach-O binary. More than one of these options can be specified. If the Mach-O binary does not contains the old rpath path name specified in -delete_rpath it is an error. SEE ALSO ld(1) Apple, Inc. March 4, 2009 INSTALL_NAME_TOOL(1)
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install_name_tool - change dynamic shared library install names
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install_name_tool [-change old new ] ... [-rpath old new ] ... [-add_rpath new ] ... [-delete_rpath new ] ... [-id name] file
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tiff2fsspec
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xxh32sum
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Print or check xxHash (32, 64 or 128 bits) checksums. When no FILE, read standard input, except if it´s the console. When FILE is -, read standard input even if it´s the console. xxhsum supports a command line syntax similar but not identical to md5sum(1). Differences are: xxhsum doesn´t have text/binary mode switch (-b, -t); xxhsum always treats files as binary file; xxhsum has a hash bit width switch (-H); As xxHash is a fast non-cryptographic checksum algorithm, xxhsum should not be used for security related purposes. xxhsum -b invokes benchmark mode. See OPTIONS and EXAMPLES for details.
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xxhsum - print or check xxHash non-cryptographic checksums
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xxhsum [<OPTION>] ... [<FILE>] ... xxhsum -b [<OPTION>] ... xxh32sum is equivalent to xxhsum -H0 xxh64sum is equivalent to xxhsum -H1 xxh128sum is equivalent to xxhsum -H2
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-V, --version Displays xxhsum version and exits -HHASHTYPE Hash selection. HASHTYPE means 0=32bits, 1=64bits, 2=128bits. Alternatively, HASHTYPE 32=32bits, 64=64bits, 128=128bits. Default value is 1 (64bits) --tag Output in the BSD style. --little-endian Set output hexadecimal checksum value as little endian convention. By default, value is displayed as big endian. -h, --help Displays help and exits The following four options are useful only when verifying checksums (-c) -c, --check FILE Read xxHash sums from FILE and check them -q, --quiet Don´t print OK for each successfully verified file --strict Return an error code if any line in the file is invalid, not just if some checksums are wrong. This policy is disabled by default, though UI will prompt an informational message if any line in the file is detected invalid. --status Don´t output anything. Status code shows success. -w, --warn Emit a warning message about each improperly formatted checksum line. The following options are useful only benchmark purpose -b Benchmark mode. See EXAMPLES for details. -b# Specify ID of variant to be tested. Multiple variants can be selected, separated by a ´,´ comma. -BBLOCKSIZE Only useful for benchmark mode (-b). See EXAMPLES for details. BLOCKSIZE specifies benchmark mode´s test data block size in bytes. Default value is 102400 -iITERATIONS Only useful for benchmark mode (-b). See EXAMPLES for details. ITERATIONS specifies number of iterations in benchmark. Single iteration lasts approximately 1000 milliseconds. Default value is 3 EXIT STATUS xxhsum exit 0 on success, 1 if at least one file couldn´t be read or doesn´t have the same checksum as the -c option.
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Output xxHash (64bit) checksum values of specific files to standard output $ xxhsum -H1 foo bar baz Output xxHash (32bit and 64bit) checksum values of specific files to standard output, and redirect it to xyz.xxh32 and qux.xxh64 $ xxhsum -H0 foo bar baz > xyz.xxh32 $ xxhsum -H1 foo bar baz > qux.xxh64 Read xxHash sums from specific files and check them $ xxhsum -c xyz.xxh32 qux.xxh64 Benchmark xxHash algorithm. By default, xxhsum benchmarks xxHash main variants on a synthetic sample of 100 KB, and print results into standard output. The first column is the algorithm, the second column is the source data size in bytes, the third column is the number of hashes generated per second (throughput), and finally the last column translates speed in megabytes per second. $ xxhsum -b In the following example, the sample to hash is set to 16384 bytes, the variants to be benched are selected by their IDs, and each benchmark test is repeated 10 times, for increased accuracy. $ xxhsum -b1,2,3 -i10 -B16384 BUGS Report bugs at: https://github.com/Cyan4973/xxHash/issues/ AUTHOR Yann Collet SEE ALSO md5sum(1) xxhsum 0.7.4 July 2020 XXHSUM(1)
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zstd
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zstd is a fast lossless compression algorithm and data compression tool, with command line syntax similar to gzip(1) and xz(1). It is based on the LZ77 family, with further FSE & huff0 entropy stages. zstd offers highly configurable compression speed, from fast modes at > 200 MB/s per core, to strong modes with excellent compression ratios. It also features a very fast decoder, with speeds > 500 MB/s per core, which remains roughly stable at all compression settings. zstd command line syntax is generally similar to gzip, but features the following few differences: • Source files are preserved by default. It´s possible to remove them automatically by using the --rm command. • When compressing a single file, zstd displays progress notifications and result summary by default. Use -q to turn them off. • zstd displays a short help page when command line is an error. Use -q to turn it off. • zstd does not accept input from console, though it does accept stdin when it´s not the console. • zstd does not store the input´s filename or attributes, only its contents. zstd processes each file according to the selected operation mode. If no files are given or file is -, zstd reads from standard input and writes the processed data to standard output. zstd will refuse to write compressed data to standard output if it is a terminal: it will display an error message and skip the file. Similarly, zstd will refuse to read compressed data from standard input if it is a terminal. Unless --stdout or -o is specified, files are written to a new file whose name is derived from the source file name: • When compressing, the suffix .zst is appended to the source filename to get the target filename. • When decompressing, the .zst suffix is removed from the source filename to get the target filename Concatenation with .zst Files It is possible to concatenate multiple .zst files. zstd will decompress such agglomerated file as if it was a single .zst file.
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zstd - zstd, zstdmt, unzstd, zstdcat - Compress or decompress .zst files
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zstd [OPTIONS] [-|INPUT-FILE] [-o OUTPUT-FILE] zstdmt is equivalent to zstd -T0 unzstd is equivalent to zstd -d zstdcat is equivalent to zstd -dcf
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Integer Suffixes and Special Values In most places where an integer argument is expected, an optional suffix is supported to easily indicate large integers. There must be no space between the integer and the suffix. KiB Multiply the integer by 1,024 (2^10). Ki, K, and KB are accepted as synonyms for KiB. MiB Multiply the integer by 1,048,576 (2^20). Mi, M, and MB are accepted as synonyms for MiB. Operation Mode If multiple operation mode options are given, the last one takes effect. -z, --compress Compress. This is the default operation mode when no operation mode option is specified and no other operation mode is implied from the command name (for example, unzstd implies --decompress). -d, --decompress, --uncompress Decompress. -t, --test Test the integrity of compressed files. This option is equivalent to --decompress --stdout > /dev/null, decompressed data is discarded and checksummed for errors. No files are created or removed. -b# Benchmark file(s) using compression level #. See BENCHMARK below for a description of this operation. --train FILES Use FILES as a training set to create a dictionary. The training set should contain a lot of small files (> 100). See DICTIONARY BUILDER below for a description of this operation. -l, --list Display information related to a zstd compressed file, such as size, ratio, and checksum. Some of these fields may not be available. This command´s output can be augmented with the -v modifier. Operation Modifiers • -#: selects # compression level [1-19] (default: 3). Higher compression levels generally produce higher compression ratio at the expense of speed and memory. A rough rule of thumb is that compression speed is expected to be divided by 2 every 2 levels. Technically, each level is mapped to a set of advanced parameters (that can also be modified individually, see below). Because the compressor´s behavior highly depends on the content to compress, there´s no guarantee of a smooth progression from one level to another. • --ultra: unlocks high compression levels 20+ (maximum 22), using a lot more memory. Note that decompression will also require more memory when using these levels. • --fast[=#]: switch to ultra-fast compression levels. If =# is not present, it defaults to 1. The higher the value, the faster the compression speed, at the cost of some compression ratio. This setting overwrites compression level if one was set previously. Similarly, if a compression level is set after --fast, it overrides it. • -T#, --threads=#: Compress using # working threads (default: 1). If # is 0, attempt to detect and use the number of physical CPU cores. In all cases, the nb of threads is capped to ZSTDMT_NBWORKERS_MAX, which is either 64 in 32-bit mode, or 256 for 64-bit environments. This modifier does nothing if zstd is compiled without multithread support. • --single-thread: Use a single thread for both I/O and compression. As compression is serialized with I/O, this can be slightly slower. Single-thread mode features significantly lower memory usage, which can be useful for systems with limited amount of memory, such as 32-bit systems. Note 1: this mode is the only available one when multithread support is disabled. Note 2: this mode is different from -T1, which spawns 1 compression thread in parallel with I/O. Final compressed result is also slightly different from -T1. • --auto-threads={physical,logical} (default: physical): When using a default amount of threads via -T0, choose the default based on the number of detected physical or logical cores. • --adapt[=min=#,max=#]: zstd will dynamically adapt compression level to perceived I/O conditions. Compression level adaptation can be observed live by using command -v. Adaptation can be constrained between supplied min and max levels. The feature works when combined with multi-threading and --long mode. It does not work with --single-thread. It sets window size to 8 MiB by default (can be changed manually, see wlog). Due to the chaotic nature of dynamic adaptation, compressed result is not reproducible. Note: at the time of this writing, --adapt can remain stuck at low speed when combined with multiple worker threads (>=2). • --long[=#]: enables long distance matching with # windowLog, if # is not present it defaults to 27. This increases the window size (windowLog) and memory usage for both the compressor and decompressor. This setting is designed to improve the compression ratio for files with long matches at a large distance. Note: If windowLog is set to larger than 27, --long=windowLog or --memory=windowSize needs to be passed to the decompressor. • -D DICT: use DICT as Dictionary to compress or decompress FILE(s) • --patch-from FILE: Specify the file to be used as a reference point for zstd´s diff engine. This is effectively dictionary compression with some convenient parameter selection, namely that windowSize > srcSize. Note: cannot use both this and -D together. Note: --long mode will be automatically activated if chainLog < fileLog (fileLog being the windowLog required to cover the whole file). You can also manually force it. Note: for all levels, you can use --patch-from in --single-thread mode to improve compression ratio at the cost of speed. Note: for level 19, you can get increased compression ratio at the cost of speed by specifying --zstd=targetLength= to be something large (i.e. 4096), and by setting a large --zstd=chainLog=. • --rsyncable: zstd will periodically synchronize the compression state to make the compressed file more rsync-friendly. There is a negligible impact to compression ratio, and a potential impact to compression speed, perceptible at higher speeds, for example when combining --rsyncable with many parallel worker threads. This feature does not work with --single-thread. You probably don´t want to use it with long range mode, since it will decrease the effectiveness of the synchronization points, but your mileage may vary. • -C, --[no-]check: add integrity check computed from uncompressed data (default: enabled) • --[no-]content-size: enable / disable whether or not the original size of the file is placed in the header of the compressed file. The default option is --content-size (meaning that the original size will be placed in the header). • --no-dictID: do not store dictionary ID within frame header (dictionary compression). The decoder will have to rely on implicit knowledge about which dictionary to use, it won´t be able to check if it´s correct. • -M#, --memory=#: Set a memory usage limit. By default, zstd uses 128 MiB for decompression as the maximum amount of memory the decompressor is allowed to use, but you can override this manually if need be in either direction (i.e. you can increase or decrease it). This is also used during compression when using with --patch-from=. In this case, this parameter overrides that maximum size allowed for a dictionary. (128 MiB). Additionally, this can be used to limit memory for dictionary training. This parameter overrides the default limit of 2 GiB. zstd will load training samples up to the memory limit and ignore the rest. • --stream-size=#: Sets the pledged source size of input coming from a stream. This value must be exact, as it will be included in the produced frame header. Incorrect stream sizes will cause an error. This information will be used to better optimize compression parameters, resulting in better and potentially faster compression, especially for smaller source sizes. • --size-hint=#: When handling input from a stream, zstd must guess how large the source size will be when optimizing compression parameters. If the stream size is relatively small, this guess may be a poor one, resulting in a higher compression ratio than expected. This feature allows for controlling the guess when needed. Exact guesses result in better compression ratios. Overestimates result in slightly degraded compression ratios, while underestimates may result in significant degradation. • --target-compressed-block-size=#: Attempt to produce compressed blocks of approximately this size. This will split larger blocks in order to approach this target. This feature is notably useful for improved latency, when the receiver can leverage receiving early incomplete data. This parameter defines a loose target: compressed blocks will target this size "on average", but individual blocks can still be larger or smaller. Enabling this feature can decrease compression speed by up to ~10% at level 1. Higher levels will see smaller relative speed regression, becoming invisible at higher settings. • -f, --force: disable input and output checks. Allows overwriting existing files, input from console, output to stdout, operating on links, block devices, etc. During decompression and when the output destination is stdout, pass-through unrecognized formats as-is. • -c, --stdout: write to standard output (even if it is the console); keep original files (disable --rm). • -o FILE: save result into FILE. Note that this operation is in conflict with -c. If both operations are present on the command line, the last expressed one wins. • --[no-]sparse: enable / disable sparse FS support, to make files with many zeroes smaller on disk. Creating sparse files may save disk space and speed up decompression by reducing the amount of disk I/O. default: enabled when output is into a file, and disabled when output is stdout. This setting overrides default and can force sparse mode over stdout. • --[no-]pass-through enable / disable passing through uncompressed files as-is. During decompression when pass-through is enabled, unrecognized formats will be copied as-is from the input to the output. By default, pass-through will occur when the output destination is stdout and the force (-f) option is set. • --rm: remove source file(s) after successful compression or decompression. This command is silently ignored if output is stdout. If used in combination with -o, triggers a confirmation prompt (which can be silenced with -f), as this is a destructive operation. • -k, --keep: keep source file(s) after successful compression or decompression. This is the default behavior. • -r: operate recursively on directories. It selects all files in the named directory and all its subdirectories. This can be useful both to reduce command line typing, and to circumvent shell expansion limitations, when there are a lot of files and naming breaks the maximum size of a command line. • --filelist FILE read a list of files to process as content from FILE. Format is compatible with ls output, with one file per line. • --output-dir-flat DIR: resulting files are stored into target DIR directory, instead of same directory as origin file. Be aware that this command can introduce name collision issues, if multiple files, from different directories, end up having the same name. Collision resolution ensures first file with a given name will be present in DIR, while in combination with -f, the last file will be present instead. • --output-dir-mirror DIR: similar to --output-dir-flat, the output files are stored underneath target DIR directory, but this option will replicate input directory hierarchy into output DIR. If input directory contains "..", the files in this directory will be ignored. If input directory is an absolute directory (i.e. "/var/tmp/abc"), it will be stored into the "output-dir/var/tmp/abc". If there are multiple input files or directories, name collision resolution will follow the same rules as --output-dir-flat. • --format=FORMAT: compress and decompress in other formats. If compiled with support, zstd can compress to or decompress from other compression algorithm formats. Possibly available options are zstd, gzip, xz, lzma, and lz4. If no such format is provided, zstd is the default. • -h/-H, --help: display help/long help and exit • -V, --version: display version number and immediately exit. note that, since it exits, flags specified after -V are effectively ignored. Advanced: -vV also displays supported formats. -vvV also displays POSIX support. -qV will only display the version number, suitable for machine reading. • -v, --verbose: verbose mode, display more information • -q, --quiet: suppress warnings, interactivity, and notifications. specify twice to suppress errors too. • --no-progress: do not display the progress bar, but keep all other messages. • --show-default-cparams: shows the default compression parameters that will be used for a particular input file, based on the provided compression level and the input size. If the provided file is not a regular file (e.g. a pipe), this flag will output the parameters used for inputs of unknown size. • --exclude-compressed: only compress files that are not already compressed. • --: All arguments after -- are treated as files gzip Operation Modifiers When invoked via a gzip symlink, zstd will support further options that intend to mimic the gzip behavior: -n, --no-name do not store the original filename and timestamps when compressing a file. This is the default behavior and hence a no-op. --best alias to the option -9. Environment Variables Employing environment variables to set parameters has security implications. Therefore, this avenue is intentionally limited. Only ZSTD_CLEVEL and ZSTD_NBTHREADS are currently supported. They set the default compression level and number of threads to use during compression, respectively. ZSTD_CLEVEL can be used to set the level between 1 and 19 (the "normal" range). If the value of ZSTD_CLEVEL is not a valid integer, it will be ignored with a warning message. ZSTD_CLEVEL just replaces the default compression level (3). ZSTD_NBTHREADS can be used to set the number of threads zstd will attempt to use during compression. If the value of ZSTD_NBTHREADS is not a valid unsigned integer, it will be ignored with a warning message. ZSTD_NBTHREADS has a default value of (1), and is capped at ZSTDMT_NBWORKERS_MAX==200. zstd must be compiled with multithread support for this variable to have any effect. They can both be overridden by corresponding command line arguments: -# for compression level and -T# for number of compression threads. ADVANCED COMPRESSION OPTIONS zstd provides 22 predefined regular compression levels plus the fast levels. A compression level is translated internally into multiple advanced parameters that control the behavior of the compressor (one can observe the result of this translation with --show-default-cparams). These advanced parameters can be overridden using advanced compression options. --zstd[=options]: The options are provided as a comma-separated list. You may specify only the options you want to change and the rest will be taken from the selected or default compression level. The list of available options: strategy=strat, strat=strat Specify a strategy used by a match finder. There are 9 strategies numbered from 1 to 9, from fastest to strongest: 1=ZSTD_fast, 2=ZSTD_dfast, 3=ZSTD_greedy, 4=ZSTD_lazy, 5=ZSTD_lazy2, 6=ZSTD_btlazy2, 7=ZSTD_btopt, 8=ZSTD_btultra, 9=ZSTD_btultra2. windowLog=wlog, wlog=wlog Specify the maximum number of bits for a match distance. The higher number of increases the chance to find a match which usually improves compression ratio. It also increases memory requirements for the compressor and decompressor. The minimum wlog is 10 (1 KiB) and the maximum is 30 (1 GiB) on 32-bit platforms and 31 (2 GiB) on 64-bit platforms. Note: If windowLog is set to larger than 27, --long=windowLog or --memory=windowSize needs to be passed to the decompressor. hashLog=hlog, hlog=hlog Specify the maximum number of bits for a hash table. Bigger hash tables cause fewer collisions which usually makes compression faster, but requires more memory during compression. The minimum hlog is 6 (64 entries / 256 B) and the maximum is 30 (1B entries / 4 GiB). chainLog=clog, clog=clog Specify the maximum number of bits for the secondary search structure, whose form depends on the selected strategy. Higher numbers of bits increases the chance to find a match which usually improves compression ratio. It also slows down compression speed and increases memory requirements for compression. This option is ignored for the ZSTD_fast strategy, which only has the primary hash table. The minimum clog is 6 (64 entries / 256 B) and the maximum is 29 (512M entries / 2 GiB) on 32-bit platforms and 30 (1B entries / 4 GiB) on 64-bit platforms. searchLog=slog, slog=slog Specify the maximum number of searches in a hash chain or a binary tree using logarithmic scale. More searches increases the chance to find a match which usually increases compression ratio but decreases compression speed. The minimum slog is 1 and the maximum is ´windowLog´ - 1. minMatch=mml, mml=mml Specify the minimum searched length of a match in a hash table. Larger search lengths usually decrease compression ratio but improve decompression speed. The minimum mml is 3 and the maximum is 7. targetLength=tlen, tlen=tlen The impact of this field vary depending on selected strategy. For ZSTD_btopt, ZSTD_btultra and ZSTD_btultra2, it specifies the minimum match length that causes match finder to stop searching. A larger targetLength usually improves compression ratio but decreases compression speed. For ZSTD_fast, it triggers ultra-fast mode when > 0. The value represents the amount of data skipped between match sampling. Impact is reversed: a larger targetLength increases compression speed but decreases compression ratio. For all other strategies, this field has no impact. The minimum tlen is 0 and the maximum is 128 KiB. overlapLog=ovlog, ovlog=ovlog Determine overlapSize, amount of data reloaded from previous job. This parameter is only available when multithreading is enabled. Reloading more data improves compression ratio, but decreases speed. The minimum ovlog is 0, and the maximum is 9. 1 means "no overlap", hence completely independent jobs. 9 means "full overlap", meaning up to windowSize is reloaded from previous job. Reducing ovlog by 1 reduces the reloaded amount by a factor 2. For example, 8 means "windowSize/2", and 6 means "windowSize/8". Value 0 is special and means "default": ovlog is automatically determined by zstd. In which case, ovlog will range from 6 to 9, depending on selected strat. ldmHashLog=lhlog, lhlog=lhlog Specify the maximum size for a hash table used for long distance matching. This option is ignored unless long distance matching is enabled. Bigger hash tables usually improve compression ratio at the expense of more memory during compression and a decrease in compression speed. The minimum lhlog is 6 and the maximum is 30 (default: 20). ldmMinMatch=lmml, lmml=lmml Specify the minimum searched length of a match for long distance matching. This option is ignored unless long distance matching is enabled. Larger/very small values usually decrease compression ratio. The minimum lmml is 4 and the maximum is 4096 (default: 64). ldmBucketSizeLog=lblog, lblog=lblog Specify the size of each bucket for the hash table used for long distance matching. This option is ignored unless long distance matching is enabled. Larger bucket sizes improve collision resolution but decrease compression speed. The minimum lblog is 1 and the maximum is 8 (default: 3). ldmHashRateLog=lhrlog, lhrlog=lhrlog Specify the frequency of inserting entries into the long distance matching hash table. This option is ignored unless long distance matching is enabled. Larger values will improve compression speed. Deviating far from the default value will likely result in a decrease in compression ratio. The default value is wlog - lhlog. Example The following parameters sets advanced compression options to something similar to predefined level 19 for files bigger than 256 KB: --zstd=wlog=23,clog=23,hlog=22,slog=6,mml=3,tlen=48,strat=6 -B#: Specify the size of each compression job. This parameter is only available when multi-threading is enabled. Each compression job is run in parallel, so this value indirectly impacts the nb of active threads. Default job size varies depending on compression level (generally 4 * windowSize). -B# makes it possible to manually select a custom size. Note that job size must respect a minimum value which is enforced transparently. This minimum is either 512 KB, or overlapSize, whichever is largest. Different job sizes will lead to non-identical compressed frames. DICTIONARY BUILDER zstd offers dictionary compression, which greatly improves efficiency on small files and messages. It´s possible to train zstd with a set of samples, the result of which is saved into a file called a dictionary. Then, during compression and decompression, reference the same dictionary, using command -D dictionaryFileName. Compression of small files similar to the sample set will be greatly improved. --train FILEs Use FILEs as training set to create a dictionary. The training set should ideally contain a lot of samples (> 100), and weight typically 100x the target dictionary size (for example, ~10 MB for a 100 KB dictionary). --train can be combined with -r to indicate a directory rather than listing all the files, which can be useful to circumvent shell expansion limits. Since dictionary compression is mostly effective for small files, the expectation is that the training set will only contain small files. In the case where some samples happen to be large, only the first 128 KiB of these samples will be used for training. --train supports multithreading if zstd is compiled with threading support (default). Additional advanced parameters can be specified with --train-fastcover. The legacy dictionary builder can be accessed with --train-legacy. The slower cover dictionary builder can be accessed with --train-cover. Default --train is equivalent to --train-fastcover=d=8,steps=4. -o FILE Dictionary saved into FILE (default name: dictionary). --maxdict=# Limit dictionary to specified size (default: 112640 bytes). As usual, quantities are expressed in bytes by default, and it´s possible to employ suffixes (like KB or MB) to specify larger values. -# Use # compression level during training (optional). Will generate statistics more tuned for selected compression level, resulting in a small compression ratio improvement for this level. -B# Split input files into blocks of size # (default: no split) -M#, --memory=# Limit the amount of sample data loaded for training (default: 2 GB). Note that the default (2 GB) is also the maximum. This parameter can be useful in situations where the training set size is not well controlled and could be potentially very large. Since speed of the training process is directly correlated to the size of the training sample set, a smaller sample set leads to faster training. In situations where the training set is larger than maximum memory, the CLI will randomly select samples among the available ones, up to the maximum allowed memory budget. This is meant to improve dictionary relevance by mitigating the potential impact of clustering, such as selecting only files from the beginning of a list sorted by modification date, or sorted by alphabetical order. The randomization process is deterministic, so training of the same list of files with the same parameters will lead to the creation of the same dictionary. --dictID=# A dictionary ID is a locally unique ID. The decoder will use this value to verify it is using the right dictionary. By default, zstd will create a 4-bytes random number ID. It´s possible to provide an explicit number ID instead. It´s up to the dictionary manager to not assign twice the same ID to 2 different dictionaries. Note that short numbers have an advantage: an ID < 256 will only need 1 byte in the compressed frame header, and an ID < 65536 will only need 2 bytes. This compares favorably to 4 bytes default. Note that RFC8878 reserves IDs less than 32768 and greater than or equal to 2^31, so they should not be used in public. --train-cover[=k#,d=#,steps=#,split=#,shrink[=#]] Select parameters for the default dictionary builder algorithm named cover. If d is not specified, then it tries d = 6 and d = 8. If k is not specified, then it tries steps values in the range [50, 2000]. If steps is not specified, then the default value of 40 is used. If split is not specified or split <= 0, then the default value of 100 is used. Requires that d <= k. If shrink flag is not used, then the default value for shrinkDict of 0 is used. If shrink is not specified, then the default value for shrinkDictMaxRegression of 1 is used. Selects segments of size k with highest score to put in the dictionary. The score of a segment is computed by the sum of the frequencies of all the subsegments of size d. Generally d should be in the range [6, 8], occasionally up to 16, but the algorithm will run faster with d <= 8. Good values for k vary widely based on the input data, but a safe range is [2 * d, 2000]. If split is 100, all input samples are used for both training and testing to find optimal d and k to build dictionary. Supports multithreading if zstd is compiled with threading support. Having shrink enabled takes a truncated dictionary of minimum size and doubles in size until compression ratio of the truncated dictionary is at most shrinkDictMaxRegression% worse than the compression ratio of the largest dictionary. Examples: zstd --train-cover FILEs zstd --train-cover=k=50,d=8 FILEs zstd --train-cover=d=8,steps=500 FILEs zstd --train-cover=k=50 FILEs zstd --train-cover=k=50,split=60 FILEs zstd --train-cover=shrink FILEs zstd --train-cover=shrink=2 FILEs --train-fastcover[=k#,d=#,f=#,steps=#,split=#,accel=#] Same as cover but with extra parameters f and accel and different default value of split If split is not specified, then it tries split = 75. If f is not specified, then it tries f = 20. Requires that 0 < f < 32. If accel is not specified, then it tries accel = 1. Requires that 0 < accel <= 10. Requires that d = 6 or d = 8. f is log of size of array that keeps track of frequency of subsegments of size d. The subsegment is hashed to an index in the range [0,2^f - 1]. It is possible that 2 different subsegments are hashed to the same index, and they are considered as the same subsegment when computing frequency. Using a higher f reduces collision but takes longer. Examples: zstd --train-fastcover FILEs zstd --train-fastcover=d=8,f=15,accel=2 FILEs --train-legacy[=selectivity=#] Use legacy dictionary builder algorithm with the given dictionary selectivity (default: 9). The smaller the selectivity value, the denser the dictionary, improving its efficiency but reducing its achievable maximum size. --train-legacy=s=# is also accepted. Examples: zstd --train-legacy FILEs zstd --train-legacy=selectivity=8 FILEs BENCHMARK The zstd CLI provides a benchmarking mode that can be used to easily find suitable compression parameters, or alternatively to benchmark a computer´s performance. Note that the results are highly dependent on the content being compressed. -b# benchmark file(s) using compression level # -e# benchmark file(s) using multiple compression levels, from -b# to -e# (inclusive) -d benchmark decompression speed only (requires providing an already zstd-compressed content) -i# minimum evaluation time, in seconds (default: 3s), benchmark mode only -B#, --block-size=# cut file(s) into independent chunks of size # (default: no chunking) --priority=rt set process priority to real-time (Windows) Output Format: CompressionLevel#Filename: InputSize -> OutputSize (CompressionRatio), CompressionSpeed, DecompressionSpeed Methodology: For both compression and decompression speed, the entire input is compressed/decompressed in-memory to measure speed. A run lasts at least 1 sec, so when files are small, they are compressed/decompressed several times per run, in order to improve measurement accuracy. SEE ALSO zstdgrep(1), zstdless(1), gzip(1), xz(1) The zstandard format is specified in Y. Collet, "Zstandard Compression and the ´application/zstd´ Media Type", https://www.ietf.org/rfc/rfc8878.txt, Internet RFC 8878 (February 2021). BUGS Report bugs at: https://github.com/facebook/zstd/issues AUTHOR Yann Collet zstd 1.5.6 March 2024 ZSTD(1)
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qtpaths
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msgcmp
|
Compare two Uniforum style .po files to check that both contain the same set of msgid strings. The def.po file is an existing PO file with the translations. The ref.pot file is the last created PO file, or a PO Template file (generally created by xgettext). This is useful for checking that you have translated each and every message in your program. Where an exact match cannot be found, fuzzy matching is used to produce better diagnostics. Mandatory arguments to long options are mandatory for short options too. Input file location: def.po translations ref.pot references to the sources -D, --directory=DIRECTORY add DIRECTORY to list for input files search Operation modifiers: -m, --multi-domain apply ref.pot to each of the domains in def.po -N, --no-fuzzy-matching do not use fuzzy matching --use-fuzzy consider fuzzy entries --use-untranslated consider untranslated entries Input file syntax: -P, --properties-input input files are in Java .properties syntax --stringtable-input input files are in NeXTstep/GNUstep .strings syntax Informative output: -h, --help display this help and exit -V, --version output version information and exit AUTHOR Written by Peter Miller. REPORTING BUGS Report bugs in the bug tracker at <https://savannah.gnu.org/projects/gettext> or by email to <bug-gettext@gnu.org>. COPYRIGHT Copyright © 1995-2023 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. SEE ALSO The full documentation for msgcmp is maintained as a Texinfo manual. If the info and msgcmp programs are properly installed at your site, the command info msgcmp should give you access to the complete manual. GNU gettext-tools 0.22.5 February 2024 MSGCMP(1)
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msgcmp - compare message catalog and template
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msgcmp [OPTION] def.po ref.pot
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lzcmp
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xzcmp and xzdiff compare uncompressed contents of two files. Uncompressed data and options are passed to cmp(1) or diff(1) unless --help or --version is specified. If both file1 and file2 are specified, they can be uncompressed files or files in formats that xz(1), gzip(1), bzip2(1), lzop(1), zstd(1), or lz4(1) can decompress. The required decompression commands are determined from the filename suffixes of file1 and file2. A file with an unknown suffix is assumed to be either uncompressed or in a format that xz(1) can decompress. If only one filename is provided, file1 must have a suffix of a supported compression format and the name for file2 is assumed to be file1 with the compression format suffix removed. The commands lzcmp and lzdiff are provided for backward compatibility with LZMA Utils. EXIT STATUS If a decompression error occurs, the exit status is 2. Otherwise the exit status of cmp(1) or diff(1) is used. SEE ALSO cmp(1), diff(1), xz(1), gzip(1), bzip2(1), lzop(1), zstd(1), lz4(1) Tukaani 2024-02-13 XZDIFF(1)
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xzcmp, xzdiff, lzcmp, lzdiff - compare compressed files
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xzcmp [option...] file1 [file2] xzdiff ... lzcmp ... lzdiff ...
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sphinx-apidoc
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orc-memory
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mysql_ssl_rsa_setup
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Note mysql_ssl_rsa_setup is deprecated. Instead, consider using MySQL server to generate missing SSL and RSA files automatically at startup (see the section called “Automatic SSL and RSA File Generation”). This program creates the SSL certificate and key files and RSA key-pair files required to support secure connections using SSL and secure password exchange using RSA over unencrypted connections, if those files are missing. mysql_ssl_rsa_setup can also be used to create new SSL files if the existing ones have expired. Note mysql_ssl_rsa_setup uses the openssl command, so its use is contingent on having OpenSSL installed on your machine. Another way to generate SSL and RSA files, for MySQL distributions compiled using OpenSSL, is to have the server generate them automatically. See Section 6.3.3.1, “Creating SSL and RSA Certificates and Keys using MySQL”. Important mysql_ssl_rsa_setup helps lower the barrier to using SSL by making it easier to generate the required files. However, certificates generated by mysql_ssl_rsa_setup are self-signed, which is not very secure. After you gain experience using the files created by mysql_ssl_rsa_setup, consider obtaining a CA certificate from a registered certificate authority. Invoke mysql_ssl_rsa_setup like this: mysql_ssl_rsa_setup [options] Typical options are --datadir to specify where to create the files, and --verbose to see the openssl commands that mysql_ssl_rsa_setup executes. mysql_ssl_rsa_setup attempts to create SSL and RSA files using a default set of file names. It works as follows: 1. mysql_ssl_rsa_setup checks for the openssl binary at the locations specified by the PATH environment variable. If openssl is not found, mysql_ssl_rsa_setup does nothing. If openssl is present, mysql_ssl_rsa_setup looks for default SSL and RSA files in the MySQL data directory specified by the --datadir option, or the compiled-in data directory if the --datadir option is not given. 2. mysql_ssl_rsa_setup checks the data directory for SSL files with the following names: ca.pem server-cert.pem server-key.pem 3. If any of those files are present, mysql_ssl_rsa_setup creates no SSL files. Otherwise, it invokes openssl to create them, plus some additional files: ca.pem Self-signed CA certificate ca-key.pem CA private key server-cert.pem Server certificate server-key.pem Server private key client-cert.pem Client certificate client-key.pem Client private key These files enable secure client connections using SSL; see Section 6.3.1, “Configuring MySQL to Use Encrypted Connections”. 4. mysql_ssl_rsa_setup checks the data directory for RSA files with the following names: private_key.pem Private member of private/public key pair public_key.pem Public member of private/public key pair 5. If any of these files are present, mysql_ssl_rsa_setup creates no RSA files. Otherwise, it invokes openssl to create them. These files enable secure password exchange using RSA over unencrypted connections for accounts authenticated by the sha256_password or caching_sha2_password plugin; see Section 6.4.1.3, “SHA-256 Pluggable Authentication”, and Section 6.4.1.2, “Caching SHA-2 Pluggable Authentication”. For information about the characteristics of files created by mysql_ssl_rsa_setup, see Section 6.3.3.1, “Creating SSL and RSA Certificates and Keys using MySQL”. At startup, the MySQL server automatically uses the SSL files created by mysql_ssl_rsa_setup to enable SSL if no explicit SSL options are given other than --ssl (possibly along with ssl_cipher). If you prefer to designate the files explicitly, invoke clients with the --ssl-ca, --ssl-cert, and --ssl-key options at startup to name the ca.pem, server-cert.pem, and server-key.pem files, respectively. The server also automatically uses the RSA files created by mysql_ssl_rsa_setup to enable RSA if no explicit RSA options are given. If the server is SSL-enabled, clients use SSL by default for the connection. To specify certificate and key files explicitly, use the --ssl-ca, --ssl-cert, and --ssl-key options to name the ca.pem, client-cert.pem, and client-key.pem files, respectively. However, some additional client setup may be required first because mysql_ssl_rsa_setup by default creates those files in the data directory. The permissions for the data directory normally enable access only to the system account that runs the MySQL server, so client programs cannot use files located there. To make the files available, copy them to a directory that is readable (but not writable) by clients: • For local clients, the MySQL installation directory can be used. For example, if the data directory is a subdirectory of the installation directory and your current location is the data directory, you can copy the files like this: cp ca.pem client-cert.pem client-key.pem .. • For remote clients, distribute the files using a secure channel to ensure they are not tampered with during transit. If the SSL files used for a MySQL installation have expired, you can use mysql_ssl_rsa_setup to create new ones: 1. Stop the server. 2. Rename or remove the existing SSL files. You may wish to make a backup of them first. (The RSA files do not expire, so you need not remove them. mysql_ssl_rsa_setup can see that they exist and does not overwrite them.) 3. Run mysql_ssl_rsa_setup with the --datadir option to specify where to create the new files. 4. Restart the server. mysql_ssl_rsa_setup supports the following command-line options, which can be specified on the command line or in the [mysql_ssl_rsa_setup] and [mysqld] groups of an option file. For information about option files used by MySQL programs, see Section 4.2.2.2, “Using Option Files”. • --help, ? ┌────────────────────┬────────┐ │Command-Line Format │ --help │ ├────────────────────┼────────┤ │Deprecated │ Yes │ └────────────────────┴────────┘ Display a help message and exit. • --datadir=dir_name ┌────────────────────┬────────────────────┐ │Command-Line Format │ --datadir=dir_name │ ├────────────────────┼────────────────────┤ │Deprecated │ Yes │ ├────────────────────┼────────────────────┤ │Type │ Directory name │ └────────────────────┴────────────────────┘ The path to the directory that mysql_ssl_rsa_setup should check for default SSL and RSA files and in which it should create files if they are missing. The default is the compiled-in data directory. • --suffix=str ┌────────────────────┬──────────────┐ │Command-Line Format │ --suffix=str │ ├────────────────────┼──────────────┤ │Deprecated │ Yes │ ├────────────────────┼──────────────┤ │Type │ String │ └────────────────────┴──────────────┘ The suffix for the Common Name attribute in X.509 certificates. The suffix value is limited to 17 characters. The default is based on the MySQL version number. • --uid=name, -v ┌────────────────────┬────────────┐ │Command-Line Format │ --uid=name │ ├────────────────────┼────────────┤ │Deprecated │ Yes │ └────────────────────┴────────────┘ The name of the user who should be the owner of any created files. The value is a user name, not a numeric user ID. In the absence of this option, files created by mysql_ssl_rsa_setup are owned by the user who executes it. This option is valid only if you execute the program as root on a system that supports the chown() system call. • --verbose, -v ┌────────────────────┬───────────┐ │Command-Line Format │ --verbose │ ├────────────────────┼───────────┤ │Deprecated │ Yes │ └────────────────────┴───────────┘ Verbose mode. Produce more output about what the program does. For example, the program shows the openssl commands it runs, and produces output to indicate whether it skips SSL or RSA file creation because some default file already exists. • --version, -V ┌────────────────────┬───────────┐ │Command-Line Format │ --version │ ├────────────────────┼───────────┤ │Deprecated │ Yes │ └────────────────────┴───────────┘ Display version information and exit. COPYRIGHT Copyright © 1997, 2023, Oracle and/or its affiliates. This documentation is free software; you can redistribute it and/or modify it only under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This documentation is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with the program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or see http://www.gnu.org/licenses/. SEE ALSO For more information, please refer to the MySQL Reference Manual, which may already be installed locally and which is also available online at http://dev.mysql.com/doc/. AUTHOR Oracle Corporation (http://dev.mysql.com/). MySQL 8.3 11/23/2023 MYSQL_SSL_RSA_SETUP(1)
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mysql_ssl_rsa_setup - create SSL/RSA files
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mysql_ssl_rsa_setup [options]
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jupyter-nbclassic-bundlerextension
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check_dylib
| null | null | null | null | null |
mysql
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mysql is a simple SQL shell with input line editing capabilities. It supports interactive and noninteractive use. When used interactively, query results are presented in an ASCII-table format. When used noninteractively (for example, as a filter), the result is presented in tab-separated format. The output format can be changed using command options. If you have problems due to insufficient memory for large result sets, use the --quick option. This forces mysql to retrieve results from the server a row at a time rather than retrieving the entire result set and buffering it in memory before displaying it. This is done by returning the result set using the mysql_use_result() C API function in the client/server library rather than mysql_store_result(). Note Alternatively, MySQL Shell offers access to the X DevAPI. For details, see MySQL Shell 8.2[1]. Using mysql is very easy. Invoke it from the prompt of your command interpreter as follows: mysql db_name Or: mysql --user=user_name --password db_name In this case, you'll need to enter your password in response to the prompt that mysql displays: Enter password: your_password Then type an SQL statement, end it with ;, \g, or \G and press Enter. Typing Control+C interrupts the current statement if there is one, or cancels any partial input line otherwise. You can execute SQL statements in a script file (batch file) like this: mysql db_name < script.sql > output.tab On Unix, the mysql client logs statements executed interactively to a history file. See the section called “MYSQL CLIENT LOGGING”. MYSQL CLIENT OPTIONS mysql supports the following options, which can be specified on the command line or in the [mysql] and [client] groups of an option file. For information about option files used by MySQL programs, see Section 4.2.2.2, “Using Option Files”. • --help, -? ┌────────────────────┬────────┐ │Command-Line Format │ --help │ └────────────────────┴────────┘ Display a help message and exit. • --auto-rehash ┌────────────────────┬──────────────────┐ │Command-Line Format │ --auto-rehash │ ├────────────────────┼──────────────────┤ │Disabled by │ skip-auto-rehash │ └────────────────────┴──────────────────┘ Enable automatic rehashing. This option is on by default, which enables database, table, and column name completion. Use --disable-auto-rehash to disable rehashing. That causes mysql to start faster, but you must issue the rehash command or its \# shortcut if you want to use name completion. To complete a name, enter the first part and press Tab. If the name is unambiguous, mysql completes it. Otherwise, you can press Tab again to see the possible names that begin with what you have typed so far. Completion does not occur if there is no default database. Note This feature requires a MySQL client that is compiled with the readline library. Typically, the readline library is not available on Windows. • --auto-vertical-output ┌────────────────────┬────────────────────────┐ │Command-Line Format │ --auto-vertical-output │ └────────────────────┴────────────────────────┘ Cause result sets to be displayed vertically if they are too wide for the current window, and using normal tabular format otherwise. (This applies to statements terminated by ; or \G.) • --batch, -B ┌────────────────────┬─────────┐ │Command-Line Format │ --batch │ └────────────────────┴─────────┘ Print results using tab as the column separator, with each row on a new line. With this option, mysql does not use the history file. Batch mode results in nontabular output format and escaping of special characters. Escaping may be disabled by using raw mode; see the description for the --raw option. • --binary-as-hex ┌────────────────────┬─────────────────────────┐ │Command-Line Format │ --binary-as-hex │ ├────────────────────┼─────────────────────────┤ │Type │ Boolean │ ├────────────────────┼─────────────────────────┤ │Default Value │ FALSE in noninteractive │ │ │ mode │ └────────────────────┴─────────────────────────┘ When this option is given, mysql displays binary data using hexadecimal notation (0xvalue). This occurs whether the overall output display format is tabular, vertical, HTML, or XML. --binary-as-hex when enabled affects display of all binary strings, including those returned by functions such as CHAR() and UNHEX(). The following example demonstrates this using the ASCII code for A (65 decimal, 41 hexadecimal): • --binary-as-hex disabled: mysql> SELECT CHAR(0x41), UNHEX('41'); +------------+-------------+ | CHAR(0x41) | UNHEX('41') | +------------+-------------+ | A | A | +------------+-------------+ • --binary-as-hex enabled: mysql> SELECT CHAR(0x41), UNHEX('41'); +------------------------+--------------------------+ | CHAR(0x41) | UNHEX('41') | +------------------------+--------------------------+ | 0x41 | 0x41 | +------------------------+--------------------------+ To write a binary string expression so that it displays as a character string regardless of whether --binary-as-hex is enabled, use these techniques: • The CHAR() function has a USING charset clause: mysql> SELECT CHAR(0x41 USING utf8mb4); +--------------------------+ | CHAR(0x41 USING utf8mb4) | +--------------------------+ | A | +--------------------------+ • More generally, use CONVERT() to convert an expression to a given character set: mysql> SELECT CONVERT(UNHEX('41') USING utf8mb4); +------------------------------------+ | CONVERT(UNHEX('41') USING utf8mb4) | +------------------------------------+ | A | +------------------------------------+ When mysql operates in interactive mode, this option is enabled by default. In addition, output from the status (or \s) command includes this line when the option is enabled implicitly or explicitly: Binary data as: Hexadecimal To disable hexadecimal notation, use --skip-binary-as-hex • --binary-mode ┌────────────────────┬───────────────┐ │Command-Line Format │ --binary-mode │ └────────────────────┴───────────────┘ This option helps when processing mysqlbinlog output that may contain BLOB values. By default, mysql translates \r\n in statement strings to \n and interprets \0 as the statement terminator. --binary-mode disables both features. It also disables all mysql commands except charset and delimiter in noninteractive mode (for input piped to mysql or loaded using the source command). • --bind-address=ip_address ┌────────────────────┬───────────────────────────┐ │Command-Line Format │ --bind-address=ip_address │ └────────────────────┴───────────────────────────┘ On a computer having multiple network interfaces, use this option to select which interface to use for connecting to the MySQL server. • --character-sets-dir=dir_name ┌────────────────────┬───────────────────────────────┐ │Command-Line Format │ --character-sets-dir=dir_name │ ├────────────────────┼───────────────────────────────┤ │Type │ Directory name │ └────────────────────┴───────────────────────────────┘ The directory where character sets are installed. See Section 10.15, “Character Set Configuration”. • --column-names ┌────────────────────┬────────────────┐ │Command-Line Format │ --column-names │ └────────────────────┴────────────────┘ Write column names in results. • --column-type-info ┌────────────────────┬────────────────────┐ │Command-Line Format │ --column-type-info │ └────────────────────┴────────────────────┘ Display result set metadata. This information corresponds to the contents of C API MYSQL_FIELD data structures. See C API Basic Data Structures[2]. • --comments, -c ┌────────────────────┬────────────┐ │Command-Line Format │ --comments │ ├────────────────────┼────────────┤ │Type │ Boolean │ ├────────────────────┼────────────┤ │Default Value │ TRUE │ └────────────────────┴────────────┘ Whether to preserve or strip comments in statements sent to the server. The default is to preserve them; to strip them, start mysql with --skip-comments. Note The mysql client always passes optimizer hints to the server, regardless of whether this option is given. Comment stripping is deprecated. Expect this feature and the options to control it to be removed in a future MySQL release. • --compress, -C ┌────────────────────┬───────────────────────┐ │Command-Line Format │ --compress[={OFF|ON}] │ ├────────────────────┼───────────────────────┤ │Deprecated │ Yes │ ├────────────────────┼───────────────────────┤ │Type │ Boolean │ ├────────────────────┼───────────────────────┤ │Default Value │ OFF │ └────────────────────┴───────────────────────┘ Compress all information sent between the client and the server if possible. See Section 4.2.8, “Connection Compression Control”. This option is deprecated. Expect it to be removed in a future version of MySQL. See the section called “Configuring Legacy Connection Compression”. • --compression-algorithms=value ┌────────────────────┬────────────────────────────────┐ │Command-Line Format │ --compression-algorithms=value │ ├────────────────────┼────────────────────────────────┤ │Type │ Set │ ├────────────────────┼────────────────────────────────┤ │Default Value │ uncompressed │ ├────────────────────┼────────────────────────────────┤ │Valid Values │ zlib zstd uncompressed │ └────────────────────┴────────────────────────────────┘ The permitted compression algorithms for connections to the server. The available algorithms are the same as for the protocol_compression_algorithms system variable. The default value is uncompressed. For more information, see Section 4.2.8, “Connection Compression Control”. • --connect-expired-password ┌────────────────────┬────────────────────────────┐ │Command-Line Format │ --connect-expired-password │ └────────────────────┴────────────────────────────┘ Indicate to the server that the client can handle sandbox mode if the account used to connect has an expired password. This can be useful for noninteractive invocations of mysql because normally the server disconnects noninteractive clients that attempt to connect using an account with an expired password. (See Section 6.2.16, “Server Handling of Expired Passwords”.) • --connect-timeout=value ┌────────────────────┬─────────────────────────┐ │Command-Line Format │ --connect-timeout=value │ ├────────────────────┼─────────────────────────┤ │Type │ Numeric │ ├────────────────────┼─────────────────────────┤ │Default Value │ 0 │ └────────────────────┴─────────────────────────┘ The number of seconds before connection timeout. (Default value is 0.) • --database=db_name, -D db_name ┌────────────────────┬───────────────────┐ │Command-Line Format │ --database=dbname │ ├────────────────────┼───────────────────┤ │Type │ String │ └────────────────────┴───────────────────┘ The database to use. This is useful primarily in an option file. • --debug[=debug_options], -# [debug_options] ┌────────────────────┬─────────────────────────┐ │Command-Line Format │ --debug[=debug_options] │ ├────────────────────┼─────────────────────────┤ │Type │ String │ ├────────────────────┼─────────────────────────┤ │Default Value │ d:t:o,/tmp/mysql.trace │ └────────────────────┴─────────────────────────┘ Write a debugging log. A typical debug_options string is d:t:o,file_name. The default is d:t:o,/tmp/mysql.trace. This option is available only if MySQL was built using WITH_DEBUG. MySQL release binaries provided by Oracle are not built using this option. • --debug-check ┌────────────────────┬───────────────┐ │Command-Line Format │ --debug-check │ ├────────────────────┼───────────────┤ │Type │ Boolean │ ├────────────────────┼───────────────┤ │Default Value │ FALSE │ └────────────────────┴───────────────┘ Print some debugging information when the program exits. This option is available only if MySQL was built using WITH_DEBUG. MySQL release binaries provided by Oracle are not built using this option. • --debug-info, -T ┌────────────────────┬──────────────┐ │Command-Line Format │ --debug-info │ ├────────────────────┼──────────────┤ │Type │ Boolean │ ├────────────────────┼──────────────┤ │Default Value │ FALSE │ └────────────────────┴──────────────┘ Print debugging information and memory and CPU usage statistics when the program exits. This option is available only if MySQL was built using WITH_DEBUG. MySQL release binaries provided by Oracle are not built using this option. • --default-auth=plugin ┌────────────────────┬───────────────────────┐ │Command-Line Format │ --default-auth=plugin │ ├────────────────────┼───────────────────────┤ │Type │ String │ └────────────────────┴───────────────────────┘ A hint about which client-side authentication plugin to use. See Section 6.2.17, “Pluggable Authentication”. • --default-character-set=charset_name ┌────────────────────┬──────────────────────────────────────┐ │Command-Line Format │ --default-character-set=charset_name │ ├────────────────────┼──────────────────────────────────────┤ │Type │ String │ └────────────────────┴──────────────────────────────────────┘ Use charset_name as the default character set for the client and connection. This option can be useful if the operating system uses one character set and the mysql client by default uses another. In this case, output may be formatted incorrectly. You can usually fix such issues by using this option to force the client to use the system character set instead. For more information, see Section 10.4, “Connection Character Sets and Collations”, and Section 10.15, “Character Set Configuration”. • --defaults-extra-file=file_name ┌────────────────────┬─────────────────────────────────┐ │Command-Line Format │ --defaults-extra-file=file_name │ ├────────────────────┼─────────────────────────────────┤ │Type │ File name │ └────────────────────┴─────────────────────────────────┘ Read this option file after the global option file but (on Unix) before the user option file. If the file does not exist or is otherwise inaccessible, an error occurs. If file_name is not an absolute path name, it is interpreted relative to the current directory. For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”. • --defaults-file=file_name ┌────────────────────┬───────────────────────────┐ │Command-Line Format │ --defaults-file=file_name │ ├────────────────────┼───────────────────────────┤ │Type │ File name │ └────────────────────┴───────────────────────────┘ Use only the given option file. If the file does not exist or is otherwise inaccessible, an error occurs. If file_name is not an absolute path name, it is interpreted relative to the current directory. Exception: Even with --defaults-file, client programs read .mylogin.cnf. For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”. • --defaults-group-suffix=str ┌────────────────────┬─────────────────────────────┐ │Command-Line Format │ --defaults-group-suffix=str │ ├────────────────────┼─────────────────────────────┤ │Type │ String │ └────────────────────┴─────────────────────────────┘ Read not only the usual option groups, but also groups with the usual names and a suffix of str. For example, mysql normally reads the [client] and [mysql] groups. If this option is given as --defaults-group-suffix=_other, mysql also reads the [client_other] and [mysql_other] groups. For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”. • --delimiter=str ┌────────────────────┬─────────────────┐ │Command-Line Format │ --delimiter=str │ ├────────────────────┼─────────────────┤ │Type │ String │ ├────────────────────┼─────────────────┤ │Default Value │ ; │ └────────────────────┴─────────────────┘ Set the statement delimiter. The default is the semicolon character (;). • --disable-named-commands Disable named commands. Use the \* form only, or use named commands only at the beginning of a line ending with a semicolon (;). mysql starts with this option enabled by default. However, even with this option, long-format commands still work from the first line. See the section called “MYSQL CLIENT COMMANDS”. • --dns-srv-name=name ┌────────────────────┬─────────────────────┐ │Command-Line Format │ --dns-srv-name=name │ ├────────────────────┼─────────────────────┤ │Type │ String │ └────────────────────┴─────────────────────┘ Specifies the name of a DNS SRV record that determines the candidate hosts to use for establishing a connection to a MySQL server. For information about DNS SRV support in MySQL, see Section 4.2.6, “Connecting to the Server Using DNS SRV Records”. Suppose that DNS is configured with this SRV information for the example.com domain: Name TTL Class Priority Weight Port Target _mysql._tcp.example.com. 86400 IN SRV 0 5 3306 host1.example.com _mysql._tcp.example.com. 86400 IN SRV 0 10 3306 host2.example.com _mysql._tcp.example.com. 86400 IN SRV 10 5 3306 host3.example.com _mysql._tcp.example.com. 86400 IN SRV 20 5 3306 host4.example.com To use that DNS SRV record, invoke mysql like this: mysql --dns-srv-name=_mysql._tcp.example.com mysql then attempts a connection to each server in the group until a successful connection is established. A failure to connect occurs only if a connection cannot be established to any of the servers. The priority and weight values in the DNS SRV record determine the order in which servers should be tried. When invoked with --dns-srv-name, mysql attempts to establish TCP connections only. The --dns-srv-name option takes precedence over the --host option if both are given. --dns-srv-name causes connection establishment to use the mysql_real_connect_dns_srv() C API function rather than mysql_real_connect(). However, if the connect command is subsequently used at runtime and specifies a host name argument, that host name takes precedence over any --dns-srv-name option given at mysql startup to specify a DNS SRV record. • --enable-cleartext-plugin ┌────────────────────┬───────────────────────────┐ │Command-Line Format │ --enable-cleartext-plugin │ ├────────────────────┼───────────────────────────┤ │Type │ Boolean │ ├────────────────────┼───────────────────────────┤ │Default Value │ FALSE │ └────────────────────┴───────────────────────────┘ Enable the mysql_clear_password cleartext authentication plugin. (See Section 6.4.1.4, “Client-Side Cleartext Pluggable Authentication”.) • --execute=statement, -e statement ┌────────────────────┬─────────────────────┐ │Command-Line Format │ --execute=statement │ ├────────────────────┼─────────────────────┤ │Type │ String │ └────────────────────┴─────────────────────┘ Execute the statement and quit. The default output format is like that produced with --batch. See Section 4.2.2.1, “Using Options on the Command Line”, for some examples. With this option, mysql does not use the history file. • --fido-register-factor=value ┌────────────────────┬──────────────────────────────┐ │Command-Line Format │ --fido-register-factor=value │ ├────────────────────┼──────────────────────────────┤ │Deprecated │ Yes │ ├────────────────────┼──────────────────────────────┤ │Type │ String │ └────────────────────┴──────────────────────────────┘ Note This option is deprecated and subject to removal in a future MySQL release. It is superseded by the --register-factor option, which supports FIDO/FIDO2 device-based authentication. For related information, see Section 6.4.1.11, “WebAuthn Pluggable Authentication”. The factor or factors for which FIDO device registration must be performed. This option value must be a single value, or two values separated by commas. Each value must be 2 or 3, so the permitted option values are '2', '3', '2,3' and '3,2'. For example, an account that requires registration for a 3rd authentication factor invokes the mysql client as follows: mysql --user=user_name --fido-register-factor=3 An account that requires registration for a 2nd and 3rd authentication factor invokes the mysql client as follows: mysql --user=user_name --fido-register-factor=2,3 If registration is successful, a connection is established. If there is an authentication factor with a pending registration, a connection is placed into pending registration mode when attempting to connect to the server. In this case, disconnect and reconnect with the correct --fido-register-factor value to complete the registration. Registration is a two step process comprising initiate registration and finish registration steps. The initiate registration step executes this statement: ALTER USER user factor INITIATE REGISTRATION The statement returns a result set containing a 32 byte challenge, the user name, and the relying party ID (see authentication_fido_rp_id). The finish registration step executes this statement: ALTER USER user factor FINISH REGISTRATION SET CHALLENGE_RESPONSE AS 'auth_string' The statement completes the registration and sends the following information to the server as part of the auth_string: authenticator data, an optional attestation certificate in X.509 format, and a signature. The initiate and registration steps must be performed in a single connection, as the challenge received by the client during the initiate step is saved to the client connection handler. Registration would fail if the registration step was performed by a different connection. The --fido-register-factor option executes both the initiate and registration steps, which avoids the failure scenario described above and prevents having to execute the ALTER USER initiate and registration statements manually. The --fido-register-factor option is only available for the mysql client and MySQL Shell. Other MySQL client programs do not support it. For related information, see the section called “Using FIDO Authentication”. • --force, -f ┌────────────────────┬─────────┐ │Command-Line Format │ --force │ └────────────────────┴─────────┘ Continue even if an SQL error occurs. • --get-server-public-key ┌────────────────────┬─────────────────────────┐ │Command-Line Format │ --get-server-public-key │ ├────────────────────┼─────────────────────────┤ │Type │ Boolean │ └────────────────────┴─────────────────────────┘ Request from the server the public key required for RSA key pair-based password exchange. This option applies to clients that authenticate with the caching_sha2_password authentication plugin. For that plugin, the server does not send the public key unless requested. This option is ignored for accounts that do not authenticate with that plugin. It is also ignored if RSA-based password exchange is not used, as is the case when the client connects to the server using a secure connection. If --server-public-key-path=file_name is given and specifies a valid public key file, it takes precedence over --get-server-public-key. For information about the caching_sha2_password plugin, see Section 6.4.1.2, “Caching SHA-2 Pluggable Authentication”. • --histignore ┌────────────────────┬───────────────────────────┐ │Command-Line Format │ --histignore=pattern_list │ ├────────────────────┼───────────────────────────┤ │Type │ String │ └────────────────────┴───────────────────────────┘ A list of one or more colon-separated patterns specifying statements to ignore for logging purposes. These patterns are added to the default pattern list ("*IDENTIFIED*:*PASSWORD*"). The value specified for this option affects logging of statements written to the history file, and to syslog if the --syslog option is given. For more information, see the section called “MYSQL CLIENT LOGGING”. • --host=host_name, -h host_name ┌────────────────────┬──────────────────┐ │Command-Line Format │ --host=host_name │ ├────────────────────┼──────────────────┤ │Type │ String │ ├────────────────────┼──────────────────┤ │Default Value │ localhost │ └────────────────────┴──────────────────┘ Connect to the MySQL server on the given host. The --dns-srv-name option takes precedence over the --host option if both are given. --dns-srv-name causes connection establishment to use the mysql_real_connect_dns_srv() C API function rather than mysql_real_connect(). However, if the connect command is subsequently used at runtime and specifies a host name argument, that host name takes precedence over any --dns-srv-name option given at mysql startup to specify a DNS SRV record. • --html, -H ┌────────────────────┬────────┐ │Command-Line Format │ --html │ └────────────────────┴────────┘ Produce HTML output. • --ignore-spaces, -i ┌────────────────────┬─────────────────┐ │Command-Line Format │ --ignore-spaces │ └────────────────────┴─────────────────┘ Ignore spaces after function names. The effect of this is described in the discussion for the IGNORE_SPACE SQL mode (see Section 5.1.11, “Server SQL Modes”). • --init-command=str ┌────────────────────┬────────────────────┐ │Command-Line Format │ --init-command=str │ └────────────────────┴────────────────────┘ Single SQL statement to execute after connecting to the server. If auto-reconnect is enabled, the statement is executed again after reconnection occurs. The definition resets existing statements defined by it or init-command-add. • --init-command-add=str ┌────────────────────┬────────────────────────┐ │Command-Line Format │ --init-command-add=str │ └────────────────────┴────────────────────────┘ Add an additional SQL statement to execute after connecting or reconnecting to the MySQL server. It's usable without --init-command but has no effect if used before it because init-command resets the list of commands to call. Option added in MySQL 8.2.0. • --line-numbers ┌────────────────────┬───────────────────┐ │Command-Line Format │ --line-numbers │ ├────────────────────┼───────────────────┤ │Disabled by │ skip-line-numbers │ └────────────────────┴───────────────────┘ Write line numbers for errors. Disable this with --skip-line-numbers. • --load-data-local-dir=dir_name ┌────────────────────┬────────────────────────────────┐ │Command-Line Format │ --load-data-local-dir=dir_name │ ├────────────────────┼────────────────────────────────┤ │Type │ Directory name │ ├────────────────────┼────────────────────────────────┤ │Default Value │ empty string │ └────────────────────┴────────────────────────────────┘ This option affects the client-side LOCAL capability for LOAD DATA operations. It specifies the directory in which files named in LOAD DATA LOCAL statements must be located. The effect of --load-data-local-dir depends on whether LOCAL data loading is enabled or disabled: • If LOCAL data loading is enabled, either by default in the MySQL client library or by specifying --local-infile[=1], the --load-data-local-dir option is ignored. • If LOCAL data loading is disabled, either by default in the MySQL client library or by specifying --local-infile=0, the --load-data-local-dir option applies. When --load-data-local-dir applies, the option value designates the directory in which local data files must be located. Comparison of the directory path name and the path name of files to be loaded is case-sensitive regardless of the case sensitivity of the underlying file system. If the option value is the empty string, it names no directory, with the result that no files are permitted for local data loading. For example, to explicitly disable local data loading except for files located in the /my/local/data directory, invoke mysql like this: mysql --local-infile=0 --load-data-local-dir=/my/local/data When both --local-infile and --load-data-local-dir are given, the order in which they are given does not matter. Successful use of LOCAL load operations within mysql also requires that the server permits local loading; see Section 6.1.6, “Security Considerations for LOAD DATA LOCAL” • --local-infile[={0|1}] ┌────────────────────┬────────────────────────┐ │Command-Line Format │ --local-infile[={0|1}] │ ├────────────────────┼────────────────────────┤ │Type │ Boolean │ ├────────────────────┼────────────────────────┤ │Default Value │ FALSE │ └────────────────────┴────────────────────────┘ By default, LOCAL capability for LOAD DATA is determined by the default compiled into the MySQL client library. To enable or disable LOCAL data loading explicitly, use the --local-infile option. When given with no value, the option enables LOCAL data loading. When given as --local-infile=0 or --local-infile=1, the option disables or enables LOCAL data loading. If LOCAL capability is disabled, the --load-data-local-dir option can be used to permit restricted local loading of files located in a designated directory. Successful use of LOCAL load operations within mysql also requires that the server permits local loading; see Section 6.1.6, “Security Considerations for LOAD DATA LOCAL” • --login-path=name ┌────────────────────┬───────────────────┐ │Command-Line Format │ --login-path=name │ ├────────────────────┼───────────────────┤ │Type │ String │ └────────────────────┴───────────────────┘ Read options from the named login path in the .mylogin.cnf login path file. A “login path” is an option group containing options that specify which MySQL server to connect to and which account to authenticate as. To create or modify a login path file, use the mysql_config_editor utility. See mysql_config_editor(1). For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”. • --no-login-paths ┌────────────────────┬──────────────────┐ │Command-Line Format │ --no-login-paths │ └────────────────────┴──────────────────┘ Skips reading options from the login path file. See --login-path for related information. For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”. • --max-allowed-packet=value ┌────────────────────┬────────────────────────────┐ │Command-Line Format │ --max-allowed-packet=value │ ├────────────────────┼────────────────────────────┤ │Type │ Numeric │ ├────────────────────┼────────────────────────────┤ │Default Value │ 16777216 │ └────────────────────┴────────────────────────────┘ The maximum size of the buffer for client/server communication. The default is 16MB, the maximum is 1GB. • --max-join-size=value ┌────────────────────┬───────────────────────┐ │Command-Line Format │ --max-join-size=value │ ├────────────────────┼───────────────────────┤ │Type │ Numeric │ ├────────────────────┼───────────────────────┤ │Default Value │ 1000000 │ └────────────────────┴───────────────────────┘ The automatic limit for rows in a join when using --safe-updates. (Default value is 1,000,000.) • --named-commands, -G ┌────────────────────┬─────────────────────┐ │Command-Line Format │ --named-commands │ ├────────────────────┼─────────────────────┤ │Disabled by │ skip-named-commands │ └────────────────────┴─────────────────────┘ Enable named mysql commands. Long-format commands are permitted, not just short-format commands. For example, quit and \q both are recognized. Use --skip-named-commands to disable named commands. See the section called “MYSQL CLIENT COMMANDS”. • --net-buffer-length=value ┌────────────────────┬───────────────────────────┐ │Command-Line Format │ --net-buffer-length=value │ ├────────────────────┼───────────────────────────┤ │Type │ Numeric │ ├────────────────────┼───────────────────────────┤ │Default Value │ 16384 │ └────────────────────┴───────────────────────────┘ The buffer size for TCP/IP and socket communication. (Default value is 16KB.) • --network-namespace=name ┌────────────────────┬──────────────────────────┐ │Command-Line Format │ --network-namespace=name │ ├────────────────────┼──────────────────────────┤ │Type │ String │ └────────────────────┴──────────────────────────┘ The network namespace to use for TCP/IP connections. If omitted, the connection uses the default (global) namespace. For information about network namespaces, see Section 5.1.14, “Network Namespace Support”. This option is available only on platforms that implement network namespace support. • --no-auto-rehash, -A ┌────────────────────┬──────────────────┐ │Command-Line Format │ --no-auto-rehash │ ├────────────────────┼──────────────────┤ │Deprecated │ Yes │ └────────────────────┴──────────────────┘ This has the same effect as --skip-auto-rehash. See the description for --auto-rehash. • --no-beep, -b ┌────────────────────┬───────────┐ │Command-Line Format │ --no-beep │ └────────────────────┴───────────┘ Do not beep when errors occur. • --no-defaults ┌────────────────────┬───────────────┐ │Command-Line Format │ --no-defaults │ └────────────────────┴───────────────┘ Do not read any option files. If program startup fails due to reading unknown options from an option file, --no-defaults can be used to prevent them from being read. The exception is that the .mylogin.cnf file is read in all cases, if it exists. This permits passwords to be specified in a safer way than on the command line even when --no-defaults is used. To create .mylogin.cnf, use the mysql_config_editor utility. See mysql_config_editor(1). For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”. • --oci-config-file=PATH ┌────────────────────┬───────────────────┐ │Command-Line Format │ --oci-config-file │ ├────────────────────┼───────────────────┤ │Type │ String │ ├────────────────────┼───────────────────┤ │Default Value │ │ └────────────────────┴───────────────────┘ Alternate path to the Oracle Cloud Infrastructure CLI configuration file. Specify the location of the configuration file. If your existing default profile is the correct one, you do not need to specify this option. However, if you have an existing configuration file, with multiple profiles or a different default from the tenancy of the user you want to connect with, specify this option. • --one-database, -o ┌────────────────────┬────────────────┐ │Command-Line Format │ --one-database │ └────────────────────┴────────────────┘ Ignore statements except those that occur while the default database is the one named on the command line. This option is rudimentary and should be used with care. Statement filtering is based only on USE statements. Initially, mysql executes statements in the input because specifying a database db_name on the command line is equivalent to inserting USE db_name at the beginning of the input. Then, for each USE statement encountered, mysql accepts or rejects following statements depending on whether the database named is the one on the command line. The content of the statements is immaterial. Suppose that mysql is invoked to process this set of statements: DELETE FROM db2.t2; USE db2; DROP TABLE db1.t1; CREATE TABLE db1.t1 (i INT); USE db1; INSERT INTO t1 (i) VALUES(1); CREATE TABLE db2.t1 (j INT); If the command line is mysql --force --one-database db1, mysql handles the input as follows: • The DELETE statement is executed because the default database is db1, even though the statement names a table in a different database. • The DROP TABLE and CREATE TABLE statements are not executed because the default database is not db1, even though the statements name a table in db1. • The INSERT and CREATE TABLE statements are executed because the default database is db1, even though the CREATE TABLE statement names a table in a different database. • --pager[=command] ┌────────────────────┬───────────────────┐ │Command-Line Format │ --pager[=command] │ ├────────────────────┼───────────────────┤ │Disabled by │ skip-pager │ ├────────────────────┼───────────────────┤ │Type │ String │ └────────────────────┴───────────────────┘ Use the given command for paging query output. If the command is omitted, the default pager is the value of your PAGER environment variable. Valid pagers are less, more, cat [> filename], and so forth. This option works only on Unix and only in interactive mode. To disable paging, use --skip-pager. the section called “MYSQL CLIENT COMMANDS”, discusses output paging further. • --password[=password], -p[password] ┌────────────────────┬───────────────────────┐ │Command-Line Format │ --password[=password] │ ├────────────────────┼───────────────────────┤ │Type │ String │ └────────────────────┴───────────────────────┘ The password of the MySQL account used for connecting to the server. The password value is optional. If not given, mysql prompts for one. If given, there must be no space between --password= or -p and the password following it. If no password option is specified, the default is to send no password. Specifying a password on the command line should be considered insecure. To avoid giving the password on the command line, use an option file. See Section 6.1.2.1, “End-User Guidelines for Password Security”. To explicitly specify that there is no password and that mysql should not prompt for one, use the --skip-password option. • --password1[=pass_val] The password for multifactor authentication factor 1 of the MySQL account used for connecting to the server. The password value is optional. If not given, mysql prompts for one. If given, there must be no space between --password1= and the password following it. If no password option is specified, the default is to send no password. Specifying a password on the command line should be considered insecure. To avoid giving the password on the command line, use an option file. See Section 6.1.2.1, “End-User Guidelines for Password Security”. To explicitly specify that there is no password and that mysql should not prompt for one, use the --skip-password1 option. --password1 and --password are synonymous, as are --skip-password1 and --skip-password. • --password2[=pass_val] The password for multifactor authentication factor 2 of the MySQL account used for connecting to the server. The semantics of this option are similar to the semantics for --password1; see the description of that option for details. • --password3[=pass_val] The password for multifactor authentication factor 3 of the MySQL account used for connecting to the server. The semantics of this option are similar to the semantics for --password1; see the description of that option for details. • --pipe, -W ┌────────────────────┬────────┐ │Command-Line Format │ --pipe │ ├────────────────────┼────────┤ │Type │ String │ └────────────────────┴────────┘ On Windows, connect to the server using a named pipe. This option applies only if the server was started with the named_pipe system variable enabled to support named-pipe connections. In addition, the user making the connection must be a member of the Windows group specified by the named_pipe_full_access_group system variable. • --plugin-authentication-kerberos-client-mode=value ┌────────────────────┬──────────────────────────────────────────────┐ │Command-Line Format │ --plugin-authentication-kerberos-client-mode │ ├────────────────────┼──────────────────────────────────────────────┤ │Type │ String │ ├────────────────────┼──────────────────────────────────────────────┤ │Default Value │ SSPI │ ├────────────────────┼──────────────────────────────────────────────┤ │Valid Values │ GSSAPI SSPI │ └────────────────────┴──────────────────────────────────────────────┘ On Windows, the authentication_kerberos_client authentication plugin supports this plugin option. It provides two possible values that the client user can set at runtime: SSPI and GSSAPI. The default value for the client-side plugin option uses Security Support Provider Interface (SSPI), which is capable of acquiring credentials from the Windows in-memory cache. Alternatively, the client user can select a mode that supports Generic Security Service Application Program Interface (GSSAPI) through the MIT Kerberos library on Windows. GSSAPI is capable of acquiring cached credentials previously generated by using the kinit command. For more information, see Commands for Windows Clients in GSSAPI Mode. • --plugin-authentication-webauthn-client-preserve-privacy={OFF|ON} ┌────────────────────┬──────────────────────────────────────────────────────────┐ │Command-Line Format │ --plugin-authentication-webauthn-client-preserve-privacy │ ├────────────────────┼──────────────────────────────────────────────────────────┤ │Type │ Boolean │ ├────────────────────┼──────────────────────────────────────────────────────────┤ │Default Value │ OFF │ └────────────────────┴──────────────────────────────────────────────────────────┘ Determines how assertions are sent to server in case there are more than one discoverable credentials stored for a given RP ID (a unique name given to the relying-party server, which is the MySQL server). If the FIDO2 device contains multiple resident keys for a given RP ID, this option allows the user to choose a key to be used for assertion. It provides two possible values that the client user can set. The default value is OFF. If set to OFF, the challenge is signed by all credentials available for a given RP ID and all signatures are sent to server. If set to ON, the user is prompted to choose the credential to be used for signature. Note This option has no effect if the device does not support the resident-key feature. For more information, see Section 6.4.1.11, “WebAuthn Pluggable Authentication”. • --plugin-dir=dir_name ┌────────────────────┬───────────────────────┐ │Command-Line Format │ --plugin-dir=dir_name │ ├────────────────────┼───────────────────────┤ │Type │ Directory name │ └────────────────────┴───────────────────────┘ The directory in which to look for plugins. Specify this option if the --default-auth option is used to specify an authentication plugin but mysql does not find it. See Section 6.2.17, “Pluggable Authentication”. • --port=port_num, -P port_num ┌────────────────────┬─────────────────┐ │Command-Line Format │ --port=port_num │ ├────────────────────┼─────────────────┤ │Type │ Numeric │ ├────────────────────┼─────────────────┤ │Default Value │ 3306 │ └────────────────────┴─────────────────┘ For TCP/IP connections, the port number to use. • --print-defaults ┌────────────────────┬──────────────────┐ │Command-Line Format │ --print-defaults │ └────────────────────┴──────────────────┘ Print the program name and all options that it gets from option files. For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”. • --prompt=format_str ┌────────────────────┬─────────────────────┐ │Command-Line Format │ --prompt=format_str │ ├────────────────────┼─────────────────────┤ │Type │ String │ ├────────────────────┼─────────────────────┤ │Default Value │ mysql> │ └────────────────────┴─────────────────────┘ Set the prompt to the specified format. The default is mysql>. The special sequences that the prompt can contain are described in the section called “MYSQL CLIENT COMMANDS”. • --protocol={TCP|SOCKET|PIPE|MEMORY} ┌────────────────────┬────────────────────────┐ │Command-Line Format │ --protocol=type │ ├────────────────────┼────────────────────────┤ │Type │ String │ ├────────────────────┼────────────────────────┤ │Default Value │ [see text] │ ├────────────────────┼────────────────────────┤ │Valid Values │ TCP SOCKET PIPE │ │ │ MEMORY │ └────────────────────┴────────────────────────┘ The transport protocol to use for connecting to the server. It is useful when the other connection parameters normally result in use of a protocol other than the one you want. For details on the permissible values, see Section 4.2.7, “Connection Transport Protocols”. • --quick, -q ┌────────────────────┬─────────┐ │Command-Line Format │ --quick │ └────────────────────┴─────────┘ Do not cache each query result, print each row as it is received. This may slow down the server if the output is suspended. With this option, mysql does not use the history file. • --raw, -r ┌────────────────────┬───────┐ │Command-Line Format │ --raw │ └────────────────────┴───────┘ For tabular output, the “boxing” around columns enables one column value to be distinguished from another. For nontabular output (such as is produced in batch mode or when the --batch or --silent option is given), special characters are escaped in the output so they can be identified easily. Newline, tab, NUL, and backslash are written as \n, \t, \0, and \\. The --raw option disables this character escaping. The following example demonstrates tabular versus nontabular output and the use of raw mode to disable escaping: % mysql mysql> SELECT CHAR(92); +----------+ | CHAR(92) | +----------+ | \ | +----------+ % mysql -s mysql> SELECT CHAR(92); CHAR(92) \\ % mysql -s -r mysql> SELECT CHAR(92); CHAR(92) \ • --reconnect ┌────────────────────┬────────────────┐ │Command-Line Format │ --reconnect │ ├────────────────────┼────────────────┤ │Disabled by │ skip-reconnect │ └────────────────────┴────────────────┘ If the connection to the server is lost, automatically try to reconnect. A single reconnect attempt is made each time the connection is lost. To suppress reconnection behavior, use --skip-reconnect. • --register-factor=value ┌────────────────────┬─────────────────────────┐ │Command-Line Format │ --register-factor=value │ ├────────────────────┼─────────────────────────┤ │Type │ String │ └────────────────────┴─────────────────────────┘ The factor or factors for which FIDO/FIDO2 device registration must be performed before WebAuthn device-based authentication can be used. This option value must be a single value, or two values separated by commas. Each value must be 2 or 3, so the permitted option values are '2', '3', '2,3' and '3,2'. For example, an account that requires registration for a 3rd authentication factor invokes the mysql client as follows: mysql --user=user_name --register-factor=3 An account that requires registration for a 2nd and 3rd authentication factor invokes the mysql client as follows: mysql --user=user_name --register-factor=2,3 If registration is successful, a connection is established. If there is an authentication factor with a pending registration, a connection is placed into pending registration mode when attempting to connect to the server. In this case, disconnect and reconnect with the correct --register-factor value to complete the registration. Registration is a two step process comprising initiate registration and finish registration steps. The initiate registration step executes this statement: ALTER USER user factor INITIATE REGISTRATION The statement returns a result set containing a 32 byte challenge, the user name, and the relying party ID (see authentication_webauthn_rp_id). The finish registration step executes this statement: ALTER USER user factor FINISH REGISTRATION SET CHALLENGE_RESPONSE AS 'auth_string' The statement completes the registration and sends the following information to the server as part of the auth_string: authenticator data, an optional attestation certificate in X.509 format, and a signature. The initiate and registration steps must be performed in a single connection, as the challenge received by the client during the initiate step is saved to the client connection handler. Registration would fail if the registration step was performed by a different connection. The --register-factor option executes both the initiate and registration steps, which avoids the failure scenario described above and prevents having to execute the ALTER USER initiate and registration statements manually. The --register-factor option is only available for the mysql client. Other MySQL client programs do not support it. For related information, see the section called “Using WebAuthn Authentication”. • --safe-updates, --i-am-a-dummy, -U ┌────────────────────┬────────────────┐ │Command-Line Format │ --safe-updates │ │ │ --i-am-a-dummy │ ├────────────────────┼────────────────┤ │Type │ Boolean │ ├────────────────────┼────────────────┤ │Default Value │ FALSE │ └────────────────────┴────────────────┘ If this option is enabled, UPDATE and DELETE statements that do not use a key in the WHERE clause or a LIMIT clause produce an error. In addition, restrictions are placed on SELECT statements that produce (or are estimated to produce) very large result sets. If you have set this option in an option file, you can use --skip-safe-updates on the command line to override it. For more information about this option, see Using Safe-Updates Mode (--safe- updates). • --select-limit=value ┌────────────────────┬──────────────────────┐ │Command-Line Format │ --select-limit=value │ ├────────────────────┼──────────────────────┤ │Type │ Numeric │ ├────────────────────┼──────────────────────┤ │Default Value │ 1000 │ └────────────────────┴──────────────────────┘ The automatic limit for SELECT statements when using --safe-updates. (Default value is 1,000.) • --server-public-key-path=file_name ┌────────────────────┬────────────────────────────────────┐ │Command-Line Format │ --server-public-key-path=file_name │ ├────────────────────┼────────────────────────────────────┤ │Type │ File name │ └────────────────────┴────────────────────────────────────┘ The path name to a file in PEM format containing a client-side copy of the public key required by the server for RSA key pair-based password exchange. This option applies to clients that authenticate with the sha256_password or caching_sha2_password authentication plugin. This option is ignored for accounts that do not authenticate with one of those plugins. It is also ignored if RSA-based password exchange is not used, as is the case when the client connects to the server using a secure connection. If --server-public-key-path=file_name is given and specifies a valid public key file, it takes precedence over --get-server-public-key. For sha256_password, this option applies only if MySQL was built using OpenSSL. For information about the sha256_password and caching_sha2_password plugins, see Section 6.4.1.3, “SHA-256 Pluggable Authentication”, and Section 6.4.1.2, “Caching SHA-2 Pluggable Authentication”. • --shared-memory-base-name=name ┌────────────────────┬────────────────────────────────┐ │Command-Line Format │ --shared-memory-base-name=name │ ├────────────────────┼────────────────────────────────┤ │Platform Specific │ Windows │ └────────────────────┴────────────────────────────────┘ On Windows, the shared-memory name to use for connections made using shared memory to a local server. The default value is MYSQL. The shared-memory name is case-sensitive. This option applies only if the server was started with the shared_memory system variable enabled to support shared-memory connections. • --show-warnings ┌────────────────────┬─────────────────┐ │Command-Line Format │ --show-warnings │ └────────────────────┴─────────────────┘ Cause warnings to be shown after each statement if there are any. This option applies to interactive and batch mode. • --sigint-ignore ┌────────────────────┬─────────────────┐ │Command-Line Format │ --sigint-ignore │ └────────────────────┴─────────────────┘ Ignore SIGINT signals (typically the result of typing Control+C). Without this option, typing Control+C interrupts the current statement if there is one, or cancels any partial input line otherwise. • --silent, -s ┌────────────────────┬──────────┐ │Command-Line Format │ --silent │ └────────────────────┴──────────┘ Silent mode. Produce less output. This option can be given multiple times to produce less and less output. This option results in nontabular output format and escaping of special characters. Escaping may be disabled by using raw mode; see the description for the --raw option. • --skip-column-names, -N ┌────────────────────┬─────────────────────┐ │Command-Line Format │ --skip-column-names │ └────────────────────┴─────────────────────┘ Do not write column names in results. • --skip-line-numbers, -L ┌────────────────────┬─────────────────────┐ │Command-Line Format │ --skip-line-numbers │ └────────────────────┴─────────────────────┘ Do not write line numbers for errors. Useful when you want to compare result files that include error messages. • --socket=path, -S path ┌────────────────────┬────────────────────────────────┐ │Command-Line Format │ --socket={file_name|pipe_name} │ ├────────────────────┼────────────────────────────────┤ │Type │ String │ └────────────────────┴────────────────────────────────┘ For connections to localhost, the Unix socket file to use, or, on Windows, the name of the named pipe to use. On Windows, this option applies only if the server was started with the named_pipe system variable enabled to support named-pipe connections. In addition, the user making the connection must be a member of the Windows group specified by the named_pipe_full_access_group system variable. • --ssl* Options that begin with --ssl specify whether to connect to the server using encryption and indicate where to find SSL keys and certificates. See the section called “Command Options for Encrypted Connections”. • --ssl-fips-mode={OFF|ON|STRICT} ┌────────────────────┬─────────────────────────────────┐ │Command-Line Format │ --ssl-fips-mode={OFF|ON|STRICT} │ ├────────────────────┼─────────────────────────────────┤ │Deprecated │ Yes │ ├────────────────────┼─────────────────────────────────┤ │Type │ Enumeration │ ├────────────────────┼─────────────────────────────────┤ │Default Value │ OFF │ ├────────────────────┼─────────────────────────────────┤ │Valid Values │ OFF ON STRICT │ └────────────────────┴─────────────────────────────────┘ Controls whether to enable FIPS mode on the client side. The --ssl-fips-mode option differs from other --ssl-xxx options in that it is not used to establish encrypted connections, but rather to affect which cryptographic operations to permit. See Section 6.8, “FIPS Support”. These --ssl-fips-mode values are permitted: • OFF: Disable FIPS mode. • ON: Enable FIPS mode. • STRICT: Enable “strict” FIPS mode. Note If the OpenSSL FIPS Object Module is not available, the only permitted value for --ssl-fips-mode is OFF. In this case, setting --ssl-fips-mode to ON or STRICT causes the client to produce a warning at startup and to operate in non-FIPS mode. This option is deprecated. Expect it to be removed in a future version of MySQL. • --syslog, -j ┌────────────────────┬──────────┐ │Command-Line Format │ --syslog │ └────────────────────┴──────────┘ This option causes mysql to send interactive statements to the system logging facility. On Unix, this is syslog; on Windows, it is the Windows Event Log. The destination where logged messages appear is system dependent. On Linux, the destination is often the /var/log/messages file. Here is a sample of output generated on Linux by using --syslog. This output is formatted for readability; each logged message actually takes a single line. Mar 7 12:39:25 myhost MysqlClient[20824]: SYSTEM_USER:'oscar', MYSQL_USER:'my_oscar', CONNECTION_ID:23, DB_SERVER:'127.0.0.1', DB:'--', QUERY:'USE test;' Mar 7 12:39:28 myhost MysqlClient[20824]: SYSTEM_USER:'oscar', MYSQL_USER:'my_oscar', CONNECTION_ID:23, DB_SERVER:'127.0.0.1', DB:'test', QUERY:'SHOW TABLES;' For more information, see the section called “MYSQL CLIENT LOGGING”. • --table, -t ┌────────────────────┬─────────┐ │Command-Line Format │ --table │ └────────────────────┴─────────┘ Display output in table format. This is the default for interactive use, but can be used to produce table output in batch mode. • --tee=file_name ┌────────────────────┬─────────────────┐ │Command-Line Format │ --tee=file_name │ ├────────────────────┼─────────────────┤ │Type │ File name │ └────────────────────┴─────────────────┘ Append a copy of output to the given file. This option works only in interactive mode. the section called “MYSQL CLIENT COMMANDS”, discusses tee files further. • --tls-ciphersuites=ciphersuite_list ┌────────────────────┬─────────────────────────────────────┐ │Command-Line Format │ --tls-ciphersuites=ciphersuite_list │ ├────────────────────┼─────────────────────────────────────┤ │Type │ String │ └────────────────────┴─────────────────────────────────────┘ The permissible ciphersuites for encrypted connections that use TLSv1.3. The value is a list of one or more colon-separated ciphersuite names. The ciphersuites that can be named for this option depend on the SSL library used to compile MySQL. For details, see Section 6.3.2, “Encrypted Connection TLS Protocols and Ciphers”. • --tls-sni-servername=server_name ┌────────────────────┬──────────────────────────────────┐ │Command-Line Format │ --tls-sni-servername=server_name │ ├────────────────────┼──────────────────────────────────┤ │Type │ String │ └────────────────────┴──────────────────────────────────┘ When specified, the name is passed to the libmysqlclient C API library using the MYSQL_OPT_TLS_SNI_SERVERNAME option of mysql_options(). The server name is not case-sensitive. To show which server name the client specified for the current session, if any, check the Tls_sni_server_name status variable. Server Name Indication (SNI) is an extension to the TLS protocol (OpenSSL must be compiled using TLS extensions for this option to function). The MySQL implementation of SNI represents the client-side only. • --tls-version=protocol_list ┌────────────────────┬───────────────────────────────┐ │Command-Line Format │ --tls-version=protocol_list │ ├────────────────────┼───────────────────────────────┤ │Type │ String │ ├────────────────────┼───────────────────────────────┤ │Default Value │ TLSv1,TLSv1.1,TLSv1.2,TLSv1.3 │ │ │ (OpenSSL 1.1.1 or higher) │ │ │ TLSv1,TLSv1.1,TLSv1.2 │ │ │ (otherwise) │ └────────────────────┴───────────────────────────────┘ The permissible TLS protocols for encrypted connections. The value is a list of one or more comma-separated protocol names. The protocols that can be named for this option depend on the SSL library used to compile MySQL. For details, see Section 6.3.2, “Encrypted Connection TLS Protocols and Ciphers”. • --unbuffered, -n ┌────────────────────┬──────────────┐ │Command-Line Format │ --unbuffered │ └────────────────────┴──────────────┘ Flush the buffer after each query. • --user=user_name, -u user_name ┌────────────────────┬──────────────────┐ │Command-Line Format │ --user=user_name │ ├────────────────────┼──────────────────┤ │Type │ String │ └────────────────────┴──────────────────┘ The user name of the MySQL account to use for connecting to the server. • --verbose, -v ┌────────────────────┬───────────┐ │Command-Line Format │ --verbose │ └────────────────────┴───────────┘ Verbose mode. Produce more output about what the program does. This option can be given multiple times to produce more and more output. (For example, -v -v -v produces table output format even in batch mode.) • --version, -V ┌────────────────────┬───────────┐ │Command-Line Format │ --version │ └────────────────────┴───────────┘ Display version information and exit. • --vertical, -E ┌────────────────────┬────────────┐ │Command-Line Format │ --vertical │ └────────────────────┴────────────┘ Print query output rows vertically (one line per column value). Without this option, you can specify vertical output for individual statements by terminating them with \G. • --wait, -w ┌────────────────────┬────────┐ │Command-Line Format │ --wait │ └────────────────────┴────────┘ If the connection cannot be established, wait and retry instead of aborting. • --xml, -X ┌────────────────────┬───────┐ │Command-Line Format │ --xml │ └────────────────────┴───────┘ Produce XML output. <field name="column_name">NULL</field> The output when --xml is used with mysql matches that of mysqldump --xml. See mysqldump(1), for details. The XML output also uses an XML namespace, as shown here: $> mysql --xml -uroot -e "SHOW VARIABLES LIKE 'version%'" <?xml version="1.0"?> <resultset statement="SHOW VARIABLES LIKE 'version%'" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <row> <field name="Variable_name">version</field> <field name="Value">5.0.40-debug</field> </row> <row> <field name="Variable_name">version_comment</field> <field name="Value">Source distribution</field> </row> <row> <field name="Variable_name">version_compile_machine</field> <field name="Value">i686</field> </row> <row> <field name="Variable_name">version_compile_os</field> <field name="Value">suse-linux-gnu</field> </row> </resultset> • --zstd-compression-level=level ┌────────────────────┬────────────────────────────┐ │Command-Line Format │ --zstd-compression-level=# │ ├────────────────────┼────────────────────────────┤ │Type │ Integer │ └────────────────────┴────────────────────────────┘ The compression level to use for connections to the server that use the zstd compression algorithm. The permitted levels are from 1 to 22, with larger values indicating increasing levels of compression. The default zstd compression level is 3. The compression level setting has no effect on connections that do not use zstd compression. For more information, see Section 4.2.8, “Connection Compression Control”. • telemetry_client ┌────────────────────┬────────────────────┐ │Command-Line Format │ --telemetry_client │ ├────────────────────┼────────────────────┤ │Type │ Boolean │ ├────────────────────┼────────────────────┤ │Default Value │ OFF │ └────────────────────┴────────────────────┘ Enables the telemetry client plugin (Linux only). For more information, see Chapter 33, Telemetry. MYSQL CLIENT COMMANDS mysql sends each SQL statement that you issue to the server to be executed. There is also a set of commands that mysql itself interprets. For a list of these commands, type help or \h at the mysql> prompt: mysql> help List of all MySQL commands: Note that all text commands must be first on line and end with ';' ? (\?) Synonym for `help'. clear (\c) Clear the current input statement. connect (\r) Reconnect to the server. Optional arguments are db and host. delimiter (\d) Set statement delimiter. edit (\e) Edit command with $EDITOR. ego (\G) Send command to mysql server, display result vertically. exit (\q) Exit mysql. Same as quit. go (\g) Send command to mysql server. help (\h) Display this help. nopager (\n) Disable pager, print to stdout. notee (\t) Don't write into outfile. pager (\P) Set PAGER [to_pager]. Print the query results via PAGER. print (\p) Print current command. prompt (\R) Change your mysql prompt. quit (\q) Quit mysql. rehash (\#) Rebuild completion hash. source (\.) Execute an SQL script file. Takes a file name as an argument. status (\s) Get status information from the server. system (\!) Execute a system shell command. tee (\T) Set outfile [to_outfile]. Append everything into given outfile. use (\u) Use another database. Takes database name as argument. charset (\C) Switch to another charset. Might be needed for processing binlog with multi-byte charsets. warnings (\W) Show warnings after every statement. nowarning (\w) Don't show warnings after every statement. resetconnection(\x) Clean session context. query_attributes Sets string parameters (name1 value1 name2 value2 ...) for the next query to pick up. ssl_session_data_print Serializes the current SSL session data to stdout or file. For server side help, type 'help contents' If mysql is invoked with the --binary-mode option, all mysql commands are disabled except charset and delimiter in noninteractive mode (for input piped to mysql or loaded using the source command). Each command has both a long and short form. The long form is not case-sensitive; the short form is. The long form can be followed by an optional semicolon terminator, but the short form should not. The use of short-form commands within multiple-line /* ... */ comments is not supported. Short-form commands do work within single-line /*! ... */ version comments, as do /*+ ... */ optimizer-hint comments, which are stored in object definitions. If there is a concern that optimizer-hint comments may be stored in object definitions so that dump files when reloaded with mysql would result in execution of such commands, either invoke mysql with the --binary-mode option or use a reload client other than mysql. • help [arg], \h [arg], \? [arg], ? [arg] Display a help message listing the available mysql commands. If you provide an argument to the help command, mysql uses it as a search string to access server-side help from the contents of the MySQL Reference Manual. For more information, see the section called “MYSQL CLIENT SERVER-SIDE HELP”. • charset charset_name, \C charset_name Change the default character set and issue a SET NAMES statement. This enables the character set to remain synchronized on the client and server if mysql is run with auto-reconnect enabled (which is not recommended), because the specified character set is used for reconnects. • clear, \c Clear the current input. Use this if you change your mind about executing the statement that you are entering. • connect [db_name [host_name]], \r [db_name [host_name]] Reconnect to the server. The optional database name and host name arguments may be given to specify the default database or the host where the server is running. If omitted, the current values are used. If the connect command specifies a host name argument, that host takes precedence over any --dns-srv-name option given at mysql startup to specify a DNS SRV record. • delimiter str, \d str Change the string that mysql interprets as the separator between SQL statements. The default is the semicolon character (;). The delimiter string can be specified as an unquoted or quoted argument on the delimiter command line. Quoting can be done with either single quote ('), double quote ("), or backtick (`) characters. To include a quote within a quoted string, either quote the string with a different quote character or escape the quote with a backslash (\) character. Backslash should be avoided outside of quoted strings because it is the escape character for MySQL. For an unquoted argument, the delimiter is read up to the first space or end of line. For a quoted argument, the delimiter is read up to the matching quote on the line. mysql interprets instances of the delimiter string as a statement delimiter anywhere it occurs, except within quoted strings. Be careful about defining a delimiter that might occur within other words. For example, if you define the delimiter as X, it is not possible to use the word INDEX in statements. mysql interprets this as INDE followed by the delimiter X. When the delimiter recognized by mysql is set to something other than the default of ;, instances of that character are sent to the server without interpretation. However, the server itself still interprets ; as a statement delimiter and processes statements accordingly. This behavior on the server side comes into play for multiple-statement execution (see Multiple Statement Execution Support[3]), and for parsing the body of stored procedures and functions, triggers, and events (see Section 25.1, “Defining Stored Programs”). • edit, \e Edit the current input statement. mysql checks the values of the EDITOR and VISUAL environment variables to determine which editor to use. The default editor is vi if neither variable is set. The edit command works only in Unix. • ego, \G Send the current statement to the server to be executed and display the result using vertical format. • exit, \q Exit mysql. • go, \g Send the current statement to the server to be executed. • nopager, \n Disable output paging. See the description for pager. The nopager command works only in Unix. • notee, \t Disable output copying to the tee file. See the description for tee. • nowarning, \w Disable display of warnings after each statement. • pager [command], \P [command] Enable output paging. By using the --pager option when you invoke mysql, it is possible to browse or search query results in interactive mode with Unix programs such as less, more, or any other similar program. If you specify no value for the option, mysql checks the value of the PAGER environment variable and sets the pager to that. Pager functionality works only in interactive mode. Output paging can be enabled interactively with the pager command and disabled with nopager. The command takes an optional argument; if given, the paging program is set to that. With no argument, the pager is set to the pager that was set on the command line, or stdout if no pager was specified. Output paging works only in Unix because it uses the popen() function, which does not exist on Windows. For Windows, the tee option can be used instead to save query output, although it is not as convenient as pager for browsing output in some situations. • print, \p Print the current input statement without executing it. • prompt [str], \R [str] Reconfigure the mysql prompt to the given string. The special character sequences that can be used in the prompt are described later in this section. If you specify the prompt command with no argument, mysql resets the prompt to the default of mysql>. • query_attributes name value [name value ...] Define query attributes that apply to the next query sent to the server. For discussion of the purpose and use of query attributes, see Section 9.6, “Query Attributes”. The query_attributes command follows these rules: • The format and quoting rules for attribute names and values are the same as for the delimiter command. • The command permits up to 32 attribute name/value pairs. Names and values may be up to 1024 characters long. If a name is given without a value, an error occurs. • If multiple query_attributes commands are issued prior to query execution, only the last command applies. After sending the query, mysql clears the attribute set. • If multiple attributes are defined with the same name, attempts to retrieve the attribute value have an undefined result. • An attribute defined with an empty name cannot be retrieved by name. • If a reconnect occurs while mysql executes the query, mysql restores the attributes after reconnecting so the query can be executed again with the same attributes. • quit, \q Exit mysql. • rehash, \# Rebuild the completion hash that enables database, table, and column name completion while you are entering statements. (See the description for the --auto-rehash option.) • resetconnection, \x Reset the connection to clear the session state. This includes clearing any current query attributes defined using the query_attributes command. Resetting a connection has effects similar to mysql_change_user() or an auto-reconnect except that the connection is not closed and reopened, and re-authentication is not done. See mysql_change_user()[4], and Automatic Reconnection Control[5]. This example shows how resetconnection clears a value maintained in the session state: mysql> SELECT LAST_INSERT_ID(3); +-------------------+ | LAST_INSERT_ID(3) | +-------------------+ | 3 | +-------------------+ mysql> SELECT LAST_INSERT_ID(); +------------------+ | LAST_INSERT_ID() | +------------------+ | 3 | +------------------+ mysql> resetconnection; mysql> SELECT LAST_INSERT_ID(); +------------------+ | LAST_INSERT_ID() | +------------------+ | 0 | +------------------+ • source file_name, \. file_name Read the named file and executes the statements contained therein. On Windows, specify path name separators as / or \\. Quote characters are taken as part of the file name itself. For best results, the name should not include space characters. • ssl_session_data_print [file_name] Fetches, serializes, and optionally stores the session data of a successful connection. The optional file name and arguments may be given to specify the file to store serialized session data. If omitted, the session data is printed to stdout. If the MySQL session is configured for reuse, session data from the file is deserialized and supplied to the connect command to reconnect. When the session is reused successfully, the status command contains a row showing SSL session reused: true while the client remains reconnected to the server. • status, \s Provide status information about the connection and the server you are using. If you are running with --safe-updates enabled, status also prints the values for the mysql variables that affect your queries. • system command, \! command Execute the given command using your default command interpreter. • tee [file_name], \T [file_name] By using the --tee option when you invoke mysql, you can log statements and their output. All the data displayed on the screen is appended into a given file. This can be very useful for debugging purposes also. mysql flushes results to the file after each statement, just before it prints its next prompt. Tee functionality works only in interactive mode. You can enable this feature interactively with the tee command. Without a parameter, the previous file is used. The tee file can be disabled with the notee command. Executing tee again re-enables logging. • use db_name, \u db_name Use db_name as the default database. • warnings, \W Enable display of warnings after each statement (if there are any). Here are a few tips about the pager command: • You can use it to write to a file and the results go only to the file: mysql> pager cat > /tmp/log.txt You can also pass any options for the program that you want to use as your pager: mysql> pager less -n -i -S • In the preceding example, note the -S option. You may find it very useful for browsing wide query results. Sometimes a very wide result set is difficult to read on the screen. The -S option to less can make the result set much more readable because you can scroll it horizontally using the left-arrow and right-arrow keys. You can also use -S interactively within less to switch the horizontal-browse mode on and off. For more information, read the less manual page: man less • The -F and -X options may be used with less to cause it to exit if output fits on one screen, which is convenient when no scrolling is necessary: mysql> pager less -n -i -S -F -X • You can specify very complex pager commands for handling query output: mysql> pager cat | tee /dr1/tmp/res.txt \ | tee /dr2/tmp/res2.txt | less -n -i -S In this example, the command would send query results to two files in two different directories on two different file systems mounted on /dr1 and /dr2, yet still display the results onscreen using less. You can also combine the tee and pager functions. Have a tee file enabled and pager set to less, and you are able to browse the results using the less program and still have everything appended into a file the same time. The difference between the Unix tee used with the pager command and the mysql built-in tee command is that the built-in tee works even if you do not have the Unix tee available. The built-in tee also logs everything that is printed on the screen, whereas the Unix tee used with pager does not log quite that much. Additionally, tee file logging can be turned on and off interactively from within mysql. This is useful when you want to log some queries to a file, but not others. The prompt command reconfigures the default mysql> prompt. The string for defining the prompt can contain the following special sequences. ┌───────┬────────────────────────────┐ │Option │ Description │ ├───────┼────────────────────────────┤ │ │ The current connection │ │ │ identifier │ ├───────┼────────────────────────────┤ │ │ A counter that increments │ │ │ for each statement you │ │ │ issue │ ├───────┼────────────────────────────┤ │ │ The full current date │ ├───────┼────────────────────────────┤ │ │ The default database │ ├───────┼────────────────────────────┤ │ │ The server host │ ├───────┼────────────────────────────┤ │ │ The current delimiter │ ├───────┼────────────────────────────┤ │ │ Minutes of the current │ │ │ time │ ├───────┼────────────────────────────┤ │ │ A newline character │ ├───────┼────────────────────────────┤ │ │ The current month in │ │ │ three-letter format (Jan, │ │ │ Feb, ...) │ ├───────┼────────────────────────────┤ │ │ The current month in │ │ │ numeric format │ ├───────┼────────────────────────────┤ │P │ am/pm │ ├───────┼────────────────────────────┤ │ │ The current TCP/IP port or │ │ │ socket file │ ├───────┼────────────────────────────┤ │ │ The current time, in │ │ │ 24-hour military time │ │ │ (0–23) │ ├───────┼────────────────────────────┤ │ │ The current time, standard │ │ │ 12-hour time (1–12) │ ├───────┼────────────────────────────┤ │ │ Semicolon │ ├───────┼────────────────────────────┤ │ │ Seconds of the current │ │ │ time │ ├───────┼────────────────────────────┤ │T │ Print an asterisk (*) if │ │ │ the current session is │ │ │ inside a transaction block │ ├───────┼────────────────────────────┤ │ │ A tab character │ ├───────┼────────────────────────────┤ │U │ Your full │ │ │ user_name@host_name │ │ │ account name │ ├───────┼────────────────────────────┤ │ │ Your user name │ ├───────┼────────────────────────────┤ │ │ The server version │ ├───────┼────────────────────────────┤ │0 │ The current day of the │ │ │ week in three-letter │ │ │ format (Mon, Tue, ...) │ ├───────┼────────────────────────────┤ │ │ The current year, four │ │ │ digits │ ├───────┼────────────────────────────┤ │y │ The current year, two │ │ │ digits │ ├───────┼────────────────────────────┤ │_ │ A space │ ├───────┼────────────────────────────┤ │\ │ A space (a space follows │ │ │ the backslash) │ ├───────┼────────────────────────────┤ │´ │ Single quote │ ├───────┼────────────────────────────┤ │ │ Double quote │ ├───────┼────────────────────────────┤ │\ │ A literal backslash │ │ │ character │ ├───────┼────────────────────────────┤ │\fIx │ x, for any “x” not listed │ │ │ above │ └───────┴────────────────────────────┘ You can set the prompt in several ways: • Use an environment variable. You can set the MYSQL_PS1 environment variable to a prompt string. For example: export MYSQL_PS1="(\u@\h) [\d]> " • Use a command-line option. You can set the --prompt option on the command line to mysql. For example: $> mysql --prompt="(\u@\h) [\d]> " (user@host) [database]> • Use an option file. You can set the prompt option in the [mysql] group of any MySQL option file, such as /etc/my.cnf or the .my.cnf file in your home directory. For example: [mysql] prompt=(\\u@\\h) [\\d]>\\_ In this example, note that the backslashes are doubled. If you set the prompt using the prompt option in an option file, it is advisable to double the backslashes when using the special prompt options. There is some overlap in the set of permissible prompt options and the set of special escape sequences that are recognized in option files. (The rules for escape sequences in option files are listed in Section 4.2.2.2, “Using Option Files”.) The overlap may cause you problems if you use single backslashes. For example, \s is interpreted as a space rather than as the current seconds value. The following example shows how to define a prompt within an option file to include the current time in hh:mm:ss> format: [mysql] prompt="\\r:\\m:\\s> " • Set the prompt interactively. You can change your prompt interactively by using the prompt (or \R) command. For example: mysql> prompt (\u@\h) [\d]>\_ PROMPT set to '(\u@\h) [\d]>\_' (user@host) [database]> (user@host) [database]> prompt Returning to default PROMPT of mysql> mysql> MYSQL CLIENT LOGGING The mysql client can do these types of logging for statements executed interactively: • On Unix, mysql writes the statements to a history file. By default, this file is named .mysql_history in your home directory. To specify a different file, set the value of the MYSQL_HISTFILE environment variable. • On all platforms, if the --syslog option is given, mysql writes the statements to the system logging facility. On Unix, this is syslog; on Windows, it is the Windows Event Log. The destination where logged messages appear is system dependent. On Linux, the destination is often the /var/log/messages file. The following discussion describes characteristics that apply to all logging types and provides information specific to each logging type. • How Logging Occurs • Controlling the History File • syslog Logging Characteristics How Logging Occurs For each enabled logging destination, statement logging occurs as follows: • Statements are logged only when executed interactively. Statements are noninteractive, for example, when read from a file or a pipe. It is also possible to suppress statement logging by using the --batch or --execute option. • Statements are ignored and not logged if they match any pattern in the “ignore” list. This list is described later. • mysql logs each nonignored, nonempty statement line individually. • If a nonignored statement spans multiple lines (not including the terminating delimiter), mysql concatenates the lines to form the complete statement, maps newlines to spaces, and logs the result, plus a delimiter. Consequently, an input statement that spans multiple lines can be logged twice. Consider this input: mysql> SELECT -> 'Today is' -> , -> CURDATE() -> ; In this case, mysql logs the “SELECT”, “'Today is'”, “,”, “CURDATE()”, and “;” lines as it reads them. It also logs the complete statement, after mapping SELECT\n'Today is'\n,\nCURDATE() to SELECT 'Today is' , CURDATE(), plus a delimiter. Thus, these lines appear in logged output: SELECT 'Today is' , CURDATE() ; SELECT 'Today is' , CURDATE(); mysql ignores for logging purposes statements that match any pattern in the “ignore” list. By default, the pattern list is "*IDENTIFIED*:*PASSWORD*", to ignore statements that refer to passwords. Pattern matching is not case-sensitive. Within patterns, two characters are special: • ? matches any single character. • * matches any sequence of zero or more characters. To specify additional patterns, use the --histignore option or set the MYSQL_HISTIGNORE environment variable. (If both are specified, the option value takes precedence.) The value should be a list of one or more colon-separated patterns, which are appended to the default pattern list. Patterns specified on the command line might need to be quoted or escaped to prevent your command interpreter from treating them specially. For example, to suppress logging for UPDATE and DELETE statements in addition to statements that refer to passwords, invoke mysql like this: mysql --histignore="*UPDATE*:*DELETE*" Controlling the History File The .mysql_history file should be protected with a restrictive access mode because sensitive information might be written to it, such as the text of SQL statements that contain passwords. See Section 6.1.2.1, “End-User Guidelines for Password Security”. Statements in the file are accessible from the mysql client when the up-arrow key is used to recall the history. See Disabling Interactive History. If you do not want to maintain a history file, first remove .mysql_history if it exists. Then use either of the following techniques to prevent it from being created again: • Set the MYSQL_HISTFILE environment variable to /dev/null. To cause this setting to take effect each time you log in, put it in one of your shell's startup files. • Create .mysql_history as a symbolic link to /dev/null; this need be done only once: ln -s /dev/null $HOME/.mysql_history syslog Logging Characteristics If the --syslog option is given, mysql writes interactive statements to the system logging facility. Message logging has the following characteristics. Logging occurs at the “information” level. This corresponds to the LOG_INFO priority for syslog on Unix/Linux syslog capability and to EVENTLOG_INFORMATION_TYPE for the Windows Event Log. Consult your system documentation for configuration of your logging capability. Message size is limited to 1024 bytes. Messages consist of the identifier MysqlClient followed by these values: • SYSTEM_USER The operating system user name (login name) or -- if the user is unknown. • MYSQL_USER The MySQL user name (specified with the --user option) or -- if the user is unknown. • CONNECTION_ID: The client connection identifier. This is the same as the CONNECTION_ID() function value within the session. • DB_SERVER The server host or -- if the host is unknown. • DB The default database or -- if no database has been selected. • QUERY The text of the logged statement. Here is a sample of output generated on Linux by using --syslog. This output is formatted for readability; each logged message actually takes a single line. Mar 7 12:39:25 myhost MysqlClient[20824]: SYSTEM_USER:'oscar', MYSQL_USER:'my_oscar', CONNECTION_ID:23, DB_SERVER:'127.0.0.1', DB:'--', QUERY:'USE test;' Mar 7 12:39:28 myhost MysqlClient[20824]: SYSTEM_USER:'oscar', MYSQL_USER:'my_oscar', CONNECTION_ID:23, DB_SERVER:'127.0.0.1', DB:'test', QUERY:'SHOW TABLES;' MYSQL CLIENT SERVER-SIDE HELP mysql> help search_string If you provide an argument to the help command, mysql uses it as a search string to access server-side help from the contents of the MySQL Reference Manual. The proper operation of this command requires that the help tables in the mysql database be initialized with help topic information (see Section 5.1.17, “Server-Side Help Support”). If there is no match for the search string, the search fails: mysql> help me Nothing found Please try to run 'help contents' for a list of all accessible topics Use help contents to see a list of the help categories: mysql> help contents You asked for help about help category: "Contents" For more information, type 'help <item>', where <item> is one of the following categories: Account Management Administration Data Definition Data Manipulation Data Types Functions Functions and Modifiers for Use with GROUP BY Geographic Features Language Structure Plugins Storage Engines Stored Routines Table Maintenance Transactions Triggers If the search string matches multiple items, mysql shows a list of matching topics: mysql> help logs Many help items for your request exist. To make a more specific request, please type 'help <item>', where <item> is one of the following topics: SHOW SHOW BINARY LOGS SHOW ENGINE SHOW LOGS Use a topic as the search string to see the help entry for that topic: mysql> help show binary logs Name: 'SHOW BINARY LOGS' Description: Syntax: SHOW BINARY LOGS SHOW MASTER LOGS Lists the binary log files on the server. This statement is used as part of the procedure described in [purge-binary-logs], that shows how to determine which logs can be purged. mysql> SHOW BINARY LOGS; +---------------+-----------+-----------+ | Log_name | File_size | Encrypted | +---------------+-----------+-----------+ | binlog.000015 | 724935 | Yes | | binlog.000016 | 733481 | Yes | +---------------+-----------+-----------+ The search string can contain the wildcard characters % and _. These have the same meaning as for pattern-matching operations performed with the LIKE operator. For example, HELP rep% returns a list of topics that begin with rep: mysql> HELP rep% Many help items for your request exist. To make a more specific request, please type 'help <item>', where <item> is one of the following topics: REPAIR TABLE REPEAT FUNCTION REPEAT LOOP REPLACE REPLACE FUNCTION EXECUTING SQL STATEMENTS FROM A TEXT FILE The mysql client typically is used interactively, like this: mysql db_name However, it is also possible to put your SQL statements in a file and then tell mysql to read its input from that file. To do so, create a text file text_file that contains the statements you wish to execute. Then invoke mysql as shown here: mysql db_name < text_file If you place a USE db_name statement as the first statement in the file, it is unnecessary to specify the database name on the command line: mysql < text_file If you are already running mysql, you can execute an SQL script file using the source command or \. command: mysql> source file_name mysql> \. file_name Sometimes you may want your script to display progress information to the user. For this you can insert statements like this: SELECT '<info_to_display>' AS ' '; The statement shown outputs <info_to_display>. You can also invoke mysql with the --verbose option, which causes each statement to be displayed before the result that it produces. mysql ignores Unicode byte order mark (BOM) characters at the beginning of input files. Previously, it read them and sent them to the server, resulting in a syntax error. Presence of a BOM does not cause mysql to change its default character set. To do that, invoke mysql with an option such as --default-character-set=utf8mb4. For more information about batch mode, see Section 3.5, “Using mysql in Batch Mode”. MYSQL CLIENT TIPS This section provides information about techniques for more effective use of mysql and about mysql operational behavior. • Input-Line Editing • Disabling Interactive History • Unicode Support on Windows • Displaying Query Results Vertically • Using Safe-Updates Mode (--safe-updates) • Disabling mysql Auto-Reconnect • mysql Client Parser Versus Server Parser Input-Line Editing mysql supports input-line editing, which enables you to modify the current input line in place or recall previous input lines. For example, the left-arrow and right-arrow keys move horizontally within the current input line, and the up-arrow and down-arrow keys move up and down through the set of previously entered lines. Backspace deletes the character before the cursor and typing new characters enters them at the cursor position. To enter the line, press Enter. On Windows, the editing key sequences are the same as supported for command editing in console windows. On Unix, the key sequences depend on the input library used to build mysql (for example, the libedit or readline library). Documentation for the libedit and readline libraries is available online. To change the set of key sequences permitted by a given input library, define key bindings in the library startup file. This is a file in your home directory: .editrc for libedit and .inputrc for readline. For example, in libedit, Control+W deletes everything before the current cursor position and Control+U deletes the entire line. In readline, Control+W deletes the word before the cursor and Control+U deletes everything before the current cursor position. If mysql was built using libedit, a user who prefers the readline behavior for these two keys can put the following lines in the .editrc file (creating the file if necessary): bind "^W" ed-delete-prev-word bind "^U" vi-kill-line-prev To see the current set of key bindings, temporarily put a line that says only bind at the end of .editrc. mysql shows the bindings when it starts. Disabling Interactive History The up-arrow key enables you to recall input lines from current and previous sessions. In cases where a console is shared, this behavior may be unsuitable. mysql supports disabling the interactive history partially or fully, depending on the host platform. On Windows, the history is stored in memory. Alt+F7 deletes all input lines stored in memory for the current history buffer. It also deletes the list of sequential numbers in front of the input lines displayed with F7 and recalled (by number) with F9. New input lines entered after you press Alt+F7 repopulate the current history buffer. Clearing the buffer does not prevent logging to the Windows Event Viewer, if the --syslog option was used to start mysql. Closing the console window also clears the current history buffer. To disable interactive history on Unix, first delete the .mysql_history file, if it exists (previous entries are recalled otherwise). Then start mysql with the --histignore="*" option to ignore all new input lines. To re-enable the recall (and logging) behavior, restart mysql without the option. If you prevent the .mysql_history file from being created (see Controlling the History File) and use --histignore="*" to start the mysql client, the interactive history recall facility is disabled fully. Alternatively, if you omit the --histignore option, you can recall the input lines entered during the current session. Unicode Support on Windows Windows provides APIs based on UTF-16LE for reading from and writing to the console; the mysql client for Windows is able to use these APIs. The Windows installer creates an item in the MySQL menu named MySQL command line client - Unicode. This item invokes the mysql client with properties set to communicate through the console to the MySQL server using Unicode. To take advantage of this support manually, run mysql within a console that uses a compatible Unicode font and set the default character set to a Unicode character set that is supported for communication with the server: 1. Open a console window. 2. Go to the console window properties, select the font tab, and choose Lucida Console or some other compatible Unicode font. This is necessary because console windows start by default using a DOS raster font that is inadequate for Unicode. 3. Execute mysql.exe with the --default-character-set=utf8mb4 (or utf8mb3) option. This option is necessary because utf16le is one of the character sets that cannot be used as the client character set. See the section called “Impermissible Client Character Sets”. With those changes, mysql uses the Windows APIs to communicate with the console using UTF-16LE, and communicate with the server using UTF-8. (The menu item mentioned previously sets the font and character set as just described.) To avoid those steps each time you run mysql, you can create a shortcut that invokes mysql.exe. The shortcut should set the console font to Lucida Console or some other compatible Unicode font, and pass the --default-character-set=utf8mb4 (or utf8mb3) option to mysql.exe. Alternatively, create a shortcut that only sets the console font, and set the character set in the [mysql] group of your my.ini file: [mysql] default-character-set=utf8mb4 # or utf8mb3 Displaying Query Results Vertically Some query results are much more readable when displayed vertically, instead of in the usual horizontal table format. Queries can be displayed vertically by terminating the query with \G instead of a semicolon. For example, longer text values that include newlines often are much easier to read with vertical output: mysql> SELECT * FROM mails WHERE LENGTH(txt) < 300 LIMIT 300,1\G *************************** 1. row *************************** msg_nro: 3068 date: 2000-03-01 23:29:50 time_zone: +0200 mail_from: Jones reply: jones@example.com mail_to: "John Smith" <smith@example.com> sbj: UTF-8 txt: >>>>> "John" == John Smith writes: John> Hi. I think this is a good idea. Is anyone familiar John> with UTF-8 or Unicode? Otherwise, I'll put this on my John> TODO list and see what happens. Yes, please do that. Regards, Jones file: inbox-jani-1 hash: 190402944 1 row in set (0.09 sec) Using Safe-Updates Mode (--safe-updates) For beginners, a useful startup option is --safe-updates (or --i-am-a-dummy, which has the same effect). Safe-updates mode is helpful for cases when you might have issued an UPDATE or DELETE statement but forgotten the WHERE clause indicating which rows to modify. Normally, such statements update or delete all rows in the table. With --safe-updates, you can modify rows only by specifying the key values that identify them, or a LIMIT clause, or both. This helps prevent accidents. Safe-updates mode also restricts SELECT statements that produce (or are estimated to produce) very large result sets. The --safe-updates option causes mysql to execute the following statement when it connects to the MySQL server, to set the session values of the sql_safe_updates, sql_select_limit, and max_join_size system variables: SET sql_safe_updates=1, sql_select_limit=1000, max_join_size=1000000; The SET statement affects statement processing as follows: • Enabling sql_safe_updates causes UPDATE and DELETE statements to produce an error if they do not specify a key constraint in the WHERE clause, or provide a LIMIT clause, or both. For example: UPDATE tbl_name SET not_key_column=val WHERE key_column=val; UPDATE tbl_name SET not_key_column=val LIMIT 1; • Setting sql_select_limit to 1,000 causes the server to limit all SELECT result sets to 1,000 rows unless the statement includes a LIMIT clause. • Setting max_join_size to 1,000,000 causes multiple-table SELECT statements to produce an error if the server estimates it must examine more than 1,000,000 row combinations. To specify result set limits different from 1,000 and 1,000,000, you can override the defaults by using the --select-limit and --max-join-size options when you invoke mysql: mysql --safe-updates --select-limit=500 --max-join-size=10000 It is possible for UPDATE and DELETE statements to produce an error in safe-updates mode even with a key specified in the WHERE clause, if the optimizer decides not to use the index on the key column: • Range access on the index cannot be used if memory usage exceeds that permitted by the range_optimizer_max_mem_size system variable. The optimizer then falls back to a table scan. See the section called “Limiting Memory Use for Range Optimization”. • If key comparisons require type conversion, the index may not be used (see Section 8.3.1, “How MySQL Uses Indexes”). Suppose that an indexed string column c1 is compared to a numeric value using WHERE c1 = 2222. For such comparisons, the string value is converted to a number and the operands are compared numerically (see Section 12.3, “Type Conversion in Expression Evaluation”), preventing use of the index. If safe-updates mode is enabled, an error occurs. These behaviors are included in safe-updates mode: • EXPLAIN with UPDATE and DELETE statements does not produce safe-updates errors. This enables use of EXPLAIN plus SHOW WARNINGS to see why an index is not used, which can be helpful in cases such as when a range_optimizer_max_mem_size violation or type conversion occurs and the optimizer does not use an index even though a key column was specified in the WHERE clause. • When a safe-updates error occurs, the error message includes the first diagnostic that was produced, to provide information about the reason for failure. For example, the message may indicate that the range_optimizer_max_mem_size value was exceeded or type conversion occurred, either of which can preclude use of an index. • For multiple-table deletes and updates, an error is produced with safe updates enabled only if any target table uses a table scan. Disabling mysql Auto-Reconnect If the mysql client loses its connection to the server while sending a statement, it immediately and automatically tries to reconnect once to the server and send the statement again. However, even if mysql succeeds in reconnecting, your first connection has ended and all your previous session objects and settings are lost: temporary tables, the autocommit mode, and user-defined and session variables. Also, any current transaction rolls back. This behavior may be dangerous for you, as in the following example where the server was shut down and restarted between the first and second statements without you knowing it: mysql> SET @a=1; Query OK, 0 rows affected (0.05 sec) mysql> INSERT INTO t VALUES(@a); ERROR 2006: MySQL server has gone away No connection. Trying to reconnect... Connection id: 1 Current database: test Query OK, 1 row affected (1.30 sec) mysql> SELECT * FROM t; +------+ | a | +------+ | NULL | +------+ 1 row in set (0.05 sec) The @a user variable has been lost with the connection, and after the reconnection it is undefined. If it is important to have mysql terminate with an error if the connection has been lost, you can start the mysql client with the --skip-reconnect option. For more information about auto-reconnect and its effect on state information when a reconnection occurs, see Automatic Reconnection Control[5]. mysql Client Parser Versus Server Parser The mysql client uses a parser on the client side that is not a duplicate of the complete parser used by the mysqld server on the server side. This can lead to differences in treatment of certain constructs. Examples: • The server parser treats strings delimited by " characters as identifiers rather than as plain strings if the ANSI_QUOTES SQL mode is enabled. The mysql client parser does not take the ANSI_QUOTES SQL mode into account. It treats strings delimited by ", ', and ` characters the same, regardless of whether ANSI_QUOTES is enabled. • Within /*! ... */ and /*+ ... */ comments, the mysql client parser interprets short-form mysql commands. The server parser does not interpret them because these commands have no meaning on the server side. If it is desirable for mysql not to interpret short-form commands within comments, a partial workaround is to use the --binary-mode option, which causes all mysql commands to be disabled except \C and \d in noninteractive mode (for input piped to mysql or loaded using the source command). COPYRIGHT Copyright © 1997, 2023, Oracle and/or its affiliates. This documentation is free software; you can redistribute it and/or modify it only under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This documentation is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with the program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or see http://www.gnu.org/licenses/. NOTES 1. MySQL Shell 8.2 https://dev.mysql.com/doc/mysql-shell/8.1/en/ 2. C API Basic Data Structures https://dev.mysql.com/doc/c-api/8.2/en/c-api-data-structures.html 3. Multiple Statement Execution Support https://dev.mysql.com/doc/c-api/8.2/en/c-api-multiple-queries.html 4. mysql_change_user() https://dev.mysql.com/doc/c-api/8.2/en/mysql-change-user.html 5. Automatic Reconnection Control https://dev.mysql.com/doc/c-api/8.2/en/c-api-auto-reconnect.html SEE ALSO For more information, please refer to the MySQL Reference Manual, which may already be installed locally and which is also available online at http://dev.mysql.com/doc/. AUTHOR Oracle Corporation (http://dev.mysql.com/). MySQL 8.3 11/23/2023 MYSQL(1)
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mysql - the MySQL command-line client
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mysql [options] db_name
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fastapi
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pcre2-config
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pcre2-config returns the configuration of the installed PCRE2 libraries and the options required to compile a program to use them. Some of the options apply only to the 8-bit, or 16-bit, or 32-bit libraries, respectively, and are not available for libraries that have not been built. If an unavailable option is encountered, the "usage" information is output.
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pcre2-config - program to return PCRE2 configuration
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pcre2-config [--prefix] [--exec-prefix] [--version] [--libs8] [--libs16] [--libs32] [--libs-posix] [--cflags] [--cflags-posix]
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--prefix Writes the directory prefix used in the PCRE2 installation for architecture independent files (/usr on many systems, /usr/local on some systems) to the standard output. --exec-prefix Writes the directory prefix used in the PCRE2 installation for architecture dependent files (normally the same as --prefix) to the standard output. --version Writes the version number of the installed PCRE2 libraries to the standard output. --libs8 Writes to the standard output the command line options required to link with the 8-bit PCRE2 library (-lpcre2-8 on many systems). --libs16 Writes to the standard output the command line options required to link with the 16-bit PCRE2 library (-lpcre2-16 on many systems). --libs32 Writes to the standard output the command line options required to link with the 32-bit PCRE2 library (-lpcre2-32 on many systems). --libs-posix Writes to the standard output the command line options required to link with PCRE2's POSIX API wrapper library (-lpcre2-posix -lpcre2-8 on many systems). --cflags Writes to the standard output the command line options required to compile files that use PCRE2 (this may include some -I options, but is blank on many systems). --cflags-posix Writes to the standard output the command line options required to compile files that use PCRE2's POSIX API wrapper library (this may include some -I options, but is blank on many systems). SEE ALSO pcre2(3) AUTHOR This manual page was originally written by Mark Baker for the Debian GNU/Linux system. It has been subsequently revised as a generic PCRE2 man page. REVISION Last updated: 28 September 2014 PCRE2 10.00 28 September 2014 PCRE2-CONFIG(1)
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rst2html5.py
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lconvert
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pygmentize
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twistd
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xzcat
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xz is a general-purpose data compression tool with command line syntax similar to gzip(1) and bzip2(1). The native file format is the .xz format, but the legacy .lzma format used by LZMA Utils and raw compressed streams with no container format headers are also supported. In addition, decompression of the .lz format used by lzip is supported. xz compresses or decompresses each file according to the selected operation mode. If no files are given or file is -, xz reads from standard input and writes the processed data to standard output. xz will refuse (display an error and skip the file) to write compressed data to standard output if it is a terminal. Similarly, xz will refuse to read compressed data from standard input if it is a terminal. Unless --stdout is specified, files other than - are written to a new file whose name is derived from the source file name: • When compressing, the suffix of the target file format (.xz or .lzma) is appended to the source filename to get the target filename. • When decompressing, the .xz, .lzma, or .lz suffix is removed from the filename to get the target filename. xz also recognizes the suffixes .txz and .tlz, and replaces them with the .tar suffix. If the target file already exists, an error is displayed and the file is skipped. Unless writing to standard output, xz will display a warning and skip the file if any of the following applies: • File is not a regular file. Symbolic links are not followed, and thus they are not considered to be regular files. • File has more than one hard link. • File has setuid, setgid, or sticky bit set. • The operation mode is set to compress and the file already has a suffix of the target file format (.xz or .txz when compressing to the .xz format, and .lzma or .tlz when compressing to the .lzma format). • The operation mode is set to decompress and the file doesn't have a suffix of any of the supported file formats (.xz, .txz, .lzma, .tlz, or .lz). After successfully compressing or decompressing the file, xz copies the owner, group, permissions, access time, and modification time from the source file to the target file. If copying the group fails, the permissions are modified so that the target file doesn't become accessible to users who didn't have permission to access the source file. xz doesn't support copying other metadata like access control lists or extended attributes yet. Once the target file has been successfully closed, the source file is removed unless --keep was specified. The source file is never removed if the output is written to standard output or if an error occurs. Sending SIGINFO or SIGUSR1 to the xz process makes it print progress information to standard error. This has only limited use since when standard error is a terminal, using --verbose will display an automatically updating progress indicator. Memory usage The memory usage of xz varies from a few hundred kilobytes to several gigabytes depending on the compression settings. The settings used when compressing a file determine the memory requirements of the decompressor. Typically the decompressor needs 5 % to 20 % of the amount of memory that the compressor needed when creating the file. For example, decompressing a file created with xz -9 currently requires 65 MiB of memory. Still, it is possible to have .xz files that require several gigabytes of memory to decompress. Especially users of older systems may find the possibility of very large memory usage annoying. To prevent uncomfortable surprises, xz has a built-in memory usage limiter, which is disabled by default. While some operating systems provide ways to limit the memory usage of processes, relying on it wasn't deemed to be flexible enough (for example, using ulimit(1) to limit virtual memory tends to cripple mmap(2)). The memory usage limiter can be enabled with the command line option --memlimit=limit. Often it is more convenient to enable the limiter by default by setting the environment variable XZ_DEFAULTS, for example, XZ_DEFAULTS=--memlimit=150MiB. It is possible to set the limits separately for compression and decompression by using --memlimit-compress=limit and --memlimit-decompress=limit. Using these two options outside XZ_DEFAULTS is rarely useful because a single run of xz cannot do both compression and decompression and --memlimit=limit (or -M limit) is shorter to type on the command line. If the specified memory usage limit is exceeded when decompressing, xz will display an error and decompressing the file will fail. If the limit is exceeded when compressing, xz will try to scale the settings down so that the limit is no longer exceeded (except when using --format=raw or --no-adjust). This way the operation won't fail unless the limit is very small. The scaling of the settings is done in steps that don't match the compression level presets, for example, if the limit is only slightly less than the amount required for xz -9, the settings will be scaled down only a little, not all the way down to xz -8. Concatenation and padding with .xz files It is possible to concatenate .xz files as is. xz will decompress such files as if they were a single .xz file. It is possible to insert padding between the concatenated parts or after the last part. The padding must consist of null bytes and the size of the padding must be a multiple of four bytes. This can be useful, for example, if the .xz file is stored on a medium that measures file sizes in 512-byte blocks. Concatenation and padding are not allowed with .lzma files or raw streams.
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xz, unxz, xzcat, lzma, unlzma, lzcat - Compress or decompress .xz and .lzma files
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xz [option...] [file...] COMMAND ALIASES unxz is equivalent to xz --decompress. xzcat is equivalent to xz --decompress --stdout. lzma is equivalent to xz --format=lzma. unlzma is equivalent to xz --format=lzma --decompress. lzcat is equivalent to xz --format=lzma --decompress --stdout. When writing scripts that need to decompress files, it is recommended to always use the name xz with appropriate arguments (xz -d or xz -dc) instead of the names unxz and xzcat.
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Integer suffixes and special values In most places where an integer argument is expected, an optional suffix is supported to easily indicate large integers. There must be no space between the integer and the suffix. KiB Multiply the integer by 1,024 (2^10). Ki, k, kB, K, and KB are accepted as synonyms for KiB. MiB Multiply the integer by 1,048,576 (2^20). Mi, m, M, and MB are accepted as synonyms for MiB. GiB Multiply the integer by 1,073,741,824 (2^30). Gi, g, G, and GB are accepted as synonyms for GiB. The special value max can be used to indicate the maximum integer value supported by the option. Operation mode If multiple operation mode options are given, the last one takes effect. -z, --compress Compress. This is the default operation mode when no operation mode option is specified and no other operation mode is implied from the command name (for example, unxz implies --decompress). -d, --decompress, --uncompress Decompress. -t, --test Test the integrity of compressed files. This option is equivalent to --decompress --stdout except that the decompressed data is discarded instead of being written to standard output. No files are created or removed. -l, --list Print information about compressed files. No uncompressed output is produced, and no files are created or removed. In list mode, the program cannot read the compressed data from standard input or from other unseekable sources. The default listing shows basic information about files, one file per line. To get more detailed information, use also the --verbose option. For even more information, use --verbose twice, but note that this may be slow, because getting all the extra information requires many seeks. The width of verbose output exceeds 80 characters, so piping the output to, for example, less -S may be convenient if the terminal isn't wide enough. The exact output may vary between xz versions and different locales. For machine-readable output, --robot --list should be used. Operation modifiers -k, --keep Don't delete the input files. Since xz 5.2.6, this option also makes xz compress or decompress even if the input is a symbolic link to a regular file, has more than one hard link, or has the setuid, setgid, or sticky bit set. The setuid, setgid, and sticky bits are not copied to the target file. In earlier versions this was only done with --force. -f, --force This option has several effects: • If the target file already exists, delete it before compressing or decompressing. • Compress or decompress even if the input is a symbolic link to a regular file, has more than one hard link, or has the setuid, setgid, or sticky bit set. The setuid, setgid, and sticky bits are not copied to the target file. • When used with --decompress --stdout and xz cannot recognize the type of the source file, copy the source file as is to standard output. This allows xzcat --force to be used like cat(1) for files that have not been compressed with xz. Note that in future, xz might support new compressed file formats, which may make xz decompress more types of files instead of copying them as is to standard output. --format=format can be used to restrict xz to decompress only a single file format. -c, --stdout, --to-stdout Write the compressed or decompressed data to standard output instead of a file. This implies --keep. --single-stream Decompress only the first .xz stream, and silently ignore possible remaining input data following the stream. Normally such trailing garbage makes xz display an error. xz never decompresses more than one stream from .lzma files or raw streams, but this option still makes xz ignore the possible trailing data after the .lzma file or raw stream. This option has no effect if the operation mode is not --decompress or --test. --no-sparse Disable creation of sparse files. By default, if decompressing into a regular file, xz tries to make the file sparse if the decompressed data contains long sequences of binary zeros. It also works when writing to standard output as long as standard output is connected to a regular file and certain additional conditions are met to make it safe. Creating sparse files may save disk space and speed up the decompression by reducing the amount of disk I/O. -S .suf, --suffix=.suf When compressing, use .suf as the suffix for the target file instead of .xz or .lzma. If not writing to standard output and the source file already has the suffix .suf, a warning is displayed and the file is skipped. When decompressing, recognize files with the suffix .suf in addition to files with the .xz, .txz, .lzma, .tlz, or .lz suffix. If the source file has the suffix .suf, the suffix is removed to get the target filename. When compressing or decompressing raw streams (--format=raw), the suffix must always be specified unless writing to standard output, because there is no default suffix for raw streams. --files[=file] Read the filenames to process from file; if file is omitted, filenames are read from standard input. Filenames must be terminated with the newline character. A dash (-) is taken as a regular filename; it doesn't mean standard input. If filenames are given also as command line arguments, they are processed before the filenames read from file. --files0[=file] This is identical to --files[=file] except that each filename must be terminated with the null character. Basic file format and compression options -F format, --format=format Specify the file format to compress or decompress: auto This is the default. When compressing, auto is equivalent to xz. When decompressing, the format of the input file is automatically detected. Note that raw streams (created with --format=raw) cannot be auto- detected. xz Compress to the .xz file format, or accept only .xz files when decompressing. lzma, alone Compress to the legacy .lzma file format, or accept only .lzma files when decompressing. The alternative name alone is provided for backwards compatibility with LZMA Utils. lzip Accept only .lz files when decompressing. Compression is not supported. The .lz format version 0 and the unextended version 1 are supported. Version 0 files were produced by lzip 1.3 and older. Such files aren't common but may be found from file archives as a few source packages were released in this format. People might have old personal files in this format too. Decompression support for the format version 0 was removed in lzip 1.18. lzip 1.4 and later create files in the format version 1. The sync flush marker extension to the format version 1 was added in lzip 1.6. This extension is rarely used and isn't supported by xz (diagnosed as corrupt input). raw Compress or uncompress a raw stream (no headers). This is meant for advanced users only. To decode raw streams, you need use --format=raw and explicitly specify the filter chain, which normally would have been stored in the container headers. -C check, --check=check Specify the type of the integrity check. The check is calculated from the uncompressed data and stored in the .xz file. This option has an effect only when compressing into the .xz format; the .lzma format doesn't support integrity checks. The integrity check (if any) is verified when the .xz file is decompressed. Supported check types: none Don't calculate an integrity check at all. This is usually a bad idea. This can be useful when integrity of the data is verified by other means anyway. crc32 Calculate CRC32 using the polynomial from IEEE-802.3 (Ethernet). crc64 Calculate CRC64 using the polynomial from ECMA-182. This is the default, since it is slightly better than CRC32 at detecting damaged files and the speed difference is negligible. sha256 Calculate SHA-256. This is somewhat slower than CRC32 and CRC64. Integrity of the .xz headers is always verified with CRC32. It is not possible to change or disable it. --ignore-check Don't verify the integrity check of the compressed data when decompressing. The CRC32 values in the .xz headers will still be verified normally. Do not use this option unless you know what you are doing. Possible reasons to use this option: • Trying to recover data from a corrupt .xz file. • Speeding up decompression. This matters mostly with SHA-256 or with files that have compressed extremely well. It's recommended to not use this option for this purpose unless the file integrity is verified externally in some other way. -0 ... -9 Select a compression preset level. The default is -6. If multiple preset levels are specified, the last one takes effect. If a custom filter chain was already specified, setting a compression preset level clears the custom filter chain. The differences between the presets are more significant than with gzip(1) and bzip2(1). The selected compression settings determine the memory requirements of the decompressor, thus using a too high preset level might make it painful to decompress the file on an old system with little RAM. Specifically, it's not a good idea to blindly use -9 for everything like it often is with gzip(1) and bzip2(1). -0 ... -3 These are somewhat fast presets. -0 is sometimes faster than gzip -9 while compressing much better. The higher ones often have speed comparable to bzip2(1) with comparable or better compression ratio, although the results depend a lot on the type of data being compressed. -4 ... -6 Good to very good compression while keeping decompressor memory usage reasonable even for old systems. -6 is the default, which is usually a good choice for distributing files that need to be decompressible even on systems with only 16 MiB RAM. (-5e or -6e may be worth considering too. See --extreme.) -7 ... -9 These are like -6 but with higher compressor and decompressor memory requirements. These are useful only when compressing files bigger than 8 MiB, 16 MiB, and 32 MiB, respectively. On the same hardware, the decompression speed is approximately a constant number of bytes of compressed data per second. In other words, the better the compression, the faster the decompression will usually be. This also means that the amount of uncompressed output produced per second can vary a lot. The following table summarises the features of the presets: Preset DictSize CompCPU CompMem DecMem -0 256 KiB 0 3 MiB 1 MiB -1 1 MiB 1 9 MiB 2 MiB -2 2 MiB 2 17 MiB 3 MiB -3 4 MiB 3 32 MiB 5 MiB -4 4 MiB 4 48 MiB 5 MiB -5 8 MiB 5 94 MiB 9 MiB -6 8 MiB 6 94 MiB 9 MiB -7 16 MiB 6 186 MiB 17 MiB -8 32 MiB 6 370 MiB 33 MiB -9 64 MiB 6 674 MiB 65 MiB Column descriptions: • DictSize is the LZMA2 dictionary size. It is waste of memory to use a dictionary bigger than the size of the uncompressed file. This is why it is good to avoid using the presets -7 ... -9 when there's no real need for them. At -6 and lower, the amount of memory wasted is usually low enough to not matter. • CompCPU is a simplified representation of the LZMA2 settings that affect compression speed. The dictionary size affects speed too, so while CompCPU is the same for levels -6 ... -9, higher levels still tend to be a little slower. To get even slower and thus possibly better compression, see --extreme. • CompMem contains the compressor memory requirements in the single-threaded mode. It may vary slightly between xz versions. • DecMem contains the decompressor memory requirements. That is, the compression settings determine the memory requirements of the decompressor. The exact decompressor memory usage is slightly more than the LZMA2 dictionary size, but the values in the table have been rounded up to the next full MiB. Memory requirements of the multi-threaded mode are significantly higher than that of the single-threaded mode. With the default value of --block-size, each thread needs 3*3*DictSize plus CompMem or DecMem. For example, four threads with preset -6 needs 660–670 MiB of memory. -e, --extreme Use a slower variant of the selected compression preset level (-0 ... -9) to hopefully get a little bit better compression ratio, but with bad luck this can also make it worse. Decompressor memory usage is not affected, but compressor memory usage increases a little at preset levels -0 ... -3. Since there are two presets with dictionary sizes 4 MiB and 8 MiB, the presets -3e and -5e use slightly faster settings (lower CompCPU) than -4e and -6e, respectively. That way no two presets are identical. Preset DictSize CompCPU CompMem DecMem -0e 256 KiB 8 4 MiB 1 MiB -1e 1 MiB 8 13 MiB 2 MiB -2e 2 MiB 8 25 MiB 3 MiB -3e 4 MiB 7 48 MiB 5 MiB -4e 4 MiB 8 48 MiB 5 MiB -5e 8 MiB 7 94 MiB 9 MiB -6e 8 MiB 8 94 MiB 9 MiB -7e 16 MiB 8 186 MiB 17 MiB -8e 32 MiB 8 370 MiB 33 MiB -9e 64 MiB 8 674 MiB 65 MiB For example, there are a total of four presets that use 8 MiB dictionary, whose order from the fastest to the slowest is -5, -6, -5e, and -6e. --fast --best These are somewhat misleading aliases for -0 and -9, respectively. These are provided only for backwards compatibility with LZMA Utils. Avoid using these options. --block-size=size When compressing to the .xz format, split the input data into blocks of size bytes. The blocks are compressed independently from each other, which helps with multi-threading and makes limited random-access decompression possible. This option is typically used to override the default block size in multi- threaded mode, but this option can be used in single-threaded mode too. In multi-threaded mode about three times size bytes will be allocated in each thread for buffering input and output. The default size is three times the LZMA2 dictionary size or 1 MiB, whichever is more. Typically a good value is 2–4 times the size of the LZMA2 dictionary or at least 1 MiB. Using size less than the LZMA2 dictionary size is waste of RAM because then the LZMA2 dictionary buffer will never get fully used. In multi-threaded mode, the sizes of the blocks are stored in the block headers. This size information is required for multi-threaded decompression. In single-threaded mode no block splitting is done by default. Setting this option doesn't affect memory usage. No size information is stored in block headers, thus files created in single-threaded mode won't be identical to files created in multi-threaded mode. The lack of size information also means that xz won't be able decompress the files in multi-threaded mode. --block-list=items When compressing to the .xz format, start a new block with an optional custom filter chain after the given intervals of uncompressed data. The items are a comma-separated list. Each item consists of an optional filter chain number between 0 and 9 followed by a colon (:) and a required size of uncompressed data. Omitting an item (two or more consecutive commas) is a shorthand to use the size and filters of the previous item. If the input file is bigger than the sum of the sizes in items, the last item is repeated until the end of the file. A special value of 0 may be used as the last size to indicate that the rest of the file should be encoded as a single block. An alternative filter chain for each block can be specified in combination with the --filters1=filters ... --filters9=filters options. These options define filter chains with an identifier between 1–9. Filter chain 0 can be used to refer to the default filter chain, which is the same as not specifying a filter chain. The filter chain identifier can be used before the uncompressed size, followed by a colon (:). For example, if one specifies --block-list=1:2MiB,3:2MiB,2:4MiB,,2MiB,0:4MiB then blocks will be created using: • The filter chain specified by --filters1 and 2 MiB input • The filter chain specified by --filters3 and 2 MiB input • The filter chain specified by --filters2 and 4 MiB input • The filter chain specified by --filters2 and 4 MiB input • The default filter chain and 2 MiB input • The default filter chain and 4 MiB input for every block until end of input. If one specifies a size that exceeds the encoder's block size (either the default value in threaded mode or the value specified with --block-size=size), the encoder will create additional blocks while keeping the boundaries specified in items. For example, if one specifies --block-size=10MiB --block-list=5MiB,10MiB,8MiB,12MiB,24MiB and the input file is 80 MiB, one will get 11 blocks: 5, 10, 8, 10, 2, 10, 10, 4, 10, 10, and 1 MiB. In multi-threaded mode the sizes of the blocks are stored in the block headers. This isn't done in single-threaded mode, so the encoded output won't be identical to that of the multi-threaded mode. --flush-timeout=timeout When compressing, if more than timeout milliseconds (a positive integer) has passed since the previous flush and reading more input would block, all the pending input data is flushed from the encoder and made available in the output stream. This can be useful if xz is used to compress data that is streamed over a network. Small timeout values make the data available at the receiving end with a small delay, but large timeout values give better compression ratio. This feature is disabled by default. If this option is specified more than once, the last one takes effect. The special timeout value of 0 can be used to explicitly disable this feature. This feature is not available on non-POSIX systems. This feature is still experimental. Currently xz is unsuitable for decompressing the stream in real time due to how xz does buffering. --memlimit-compress=limit Set a memory usage limit for compression. If this option is specified multiple times, the last one takes effect. If the compression settings exceed the limit, xz will attempt to adjust the settings downwards so that the limit is no longer exceeded and display a notice that automatic adjustment was done. The adjustments are done in this order: reducing the number of threads, switching to single-threaded mode if even one thread in multi-threaded mode exceeds the limit, and finally reducing the LZMA2 dictionary size. When compressing with --format=raw or if --no-adjust has been specified, only the number of threads may be reduced since it can be done without affecting the compressed output. If the limit cannot be met even with the adjustments described above, an error is displayed and xz will exit with exit status 1. The limit can be specified in multiple ways: • The limit can be an absolute value in bytes. Using an integer suffix like MiB can be useful. Example: --memlimit-compress=80MiB • The limit can be specified as a percentage of total physical memory (RAM). This can be useful especially when setting the XZ_DEFAULTS environment variable in a shell initialization script that is shared between different computers. That way the limit is automatically bigger on systems with more memory. Example: --memlimit-compress=70% • The limit can be reset back to its default value by setting it to 0. This is currently equivalent to setting the limit to max (no memory usage limit). For 32-bit xz there is a special case: if the limit would be over 4020 MiB, the limit is set to 4020 MiB. On MIPS32 2000 MiB is used instead. (The values 0 and max aren't affected by this. A similar feature doesn't exist for decompression.) This can be helpful when a 32-bit executable has access to 4 GiB address space (2 GiB on MIPS32) while hopefully doing no harm in other situations. See also the section Memory usage. --memlimit-decompress=limit Set a memory usage limit for decompression. This also affects the --list mode. If the operation is not possible without exceeding the limit, xz will display an error and decompressing the file will fail. See --memlimit-compress=limit for possible ways to specify the limit. --memlimit-mt-decompress=limit Set a memory usage limit for multi-threaded decompression. This can only affect the number of threads; this will never make xz refuse to decompress a file. If limit is too low to allow any multi-threading, the limit is ignored and xz will continue in single-threaded mode. Note that if also --memlimit-decompress is used, it will always apply to both single-threaded and multi- threaded modes, and so the effective limit for multi-threading will never be higher than the limit set with --memlimit-decompress. In contrast to the other memory usage limit options, --memlimit-mt-decompress=limit has a system-specific default limit. xz --info-memory can be used to see the current value. This option and its default value exist because without any limit the threaded decompressor could end up allocating an insane amount of memory with some input files. If the default limit is too low on your system, feel free to increase the limit but never set it to a value larger than the amount of usable RAM as with appropriate input files xz will attempt to use that amount of memory even with a low number of threads. Running out of memory or swapping will not improve decompression performance. See --memlimit-compress=limit for possible ways to specify the limit. Setting limit to 0 resets the limit to the default system-specific value. -M limit, --memlimit=limit, --memory=limit This is equivalent to specifying --memlimit-compress=limit --memlimit-decompress=limit --memlimit-mt-decompress=limit. --no-adjust Display an error and exit if the memory usage limit cannot be met without adjusting settings that affect the compressed output. That is, this prevents xz from switching the encoder from multi-threaded mode to single-threaded mode and from reducing the LZMA2 dictionary size. Even when this option is used the number of threads may be reduced to meet the memory usage limit as that won't affect the compressed output. Automatic adjusting is always disabled when creating raw streams (--format=raw). -T threads, --threads=threads Specify the number of worker threads to use. Setting threads to a special value 0 makes xz use up to as many threads as the processor(s) on the system support. The actual number of threads can be fewer than threads if the input file is not big enough for threading with the given settings or if using more threads would exceed the memory usage limit. The single-threaded and multi-threaded compressors produce different output. Single-threaded compressor will give the smallest file size but only the output from the multi-threaded compressor can be decompressed using multiple threads. Setting threads to 1 will use the single-threaded mode. Setting threads to any other value, including 0, will use the multi-threaded compressor even if the system supports only one hardware thread. (xz 5.2.x used single-threaded mode in this situation.) To use multi-threaded mode with only one thread, set threads to +1. The + prefix has no effect with values other than 1. A memory usage limit can still make xz switch to single-threaded mode unless --no-adjust is used. Support for the + prefix was added in xz 5.4.0. If an automatic number of threads has been requested and no memory usage limit has been specified, then a system-specific default soft limit will be used to possibly limit the number of threads. It is a soft limit in sense that it is ignored if the number of threads becomes one, thus a soft limit will never stop xz from compressing or decompressing. This default soft limit will not make xz switch from multi-threaded mode to single- threaded mode. The active limits can be seen with xz --info-memory. Currently the only threading method is to split the input into blocks and compress them independently from each other. The default block size depends on the compression level and can be overridden with the --block-size=size option. Threaded decompression only works on files that contain multiple blocks with size information in block headers. All large enough files compressed in multi-threaded mode meet this condition, but files compressed in single-threaded mode don't even if --block-size=size has been used. The default value for threads is 0. In xz 5.4.x and older the default is 1. Custom compressor filter chains A custom filter chain allows specifying the compression settings in detail instead of relying on the settings associated to the presets. When a custom filter chain is specified, preset options (-0 ... -9 and --extreme) earlier on the command line are forgotten. If a preset option is specified after one or more custom filter chain options, the new preset takes effect and the custom filter chain options specified earlier are forgotten. A filter chain is comparable to piping on the command line. When compressing, the uncompressed input goes to the first filter, whose output goes to the next filter (if any). The output of the last filter gets written to the compressed file. The maximum number of filters in the chain is four, but typically a filter chain has only one or two filters. Many filters have limitations on where they can be in the filter chain: some filters can work only as the last filter in the chain, some only as a non-last filter, and some work in any position in the chain. Depending on the filter, this limitation is either inherent to the filter design or exists to prevent security issues. A custom filter chain can be specified in two different ways. The options --filters=filters and --filters1=filters ... --filters9=filters allow specifying an entire filter chain in one option using the liblzma filter string syntax. Alternatively, a filter chain can be specified by using one or more individual filter options in the order they are wanted in the filter chain. That is, the order of the individual filter options is significant! When decoding raw streams (--format=raw), the filter chain must be specified in the same order as it was specified when compressing. Any individual filter or preset options specified before the full chain option (--filters=filters) will be forgotten. Individual filters specified after the full chain option will reset the filter chain. Both the full and individual filter options take filter-specific options as a comma-separated list. Extra commas in options are ignored. Every option has a default value, so specify those you want to change. To see the whole filter chain and options, use xz -vv (that is, use --verbose twice). This works also for viewing the filter chain options used by presets. --filters=filters Specify the full filter chain or a preset in a single option. Each filter can be separated by spaces or two dashes (--). filters may need to be quoted on the shell command line so it is parsed as a single option. To denote options, use : or =. A preset can be prefixed with a - and followed with zero or more flags. The only supported flag is e to apply the same options as --extreme. --filters1=filters ... --filters9=filters Specify up to nine additional filter chains that can be used with --block-list. For example, when compressing an archive with executable files followed by text files, the executable part could use a filter chain with a BCJ filter and the text part only the LZMA2 filter. --filters-help Display a help message describing how to specify presets and custom filter chains in the --filters and --filters1=filters ... --filters9=filters options, and exit successfully. --lzma1[=options] --lzma2[=options] Add LZMA1 or LZMA2 filter to the filter chain. These filters can be used only as the last filter in the chain. LZMA1 is a legacy filter, which is supported almost solely due to the legacy .lzma file format, which supports only LZMA1. LZMA2 is an updated version of LZMA1 to fix some practical issues of LZMA1. The .xz format uses LZMA2 and doesn't support LZMA1 at all. Compression speed and ratios of LZMA1 and LZMA2 are practically the same. LZMA1 and LZMA2 share the same set of options: preset=preset Reset all LZMA1 or LZMA2 options to preset. Preset consist of an integer, which may be followed by single- letter preset modifiers. The integer can be from 0 to 9, matching the command line options -0 ... -9. The only supported modifier is currently e, which matches --extreme. If no preset is specified, the default values of LZMA1 or LZMA2 options are taken from the preset 6. dict=size Dictionary (history buffer) size indicates how many bytes of the recently processed uncompressed data is kept in memory. The algorithm tries to find repeating byte sequences (matches) in the uncompressed data, and replace them with references to the data currently in the dictionary. The bigger the dictionary, the higher is the chance to find a match. Thus, increasing dictionary size usually improves compression ratio, but a dictionary bigger than the uncompressed file is waste of memory. Typical dictionary size is from 64 KiB to 64 MiB. The minimum is 4 KiB. The maximum for compression is currently 1.5 GiB (1536 MiB). The decompressor already supports dictionaries up to one byte less than 4 GiB, which is the maximum for the LZMA1 and LZMA2 stream formats. Dictionary size and match finder (mf) together determine the memory usage of the LZMA1 or LZMA2 encoder. The same (or bigger) dictionary size is required for decompressing that was used when compressing, thus the memory usage of the decoder is determined by the dictionary size used when compressing. The .xz headers store the dictionary size either as 2^n or 2^n + 2^(n-1), so these sizes are somewhat preferred for compression. Other sizes will get rounded up when stored in the .xz headers. lc=lc Specify the number of literal context bits. The minimum is 0 and the maximum is 4; the default is 3. In addition, the sum of lc and lp must not exceed 4. All bytes that cannot be encoded as matches are encoded as literals. That is, literals are simply 8-bit bytes that are encoded one at a time. The literal coding makes an assumption that the highest lc bits of the previous uncompressed byte correlate with the next byte. For example, in typical English text, an upper-case letter is often followed by a lower-case letter, and a lower-case letter is usually followed by another lower-case letter. In the US-ASCII character set, the highest three bits are 010 for upper-case letters and 011 for lower-case letters. When lc is at least 3, the literal coding can take advantage of this property in the uncompressed data. The default value (3) is usually good. If you want maximum compression, test lc=4. Sometimes it helps a little, and sometimes it makes compression worse. If it makes it worse, test lc=2 too. lp=lp Specify the number of literal position bits. The minimum is 0 and the maximum is 4; the default is 0. Lp affects what kind of alignment in the uncompressed data is assumed when encoding literals. See pb below for more information about alignment. pb=pb Specify the number of position bits. The minimum is 0 and the maximum is 4; the default is 2. Pb affects what kind of alignment in the uncompressed data is assumed in general. The default means four-byte alignment (2^pb=2^2=4), which is often a good choice when there's no better guess. When the alignment is known, setting pb accordingly may reduce the file size a little. For example, with text files having one-byte alignment (US-ASCII, ISO-8859-*, UTF-8), setting pb=0 can improve compression slightly. For UTF-16 text, pb=1 is a good choice. If the alignment is an odd number like 3 bytes, pb=0 might be the best choice. Even though the assumed alignment can be adjusted with pb and lp, LZMA1 and LZMA2 still slightly favor 16-byte alignment. It might be worth taking into account when designing file formats that are likely to be often compressed with LZMA1 or LZMA2. mf=mf Match finder has a major effect on encoder speed, memory usage, and compression ratio. Usually Hash Chain match finders are faster than Binary Tree match finders. The default depends on the preset: 0 uses hc3, 1–3 use hc4, and the rest use bt4. The following match finders are supported. The memory usage formulas below are rough approximations, which are closest to the reality when dict is a power of two. hc3 Hash Chain with 2- and 3-byte hashing Minimum value for nice: 3 Memory usage: dict * 7.5 (if dict <= 16 MiB); dict * 5.5 + 64 MiB (if dict > 16 MiB) hc4 Hash Chain with 2-, 3-, and 4-byte hashing Minimum value for nice: 4 Memory usage: dict * 7.5 (if dict <= 32 MiB); dict * 6.5 (if dict > 32 MiB) bt2 Binary Tree with 2-byte hashing Minimum value for nice: 2 Memory usage: dict * 9.5 bt3 Binary Tree with 2- and 3-byte hashing Minimum value for nice: 3 Memory usage: dict * 11.5 (if dict <= 16 MiB); dict * 9.5 + 64 MiB (if dict > 16 MiB) bt4 Binary Tree with 2-, 3-, and 4-byte hashing Minimum value for nice: 4 Memory usage: dict * 11.5 (if dict <= 32 MiB); dict * 10.5 (if dict > 32 MiB) mode=mode Compression mode specifies the method to analyze the data produced by the match finder. Supported modes are fast and normal. The default is fast for presets 0–3 and normal for presets 4–9. Usually fast is used with Hash Chain match finders and normal with Binary Tree match finders. This is also what the presets do. nice=nice Specify what is considered to be a nice length for a match. Once a match of at least nice bytes is found, the algorithm stops looking for possibly better matches. Nice can be 2–273 bytes. Higher values tend to give better compression ratio at the expense of speed. The default depends on the preset. depth=depth Specify the maximum search depth in the match finder. The default is the special value of 0, which makes the compressor determine a reasonable depth from mf and nice. Reasonable depth for Hash Chains is 4–100 and 16–1000 for Binary Trees. Using very high values for depth can make the encoder extremely slow with some files. Avoid setting the depth over 1000 unless you are prepared to interrupt the compression in case it is taking far too long. When decoding raw streams (--format=raw), LZMA2 needs only the dictionary size. LZMA1 needs also lc, lp, and pb. --x86[=options] --arm[=options] --armthumb[=options] --arm64[=options] --powerpc[=options] --ia64[=options] --sparc[=options] --riscv[=options] Add a branch/call/jump (BCJ) filter to the filter chain. These filters can be used only as a non-last filter in the filter chain. A BCJ filter converts relative addresses in the machine code to their absolute counterparts. This doesn't change the size of the data but it increases redundancy, which can help LZMA2 to produce 0–15 % smaller .xz file. The BCJ filters are always reversible, so using a BCJ filter for wrong type of data doesn't cause any data loss, although it may make the compression ratio slightly worse. The BCJ filters are very fast and use an insignificant amount of memory. These BCJ filters have known problems related to the compression ratio: • Some types of files containing executable code (for example, object files, static libraries, and Linux kernel modules) have the addresses in the instructions filled with filler values. These BCJ filters will still do the address conversion, which will make the compression worse with these files. • If a BCJ filter is applied on an archive, it is possible that it makes the compression ratio worse than not using a BCJ filter. For example, if there are similar or even identical executables then filtering will likely make the files less similar and thus compression is worse. The contents of non- executable files in the same archive can matter too. In practice one has to try with and without a BCJ filter to see which is better in each situation. Different instruction sets have different alignment: the executable file must be aligned to a multiple of this value in the input data to make the filter work. Filter Alignment Notes x86 1 32-bit or 64-bit x86 ARM 4 ARM-Thumb 2 ARM64 4 4096-byte alignment is best PowerPC 4 Big endian only IA-64 16 Itanium SPARC 4 RISC-V 2 Since the BCJ-filtered data is usually compressed with LZMA2, the compression ratio may be improved slightly if the LZMA2 options are set to match the alignment of the selected BCJ filter. Examples: • IA-64 filter has 16-byte alignment so pb=4,lp=4,lc=0 is good with LZMA2 (2^4=16). • RISC-V code has 2-byte or 4-byte alignment depending on whether the file contains 16-bit compressed instructions (the C extension). When 16-bit instructions are used, pb=2,lp=1,lc=3 or pb=1,lp=1,lc=3 is good. When 16-bit instructions aren't present, pb=2,lp=2,lc=2 is the best. readelf -h can be used to check if "RVC" appears on the "Flags" line. • ARM64 is always 4-byte aligned so pb=2,lp=2,lc=2 is the best. • The x86 filter is an exception. It's usually good to stick to LZMA2's defaults (pb=2,lp=0,lc=3) when compressing x86 executables. All BCJ filters support the same options: start=offset Specify the start offset that is used when converting between relative and absolute addresses. The offset must be a multiple of the alignment of the filter (see the table above). The default is zero. In practice, the default is good; specifying a custom offset is almost never useful. --delta[=options] Add the Delta filter to the filter chain. The Delta filter can be only used as a non-last filter in the filter chain. Currently only simple byte-wise delta calculation is supported. It can be useful when compressing, for example, uncompressed bitmap images or uncompressed PCM audio. However, special purpose algorithms may give significantly better results than Delta + LZMA2. This is true especially with audio, which compresses faster and better, for example, with flac(1). Supported options: dist=distance Specify the distance of the delta calculation in bytes. distance must be 1–256. The default is 1. For example, with dist=2 and eight-byte input A1 B1 A2 B3 A3 B5 A4 B7, the output will be A1 B1 01 02 01 02 01 02. Other options -q, --quiet Suppress warnings and notices. Specify this twice to suppress errors too. This option has no effect on the exit status. That is, even if a warning was suppressed, the exit status to indicate a warning is still used. -v, --verbose Be verbose. If standard error is connected to a terminal, xz will display a progress indicator. Specifying --verbose twice will give even more verbose output. The progress indicator shows the following information: • Completion percentage is shown if the size of the input file is known. That is, the percentage cannot be shown in pipes. • Amount of compressed data produced (compressing) or consumed (decompressing). • Amount of uncompressed data consumed (compressing) or produced (decompressing). • Compression ratio, which is calculated by dividing the amount of compressed data processed so far by the amount of uncompressed data processed so far. • Compression or decompression speed. This is measured as the amount of uncompressed data consumed (compression) or produced (decompression) per second. It is shown after a few seconds have passed since xz started processing the file. • Elapsed time in the format M:SS or H:MM:SS. • Estimated remaining time is shown only when the size of the input file is known and a couple of seconds have already passed since xz started processing the file. The time is shown in a less precise format which never has any colons, for example, 2 min 30 s. When standard error is not a terminal, --verbose will make xz print the filename, compressed size, uncompressed size, compression ratio, and possibly also the speed and elapsed time on a single line to standard error after compressing or decompressing the file. The speed and elapsed time are included only when the operation took at least a few seconds. If the operation didn't finish, for example, due to user interruption, also the completion percentage is printed if the size of the input file is known. -Q, --no-warn Don't set the exit status to 2 even if a condition worth a warning was detected. This option doesn't affect the verbosity level, thus both --quiet and --no-warn have to be used to not display warnings and to not alter the exit status. --robot Print messages in a machine-parsable format. This is intended to ease writing frontends that want to use xz instead of liblzma, which may be the case with various scripts. The output with this option enabled is meant to be stable across xz releases. See the section ROBOT MODE for details. --info-memory Display, in human-readable format, how much physical memory (RAM) and how many processor threads xz thinks the system has and the memory usage limits for compression and decompression, and exit successfully. -h, --help Display a help message describing the most commonly used options, and exit successfully. -H, --long-help Display a help message describing all features of xz, and exit successfully -V, --version Display the version number of xz and liblzma in human readable format. To get machine-parsable output, specify --robot before --version. ROBOT MODE The robot mode is activated with the --robot option. It makes the output of xz easier to parse by other programs. Currently --robot is supported only together with --list, --filters-help, --info-memory, and --version. It will be supported for compression and decompression in the future. List mode xz --robot --list uses tab-separated output. The first column of every line has a string that indicates the type of the information found on that line: name This is always the first line when starting to list a file. The second column on the line is the filename. file This line contains overall information about the .xz file. This line is always printed after the name line. stream This line type is used only when --verbose was specified. There are as many stream lines as there are streams in the .xz file. block This line type is used only when --verbose was specified. There are as many block lines as there are blocks in the .xz file. The block lines are shown after all the stream lines; different line types are not interleaved. summary This line type is used only when --verbose was specified twice. This line is printed after all block lines. Like the file line, the summary line contains overall information about the .xz file. totals This line is always the very last line of the list output. It shows the total counts and sizes. The columns of the file lines: 2. Number of streams in the file 3. Total number of blocks in the stream(s) 4. Compressed size of the file 5. Uncompressed size of the file 6. Compression ratio, for example, 0.123. If ratio is over 9.999, three dashes (---) are displayed instead of the ratio. 7. Comma-separated list of integrity check names. The following strings are used for the known check types: None, CRC32, CRC64, and SHA-256. For unknown check types, Unknown-N is used, where N is the Check ID as a decimal number (one or two digits). 8. Total size of stream padding in the file The columns of the stream lines: 2. Stream number (the first stream is 1) 3. Number of blocks in the stream 4. Compressed start offset 5. Uncompressed start offset 6. Compressed size (does not include stream padding) 7. Uncompressed size 8. Compression ratio 9. Name of the integrity check 10. Size of stream padding The columns of the block lines: 2. Number of the stream containing this block 3. Block number relative to the beginning of the stream (the first block is 1) 4. Block number relative to the beginning of the file 5. Compressed start offset relative to the beginning of the file 6. Uncompressed start offset relative to the beginning of the file 7. Total compressed size of the block (includes headers) 8. Uncompressed size 9. Compression ratio 10. Name of the integrity check If --verbose was specified twice, additional columns are included on the block lines. These are not displayed with a single --verbose, because getting this information requires many seeks and can thus be slow: 11. Value of the integrity check in hexadecimal 12. Block header size 13. Block flags: c indicates that compressed size is present, and u indicates that uncompressed size is present. If the flag is not set, a dash (-) is shown instead to keep the string length fixed. New flags may be added to the end of the string in the future. 14. Size of the actual compressed data in the block (this excludes the block header, block padding, and check fields) 15. Amount of memory (in bytes) required to decompress this block with this xz version 16. Filter chain. Note that most of the options used at compression time cannot be known, because only the options that are needed for decompression are stored in the .xz headers. The columns of the summary lines: 2. Amount of memory (in bytes) required to decompress this file with this xz version 3. yes or no indicating if all block headers have both compressed size and uncompressed size stored in them Since xz 5.1.2alpha: 4. Minimum xz version required to decompress the file The columns of the totals line: 2. Number of streams 3. Number of blocks 4. Compressed size 5. Uncompressed size 6. Average compression ratio 7. Comma-separated list of integrity check names that were present in the files 8. Stream padding size 9. Number of files. This is here to keep the order of the earlier columns the same as on file lines. If --verbose was specified twice, additional columns are included on the totals line: 10. Maximum amount of memory (in bytes) required to decompress the files with this xz version 11. yes or no indicating if all block headers have both compressed size and uncompressed size stored in them Since xz 5.1.2alpha: 12. Minimum xz version required to decompress the file Future versions may add new line types and new columns can be added to the existing line types, but the existing columns won't be changed. Filters help xz --robot --filters-help prints the supported filters in the following format: filter:option=<value>,option=<value>... filter Name of the filter option Name of a filter specific option value Numeric value ranges appear as <min-max>. String value choices are shown within < > and separated by a | character. Each filter is printed on its own line. Memory limit information xz --robot --info-memory prints a single line with multiple tab- separated columns: 1. Total amount of physical memory (RAM) in bytes. 2. Memory usage limit for compression in bytes (--memlimit-compress). A special value of 0 indicates the default setting which for single-threaded mode is the same as no limit. 3. Memory usage limit for decompression in bytes (--memlimit-decompress). A special value of 0 indicates the default setting which for single-threaded mode is the same as no limit. 4. Since xz 5.3.4alpha: Memory usage for multi-threaded decompression in bytes (--memlimit-mt-decompress). This is never zero because a system-specific default value shown in the column 5 is used if no limit has been specified explicitly. This is also never greater than the value in the column 3 even if a larger value has been specified with --memlimit-mt-decompress. 5. Since xz 5.3.4alpha: A system-specific default memory usage limit that is used to limit the number of threads when compressing with an automatic number of threads (--threads=0) and no memory usage limit has been specified (--memlimit-compress). This is also used as the default value for --memlimit-mt-decompress. 6. Since xz 5.3.4alpha: Number of available processor threads. In the future, the output of xz --robot --info-memory may have more columns, but never more than a single line. Version xz --robot --version prints the version number of xz and liblzma in the following format: XZ_VERSION=XYYYZZZS LIBLZMA_VERSION=XYYYZZZS X Major version. YYY Minor version. Even numbers are stable. Odd numbers are alpha or beta versions. ZZZ Patch level for stable releases or just a counter for development releases. S Stability. 0 is alpha, 1 is beta, and 2 is stable. S should be always 2 when YYY is even. XYYYZZZS are the same on both lines if xz and liblzma are from the same XZ Utils release. Examples: 4.999.9beta is 49990091 and 5.0.0 is 50000002. EXIT STATUS 0 All is good. 1 An error occurred. 2 Something worth a warning occurred, but no actual errors occurred. Notices (not warnings or errors) printed on standard error don't affect the exit status. ENVIRONMENT xz parses space-separated lists of options from the environment variables XZ_DEFAULTS and XZ_OPT, in this order, before parsing the options from the command line. Note that only options are parsed from the environment variables; all non-options are silently ignored. Parsing is done with getopt_long(3) which is used also for the command line arguments. XZ_DEFAULTS User-specific or system-wide default options. Typically this is set in a shell initialization script to enable xz's memory usage limiter by default. Excluding shell initialization scripts and similar special cases, scripts must never set or unset XZ_DEFAULTS. XZ_OPT This is for passing options to xz when it is not possible to set the options directly on the xz command line. This is the case when xz is run by a script or tool, for example, GNU tar(1): XZ_OPT=-2v tar caf foo.tar.xz foo Scripts may use XZ_OPT, for example, to set script-specific default compression options. It is still recommended to allow users to override XZ_OPT if that is reasonable. For example, in sh(1) scripts one may use something like this: XZ_OPT=${XZ_OPT-"-7e"} export XZ_OPT LZMA UTILS COMPATIBILITY The command line syntax of xz is practically a superset of lzma, unlzma, and lzcat as found from LZMA Utils 4.32.x. In most cases, it is possible to replace LZMA Utils with XZ Utils without breaking existing scripts. There are some incompatibilities though, which may sometimes cause problems. Compression preset levels The numbering of the compression level presets is not identical in xz and LZMA Utils. The most important difference is how dictionary sizes are mapped to different presets. Dictionary size is roughly equal to the decompressor memory usage. Level xz LZMA Utils -0 256 KiB N/A -1 1 MiB 64 KiB -2 2 MiB 1 MiB -3 4 MiB 512 KiB -4 4 MiB 1 MiB -5 8 MiB 2 MiB -6 8 MiB 4 MiB -7 16 MiB 8 MiB -8 32 MiB 16 MiB -9 64 MiB 32 MiB The dictionary size differences affect the compressor memory usage too, but there are some other differences between LZMA Utils and XZ Utils, which make the difference even bigger: Level xz LZMA Utils 4.32.x -0 3 MiB N/A -1 9 MiB 2 MiB -2 17 MiB 12 MiB -3 32 MiB 12 MiB -4 48 MiB 16 MiB -5 94 MiB 26 MiB -6 94 MiB 45 MiB -7 186 MiB 83 MiB -8 370 MiB 159 MiB -9 674 MiB 311 MiB The default preset level in LZMA Utils is -7 while in XZ Utils it is -6, so both use an 8 MiB dictionary by default. Streamed vs. non-streamed .lzma files The uncompressed size of the file can be stored in the .lzma header. LZMA Utils does that when compressing regular files. The alternative is to mark that uncompressed size is unknown and use end-of-payload marker to indicate where the decompressor should stop. LZMA Utils uses this method when uncompressed size isn't known, which is the case, for example, in pipes. xz supports decompressing .lzma files with or without end-of-payload marker, but all .lzma files created by xz will use end-of-payload marker and have uncompressed size marked as unknown in the .lzma header. This may be a problem in some uncommon situations. For example, a .lzma decompressor in an embedded device might work only with files that have known uncompressed size. If you hit this problem, you need to use LZMA Utils or LZMA SDK to create .lzma files with known uncompressed size. Unsupported .lzma files The .lzma format allows lc values up to 8, and lp values up to 4. LZMA Utils can decompress files with any lc and lp, but always creates files with lc=3 and lp=0. Creating files with other lc and lp is possible with xz and with LZMA SDK. The implementation of the LZMA1 filter in liblzma requires that the sum of lc and lp must not exceed 4. Thus, .lzma files, which exceed this limitation, cannot be decompressed with xz. LZMA Utils creates only .lzma files which have a dictionary size of 2^n (a power of 2) but accepts files with any dictionary size. liblzma accepts only .lzma files which have a dictionary size of 2^n or 2^n + 2^(n-1). This is to decrease false positives when detecting .lzma files. These limitations shouldn't be a problem in practice, since practically all .lzma files have been compressed with settings that liblzma will accept. Trailing garbage When decompressing, LZMA Utils silently ignore everything after the first .lzma stream. In most situations, this is a bug. This also means that LZMA Utils don't support decompressing concatenated .lzma files. If there is data left after the first .lzma stream, xz considers the file to be corrupt unless --single-stream was used. This may break obscure scripts which have assumed that trailing garbage is ignored. NOTES Compressed output may vary The exact compressed output produced from the same uncompressed input file may vary between XZ Utils versions even if compression options are identical. This is because the encoder can be improved (faster or better compression) without affecting the file format. The output can vary even between different builds of the same XZ Utils version, if different build options are used. The above means that once --rsyncable has been implemented, the resulting files won't necessarily be rsyncable unless both old and new files have been compressed with the same xz version. This problem can be fixed if a part of the encoder implementation is frozen to keep rsyncable output stable across xz versions. Embedded .xz decompressors Embedded .xz decompressor implementations like XZ Embedded don't necessarily support files created with integrity check types other than none and crc32. Since the default is --check=crc64, you must use --check=none or --check=crc32 when creating files for embedded systems. Outside embedded systems, all .xz format decompressors support all the check types, or at least are able to decompress the file without verifying the integrity check if the particular check is not supported. XZ Embedded supports BCJ filters, but only with the default start offset.
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Basics Compress the file foo into foo.xz using the default compression level (-6), and remove foo if compression is successful: xz foo Decompress bar.xz into bar and don't remove bar.xz even if decompression is successful: xz -dk bar.xz Create baz.tar.xz with the preset -4e (-4 --extreme), which is slower than the default -6, but needs less memory for compression and decompression (48 MiB and 5 MiB, respectively): tar cf - baz | xz -4e > baz.tar.xz A mix of compressed and uncompressed files can be decompressed to standard output with a single command: xz -dcf a.txt b.txt.xz c.txt d.txt.lzma > abcd.txt Parallel compression of many files On GNU and *BSD, find(1) and xargs(1) can be used to parallelize compression of many files: find . -type f \! -name '*.xz' -print0 \ | xargs -0r -P4 -n16 xz -T1 The -P option to xargs(1) sets the number of parallel xz processes. The best value for the -n option depends on how many files there are to be compressed. If there are only a couple of files, the value should probably be 1; with tens of thousands of files, 100 or even more may be appropriate to reduce the number of xz processes that xargs(1) will eventually create. The option -T1 for xz is there to force it to single-threaded mode, because xargs(1) is used to control the amount of parallelization. Robot mode Calculate how many bytes have been saved in total after compressing multiple files: xz --robot --list *.xz | awk '/^totals/{print $5-$4}' A script may want to know that it is using new enough xz. The following sh(1) script checks that the version number of the xz tool is at least 5.0.0. This method is compatible with old beta versions, which didn't support the --robot option: if ! eval "$(xz --robot --version 2> /dev/null)" || [ "$XZ_VERSION" -lt 50000002 ]; then echo "Your xz is too old." fi unset XZ_VERSION LIBLZMA_VERSION Set a memory usage limit for decompression using XZ_OPT, but if a limit has already been set, don't increase it: NEWLIM=$((123 << 20)) # 123 MiB OLDLIM=$(xz --robot --info-memory | cut -f3) if [ $OLDLIM -eq 0 -o $OLDLIM -gt $NEWLIM ]; then XZ_OPT="$XZ_OPT --memlimit-decompress=$NEWLIM" export XZ_OPT fi Custom compressor filter chains The simplest use for custom filter chains is customizing a LZMA2 preset. This can be useful, because the presets cover only a subset of the potentially useful combinations of compression settings. The CompCPU columns of the tables from the descriptions of the options -0 ... -9 and --extreme are useful when customizing LZMA2 presets. Here are the relevant parts collected from those two tables: Preset CompCPU -0 0 -1 1 -2 2 -3 3 -4 4 -5 5 -6 6 -5e 7 -6e 8 If you know that a file requires somewhat big dictionary (for example, 32 MiB) to compress well, but you want to compress it quicker than xz -8 would do, a preset with a low CompCPU value (for example, 1) can be modified to use a bigger dictionary: xz --lzma2=preset=1,dict=32MiB foo.tar With certain files, the above command may be faster than xz -6 while compressing significantly better. However, it must be emphasized that only some files benefit from a big dictionary while keeping the CompCPU value low. The most obvious situation, where a big dictionary can help a lot, is an archive containing very similar files of at least a few megabytes each. The dictionary size has to be significantly bigger than any individual file to allow LZMA2 to take full advantage of the similarities between consecutive files. If very high compressor and decompressor memory usage is fine, and the file being compressed is at least several hundred megabytes, it may be useful to use an even bigger dictionary than the 64 MiB that xz -9 would use: xz -vv --lzma2=dict=192MiB big_foo.tar Using -vv (--verbose --verbose) like in the above example can be useful to see the memory requirements of the compressor and decompressor. Remember that using a dictionary bigger than the size of the uncompressed file is waste of memory, so the above command isn't useful for small files. Sometimes the compression time doesn't matter, but the decompressor memory usage has to be kept low, for example, to make it possible to decompress the file on an embedded system. The following command uses -6e (-6 --extreme) as a base and sets the dictionary to only 64 KiB. The resulting file can be decompressed with XZ Embedded (that's why there is --check=crc32) using about 100 KiB of memory. xz --check=crc32 --lzma2=preset=6e,dict=64KiB foo If you want to squeeze out as many bytes as possible, adjusting the number of literal context bits (lc) and number of position bits (pb) can sometimes help. Adjusting the number of literal position bits (lp) might help too, but usually lc and pb are more important. For example, a source code archive contains mostly US-ASCII text, so something like the following might give slightly (like 0.1 %) smaller file than xz -6e (try also without lc=4): xz --lzma2=preset=6e,pb=0,lc=4 source_code.tar Using another filter together with LZMA2 can improve compression with certain file types. For example, to compress a x86-32 or x86-64 shared library using the x86 BCJ filter: xz --x86 --lzma2 libfoo.so Note that the order of the filter options is significant. If --x86 is specified after --lzma2, xz will give an error, because there cannot be any filter after LZMA2, and also because the x86 BCJ filter cannot be used as the last filter in the chain. The Delta filter together with LZMA2 can give good results with bitmap images. It should usually beat PNG, which has a few more advanced filters than simple delta but uses Deflate for the actual compression. The image has to be saved in uncompressed format, for example, as uncompressed TIFF. The distance parameter of the Delta filter is set to match the number of bytes per pixel in the image. For example, 24-bit RGB bitmap needs dist=3, and it is also good to pass pb=0 to LZMA2 to accommodate the three-byte alignment: xz --delta=dist=3 --lzma2=pb=0 foo.tiff If multiple images have been put into a single archive (for example, .tar), the Delta filter will work on that too as long as all images have the same number of bytes per pixel. SEE ALSO xzdec(1), xzdiff(1), xzgrep(1), xzless(1), xzmore(1), gzip(1), bzip2(1), 7z(1) XZ Utils: <https://tukaani.org/xz/> XZ Embedded: <https://tukaani.org/xz/embedded.html> LZMA SDK: <https://7-zip.org/sdk.html> Tukaani 2024-04-08 XZ(1)
|
qmlcachegen
| null | null | null | null | null |
myisampack
|
The myisampack utility compresses MyISAM tables. myisampack works by compressing each column in the table separately. Usually, myisampack packs the data file 40% to 70%. When the table is used later, the server reads into memory the information needed to decompress columns. This results in much better performance when accessing individual rows, because you only have to uncompress exactly one row. MySQL uses mmap() when possible to perform memory mapping on compressed tables. If mmap() does not work, MySQL falls back to normal read/write file operations. Please note the following: • If the mysqld server was invoked with external locking disabled, it is not a good idea to invoke myisampack if the table might be updated by the server during the packing process. It is safest to compress tables with the server stopped. • After packing a table, it becomes read only. This is generally intended (such as when accessing packed tables on a CD). • myisampack does not support partitioned tables. Invoke myisampack like this: myisampack [options] file_name ... Each file name argument should be the name of an index (.MYI) file. If you are not in the database directory, you should specify the path name to the file. It is permissible to omit the .MYI extension. After you compress a table with myisampack, use myisamchk -rq to rebuild its indexes. myisamchk(1). myisampack supports the following options. It also reads option files and supports the options for processing them described at Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”. • --help, -? ┌────────────────────┬────────┐ │Command-Line Format │ --help │ └────────────────────┴────────┘ Display a help message and exit. • --backup, -b ┌────────────────────┬──────────┐ │Command-Line Format │ --backup │ └────────────────────┴──────────┘ Make a backup of each table's data file using the name tbl_name.OLD. • --character-sets-dir=dir_name ┌────────────────────┬───────────────────────────────┐ │Command-Line Format │ --character-sets-dir=dir_name │ ├────────────────────┼───────────────────────────────┤ │Type │ Directory name │ └────────────────────┴───────────────────────────────┘ The directory where character sets are installed. See Section 10.15, “Character Set Configuration”. • --debug[=debug_options], -# [debug_options] ┌────────────────────┬─────────────────────────┐ │Command-Line Format │ --debug[=debug_options] │ ├────────────────────┼─────────────────────────┤ │Type │ String │ ├────────────────────┼─────────────────────────┤ │Default Value │ d:t:o │ └────────────────────┴─────────────────────────┘ Write a debugging log. A typical debug_options string is d:t:o,file_name. The default is d:t:o. This option is available only if MySQL was built using WITH_DEBUG. MySQL release binaries provided by Oracle are not built using this option. • --force, -f ┌────────────────────┬─────────┐ │Command-Line Format │ --force │ └────────────────────┴─────────┘ Produce a packed table even if it becomes larger than the original or if the intermediate file from an earlier invocation of myisampack exists. (myisampack creates an intermediate file named tbl_name.TMD in the database directory while it compresses the table. If you kill myisampack, the .TMD file might not be deleted.) Normally, myisampack exits with an error if it finds that tbl_name.TMD exists. With --force, myisampack packs the table anyway. • --join=big_tbl_name, -j big_tbl_name ┌────────────────────┬─────────────────────┐ │Command-Line Format │ --join=big_tbl_name │ ├────────────────────┼─────────────────────┤ │Type │ String │ └────────────────────┴─────────────────────┘ Join all tables named on the command line into a single packed table big_tbl_name. All tables that are to be combined must have identical structure (same column names and types, same indexes, and so forth). big_tbl_name must not exist prior to the join operation. All source tables named on the command line to be merged into big_tbl_name must exist. The source tables are read for the join operation but not modified. • --silent, -s ┌────────────────────┬──────────┐ │Command-Line Format │ --silent │ └────────────────────┴──────────┘ Silent mode. Write output only when errors occur. • --test, -t ┌────────────────────┬────────┐ │Command-Line Format │ --test │ └────────────────────┴────────┘ Do not actually pack the table, just test packing it. • --tmpdir=dir_name, -T dir_name ┌────────────────────┬───────────────────┐ │Command-Line Format │ --tmpdir=dir_name │ ├────────────────────┼───────────────────┤ │Type │ Directory name │ └────────────────────┴───────────────────┘ Use the named directory as the location where myisampack creates temporary files. • --verbose, -v ┌────────────────────┬───────────┐ │Command-Line Format │ --verbose │ └────────────────────┴───────────┘ Verbose mode. Write information about the progress of the packing operation and its result. • --version, -V ┌────────────────────┬───────────┐ │Command-Line Format │ --version │ └────────────────────┴───────────┘ Display version information and exit. • --wait, -w ┌────────────────────┬────────┐ │Command-Line Format │ --wait │ └────────────────────┴────────┘ Wait and retry if the table is in use. If the mysqld server was invoked with external locking disabled, it is not a good idea to invoke myisampack if the table might be updated by the server during the packing process. The following sequence of commands illustrates a typical table compression session: $> ls -l station.* -rw-rw-r-- 1 jones my 994128 Apr 17 19:00 station.MYD -rw-rw-r-- 1 jones my 53248 Apr 17 19:00 station.MYI $> myisamchk -dvv station MyISAM file: station Isam-version: 2 Creation time: 1996-03-13 10:08:58 Recover time: 1997-02-02 3:06:43 Data records: 1192 Deleted blocks: 0 Datafile parts: 1192 Deleted data: 0 Datafile pointer (bytes): 2 Keyfile pointer (bytes): 2 Max datafile length: 54657023 Max keyfile length: 33554431 Recordlength: 834 Record format: Fixed length table description: Key Start Len Index Type Root Blocksize Rec/key 1 2 4 unique unsigned long 1024 1024 1 2 32 30 multip. text 10240 1024 1 Field Start Length Type 1 1 1 2 2 4 3 6 4 4 10 1 5 11 20 6 31 1 7 32 30 8 62 35 9 97 35 10 132 35 11 167 4 12 171 16 13 187 35 14 222 4 15 226 16 16 242 20 17 262 20 18 282 20 19 302 30 20 332 4 21 336 4 22 340 1 23 341 8 24 349 8 25 357 8 26 365 2 27 367 2 28 369 4 29 373 4 30 377 1 31 378 2 32 380 8 33 388 4 34 392 4 35 396 4 36 400 4 37 404 1 38 405 4 39 409 4 40 413 4 41 417 4 42 421 4 43 425 4 44 429 20 45 449 30 46 479 1 47 480 1 48 481 79 49 560 79 50 639 79 51 718 79 52 797 8 53 805 1 54 806 1 55 807 20 56 827 4 57 831 4 $> myisampack station.MYI Compressing station.MYI: (1192 records) - Calculating statistics normal: 20 empty-space: 16 empty-zero: 12 empty-fill: 11 pre-space: 0 end-space: 12 table-lookups: 5 zero: 7 Original trees: 57 After join: 17 - Compressing file 87.14% Remember to run myisamchk -rq on compressed tables $> myisamchk -rq station - check record delete-chain - recovering (with sort) MyISAM-table 'station' Data records: 1192 - Fixing index 1 - Fixing index 2 $> mysqladmin -uroot flush-tables $> ls -l station.* -rw-rw-r-- 1 jones my 127874 Apr 17 19:00 station.MYD -rw-rw-r-- 1 jones my 55296 Apr 17 19:04 station.MYI $> myisamchk -dvv station MyISAM file: station Isam-version: 2 Creation time: 1996-03-13 10:08:58 Recover time: 1997-04-17 19:04:26 Data records: 1192 Deleted blocks: 0 Datafile parts: 1192 Deleted data: 0 Datafile pointer (bytes): 3 Keyfile pointer (bytes): 1 Max datafile length: 16777215 Max keyfile length: 131071 Recordlength: 834 Record format: Compressed table description: Key Start Len Index Type Root Blocksize Rec/key 1 2 4 unique unsigned long 10240 1024 1 2 32 30 multip. text 54272 1024 1 Field Start Length Type Huff tree Bits 1 1 1 constant 1 0 2 2 4 zerofill(1) 2 9 3 6 4 no zeros, zerofill(1) 2 9 4 10 1 3 9 5 11 20 table-lookup 4 0 6 31 1 3 9 7 32 30 no endspace, not_always 5 9 8 62 35 no endspace, not_always, no empty 6 9 9 97 35 no empty 7 9 10 132 35 no endspace, not_always, no empty 6 9 11 167 4 zerofill(1) 2 9 12 171 16 no endspace, not_always, no empty 5 9 13 187 35 no endspace, not_always, no empty 6 9 14 222 4 zerofill(1) 2 9 15 226 16 no endspace, not_always, no empty 5 9 16 242 20 no endspace, not_always 8 9 17 262 20 no endspace, no empty 8 9 18 282 20 no endspace, no empty 5 9 19 302 30 no endspace, no empty 6 9 20 332 4 always zero 2 9 21 336 4 always zero 2 9 22 340 1 3 9 23 341 8 table-lookup 9 0 24 349 8 table-lookup 10 0 25 357 8 always zero 2 9 26 365 2 2 9 27 367 2 no zeros, zerofill(1) 2 9 28 369 4 no zeros, zerofill(1) 2 9 29 373 4 table-lookup 11 0 30 377 1 3 9 31 378 2 no zeros, zerofill(1) 2 9 32 380 8 no zeros 2 9 33 388 4 always zero 2 9 34 392 4 table-lookup 12 0 35 396 4 no zeros, zerofill(1) 13 9 36 400 4 no zeros, zerofill(1) 2 9 37 404 1 2 9 38 405 4 no zeros 2 9 39 409 4 always zero 2 9 40 413 4 no zeros 2 9 41 417 4 always zero 2 9 42 421 4 no zeros 2 9 43 425 4 always zero 2 9 44 429 20 no empty 3 9 45 449 30 no empty 3 9 46 479 1 14 4 47 480 1 14 4 48 481 79 no endspace, no empty 15 9 49 560 79 no empty 2 9 50 639 79 no empty 2 9 51 718 79 no endspace 16 9 52 797 8 no empty 2 9 53 805 1 17 1 54 806 1 3 9 55 807 20 no empty 3 9 56 827 4 no zeros, zerofill(2) 2 9 57 831 4 no zeros, zerofill(1) 2 9 myisampack displays the following kinds of information: • normal The number of columns for which no extra packing is used. • empty-space The number of columns containing values that are only spaces. These occupy one bit. • empty-zero The number of columns containing values that are only binary zeros. These occupy one bit. • empty-fill The number of integer columns that do not occupy the full byte range of their type. These are changed to a smaller type. For example, a BIGINT column (eight bytes) can be stored as a TINYINT column (one byte) if all its values are in the range from -128 to 127. • pre-space The number of decimal columns that are stored with leading spaces. In this case, each value contains a count for the number of leading spaces. • end-space The number of columns that have a lot of trailing spaces. In this case, each value contains a count for the number of trailing spaces. • table-lookup The column had only a small number of different values, which were converted to an ENUM before Huffman compression. • zero The number of columns for which all values are zero. • Original trees The initial number of Huffman trees. • After join The number of distinct Huffman trees left after joining trees to save some header space. After a table has been compressed, the Field lines displayed by myisamchk -dvv include additional information about each column: • Type The data type. The value may contain any of the following descriptors: • constant All rows have the same value. • no endspace Do not store endspace. • no endspace, not_always Do not store endspace and do not do endspace compression for all values. • no endspace, no empty Do not store endspace. Do not store empty values. • table-lookup The column was converted to an ENUM. • zerofill(N) The most significant N bytes in the value are always 0 and are not stored. • no zeros Do not store zeros. • always zero Zero values are stored using one bit. • Huff tree The number of the Huffman tree associated with the column. • Bits The number of bits used in the Huffman tree. After you run myisampack, use myisamchk to re-create any indexes. At this time, you can also sort the index blocks and create statistics needed for the MySQL optimizer to work more efficiently: myisamchk -rq --sort-index --analyze tbl_name.MYI After you have installed the packed table into the MySQL database directory, you should execute mysqladmin flush-tables to force mysqld to start using the new table. To unpack a packed table, use the --unpack option to myisamchk. COPYRIGHT Copyright © 1997, 2023, Oracle and/or its affiliates. This documentation is free software; you can redistribute it and/or modify it only under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This documentation is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with the program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or see http://www.gnu.org/licenses/. SEE ALSO For more information, please refer to the MySQL Reference Manual, which may already be installed locally and which is also available online at http://dev.mysql.com/doc/. AUTHOR Oracle Corporation (http://dev.mysql.com/). MySQL 8.3 11/23/2023 MYISAMPACK(1)
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myisampack - generate compressed, read-only MyISAM tables
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myisampack [options] file_name ...
| null | null |
qdarkstyle.utils
| null | null | null | null | null |
pcre2posix_test
| null | null | null | null | null |
jupyter-migrate
| null | null | null | null | null |
dav1d
| null | null | null | null | null |
ar
|
The ar utility creates and maintains groups of files combined into an archive. Once an archive has been created, new files can be added and existing files can be extracted, deleted, or replaced. Files are named in the archive by a single component, i.e., if a file referenced by a path containing a slash (``/'') is archived it will be named by the last component of that path. When matching paths listed on the command line against file names stored in the archive, only the last component of the path will be compared. All informational and error messages use the path listed on the command line, if any was specified, otherwise the name in the archive is used. If multiple files in the archive have the same name, and paths are listed on the command line to ``select'' archive files for an operation, only the first file with a matching name will be selected. The normal use of ar is for the creation and maintenance of libraries suitable for use with the loader (see ld(1)) although it is not restricted to this purpose. The options are as follows: -a A positioning modifier used with the options -r and -m. The files are entered or moved after the archive member position, which must be specified. -b A positioning modifier used with the options -r and -m. The files are entered or moved before the archive member position, which must be specified. -c Whenever an archive is created, an informational message to that effect is written to standard error. If the -c option is specified, ar creates the archive silently. -d Delete the specified archive files. -i Identical to the -b option. -m Move the specified archive files within the archive. If one of the options -a, -b or -i are specified, the files are moved before or after the position file in the archive. If none of those options are specified, the files are moved to the end of the archive. -o Set the access and modification times of extracted files to the modification time of the file when it was entered into the archive. This will fail if the user is not the owner of the extracted file or the super-user. -p Write the contents of the specified archive files to the standard output. If no files are specified, the contents of all the files in the archive are written in the order they appear in the archive. -q (Quickly) append the specified files to the archive. If the archive does not exist a new archive file is created. Much faster than the -r option, when creating a large archive piece- by-piece, as no checking is done to see if the files already exist in the archive. -r Replace or add the specified files to the archive. If the archive does not exist a new archive file is created. Files that replace existing files do not change the order of the files within the archive. New files are appended to the archive unless one of the options -a, -b or -i is specified. -T Select and/or name archive members using only the first fifteen characters of the archive member or command line file name. The historic archive format had sixteen bytes for the name, but some historic archiver and loader implementations were unable to handle names that used the entire space. This means that file names that are not unique in their first fifteen characters can subsequently be confused. A warning message is printed to the standard error output if any file names are truncated. (See ar(5) for more information.) -L Used the extended format to allow long archive member names. This is the default. -s Write an object-file index into the archive, or update an existing one, even if no other change is made to the archive. You may use this modifier flag either with any operation, or alone. Running `ar s' on an archive is equivalent to running `ranlib' on it. -S Do not generate an archive symbol table. This can speed up building a large library in several steps. The resulting archive can not be used with the linker. In order to build a symbol table, you must omit the S modifier on the last execution of ar, or you must run ranlib on the archive. -t List the specified files in the order in which they appear in the archive, each on a separate line. If no files are specified, all files in the archive are listed. -u Update files. When used with the -r option, files in the archive will be replaced only if the disk file has a newer modification time than the file in the archive. When used with the -x option, files in the archive will be extracted only if the archive file has a newer modification time than the file on disk. -v Provide verbose output. When used with the -d, -m, -q or -x options, ar gives a file-by-file description of the archive modification. This description consists of three, white-space separated fields: the option letter, a dash (``-'') and the file name. When used with the -r option, ar displays the description as above, but the initial letter is an ``a'' if the file is added to the archive and an ``r'' if the file replaces a file already in the archive. When used with the -p option, the name of each printed file is written to the standard output before the contents of the file, preceded by a single newline character, and followed by two newline characters, enclosed in less-than (``<'') and greater- than (``>'') characters. When used with the -t option, ar displays an ``ls -l'' style listing of information about the members of the archive. This listing consists of eight, white-space separated fields: the file permissions (see strmode(3) ), the decimal user and group ID's, separated by a single slash (``/''), the file size (in bytes), the file modification time (in the date(1) format ``%b %e %H:%M %Y''), and the name of the file. -x Extract the specified archive members into the files named by the command line arguments. If no members are specified, all the members of the archive are extracted into the current directory. If the file does not exist, it is created; if it does exist, the owner and group will be unchanged. The file access and modification times are the time of the extraction (but see the -o option). The file permissions will be set to those of the file when it was entered into the archive; this will fail if the user is not the owner of the extracted file or the super-user. The ar utility exits 0 on success, and >0 if an error occurs. ENVIRONMENT TMPDIR The pathname of the directory to use when creating temporary files. FILES /tmp default temporary file directory ar.XXXXXX temporary file names COMPATIBILITY By default, ar writes archives that may be incompatible with historic archives, as the format used for storing archive members with names longer than fifteen characters has changed. This implementation of ar is backward compatible with previous versions of ar in that it can read and write (using the -T option) historic archives. The -T option is provided for compatibility only, and will be deleted in a future release. See ar(5) for more information. STANDARDS The ar utility is expected to offer a superset of the IEEE Std 1003.2 (“POSIX.2”) functionality. SEE ALSO ld(1), ranlib(1), strmode(3), ar(5) Darwin July 27, 2005 Darwin
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ar – create and maintain library archives
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ar -d [-TLsv] archive file ... ar -m [-TLsv] archive file ... ar -m [-abiTLsv] position archive file ... ar -p [-TLsv] archive [file ...] ar -q [-cTLsv] archive file ... ar -r [-cuTLsv] archive file ... ar -r [-abciuTLsv] position archive file ... ar -t [-TLsv] archive [file ...] ar -x [-ouTLsv] archive [file ...]
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transicc
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lcms is a standalone CMM engine, which deals with the color management. It implements a fast transformation between ICC profiles. transicc is a lcms ColorSpace conversion calculator.
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transicc - little cms ColorSpace conversion calculator.
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transicc [options] [CGATSINPUT] [CGATSOUTPUT]
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-b Black point compensation. -c NUM Precalculates transform (0=Off, 1=Normal, 2=Hi-res, 3=LoRes) [defaults to 1]. -d NUM Observer adaptation state (abs.col. only), (0..1.0, float value) [defaults to 0.0]. -e Encoded representation of numbers is not float (Option -w=use 16 bits, Option -x=hexadecimal). -g Marks out-of-gamut colors on softproof. -i profile Input profile (defaults to sRGB). -l Transform by device-link profile. -m NUM SoftProof intent (0,1,2,3) [defaults to 0]. -n Terse output, intended for pipe usage. -o profile Output profile (defaults to sRGB). -q Quantize CGATS to 8 bits. -s Bounded mode. -t NUM Rendering intent 0=Perceptual [default] 1=Relative colorimetric 2=Saturation 3=Absolute colorimetric 10=Perceptual preserving black ink 11=Relative colorimetric preserving black ink 12=Saturation preserving black ink 13=Perceptual preserving black plane 14=Relative colorimetric preserving black plane 15=Saturation preserving black plane -v verbosity Verbosity level, (0=None, 1=Normal, 2=High, 3=Very High) [defaults to 1]. -w Use 16 bits. -x Hexadecimal. You can use '*Lab' and '*xyz' as built-in profiles. NOTES For suggestions, comments, bug reports etc. send mail to info@littlecms.com. SEE ALSO jpgicc(1), linkicc(1), psicc(1), tificc(1) AUTHOR This manual page was written by Shiju p. Nair <shiju.p@gmail.com>, for the Debian project. May 30, 2011 TRANSICC(1)
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conda-skeleton
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arm64-apple-darwin20.0.0-nm
|
As of Xcode 8.0 the default nm(1) tool is llvm-nm(1). For the most part nm(1) and llvm-nm(1) have the same options; notable exceptions include -f, -s, and -L as described below. This document explains options common between the two commands as well as some historically relevant options supported by nm-classic(1). More help on options for llvm-nm(1) is provided when running it with the --help option. nm displays the name list (symbol table of nlist structures) of each object file in the argument list. In some cases, as with an object that has had strip(1) with its -T option used on the object, that can be different than the dyld information. For that information use dyldinfo(1). If an argument is an archive, a listing for each object file in the archive will be produced. File can be of the form libx.a(x.o), in which case only symbols from that member of the object file are listed. (The parentheses have to be quoted to get by the shell.) If no file is given, the symbols in a.out are listed. Each symbol name is preceded by its value (blanks if undefined). Unless the -m option is specified, this value is followed by one of the following characters, representing the symbol type: U (undefined), A (absolute), T (text section symbol), D (data section symbol), B (bss section symbol), C (common symbol), - (for debugger symbol table entries; see -a below), S (symbol in a section other than those above), or I (indirect symbol). If the symbol is local (non-external), the symbol's type is instead represented by the corresponding lowercase letter. A lower case u in a dynamic shared library indicates a undefined reference to a private external in another module in the same library. If the symbol is a Objective-C method, the symbol name is ±[Class_name(category_name) method:name:], where `+' is for class methods, `-' is for instance methods, and (category_name) is present only when the method is in a category. The output is sorted alphabetically by default. Options are: -a Display all symbol table entries, including those inserted for use by debuggers. -g Display only global (external) symbols. -n Sort numerically rather than alphabetically. -o Prepend file or archive element name to each output line, rather than only once. -p Don't sort; display in symbol-table order. -r Sort in reverse order. -u Display only undefined symbols. -U Don't display undefined symbols. -m Display the N_SECT type symbols (Mach-O symbols) as (segment_name, section_name) followed by either external or non-external and then the symbol name. Undefined, common, absolute and indirect symbols get displayed as (undefined), (common), (absolute), and (indirect), respectively. Other symbol details are displayed in a human-friendly manner, such as "[no dead strip]". nm will display the referenced symbol for indirect symbols and will display the name of the library expected to provide an undefined symbol. See nlist(3) and <mach- o/nlist.h> for more information on the nlist structure. -x Display the symbol table entry's fields in hexadecimal, along with the name as a string. -j Just display the symbol names (no value or type). -s segname sectname List only those symbols in the section (segname,sectname). For llvm-nm(1) this option must be last on the command line, and after the files. -l List a pseudo symbol .section_start if no symbol has as its value the starting address of the section. (This is used with the -s option above.) -arch arch_type Specifies the architecture, arch_type, of the file for nm(1) to operate on when the file is a universal file (see arch(3) for the currently known arch_types). The arch_type can be "all" to operate on all architectures in the file. The default is to display the symbols from only the host architecture, if the file contains it; otherwise, symbols for all architectures in the file are displayed. -f format For llvm-nm(1) this specifies the output format. Where format can be bsd, sysv, posix or darwin. -f For nm-classic(1) this displays the symbol table of a dynamic library flat (as one file not separate modules). This is obsolete and not supported with llvm-nm(1). -A Write the pathname or library name of an object on each line. -P Write information in a portable output format. -t format For the -P output, write the numeric value in the specified format. The format shall be dependent on the single character used as the format option-argument: d The value shall be written in decimal (default). o The value shall be written in octal. x The value shall be written in hexadecimal. -L Display the symbols in the bitcode files in the (__LLVM,__bundle) section if present instead of the object's symbol table. For nm-classic(1) this is the default if the object has no symbol table and an (__LLVM,__bundle) section exists. This option is not supported by llvm-nm(1) where displaying llvm bitcode symbols is the default behavior. SEE ALSO ar(1), ar(5), Mach-O(5), stab(5), nlist(3), dyldinfo(1) BUGS Displaying Mach-O symbols with -m is too verbose. Without the -m, symbols in the Objective-C sections get displayed as an `s'. Apple, Inc. December 13, 2018 NM(1)
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nm - display name list (symbol table)
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llvm-nm [ -agnoprumxjlPA ] [ - ] [ -t format ] [[ -arch arch_flag ]...] [ file ... ] [ -s segname sectname ] nm-classic [ -agnoprumxjlfPA [ s segname sectname ]] [ - ] [ -t format ] [[ -arch arch_flag ]...] [ file ... ]
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wrjpgcom
|
wrjpgcom reads the named JPEG/JFIF file, or the standard input if no file is named, and generates a new JPEG/JFIF file on standard output. A comment block is added to the file. The JPEG standard allows "comment" (COM) blocks to occur within a JPEG file. Although the standard doesn't actually define what COM blocks are for, they are widely used to hold user-supplied text strings. This lets you add annotations, titles, index terms, etc to your JPEG files, and later retrieve them as text. COM blocks do not interfere with the image stored in the JPEG file. The maximum size of a COM block is 64K, but you can have as many of them as you like in one JPEG file. wrjpgcom adds a COM block, containing text you provide, to a JPEG file. Ordinarily, the COM block is added after any existing COM blocks; but you can delete the old COM blocks if you wish.
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wrjpgcom - insert text comments into a JPEG file
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wrjpgcom [ -replace ] [ -comment text ] [ -cfile name ] [ filename ]
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Switch names may be abbreviated, and are not case sensitive. -replace Delete any existing COM blocks from the file. -comment text Supply text for new COM block on command line. -cfile name Read text for new COM block from named file. If you have only one line of comment text to add, you can provide it on the command line with -comment. The comment text must be surrounded with quotes so that it is treated as a single argument. Longer comments can be read from a text file. If you give neither -comment nor -cfile, then wrjpgcom will read the comment text from standard input. (In this case an input image file name MUST be supplied, so that the source JPEG file comes from somewhere else.) You can enter multiple lines, up to 64KB worth. Type an end-of-file indicator (usually control-D) to terminate the comment text entry. wrjpgcom will not add a COM block if the provided comment string is empty. Therefore -replace -comment "" can be used to delete all COM blocks from a file.
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Add a short comment to in.jpg, producing out.jpg: wrjpgcom -c "View of my back yard" in.jpg > out.jpg Attach a long comment previously stored in comment.txt: wrjpgcom in.jpg < comment.txt > out.jpg or equivalently wrjpgcom -cfile comment.txt < in.jpg > out.jpg SEE ALSO cjpeg(1), djpeg(1), jpegtran(1), rdjpgcom(1) AUTHOR Independent JPEG Group 15 June 1995 WRJPGCOM(1)
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mysql_embedded
| null | null | null | null | null |
pkgdata
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pkgdata takes a set of data files and packages them for use by ICU or applications that use ICU. The typical reason to package files using pkgdata is to make their distribution easier and their loading by ICU faster and less consuming of limited system resources such as file descriptors. Packaged data also allow applications to be distributed with fewer resource files, or even with none at all if they link against the packaged data directly. pkgdata supports a few different methods of packaging data that serve different purposes. The default packaging mode is common, or archive. In this mode, the different data files are bundled together as an architecture-dependent file that can later be memory mapped for use by ICU. Data packaged using this mode will be looked up under the ICU data directory. Such packaging is easy to use for applications resource bundles, for example, as long as the application can install the packaged file in the ICU data directory. Another packaging mode is the dll, or library, mode, where the data files are compiled into a shared library. ICU used to be able to dynamically load these shared libraries, but as of ICU 2.0, such support has been removed. This mode is still useful for two main purposes: to build ICU itself, as the ICU data is packaged as a shared library by default; and to build resource bundles that are linked to the application that uses them. Such resource bundles can then be placed anywhere where the system's dynamic linker will be looking for shared libraries, instead of being forced to live inside the ICU data directory. The static packaging mode is similar to the shared library one except that it produces a static library. Finally, pkgdata supports a files mode which simply copies the data files instead of packaging them as a single file or library. This mode is mainly intended to provide support for building ICU before it is packaged as separate small packages for distribution with operating systems such as Debian GNU/Linux for example. Please refer to the packaging documentation in the ICU source distribution for further information on the use of this mode. pkgdata builds, packages, installs, or cleans the appropriate data based on the options given without the need to call GNU make anymore.
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pkgdata - package data for use by ICU
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pkgdata [ -h, -?, --help ] [ -v, --verbose ] [ -c, --copyright | -C, --comment comment ] [ -m, --mode mode ] -p, --name name -O, --bldopt options [ -e, --entrypoint name ] [ -r, --revision version ] [ -F, --rebuild ] [ -I, --install ] [ -s, --sourcedir source ] [ -d, --destdir destination ] [ -T, --tempdir directory ] [ file ... ]
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-h, -?, --help Print help about usage and exit. -v, --verbose Display extra informative messages during execution. -c, --copyright Include a copyright notice in the binary data. -C, --comment comment Includes the specified comment in the resulting data instead of the ICU copyright notice. -m, --mode mode Set the packaging mode to be used by pkgdata. The different modes and their meaning are explained in the DESCRIPTION section above. The valid mode names are common (or archive), dll (or library), and files. -O, --bldopt options Specify options for the builder. The builder is used internally by pkgdata to generate the correct packaged file. Such options include, but are not limited to, setting variables used by make(1) during the build of the packaged file. Note: If icu-config is available, then this option is not needed. -p, --name name Set the packaged file name to name. This name is also used as the default entry point name after having been turned into a valid C identifier. -e, --entrypoint name Set the data entry point (used for linking against the data in a shared library form) to name. The default entry point name is the name set by the -n, --name option. -r, --revision version Enable versioning of the shared library produced in dll, or library, mode. The version number has the format major.minor.patchlevel and all parts except for major are optional. If only major is supplied then the version is assumed to be major.0 for versioning purposes. -F, --rebuild Force the rebuilding of all data and their repackaging. -I, --install Install the packaged file (or all the files in the files mode). If the variable DESTDIR is set it will be used for installation. -s, --sourcedir source Set the source directory to source. The default source directory is the current directory. -d, --destdir destination Set the destination directory to destination. The default destination directory is the current directory. -T, --tempdir directory Set the directory used to generate temporary files to directory. The default temporary directory is the same as the destination directory as set by the -d, --destdir option. AUTHORS Steven Loomis Yves Arrouye VERSION 68.1 COPYRIGHT Copyright (C) 2000-2009 IBM, Inc. and others. ICU MANPAGE 6 February 2009 PKGDATA(1)
| null |
conda2solv
| null | null | null | null | null |
anaconda-project
| null | null | null | null | null |
deactivate
| null | null | null | null | null |
grpc_php_plugin
| null | null | null | null | null |
lz4c
|
lz4 is an extremely fast lossless compression algorithm, based on byte-aligned LZ77 family of compression scheme. lz4 offers compression speeds > 500 MB/s per core, linearly scalable with multi-core CPUs. It features an extremely fast decoder, offering speed in multiple GB/s per core, typically reaching RAM speed limit on multi-core systems. The native file format is the .lz4 format. Difference between lz4 and gzip lz4 supports a command line syntax similar but not identical to gzip(1). Differences are : • lz4 compresses a single file by default (see -m for multiple files) • lz4 file1 file2 means : compress file1 into file2 • lz4 file.lz4 will default to decompression (use -z to force compression) • lz4 preserves original files (see --rm to erase source file on completion) • lz4 shows real-time notification statistics during compression or decompression of a single file (use -q to silence them) • When no destination is specified, result is sent on implicit output, which depends on stdout status. When stdout is Not the console, it becomes the implicit output. Otherwise, if stdout is the console, the implicit output is filename.lz4. • It is considered bad practice to rely on implicit output in scripts. because the script´s environment may change. Always use explicit output in scripts. -c ensures that output will be stdout. Conversely, providing a destination name, or using -m ensures that the output will be either the specified name, or filename.lz4 respectively. Default behaviors can be modified by opt-in commands, detailed below. • lz4 -m makes it possible to provide multiple input filenames, which will be compressed into files using suffix .lz4. Progress notifications become disabled by default (use -v to enable them). This mode has a behavior which more closely mimics gzip command line, with the main remaining difference being that source files are preserved by default. • Similarly, lz4 -m -d can decompress multiple *.lz4 files. • It´s possible to opt-in to erase source files on successful compression or decompression, using --rm command. • Consequently, lz4 -m --rm behaves the same as gzip. Concatenation of .lz4 files It is possible to concatenate .lz4 files as is. lz4 will decompress such files as if they were a single .lz4 file. For example: lz4 file1 > foo.lz4 lz4 file2 >> foo.lz4 Then lz4cat foo.lz4 is equivalent to cat file1 file2.
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lz4 - lz4, unlz4, lz4cat - Compress or decompress .lz4 files
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lz4 [OPTIONS] [-|INPUT-FILE] OUTPUT-FILE unlz4 is equivalent to lz4 -d lz4cat is equivalent to lz4 -dcfm When writing scripts that need to decompress files, it is recommended to always use the name lz4 with appropriate arguments (lz4 -d or lz4 -dc) instead of the names unlz4 and lz4cat.
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Short commands concatenation In some cases, some options can be expressed using short command -x or long command --long-word. Short commands can be concatenated together. For example, -d -c is equivalent to -dc. Long commands cannot be concatenated. They must be clearly separated by a space. Multiple commands When multiple contradictory commands are issued on a same command line, only the latest one will be applied. Operation mode -z --compress Compress. This is the default operation mode when no operation mode option is specified, no other operation mode is implied from the command name (for example, unlz4 implies --decompress), nor from the input file name (for example, a file extension .lz4 implies --decompress by default). -z can also be used to force compression of an already compressed .lz4 file. -d --decompress --uncompress Decompress. --decompress is also the default operation when the input filename has an .lz4 extension. -t --test Test the integrity of compressed .lz4 files. The decompressed data is discarded. No files are created nor removed. -b# Benchmark mode, using # compression level. --list List information about .lz4 files. note : current implementation is limited to single-frame .lz4 files. Operation modifiers -# Compression level, with # being any value from 1 to 12. Higher values trade compression speed for compression ratio. Values above 12 are considered the same as 12. Recommended values are 1 for fast compression (default), and 9 for high compression. Speed/compression trade-off will vary depending on data to compress. Decompression speed remains fast at all settings. --fast[=#] Switch to ultra-fast compression levels. The higher the value, the faster the compression speed, at the cost of some compression ratio. If =# is not present, it defaults to 1. This setting overrides compression level if one was set previously. Similarly, if a compression level is set after --fast, it overrides it. --best Set highest compression level. Same as -12. --favor-decSpeed Generate compressed data optimized for decompression speed. Compressed data will be larger as a consequence (typically by ~0.5%), while decompression speed will be improved by 5-20%, depending on use cases. This option only works in combination with very high compression levels (>=10). -D dictionaryName Compress, decompress or benchmark using dictionary dictionaryName. Compression and decompression must use the same dictionary to be compatible. Using a different dictionary during decompression will either abort due to decompression error, or generate a checksum error. -f --[no-]force This option has several effects: If the target file already exists, overwrite it without prompting. When used with --decompress and lz4 cannot recognize the type of the source file, copy the source file as is to standard output. This allows lz4cat --force to be used like cat (1) for files that have not been compressed with lz4. -c --stdout --to-stdout Force write to standard output, even if it is the console. -m --multiple Multiple input files. Compressed file names will be appended a .lz4 suffix. This mode also reduces notification level. Can also be used to list multiple files. lz4 -m has a behavior equivalent to gzip -k (it preserves source files by default). -r operate recursively on directories. This mode also sets -m (multiple input files). -B# Block size [4-7](default : 7) -B4= 64KB ; -B5= 256KB ; -B6= 1MB ; -B7= 4MB -BI Produce independent blocks (default) -BD Blocks depend on predecessors (improves compression ratio, more noticeable on small blocks) -BX Generate block checksums (default:disabled) --[no-]frame-crc Select frame checksum (default:enabled) --no-crc Disable both frame and block checksums --[no-]content-size Header includes original size (default:not present) Note : this option can only be activated when the original size can be determined, hence for a file. It won´t work with unknown source size, such as stdin or pipe. --[no-]sparse Sparse mode support (default:enabled on file, disabled on stdout) -l Use Legacy format (typically for Linux Kernel compression) Note : -l is not compatible with -m (--multiple) nor -r Other options -v --verbose Verbose mode -q --quiet Suppress warnings and real-time statistics; specify twice to suppress errors too -h -H --help Display help/long help and exit -V --version Display Version number and exit -k --keep Preserve source files (default behavior) --rm Delete source files on successful compression or decompression -- Treat all subsequent arguments as files Benchmark mode -b# Benchmark file(s), using # compression level -e# Benchmark multiple compression levels, from b# to e# (included) -i# Minimum evaluation time in seconds [1-9] (default : 3) BUGS Report bugs at: https://github.com/lz4/lz4/issues AUTHOR Yann Collet lz4 v1.9.4 August 2022 LZ4(1)
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arm64-apple-darwin20.0.0-cmpdylib
|
cmpdylib compares two versions of a dynamic shared library to see if they are compatible with each other. If the two versions are incompatible, the reason is printed to stdout, and the exit status is nonzero. If they are compatible, nothing is printed, and the exit status is zero. To see if the two versions are compatible, cmpdylib first verifies that newLibrary was built for all of the architectures that oldLibrary was built for. If so, for each architecture, it checks to see if the global symbols defined in oldLibrary are still defined in newLibrary. It then looks for new symbols, symbols defined in newLibrary that are not defined in oldLibrary. If it finds new symbols, it compares the compatibility version numbers of the two libraries. If the compatibility version number of newLibrary is greater than oldLibrary, the libraries are still compatible. If the compatibility version number is the same or less, the libraries are incompatible.
|
cmpdylib - compare two dynamic shared libraries for compatibility
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cmpdylib oldLibrary newLibrary
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oldLibrary The older version of the library. newLibrary The newer version of the library.
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This example shows the result of performing cmpdylib on two incompatible versions of the Foundation library. As stated, the versions are incompatible because the newer version was not built for the ppc architecture. cmpdylib /System/Library/Frameworks/Foundation.framework/Foundation Foundation_proj/Foundation cmpdylib: file: Foundation_proj/Foundation does not contain architecture: ppc cmpdylib: new dynamic shared library: Foundation_proj/Foundation does not contain architecture ppc DIAGNOSTICS The exit status is zero if the library versions are compatible and nonzero if they are incompatible. BUGS There are lots of other things that could be checked for that are not (such as the Objective C API). Apple Computer, Inc. November 3, 1997 CMPDYLIB(1)
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mysql_client_test_embedded
| null | null | null | null | null |
jupyter-fileid
| null | null | null | null | null |
qmllint
| null | null | null | null | null |
arm64-apple-darwin20.0.0-as
|
The as command translates assembly code in the named files to object code. If no files are specified, as reads from stdin. All undefined symbols in the assembly are treated as global. The output of the assembly is left in the file a.out by default. The program /usr/bin/as is actually a driver that executes assemblers for specific target architectures. If no target architecture is specified, it defaults to the architecture of the host it is running on.
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as - Mac OS X Mach-O GNU-based assemblers
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as [ option ... ] [ file ... ]
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-o name Name the output file name instead of a.out. -arch arch_type Specifies the target architecture, arch_type, of the assembler to be executed. The target assemblers for each architecture are in /usr/libexec/gcc/darwin/arch_type/as or /usr/local/libexec/gcc/darwin/arch_type/as. There is only one assembler for an architecture family. If the specified target architecture is a machine-specific implementation, the assembler for that architecture family is executed (e.g., /usr/libexec/gcc/darwin/ppc/as for -arch ppc604e). See arch(3) for the currently known arch_types. -arch_multiple Precede any displayed messages with a line stating the program name (as) and the architecture (from the -arch arch_type flag), to distinguish which architecture the error messages refer to. When the cc(1) driver program is run with multiple -arch flags, it invokes as with the -arch_multiple option. -force_cpusubtype_ALL By default, the assembler will produce the CPU subtype ALL for the object file it is assembling if it finds no implementation- specific instructions. Also by default, the assembler will allow implementation-specific instructions and will combine the CPU subtype for those specific implementations. The combining of specific implementations is architecture-dependent; if some combination of instructions is not allowed, an error is generated. With the optional -force_cpusubtype_ALL flag, all instructions are allowed and the object file's CPU subtype will be the ALL subtype. If the target architecture specified is a machine-specific implementation (e.g., -arch ppc603, -arch i486), the assembler will flag as errors instructions that are not supported on that architecture, and it will produce an object file with the CPU subtype for that specific implementation (even if no implementation-specific instructions are used). The -force_cpusubtype_ALL flag is the default for all x86 and x86_64 architectures. -dynamic Enables dynamic linking features. This is the default. -static Causes the assembler to treat as an error any features for dynamic linking. Also causes the .text directive to not include the pure_instructions section attribute. -- Use stdin for the assembly source input. -n Instructs the assembler not to assume that the assembly file starts with a .text directive. Use this option when an output file is not to contain a (__TEXT,__text) section or this section is not to be first one in the output file. -f Fast; no need for the assembler preprocessor (``app''). The assembler preprocessor can also be turned off by starting the assembly file with "#NO_APP\n". This is intended for use by compilers which produce assembly code in a strict "clean" format that specifies exactly where whitespace can go. The assembler preprocessor needs to be run on hand-written assembly files and/or files that have been preprocessed by the C preprocessor cpp. This is typically needed when assembler files are assembled through the use of the cc(1) command, which automatically runs the C preprocessor on assembly source files. The assembler preprocessor strips out excess spaces, turns single-quoted characters into a decimal constants, and turns # <number> <filename> <level> into .line <number>;.file <filename> pairs. When the assembler preprocessor has been turned off by a "#NO_APP\n" at the start of a file, it can be turned back on and off again with pairs of "#APP\n" and "#NO_APP\n" at the beginnings of lines. This is used by the compiler to wrap assembly statements produced from asm() statements. -g Produce debugging information for the symbolic debugger gdb(1) so that the assembly source can be debugged symbolically. The debugger depends on correct use of the C preprocessor's #include directive or the assembler's .include directive: Any include file that produces instructions in the (__TEXT,__text) section must be included while a .text directive is in effect. In other words, there must be a .text directive before the include, and the .text directive must still be in effect at the end of the include file. Otherwise, the debugger will get confused when in that assembly file. -v Display the version of the assembler (both the Mac OS X version and the GNU version it is based on). -V Print the path and the command line of the assembler the assembler driver is using. -Idir Add the directory dir to the list of directories to search for files included with the .include directive. The default place to search is the current directory. -W Suppress warnings. -L Save non-global defined labels beginning with an 'L'; these labels are normally discarded to save space in the resultant symbol table. The compiler generates such temporary labels. -q Use the clang(1) integrated assembler instead of the GNU based system assembler. This is the default for the x86 and arm architectures. -Q Use the GNU based system assembler. Assembler options for the PowerPC processors -static_branch_prediction_Y_bit Treat a single trailing '+' or '-' after a conditional PowerPC branch instruction as a static branch prediction that sets the Y-bit in the opcode. Pairs of trailing "++" or "--" always set the AT-bits. This is the default for Mac OS X. -static_branch_prediction_AT_bits Treat a single trailing '+' or '-' after a conditional PowerPC branch instruction as a static branch prediction that sets the AT-bits in the opcode. Pairs of trailing "++" or "--" always set the AT-bits but with this option a warning is issued if this syntax is used. With this flag the assembler behaves like the IBM tools. -no_ppc601 Treat any PowerPC 601 instructions as an error. FILES a.out output file SEE ALSO The Mac OS X Assembler Reference in the Xcode documentation viewer: Perform a title search for "assembler" in Apple > Developer Tools Reference Library. The assembler source in the cctools module of the Darwin sources. cc(1), ld(1), nm(1), otool(1), arch(3), Mach-O(5) Apple Inc. February 12, 2015 AS(1)
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dask-scheduler
| null | null | null | null | null |
gifbuild
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gifbuild - dump GIF data in a textual format, or undump it to a GIF
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gifbuild [-v] [-a] [-d] [-t translation-table] [-h] [gif-file]
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A program to convert a series of editable text GIF icon specifications and named GIF files into a multi-image GIF, usable as a graphic resource file. It can also dump existing GIFs in this format. When dumping a GIF, certain sanity checks are performed which may result in a warning emitted to standard error. If no GIF file is given, gifbuild will try to read a text input from stdin. SPECIFICATION SYNTAX Here is a syntax summary in informal BNF. The token `NL' represents a required newline. <gif-spec> ::= <header-block> <image-block>... <header-block> ::= <header-declaration>... <header-declaration ::= | screen width <digits> NL | screen height <digits> NL | screen colors <digits> NL | screen background <digits> NL | pixel aspect byte <digits> NL | screen map <color-table> NL <color-table> ::= <color-declaration>... end NL <color-declaration> ::= rgb <digits> <digits> <digits> [ is <key>] NL | sort flag {on|off} NL <image-block> ::= include <file-name> NL | image NL <image-declaration>... <raster-picture> [ <extension> ] <image-declarations> ::= image top <digits> NL | image left <digits> NL | image interlaced NL | image map <color-table> NL | image bits <digits> by <digits> [hex|ascii] NL <raster-block> <extension> := <comment> NL <extension-block> NL end NL | <plaintext> NL <extension-block> NL end NL | graphics control NL <GCB-part> NL end NL | netscape loop <digits> NL | extension <hex-digits> NL <extension-block> NL end NL <GCB-part> ::= disposal mode <digits> NL | user input flag {on|off} NL | delay <digits> NL | transparent index <digits> NL If the data types of the “screen height”, “screen width”, “screen background”, “image top”, and “image left” declarations aren't obvious to you, what are you doing with this software? The “pixel aspect byte” declaration sets an integer denominator for a fraction expressing the puxel aspect ratio. See the GIF standard for details; this field is actually long obsolete. A color table declares color indices (in ascending order from 0) and may associate them with key characters (these associations are absent when the map is more than 94 colors lang and raster blocks using it must use hex pairs). These characters can later be used in raster blocks. As these must be printable and non-whitespace, you can only specify 94 colors per icon. Life is like that sometimes. A color table declaration can also set the table's sort flag with "sort flag on" or "sort flag off" on any line before the end. An “ascii” raster block is just a block of key characters (used for a color map of 94 or fewer colors). A “hex” raster block uses hex digit pairs instead (used for a color map with more than 94 colors). The default is ASCII. It should be sized correctly for the “image bits” declaration that leads it. Raster blocks from interlaced GIFs are dumped with the lines in non-interlaced order. The “comment”, “plaintext” or “ggraphics control” keywords lead defined GIF89 extension record data. The final GIF89 type, graphics control and application block, are not yet supported, but the code does recognize a Netscape loop block. You can also say “extension” followed by a hexadecimal record type. All of these extension declarations must be followed by an extension block, which is terminated by the keyword “end” on its own line. An extension block is a series of text lines, each interpreted as a string of bytes to fill an extension block (the terminating newline is stripped). Text may include standard C-style octal and hex escapes preceded by a backslash. A graphics control block declaration creates a graphics control extension block; for the field semantics see the GIF89 standard, part 23. A netscape loop declaration creates an application extension block containing a NETSCAPE 2.0 animation loop control with a specified repeat count (repeat count 0 means loop forever). This must be immediately after the header declaration. These loop blocks are interpreted by the Netscape/Mozilla/Firefox line of browsers. All <digits> tokens are interpreted as decimal numerals; <hex-digits> tokens are interpreted as two hex digits (a byte). All coordinates are zero-origin with the top left corner (0,0). Range checking is weak and signedness checking nonexistent; caveat hacker! In general, the amount of whitespace and order of declarations within a header or image block is not significant, except that a raster picture must immediately follow its “image bits” bits declaration. The “include” declaration includes a named GIF as the next image. The global color maps of included GIFs are merged with the base table defined by any “screen color” declaration. All images of an included multi-image GIF will be included in order. Comments (preceded with “#”) will be ignored. -v Verbose mode (show progress). Enables printout of running scan lines. -d Dump the input GIF file(s) into the text form described above. -t Specify name characters to use when dumping raster blocks. Only valid with -d option. -h Print one line of command line help, similar to Usage above. BUGS Error checking is rudimentary. EXAMPLE: A sample icon file called sample.ico is included in the pic directory of the GIFLIB source distribution. AUTHOR Eric S. Raymond <esr@thyrsus.com> GIFLIB 2 May 2012 GIFBUILD(1)
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arm64-apple-darwin20.0.0-nmedit
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Nmedit changes the global symbols not listed in the list_file file of the -s list_file option to static symbols. Undefined symbols and common symbols are not affected and shouldn't be listed in list_file. For dynamic libraries symbols are turned into private extern symbols that are no longer external (rather than static symbols). This is done so that the references between modules of a dynamic library are resolved to the symbols in the dynamic library. Nmedit differs from strip(1) in that it also changes the symbolic debugging information (produce by the -g option to cc(1)) for the global symbols it changes to static symbols so that the resulting object can still be used with the debugger. Nmedit like strip(1) is useful to limit the symbols for use with later linking. This allows control of the interface that the executable wants to provide to the objects that it will dynamically load, and it will not have to publish symbols that are not part of its interface. For example an executable that wishes to allow only a subset of its global symbols but all of the shared libraries globals to be used would have its symbol table edited with: % nmedit -s interface_symbols -A executable where the file interface_symbols would contain only those symbols from the executable that it wishes the objects loaded at runtime to have access to. Another example is an object that is made up of a number of other objects that will be loaded into an executable would built and then have its symbol table edited with: % ld -o relocatable.o -r a.o b.o c.o % nmedit -s interface_symbols relocatable.o which would leave only the symbols listed in the file interface_symbols (and the undefined and common symbols) as global symbols in the object file. The one or more of the following options is required to nmedit(1) is: -s filename Leave the symbol table entries for the global symbols listed in filename global but turn all other global symbols (except undefined and common symbols) into static symbols. The symbol names listed in filename must be one per line. Leading and trailing white space are not part of the symbol name. Lines starting with # are ignored, as are lines with only white space. -R filename Change the symbol table entries for the global symbols listed in filename into static symbols. This file has the same format as the -s filename option above. If the -R filename option is specified without the -s filename option, then all symbols not listed in the -R filename option's filename are left as globals. If both a -R filename and a -s filename are given the symbols listed in the -R filename are basically ignored and only those symbols listed in the -s filename are saved. -p Change symbols to private externs instead of static. This is allowed as the only option to change all defined global symbols to private externs. The options to nmedit(1) are: -A Leave all global absolute symbols except those with a value of zero, and save objective-C class symbols as globals. This is intended for use of programs that load code at runtime and want the loaded code to use symbols from the shared libraries. - Treat all remaining arguments as file names and not options. -arch arch_type Specifies the architecture, arch_type, of the file for nmedit(1) to process when the file is a universal file (see arch(3) for the currently know arch_types). The arch_type can be all to process all architectures in the file. The default is to process all architectures that are contained in the file. -o output Write the result into the file output. SEE ALSO strip(1), ld(1), arch(3) BUGS The changing of the symbolic debugging information by nmedit is not known to be totally correct and could cause the debugger to crash, get confused or produce incorrect information. Apple Inc. May 29, 2007 NMEDIT(1)
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nmedit - change global symbols to local symbols
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nmedit -s list_file [-R list_file] [-p] [-A] [-] [[-arch arch_type] ...] object_file ... [-o output]
| null | null |
lipo
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The lipo tool creates or operates on ``universal'' (multi-architecture) files. Generally, lipo reads a single input file and writes to a single output file, although some commands and options accept multiple input files. lipo will only ever write to a single output file, and input files are never modified in place. lipo supports a number of commands for creating universal files from single-architecture files, extracting single-architecture files from universal files, and displaying architecture information. lipo can only perform one such command at a time, although some command flags may appear more than once. Some commands support additional options that can be used with that command. In addition, there are global options that are supported by multiple commands. The arch_type arguments may be any of the supported architecture names listed in the man page arch(3). COMMANDS -archs Display only the architecture names present in a single input file. Each architecture name is a single word, making this option suitable for shell scripting. Unknown architectures will be represented by "unknown" along with the numeric CPU type and CPU subtype values as a single word. -create Create one universal output file from one or more input files. When input files specified on the command-line, all of the architectures in each file will be copied into the output file, whereas when input files are included using the global -arch option, only the specified architecture will be copied from that input file. This command requires the -output option. -detailed_info Display a detailed list of the architecture types in the input universal file (all the the information in the universal header, for each architecture in the file). -extract arch_type [-extract arch_type...] Take one universal input file and copy the arch_type from that universal file into a universal output file containing only that architecture. This command requires the -output option. -extract_family arch_type [-extract_family arch_type...] Take one universal input file and copy all of the arch_types for the family that arch_type is in from that universal file into an output file containing only those architectures. The file will be thin if only one architecture is found or universal otherwise. This command requires the -output option. -info Display a brief description of each input file along with the names of each architecture type in that input file. -remove arch_type [-remove arch_type ...] Take one universal input file and remove the arch_type from that universal file, placing the result in the output file. This command requires the -output option. -replace arch_type file_name [-replace arch_type file_name...] Take one universal input file; in the output file, replace the arch_type contents of the input file with the contents of the specified file_name. This command requires the -output option. -thin arch_type Take one input file and create a thin output file with the specified arch_type. This command requires the -output option. -verify_arch arch_type ... Take one input file and verify the specified arch_types are present in the file. If so then exit with a status of 0 else exit with a status of 1. Because more than one arch_type can be verified at once, all of the input files must appear before the -verify_arch flag on the command-line.
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lipo - create or operate on universal files
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lipo input_file command [option...]
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-arch arch_type input_file Tells lipo that input_file contains the specified architecture type. The -arch arch_type specification is unnecessary if input_file is an object file, a universal file, or some other file whose architecture(s) lipo can figure out. -hideARM64 When creating a universal binary including both 32-bit and 64-bit ARM files, this option will ask lipo to add the 64-bit files at the end and not include them in the count of architectures present in the file. The files must be executable files (Mach-O filetype MH_EXECUTE). This option has no effect if neither 32-bit ARM nor 64-bit ARM files are present, and no other files may be hidden in this way. This option only works with the -create, -remove, and -replace, commands, and is only intended for tools and workflows testing a workaround on older systems. -output output_file Commands that create new files write to the output file specified by the -output flag. This option is required for the -create, -extract, -extract_family, -remove, -replace, and -thin commands. -segalign arch_type value Set the segment alignment of the specified arch_type when creating a universal file containing that architecture. value is a hexadecimal number that must be an integral power of 2. This is only needed when lipo can't figure out the alignment of an input file (currently not an object file), or when it guesses at the alignment too conservatively. The default for files unknown to lipo is 0 (2^0, or an alignment of one byte), and the default alignment for archives is 4 (2^2, or 4-byte alignment). SEE ALSO arch(3) Apple Computer, Inc. August 31, 2018 LIPO(1)
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orc-scan
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conda-convert
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h5diff
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intake-server
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bsdcat
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bsdcat expands files to standard output.
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bsdcat – expand files to standard output
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bsdcat [options] [files]
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bsdcat typically takes a filename as an argument or reads standard input when used in a pipe. In both cases decompressed data it written to standard output.
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To decompress a file: bsdcat example.txt.gz > example.txt To decompress standard input in a pipe: cat example.txt.gz | bsdcat > example.txt Both examples achieve the same results - a decompressed file by redirecting output. SEE ALSO bzcat(1), uncompress(1), xzcat(1), zcat(1), libarchive-formats(5) macOS 14.5 March 1, 2014 macOS 14.5
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msgcat
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Concatenates and merges the specified PO files. Find messages which are common to two or more of the specified PO files. By using the --more-than option, greater commonality may be requested before messages are printed. Conversely, the --less-than option may be used to specify less commonality before messages are printed (i.e. --less-than=2 will only print the unique messages). Translations, comments, extracted comments, and file positions will be cumulated, except that if --use-first is specified, they will be taken from the first PO file to define them. Mandatory arguments to long options are mandatory for short options too. Input file location: INPUTFILE ... input files -f, --files-from=FILE get list of input files from FILE -D, --directory=DIRECTORY add DIRECTORY to list for input files search If input file is -, standard input is read. Output file location: -o, --output-file=FILE write output to specified file The results are written to standard output if no output file is specified or if it is -. Message selection: -<, --less-than=NUMBER print messages with less than this many definitions, defaults to infinite if not set ->, --more-than=NUMBER print messages with more than this many definitions, defaults to 0 if not set -u, --unique shorthand for --less-than=2, requests that only unique messages be printed Input file syntax: -P, --properties-input input files are in Java .properties syntax --stringtable-input input files are in NeXTstep/GNUstep .strings syntax Output details: -t, --to-code=NAME encoding for output --use-first use first available translation for each message, don't merge several translations --lang=CATALOGNAME set 'Language' field in the header entry --color use colors and other text attributes always --color=WHEN use colors and other text attributes if WHEN. WHEN may be 'always', 'never', 'auto', or 'html'. --style=STYLEFILE specify CSS style rule file for --color -e, --no-escape do not use C escapes in output (default) -E, --escape use C escapes in output, no extended chars --force-po write PO file even if empty -i, --indent write the .po file using indented style --no-location do not write '#: filename:line' lines -n, --add-location generate '#: filename:line' lines (default) --strict write out strict Uniforum conforming .po file -p, --properties-output write out a Java .properties file --stringtable-output write out a NeXTstep/GNUstep .strings file -w, --width=NUMBER set output page width --no-wrap do not break long message lines, longer than the output page width, into several lines -s, --sort-output generate sorted output -F, --sort-by-file sort output by file location Informative output: -h, --help display this help and exit -V, --version output version information and exit AUTHOR Written by Bruno Haible. REPORTING BUGS Report bugs in the bug tracker at <https://savannah.gnu.org/projects/gettext> or by email to <bug-gettext@gnu.org>. COPYRIGHT Copyright © 2001-2023 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. SEE ALSO The full documentation for msgcat is maintained as a Texinfo manual. If the info and msgcat programs are properly installed at your site, the command info msgcat should give you access to the complete manual. GNU gettext-tools 0.22.5 February 2024 MSGCAT(1)
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msgcat - combines several message catalogs
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msgcat [OPTION] [INPUTFILE]...
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aomenc
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zstdcat
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zstd is a fast lossless compression algorithm and data compression tool, with command line syntax similar to gzip(1) and xz(1). It is based on the LZ77 family, with further FSE & huff0 entropy stages. zstd offers highly configurable compression speed, from fast modes at > 200 MB/s per core, to strong modes with excellent compression ratios. It also features a very fast decoder, with speeds > 500 MB/s per core, which remains roughly stable at all compression settings. zstd command line syntax is generally similar to gzip, but features the following few differences: • Source files are preserved by default. It´s possible to remove them automatically by using the --rm command. • When compressing a single file, zstd displays progress notifications and result summary by default. Use -q to turn them off. • zstd displays a short help page when command line is an error. Use -q to turn it off. • zstd does not accept input from console, though it does accept stdin when it´s not the console. • zstd does not store the input´s filename or attributes, only its contents. zstd processes each file according to the selected operation mode. If no files are given or file is -, zstd reads from standard input and writes the processed data to standard output. zstd will refuse to write compressed data to standard output if it is a terminal: it will display an error message and skip the file. Similarly, zstd will refuse to read compressed data from standard input if it is a terminal. Unless --stdout or -o is specified, files are written to a new file whose name is derived from the source file name: • When compressing, the suffix .zst is appended to the source filename to get the target filename. • When decompressing, the .zst suffix is removed from the source filename to get the target filename Concatenation with .zst Files It is possible to concatenate multiple .zst files. zstd will decompress such agglomerated file as if it was a single .zst file.
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zstd - zstd, zstdmt, unzstd, zstdcat - Compress or decompress .zst files
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zstd [OPTIONS] [-|INPUT-FILE] [-o OUTPUT-FILE] zstdmt is equivalent to zstd -T0 unzstd is equivalent to zstd -d zstdcat is equivalent to zstd -dcf
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Integer Suffixes and Special Values In most places where an integer argument is expected, an optional suffix is supported to easily indicate large integers. There must be no space between the integer and the suffix. KiB Multiply the integer by 1,024 (2^10). Ki, K, and KB are accepted as synonyms for KiB. MiB Multiply the integer by 1,048,576 (2^20). Mi, M, and MB are accepted as synonyms for MiB. Operation Mode If multiple operation mode options are given, the last one takes effect. -z, --compress Compress. This is the default operation mode when no operation mode option is specified and no other operation mode is implied from the command name (for example, unzstd implies --decompress). -d, --decompress, --uncompress Decompress. -t, --test Test the integrity of compressed files. This option is equivalent to --decompress --stdout > /dev/null, decompressed data is discarded and checksummed for errors. No files are created or removed. -b# Benchmark file(s) using compression level #. See BENCHMARK below for a description of this operation. --train FILES Use FILES as a training set to create a dictionary. The training set should contain a lot of small files (> 100). See DICTIONARY BUILDER below for a description of this operation. -l, --list Display information related to a zstd compressed file, such as size, ratio, and checksum. Some of these fields may not be available. This command´s output can be augmented with the -v modifier. Operation Modifiers • -#: selects # compression level [1-19] (default: 3). Higher compression levels generally produce higher compression ratio at the expense of speed and memory. A rough rule of thumb is that compression speed is expected to be divided by 2 every 2 levels. Technically, each level is mapped to a set of advanced parameters (that can also be modified individually, see below). Because the compressor´s behavior highly depends on the content to compress, there´s no guarantee of a smooth progression from one level to another. • --ultra: unlocks high compression levels 20+ (maximum 22), using a lot more memory. Note that decompression will also require more memory when using these levels. • --fast[=#]: switch to ultra-fast compression levels. If =# is not present, it defaults to 1. The higher the value, the faster the compression speed, at the cost of some compression ratio. This setting overwrites compression level if one was set previously. Similarly, if a compression level is set after --fast, it overrides it. • -T#, --threads=#: Compress using # working threads (default: 1). If # is 0, attempt to detect and use the number of physical CPU cores. In all cases, the nb of threads is capped to ZSTDMT_NBWORKERS_MAX, which is either 64 in 32-bit mode, or 256 for 64-bit environments. This modifier does nothing if zstd is compiled without multithread support. • --single-thread: Use a single thread for both I/O and compression. As compression is serialized with I/O, this can be slightly slower. Single-thread mode features significantly lower memory usage, which can be useful for systems with limited amount of memory, such as 32-bit systems. Note 1: this mode is the only available one when multithread support is disabled. Note 2: this mode is different from -T1, which spawns 1 compression thread in parallel with I/O. Final compressed result is also slightly different from -T1. • --auto-threads={physical,logical} (default: physical): When using a default amount of threads via -T0, choose the default based on the number of detected physical or logical cores. • --adapt[=min=#,max=#]: zstd will dynamically adapt compression level to perceived I/O conditions. Compression level adaptation can be observed live by using command -v. Adaptation can be constrained between supplied min and max levels. The feature works when combined with multi-threading and --long mode. It does not work with --single-thread. It sets window size to 8 MiB by default (can be changed manually, see wlog). Due to the chaotic nature of dynamic adaptation, compressed result is not reproducible. Note: at the time of this writing, --adapt can remain stuck at low speed when combined with multiple worker threads (>=2). • --long[=#]: enables long distance matching with # windowLog, if # is not present it defaults to 27. This increases the window size (windowLog) and memory usage for both the compressor and decompressor. This setting is designed to improve the compression ratio for files with long matches at a large distance. Note: If windowLog is set to larger than 27, --long=windowLog or --memory=windowSize needs to be passed to the decompressor. • -D DICT: use DICT as Dictionary to compress or decompress FILE(s) • --patch-from FILE: Specify the file to be used as a reference point for zstd´s diff engine. This is effectively dictionary compression with some convenient parameter selection, namely that windowSize > srcSize. Note: cannot use both this and -D together. Note: --long mode will be automatically activated if chainLog < fileLog (fileLog being the windowLog required to cover the whole file). You can also manually force it. Note: for all levels, you can use --patch-from in --single-thread mode to improve compression ratio at the cost of speed. Note: for level 19, you can get increased compression ratio at the cost of speed by specifying --zstd=targetLength= to be something large (i.e. 4096), and by setting a large --zstd=chainLog=. • --rsyncable: zstd will periodically synchronize the compression state to make the compressed file more rsync-friendly. There is a negligible impact to compression ratio, and a potential impact to compression speed, perceptible at higher speeds, for example when combining --rsyncable with many parallel worker threads. This feature does not work with --single-thread. You probably don´t want to use it with long range mode, since it will decrease the effectiveness of the synchronization points, but your mileage may vary. • -C, --[no-]check: add integrity check computed from uncompressed data (default: enabled) • --[no-]content-size: enable / disable whether or not the original size of the file is placed in the header of the compressed file. The default option is --content-size (meaning that the original size will be placed in the header). • --no-dictID: do not store dictionary ID within frame header (dictionary compression). The decoder will have to rely on implicit knowledge about which dictionary to use, it won´t be able to check if it´s correct. • -M#, --memory=#: Set a memory usage limit. By default, zstd uses 128 MiB for decompression as the maximum amount of memory the decompressor is allowed to use, but you can override this manually if need be in either direction (i.e. you can increase or decrease it). This is also used during compression when using with --patch-from=. In this case, this parameter overrides that maximum size allowed for a dictionary. (128 MiB). Additionally, this can be used to limit memory for dictionary training. This parameter overrides the default limit of 2 GiB. zstd will load training samples up to the memory limit and ignore the rest. • --stream-size=#: Sets the pledged source size of input coming from a stream. This value must be exact, as it will be included in the produced frame header. Incorrect stream sizes will cause an error. This information will be used to better optimize compression parameters, resulting in better and potentially faster compression, especially for smaller source sizes. • --size-hint=#: When handling input from a stream, zstd must guess how large the source size will be when optimizing compression parameters. If the stream size is relatively small, this guess may be a poor one, resulting in a higher compression ratio than expected. This feature allows for controlling the guess when needed. Exact guesses result in better compression ratios. Overestimates result in slightly degraded compression ratios, while underestimates may result in significant degradation. • --target-compressed-block-size=#: Attempt to produce compressed blocks of approximately this size. This will split larger blocks in order to approach this target. This feature is notably useful for improved latency, when the receiver can leverage receiving early incomplete data. This parameter defines a loose target: compressed blocks will target this size "on average", but individual blocks can still be larger or smaller. Enabling this feature can decrease compression speed by up to ~10% at level 1. Higher levels will see smaller relative speed regression, becoming invisible at higher settings. • -f, --force: disable input and output checks. Allows overwriting existing files, input from console, output to stdout, operating on links, block devices, etc. During decompression and when the output destination is stdout, pass-through unrecognized formats as-is. • -c, --stdout: write to standard output (even if it is the console); keep original files (disable --rm). • -o FILE: save result into FILE. Note that this operation is in conflict with -c. If both operations are present on the command line, the last expressed one wins. • --[no-]sparse: enable / disable sparse FS support, to make files with many zeroes smaller on disk. Creating sparse files may save disk space and speed up decompression by reducing the amount of disk I/O. default: enabled when output is into a file, and disabled when output is stdout. This setting overrides default and can force sparse mode over stdout. • --[no-]pass-through enable / disable passing through uncompressed files as-is. During decompression when pass-through is enabled, unrecognized formats will be copied as-is from the input to the output. By default, pass-through will occur when the output destination is stdout and the force (-f) option is set. • --rm: remove source file(s) after successful compression or decompression. This command is silently ignored if output is stdout. If used in combination with -o, triggers a confirmation prompt (which can be silenced with -f), as this is a destructive operation. • -k, --keep: keep source file(s) after successful compression or decompression. This is the default behavior. • -r: operate recursively on directories. It selects all files in the named directory and all its subdirectories. This can be useful both to reduce command line typing, and to circumvent shell expansion limitations, when there are a lot of files and naming breaks the maximum size of a command line. • --filelist FILE read a list of files to process as content from FILE. Format is compatible with ls output, with one file per line. • --output-dir-flat DIR: resulting files are stored into target DIR directory, instead of same directory as origin file. Be aware that this command can introduce name collision issues, if multiple files, from different directories, end up having the same name. Collision resolution ensures first file with a given name will be present in DIR, while in combination with -f, the last file will be present instead. • --output-dir-mirror DIR: similar to --output-dir-flat, the output files are stored underneath target DIR directory, but this option will replicate input directory hierarchy into output DIR. If input directory contains "..", the files in this directory will be ignored. If input directory is an absolute directory (i.e. "/var/tmp/abc"), it will be stored into the "output-dir/var/tmp/abc". If there are multiple input files or directories, name collision resolution will follow the same rules as --output-dir-flat. • --format=FORMAT: compress and decompress in other formats. If compiled with support, zstd can compress to or decompress from other compression algorithm formats. Possibly available options are zstd, gzip, xz, lzma, and lz4. If no such format is provided, zstd is the default. • -h/-H, --help: display help/long help and exit • -V, --version: display version number and immediately exit. note that, since it exits, flags specified after -V are effectively ignored. Advanced: -vV also displays supported formats. -vvV also displays POSIX support. -qV will only display the version number, suitable for machine reading. • -v, --verbose: verbose mode, display more information • -q, --quiet: suppress warnings, interactivity, and notifications. specify twice to suppress errors too. • --no-progress: do not display the progress bar, but keep all other messages. • --show-default-cparams: shows the default compression parameters that will be used for a particular input file, based on the provided compression level and the input size. If the provided file is not a regular file (e.g. a pipe), this flag will output the parameters used for inputs of unknown size. • --exclude-compressed: only compress files that are not already compressed. • --: All arguments after -- are treated as files gzip Operation Modifiers When invoked via a gzip symlink, zstd will support further options that intend to mimic the gzip behavior: -n, --no-name do not store the original filename and timestamps when compressing a file. This is the default behavior and hence a no-op. --best alias to the option -9. Environment Variables Employing environment variables to set parameters has security implications. Therefore, this avenue is intentionally limited. Only ZSTD_CLEVEL and ZSTD_NBTHREADS are currently supported. They set the default compression level and number of threads to use during compression, respectively. ZSTD_CLEVEL can be used to set the level between 1 and 19 (the "normal" range). If the value of ZSTD_CLEVEL is not a valid integer, it will be ignored with a warning message. ZSTD_CLEVEL just replaces the default compression level (3). ZSTD_NBTHREADS can be used to set the number of threads zstd will attempt to use during compression. If the value of ZSTD_NBTHREADS is not a valid unsigned integer, it will be ignored with a warning message. ZSTD_NBTHREADS has a default value of (1), and is capped at ZSTDMT_NBWORKERS_MAX==200. zstd must be compiled with multithread support for this variable to have any effect. They can both be overridden by corresponding command line arguments: -# for compression level and -T# for number of compression threads. ADVANCED COMPRESSION OPTIONS zstd provides 22 predefined regular compression levels plus the fast levels. A compression level is translated internally into multiple advanced parameters that control the behavior of the compressor (one can observe the result of this translation with --show-default-cparams). These advanced parameters can be overridden using advanced compression options. --zstd[=options]: The options are provided as a comma-separated list. You may specify only the options you want to change and the rest will be taken from the selected or default compression level. The list of available options: strategy=strat, strat=strat Specify a strategy used by a match finder. There are 9 strategies numbered from 1 to 9, from fastest to strongest: 1=ZSTD_fast, 2=ZSTD_dfast, 3=ZSTD_greedy, 4=ZSTD_lazy, 5=ZSTD_lazy2, 6=ZSTD_btlazy2, 7=ZSTD_btopt, 8=ZSTD_btultra, 9=ZSTD_btultra2. windowLog=wlog, wlog=wlog Specify the maximum number of bits for a match distance. The higher number of increases the chance to find a match which usually improves compression ratio. It also increases memory requirements for the compressor and decompressor. The minimum wlog is 10 (1 KiB) and the maximum is 30 (1 GiB) on 32-bit platforms and 31 (2 GiB) on 64-bit platforms. Note: If windowLog is set to larger than 27, --long=windowLog or --memory=windowSize needs to be passed to the decompressor. hashLog=hlog, hlog=hlog Specify the maximum number of bits for a hash table. Bigger hash tables cause fewer collisions which usually makes compression faster, but requires more memory during compression. The minimum hlog is 6 (64 entries / 256 B) and the maximum is 30 (1B entries / 4 GiB). chainLog=clog, clog=clog Specify the maximum number of bits for the secondary search structure, whose form depends on the selected strategy. Higher numbers of bits increases the chance to find a match which usually improves compression ratio. It also slows down compression speed and increases memory requirements for compression. This option is ignored for the ZSTD_fast strategy, which only has the primary hash table. The minimum clog is 6 (64 entries / 256 B) and the maximum is 29 (512M entries / 2 GiB) on 32-bit platforms and 30 (1B entries / 4 GiB) on 64-bit platforms. searchLog=slog, slog=slog Specify the maximum number of searches in a hash chain or a binary tree using logarithmic scale. More searches increases the chance to find a match which usually increases compression ratio but decreases compression speed. The minimum slog is 1 and the maximum is ´windowLog´ - 1. minMatch=mml, mml=mml Specify the minimum searched length of a match in a hash table. Larger search lengths usually decrease compression ratio but improve decompression speed. The minimum mml is 3 and the maximum is 7. targetLength=tlen, tlen=tlen The impact of this field vary depending on selected strategy. For ZSTD_btopt, ZSTD_btultra and ZSTD_btultra2, it specifies the minimum match length that causes match finder to stop searching. A larger targetLength usually improves compression ratio but decreases compression speed. For ZSTD_fast, it triggers ultra-fast mode when > 0. The value represents the amount of data skipped between match sampling. Impact is reversed: a larger targetLength increases compression speed but decreases compression ratio. For all other strategies, this field has no impact. The minimum tlen is 0 and the maximum is 128 KiB. overlapLog=ovlog, ovlog=ovlog Determine overlapSize, amount of data reloaded from previous job. This parameter is only available when multithreading is enabled. Reloading more data improves compression ratio, but decreases speed. The minimum ovlog is 0, and the maximum is 9. 1 means "no overlap", hence completely independent jobs. 9 means "full overlap", meaning up to windowSize is reloaded from previous job. Reducing ovlog by 1 reduces the reloaded amount by a factor 2. For example, 8 means "windowSize/2", and 6 means "windowSize/8". Value 0 is special and means "default": ovlog is automatically determined by zstd. In which case, ovlog will range from 6 to 9, depending on selected strat. ldmHashLog=lhlog, lhlog=lhlog Specify the maximum size for a hash table used for long distance matching. This option is ignored unless long distance matching is enabled. Bigger hash tables usually improve compression ratio at the expense of more memory during compression and a decrease in compression speed. The minimum lhlog is 6 and the maximum is 30 (default: 20). ldmMinMatch=lmml, lmml=lmml Specify the minimum searched length of a match for long distance matching. This option is ignored unless long distance matching is enabled. Larger/very small values usually decrease compression ratio. The minimum lmml is 4 and the maximum is 4096 (default: 64). ldmBucketSizeLog=lblog, lblog=lblog Specify the size of each bucket for the hash table used for long distance matching. This option is ignored unless long distance matching is enabled. Larger bucket sizes improve collision resolution but decrease compression speed. The minimum lblog is 1 and the maximum is 8 (default: 3). ldmHashRateLog=lhrlog, lhrlog=lhrlog Specify the frequency of inserting entries into the long distance matching hash table. This option is ignored unless long distance matching is enabled. Larger values will improve compression speed. Deviating far from the default value will likely result in a decrease in compression ratio. The default value is wlog - lhlog. Example The following parameters sets advanced compression options to something similar to predefined level 19 for files bigger than 256 KB: --zstd=wlog=23,clog=23,hlog=22,slog=6,mml=3,tlen=48,strat=6 -B#: Specify the size of each compression job. This parameter is only available when multi-threading is enabled. Each compression job is run in parallel, so this value indirectly impacts the nb of active threads. Default job size varies depending on compression level (generally 4 * windowSize). -B# makes it possible to manually select a custom size. Note that job size must respect a minimum value which is enforced transparently. This minimum is either 512 KB, or overlapSize, whichever is largest. Different job sizes will lead to non-identical compressed frames. DICTIONARY BUILDER zstd offers dictionary compression, which greatly improves efficiency on small files and messages. It´s possible to train zstd with a set of samples, the result of which is saved into a file called a dictionary. Then, during compression and decompression, reference the same dictionary, using command -D dictionaryFileName. Compression of small files similar to the sample set will be greatly improved. --train FILEs Use FILEs as training set to create a dictionary. The training set should ideally contain a lot of samples (> 100), and weight typically 100x the target dictionary size (for example, ~10 MB for a 100 KB dictionary). --train can be combined with -r to indicate a directory rather than listing all the files, which can be useful to circumvent shell expansion limits. Since dictionary compression is mostly effective for small files, the expectation is that the training set will only contain small files. In the case where some samples happen to be large, only the first 128 KiB of these samples will be used for training. --train supports multithreading if zstd is compiled with threading support (default). Additional advanced parameters can be specified with --train-fastcover. The legacy dictionary builder can be accessed with --train-legacy. The slower cover dictionary builder can be accessed with --train-cover. Default --train is equivalent to --train-fastcover=d=8,steps=4. -o FILE Dictionary saved into FILE (default name: dictionary). --maxdict=# Limit dictionary to specified size (default: 112640 bytes). As usual, quantities are expressed in bytes by default, and it´s possible to employ suffixes (like KB or MB) to specify larger values. -# Use # compression level during training (optional). Will generate statistics more tuned for selected compression level, resulting in a small compression ratio improvement for this level. -B# Split input files into blocks of size # (default: no split) -M#, --memory=# Limit the amount of sample data loaded for training (default: 2 GB). Note that the default (2 GB) is also the maximum. This parameter can be useful in situations where the training set size is not well controlled and could be potentially very large. Since speed of the training process is directly correlated to the size of the training sample set, a smaller sample set leads to faster training. In situations where the training set is larger than maximum memory, the CLI will randomly select samples among the available ones, up to the maximum allowed memory budget. This is meant to improve dictionary relevance by mitigating the potential impact of clustering, such as selecting only files from the beginning of a list sorted by modification date, or sorted by alphabetical order. The randomization process is deterministic, so training of the same list of files with the same parameters will lead to the creation of the same dictionary. --dictID=# A dictionary ID is a locally unique ID. The decoder will use this value to verify it is using the right dictionary. By default, zstd will create a 4-bytes random number ID. It´s possible to provide an explicit number ID instead. It´s up to the dictionary manager to not assign twice the same ID to 2 different dictionaries. Note that short numbers have an advantage: an ID < 256 will only need 1 byte in the compressed frame header, and an ID < 65536 will only need 2 bytes. This compares favorably to 4 bytes default. Note that RFC8878 reserves IDs less than 32768 and greater than or equal to 2^31, so they should not be used in public. --train-cover[=k#,d=#,steps=#,split=#,shrink[=#]] Select parameters for the default dictionary builder algorithm named cover. If d is not specified, then it tries d = 6 and d = 8. If k is not specified, then it tries steps values in the range [50, 2000]. If steps is not specified, then the default value of 40 is used. If split is not specified or split <= 0, then the default value of 100 is used. Requires that d <= k. If shrink flag is not used, then the default value for shrinkDict of 0 is used. If shrink is not specified, then the default value for shrinkDictMaxRegression of 1 is used. Selects segments of size k with highest score to put in the dictionary. The score of a segment is computed by the sum of the frequencies of all the subsegments of size d. Generally d should be in the range [6, 8], occasionally up to 16, but the algorithm will run faster with d <= 8. Good values for k vary widely based on the input data, but a safe range is [2 * d, 2000]. If split is 100, all input samples are used for both training and testing to find optimal d and k to build dictionary. Supports multithreading if zstd is compiled with threading support. Having shrink enabled takes a truncated dictionary of minimum size and doubles in size until compression ratio of the truncated dictionary is at most shrinkDictMaxRegression% worse than the compression ratio of the largest dictionary. Examples: zstd --train-cover FILEs zstd --train-cover=k=50,d=8 FILEs zstd --train-cover=d=8,steps=500 FILEs zstd --train-cover=k=50 FILEs zstd --train-cover=k=50,split=60 FILEs zstd --train-cover=shrink FILEs zstd --train-cover=shrink=2 FILEs --train-fastcover[=k#,d=#,f=#,steps=#,split=#,accel=#] Same as cover but with extra parameters f and accel and different default value of split If split is not specified, then it tries split = 75. If f is not specified, then it tries f = 20. Requires that 0 < f < 32. If accel is not specified, then it tries accel = 1. Requires that 0 < accel <= 10. Requires that d = 6 or d = 8. f is log of size of array that keeps track of frequency of subsegments of size d. The subsegment is hashed to an index in the range [0,2^f - 1]. It is possible that 2 different subsegments are hashed to the same index, and they are considered as the same subsegment when computing frequency. Using a higher f reduces collision but takes longer. Examples: zstd --train-fastcover FILEs zstd --train-fastcover=d=8,f=15,accel=2 FILEs --train-legacy[=selectivity=#] Use legacy dictionary builder algorithm with the given dictionary selectivity (default: 9). The smaller the selectivity value, the denser the dictionary, improving its efficiency but reducing its achievable maximum size. --train-legacy=s=# is also accepted. Examples: zstd --train-legacy FILEs zstd --train-legacy=selectivity=8 FILEs BENCHMARK The zstd CLI provides a benchmarking mode that can be used to easily find suitable compression parameters, or alternatively to benchmark a computer´s performance. Note that the results are highly dependent on the content being compressed. -b# benchmark file(s) using compression level # -e# benchmark file(s) using multiple compression levels, from -b# to -e# (inclusive) -d benchmark decompression speed only (requires providing an already zstd-compressed content) -i# minimum evaluation time, in seconds (default: 3s), benchmark mode only -B#, --block-size=# cut file(s) into independent chunks of size # (default: no chunking) --priority=rt set process priority to real-time (Windows) Output Format: CompressionLevel#Filename: InputSize -> OutputSize (CompressionRatio), CompressionSpeed, DecompressionSpeed Methodology: For both compression and decompression speed, the entire input is compressed/decompressed in-memory to measure speed. A run lasts at least 1 sec, so when files are small, they are compressed/decompressed several times per run, in order to improve measurement accuracy. SEE ALSO zstdgrep(1), zstdless(1), gzip(1), xz(1) The zstandard format is specified in Y. Collet, "Zstandard Compression and the ´application/zstd´ Media Type", https://www.ietf.org/rfc/rfc8878.txt, Internet RFC 8878 (February 2021). BUGS Report bugs at: https://github.com/facebook/zstd/issues AUTHOR Yann Collet zstd 1.5.6 March 2024 ZSTD(1)
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jp.py
| null | null | null | null | null |
tabulate
| null | null | null | null | null |
fitsinfo
| null | null | null | null | null |
protoc
| null | null | null | null | null |
texify
| null | null | null | null | null |
fitsheader
| null | null | null | null | null |
gif2webp
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This manual page documents the gif2webp command. gif2webp converts a GIF image to a WebP image.
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gif2webp - Convert a GIF image to WebP
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gif2webp [options] input_file.gif -o output_file.webp
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The basic options are: -o string Specify the name of the output WebP file. If omitted, gif2webp will perform conversion but only report statistics. Using "-" as output name will direct output to 'stdout'. -- string Explicitly specify the input file. This option is useful if the input file starts with an '-' for instance. This option must appear last. Any other options afterward will be ignored. If the input file is "-", the data will be read from stdin instead of a file. -h, -help Usage information. -version Print the version number (as major.minor.revision) and exit. -lossy Encode the image using lossy compression. -mixed Mixed compression mode: optimize compression of the image by picking either lossy or lossless compression for each frame heuristically. -q float Specify the compression factor for RGB channels between 0 and 100. The default is 75. In case of lossless compression (default), a small factor enables faster compression speed, but produces a larger file. Maximum compression is achieved by using a value of 100. In case of lossy compression (specified by the -lossy option), a small factor produces a smaller file with lower quality. Best quality is achieved by using a value of 100. -m int Specify the compression method to use. This parameter controls the trade off between encoding speed and the compressed file size and quality. Possible values range from 0 to 6. Default value is 4. When higher values are used, the encoder will spend more time inspecting additional encoding possibilities and decide on the quality gain. Lower value can result is faster processing time at the expense of larger file size and lower compression quality. -min_size Encode image to achieve smallest size. This disables key frame insertion and picks the dispose method resulting in the smallest output for each frame. It uses lossless compression by default, but can be combined with -q, -m, -lossy or -mixed options. -kmin int -kmax int Specify the minimum and maximum distance between consecutive key frames (independently decodable frames) in the output animation. The tool will insert some key frames into the output animation as needed so that this criteria is satisfied. A 'kmax' value of 0 will turn off insertion of key frames. A 'kmax' value of 1 will result in all frames being key frames. 'kmin' value is not taken into account in both these special cases. Typical values are in the range 3 to 30. Default values are kmin = 9, kmax = 17 for lossless compression and kmin = 3, kmax = 5 for lossy compression. These two options are relevant only for animated images with large number of frames (>50). When lower values are used, more frames will be converted to key frames. This may lead to smaller number of frames required to decode a frame on average, thereby improving the decoding performance. But this may lead to slightly bigger file sizes. Higher values may lead to worse decoding performance, but smaller file sizes. Some restrictions: (i) kmin < kmax, (ii) kmin >= kmax / 2 + 1 and (iii) kmax - kmin <= 30. If any of these restrictions are not met, they will be enforced automatically. -metadata string A comma separated list of metadata to copy from the input to the output if present. Valid values: all, none, icc, xmp. The default is xmp. -f int For lossy encoding only (specified by the -lossy option). Specify the strength of the deblocking filter, between 0 (no filtering) and 100 (maximum filtering). A value of 0 will turn off any filtering. Higher value will increase the strength of the filtering process applied after decoding the picture. The higher the value the smoother the picture will appear. Typical values are usually in the range of 20 to 50. -mt Use multi-threading for encoding, if possible. -loop_compatibility If enabled, handle the loop information in a compatible fashion for Chrome version prior to M62 (inclusive) and Firefox. -v Print extra information. -quiet Do not print anything. BUGS Please report all bugs to the issue tracker: https://bugs.chromium.org/p/webp Patches welcome! See this page to get started: https://www.webmproject.org/code/contribute/submitting-patches/
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gif2webp picture.gif -o picture.webp gif2webp -q 70 picture.gif -o picture.webp gif2webp -lossy -m 3 picture.gif -o picture_lossy.webp gif2webp -lossy -f 50 picture.gif -o picture.webp gif2webp -q 70 -o picture.webp -- ---picture.gif cat picture.gif | gif2webp -o - -- - > output.webp AUTHORS gif2webp is a part of libwebp and was written by the WebP team. The latest source tree is available at https://chromium.googlesource.com/webm/libwebp This manual page was written by Urvang Joshi <urvang@google.com>, for the Debian project (and may be used by others). SEE ALSO cwebp(1), dwebp(1), webpmux(1) Please refer to https://developers.google.com/speed/webp/ for additional information. November 17, 2021 GIF2WEBP(1)
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h5clear
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pyrsa-encrypt
| null | null | null | null | null |
psicc
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lcms is a standalone CMM engine, which deals with the color management. It implements a fast transformation between ICC profiles. psicc is a little cms PostScript converter.
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psicc - little cms PostScript converter.
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psicc [options]
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-b Black point compensation (CRD only). -c precision Precision (0=LowRes, 1=Normal, 2=Hi-res) (CRD only) [defaults to 1]. -i profile Input profile: Generates Color Space Array (CSA). -n gridpoints Alternate way to set precision, number of CLUT points (CRD only). -o profile Output profile: Generates Color Rendering Dictionary(CRD). -t intent Intent (0=Perceptual, 1=Colorimetric, 2=Saturation, 3=Absolute) [defaults to 0]. -u Do NOT generate resource name on CRD. NOTES For suggestions, comments, bug reports etc. send mail to info@littlecms.com. SEE ALSO jpgicc(1), linkicc(1), tificc(1), transicc(1) AUTHOR This manual page was written by Shiju p. Nair <shiju.p@gmail.com>, for the Debian project. September 30, 2004 PSICC(1)
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pcretest
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recode-sr-latin
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Recode Serbian text from Cyrillic to Latin script. The input text is read from standard input. The converted text is output to standard output. Informative output: -h, --help display this help and exit -V, --version output version information and exit AUTHOR Written by Danilo Segan and Bruno Haible. REPORTING BUGS Report bugs in the bug tracker at <https://savannah.gnu.org/projects/gettext> or by email to <bug-gettext@gnu.org>. COPYRIGHT Copyright © 2006-2023 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. SEE ALSO The full documentation for recode-sr-latin is maintained as a Texinfo manual. If the info and recode-sr-latin programs are properly installed at your site, the command info recode-sr-latin should give you access to the complete manual. GNU gettext-tools 0.22.5 February 2024 RECODE-SR-LATIN(1)
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recode-sr-latin - convert Serbian text from Cyrillic to Latin script
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recode-sr-latin [OPTION]
| null | null |
glib-gettextize
| null | null | null | null | null |
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