| .\ |
| .TH LUA 1 "$Date: 2024/05/08 18:48:27 $" |
| .SH NAME |
| lua \- Lua interpreter |
| .SH SYNOPSIS |
| .B lua |
| [ |
| .I options |
| ] |
| [ |
| .I script |
| [ |
| .I args |
| ] |
| ] |
| .SH DESCRIPTION |
| .B lua |
| is the standalone Lua interpreter. |
| It loads and executes Lua programs, |
| either in textual source form or |
| in precompiled binary form. |
| (Precompiled binaries are output by |
| .BR luac , |
| the Lua compiler.) |
| .B lua |
| can be used as a batch interpreter and also interactively. |
| .LP |
| After handling the |
| .IR options , |
| the Lua program in file |
| .I script |
| is loaded and executed. |
| The |
| .I args |
| are available to |
| .I script |
| as strings in a global table named |
| .B arg |
| and also as arguments to its main function. |
| When called without arguments, |
| .B lua |
| behaves as |
| .B "lua \-v \-i" |
| if the standard input is a terminal, |
| and as |
| .B "lua \-" |
| otherwise. |
| .LP |
| In interactive mode, |
| .B lua |
| prompts the user, |
| reads lines from the standard input, |
| and executes them as they are read. |
| If the line contains an expression, |
| then the line is evaluated and the result is printed. |
| If a line does not contain a complete statement, |
| then a secondary prompt is displayed and |
| lines are read until a complete statement is formed or |
| a syntax error is found. |
| .LP |
| Before handling command line options and scripts, |
| .B lua |
| checks the contents of the environment variables |
| .B LUA_INIT_5_4 |
| and |
| .BR LUA_INIT , |
| in that order. |
| If the contents are of the form |
| .RI '@ filename ', |
| then |
| .I filename |
| is executed. |
| Otherwise, the contents are assumed to be a Lua statement and is executed. |
| When |
| .B LUA_INIT_5_4 |
| is defined, |
| .B LUA_INIT |
| is ignored. |
| .SH OPTIONS |
| .TP |
| .BI \-e " stat" |
| execute statement |
| .IR stat . |
| .TP |
| .B \-i |
| enter interactive mode after executing |
| .IR script . |
| .TP |
| .BI \-l " mod" |
| require library |
| .I mod |
| into global |
| .IR mod . |
| .TP |
| .BI \-l " g=mod" |
| require library |
| .I mod |
| into global |
| .IR g . |
| .TP |
| .B \-v |
| show version information. |
| .TP |
| .B \-E |
| ignore environment variables. |
| .TP |
| .B \-W |
| turn warnings on. |
| .TP |
| .B \-\- |
| stop handling options. |
| .TP |
| .B \- |
| stop handling options and execute the standard input as a file. |
| .SH ENVIRONMENT VARIABLES |
| The following environment variables affect the execution of |
| .BR lua . |
| When defined, |
| the version-specific variants take priority |
| and the version-neutral variants are ignored. |
| .TP |
| .B LUA_INIT, LUA_INIT_5_4 |
| Code to be executed before command line options and scripts. |
| .TP |
| .B LUA_PATH, LUA_PATH_5_4 |
| Initial value of package.path, |
| the path used by require to search for Lua loaders. |
| .TP |
| .B LUA_CPATH, LUA_CPATH_5_4 |
| Initial value of package.cpath, |
| the path used by require to search for C loaders. |
| .SH EXIT STATUS |
| If a script calls os.exit, |
| then |
| .B lua |
| exits with the given exit status. |
| Otherwise, |
| .B lua |
| exits |
| with EXIT_SUCCESS (0 on POSIX systems) if there were no errors |
| and |
| with EXIT_FAILURE (1 on POSIX systems) if there were errors. |
| Errors raised in interactive mode do not cause exits. |
| .SH DIAGNOSTICS |
| Error messages should be self explanatory. |
| .SH "SEE ALSO" |
| .BR luac (1) |
| .br |
| The documentation at lua.org, |
| especially section 7 of the reference manual. |
| .SH AUTHORS |
| R. Ierusalimschy, |
| L. H. de Figueiredo, |
| W. Celes |
| .\ |
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