question stringlengths 25 894 | answer stringlengths 4 863 |
|---|---|
I know this is true for C++:
```
buffering output
cerr: unbuffered stderr
clog: buffered stderr
cout: buffered stdout
```
In C equivalents forcerrandcoutare:
```
cerr: fprintf(stderr, ...)
cout: fprintf(stdout, ...) or printf(...)
```
Is there an equivalent forclog?
|
Yes, usingsetvbufand full buffering (_IOFBF):
Full buffering: On output, data is written once the buffer is full (or
flushed). On Input, the buffer is filled when an input operation is
requested and the buffer is empty.
```
#include <stdio.h>
int main(void)
{
char buff[BUFSIZ];
setvbuf(stderr, buff, _I... |
Dogccandclhave an equivalent forifortreal-sizecompiler flag? If not, what should I use instead? MACRO?
```
#ifdef DOUBLE_PRECISION
#define REAL double
#else
#define REAL float
#endif
REAL myvar;
```
|
gfortran has compile-time option-fdefault-real-8. But not gcc.
|
I was trying to write a code to reverse the linked list but getting wrong output.
Is there something I am missing.
Here is the function
```
void reverselinklist( struct node **headreverse)
{
struct node *p = *headreverse;
if(p->next == NULL)
{
*headreverse = p;
return;
}
reversel... |
*headreverse = pis meaningless. You should set*headreverse = p->nexteach time to move forward, until the last node is reached.
Anyway, I changed your code to make it work:
```
void reverselinklist(struct node **headreverse)
{
struct node *p = *headreverse;
if(p->next == NULL){
return;
}
*head... |
I am working on socket programming using c language and linux platform and my requirement is to make a server listen only for two or three clients. How is it possible ?
|
you make that by specifying second argument on listen() call.i assume that you are using TCP protocol.from man pages:
```
int listen(int sockfd, int backlog);
```
The backlog argument defines the maximum length to which the queue
of pending
connections for sockfd may grow. If a connection request arri... |
I'm using a 3rd party dll with no source code available. It runs perfectly fine, but every time I run my program, an annoying pop-up says "MyProgram.exe has triggered a breakpoint".
If I press continue, my program runs 100% correctly.
If I press break, I can see that the breakpoint is occurring in the 3rd party file ... |
I eventually checked in with the company that distributed the dll, and indeed there are breakpoints in there for reasons that I won't get into. However, if I run the program outside the debugger (even simply open the binary from windows), these popup windows do not occur.
Thank you all for your help!
|
I am trying to compile a mex file using openMp on win7_64. The file compiles fine, but when I try to run it I get the error:
```
Error: Invalid MEX file, the specified module could not be found
```
DependecyWalker tells me, that LIBGOMP_64-1.DLL is missing which I guess is the openmp library.
I installed the latest... |
I copied the LIBGOMP_64-1.DLL from the mingw/bin directory to the directory where the mex file is and now it works...
|
I'm trying to understand function which copies characters from stdin but I can't understand the while loop and the code following it exactly.....How does the while loop here work??
From what I understand it means untilithcharacter fromto[]isn't equal toithcharacter offrom[]keep on addingiam I correct??If yes than how ... |
Rewriting it might help:
```
do{
to[i] = from[i];
++i;
}while (from[i-1] != '\0') // -1 here because we incremented i in the line before and need to check the copied position
```
Do you understand now?
|
If I have the following:
```
int a = -10 && 0;
```
then does C evaluate-10as1because-10is different from0and then make
the comparation between1 && 0to get0as result?
Or does let-10and make the comparation as written?
Instead if I write:
```
int c = 10;
int b = 11;
int res = c > 10 && b == 11;
```
then the C make... |
The operator&&and||hasshort circuit behavior1. In
```
int a = -10 && 0;
```
since left operand is-10, which is non-zero and hencetrue, therefore right operand, i.e0is checked. In
```
int res = c > 10 && b == 11;
```
since left operand is evaluated tofalse, right operand is not evaluated.
1C11 6.5.13 (p4):If th... |
This is my little program:
```
#include <unistd.h>
#include <stdio.h>
int main() {
printf("1");
fork();
printf("2");
fork();
return 0;
}
```
The output of this code is12121212and I ask:Why does it print more than122?
|
Because printf is buffered and the text is printed only when program exits. Try to flush stdout after each print.
|
I know this is true for C++:
```
buffering output
cerr: unbuffered stderr
clog: buffered stderr
cout: buffered stdout
```
In C equivalents forcerrandcoutare:
```
cerr: fprintf(stderr, ...)
cout: fprintf(stdout, ...) or printf(...)
```
Is there an equivalent forclog?
|
Yes, usingsetvbufand full buffering (_IOFBF):
Full buffering: On output, data is written once the buffer is full (or
flushed). On Input, the buffer is filled when an input operation is
requested and the buffer is empty.
```
#include <stdio.h>
int main(void)
{
char buff[BUFSIZ];
setvbuf(stderr, buff, _I... |
Dogccandclhave an equivalent forifortreal-sizecompiler flag? If not, what should I use instead? MACRO?
```
#ifdef DOUBLE_PRECISION
#define REAL double
#else
#define REAL float
#endif
REAL myvar;
```
|
gfortran has compile-time option-fdefault-real-8. But not gcc.
|
I was trying to write a code to reverse the linked list but getting wrong output.
Is there something I am missing.
Here is the function
```
void reverselinklist( struct node **headreverse)
{
struct node *p = *headreverse;
if(p->next == NULL)
{
*headreverse = p;
return;
}
reversel... |
*headreverse = pis meaningless. You should set*headreverse = p->nexteach time to move forward, until the last node is reached.
Anyway, I changed your code to make it work:
```
void reverselinklist(struct node **headreverse)
{
struct node *p = *headreverse;
if(p->next == NULL){
return;
}
*head... |
I am working on socket programming using c language and linux platform and my requirement is to make a server listen only for two or three clients. How is it possible ?
|
you make that by specifying second argument on listen() call.i assume that you are using TCP protocol.from man pages:
```
int listen(int sockfd, int backlog);
```
The backlog argument defines the maximum length to which the queue
of pending
connections for sockfd may grow. If a connection request arri... |
Ive made an app on Android and I want to be able to sell the app for iphone and android. I dont want to have to learn objective C. Is there any possible way I can do this?
|
You have a lot of options but none of them are very nice. I know of no direct converter.
To reuse the majority of your code checkout RoboVM
http://www.robovm.com/
It is used by libgdx to allow for using Java to do cross platform development.
Pretty much all your other options as far as I have seen would involve us... |
I want to get a clarification that this plug-in only works for C++ and won't work for C. I tried to run with C code in the src directory and it doesnt return anything unlike the C++ projects.
Anyway for me to run C code for free (Community versions), my cppcheck
|
The c++ community plugin will by default import any c files found under project dir, the parsing will be done using a compatibility mode (so it might not be complete). Default properties and values for this to work are:
sonar.cxx.cFilesPatterns -.c,.C
sonar.cxx.suffixes.sources - .cxx,.cpp,.cc,.c
sonar.cxx.suffixes... |
I am learning how to make Windows applications in C, and am trying to set individual pixels usingSetPixel(HDC hDC, int x, int y, COLORREF crColor).
I have never had a compile error until I added that line into it. I do have windows.h included of course. I have searched around for an answer, and I never found anything... |
Besides including the header file, I believe you also need to link to the library libgdi32.a or gdi32.lib.
As pointed out below, _imp__SetPixel@16 is a mangled name for the function SetPixel() you're calling.
|
I am trying to update a call tostrcpywith the more securestrcpy_s. The old function call looks like this:
```
char buf[6];
strcpy(buf+1, "%#c");
```
In order to turn the above code into the more secure version, what would I put in for the size parameter?
```
char buf[6];
strcpy_s(buf+1, /*SIZE GOES HERE*/, "%#c");
... |
If you were copying into thestartofbuf, you'd say:
```
strcpy_s(buf, sizeof(buf), "%#c");
```
since you're skipping the first character, you have onelesscharacter to work with, so:
```
strcpy_s(buf + 1, sizeof(buf) - 1, "%#c");
```
|
Need to get the value parsing using sscanf .. used as bellow but not getting the result..
String : abc_2_4
I need to get 4
My program
```
char sentence []="abc_1_2";
char str [20];
int i,j;
sscanf (sentence,"%s_%d_%d",str,&i,&j);
printf ("%s %d %d\n",str,i,j);
```
Output
abc_1_2 32768 134520820
My dou... |
sscanf()won't "look ahead" when parsing the%sto know that it should end with the underscore, that's not what the%sconversion specifier means.
You need to use%[^_]to capture all characters except underscore.
|
I am relatively new to C. Now I know Segmentation fault appears when we try to use memory which we don't have access to. But I fail to find out where am I going wrong and would like to know. Any help would be appreciated.
```
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main()
{
char *str1 = "United... |
```
str3 = strcat(str1,str2);
```
str1points to a string literal and you can't concatenate (modify) to it. This causesundefined behaviour.
```
strcpy(str3,str1);
strcat(str3,str2);
```
You have to ensurestr3was allocated with enough memory.
And,
casting themalloc return could be dangerous
Use a standard prototyp... |
There is a header filefoo.hthat contains a global variable declarationint i;. This header file is being included inone.candtwo.crespectively (I am aware that that's not a very good life choice, but it's not mine).
Does this mean that in each *.c file exist two different variables with namei?What is the situation with... |
Yes, global variableiwithexternal linkagewill exist in both compilation units. This will create conflict error during the linking phase.
In ideal situation,foo.hheader should contain declaration only:extern int i;and the actual definitionint i;should exist only inone.c file.
Other alternative is to usestatic int i;i... |
I am trying to figure out how to make a request in c each n seconds. I want it to be asynchronous, meaning the requests are made even if the previous ones have not been responded.
I want to achieve this in order to test a server.
Any ideas?
Thank you.
|
Use themulti interface. Add a new handle and start a new request every N seconds and let it take its time. It'll handle "any" amount of simultaneous transfers for you. "any" because there's probably a limit in number of open sockets a process is allowed to use (depending on the environment you want this for).
|
Why in the C specification only the prefix increment and decrement operators
are summarized as Unary operators?
In fact the postfix increment and decrement operators are summarized into the section Postfix operators.
I don't see the difference. Both operate on a sole operand.
|
REWRITTEN: I guess I mis-read the spec, as pointed out by @Lundin. A better answer seems to be that the names used in this part of the standard don't make a lot of sense.
Of course both postfix and prefix increment/decrement are both just as unary as the other. That's how they're used. The fact that they have differe... |
Given the following:
```
struct RES_RECORD
{
unsigned char *name;
unsigned char *rdata;
}
```
Implementing the following within a function/main:
```
struct RES_RECORD answers[20];
for (i=0;i<20;i++)
{
answers[i].name = strdup("Foo");
answers[i].rdata = malloc(SomeRunTimeValue);
}
```
How to I properly free() the ... |
Exactly the way you allocated it:
```
for (i=0;i<20;i++)
{
free(answers[i].name);
free(answers[i].rdata);
}
```
|
Recently, one of my friends encountered this question in an interview. The interviewer asked him if the special characters like$, @, |, ^, ~have any usage in C or C++ and where.
I know that|, ^ and ~are used asbitwiseOR, XOR andcomplementrespectively.
Do@and$have any special meaning? If they do, what would be an exa... |
@is generally invalid in C; it is not used for anything. It is used for various purposes by Objective-C, but that's a whole other kettle of fish.
$is invalid as well, but many implementations allow it to appear in identifiers, just like a letter. (In these implementations, for instance, you could name a variable or f... |
I have an int that I need to round down to the nearest 100.
As an example:
91 would be rounded down to 0
101 would be rounded down to 100
199 would be rounded down to 100
|
```
main()
{
int a=0;
scanf ("%d", &a)
a= ( a/100) * 100;
printf ("Result:%d", a);
}
```
The above code will satisfy your requirement.
|
I mean something like that:
```
while(lu = read(d1, buf, sizeof(buf)), lu > 0 )
```
it's good syntax ?
|
It's good syntax, but very bad semantics.
In other words, that code doesn't do what you think it does, which makes it a bit dangerous.
Since assignment (=) has lower priority than comparison (>), it will not evaluate in the way you need.
To fix it, add parentheses:
```
while((lu = read(d1, buf, sizeof buf)) > 0)
`... |
```
char path[25500]= {};//iniatize
int visited[2500]= {0};//iniatialize
void fun();//protype
int main(){
fun();
}
void fun(){
visited[2300]=1;
path[0]='9';
printf("\n%d %s",visited[2300],path);
memset(path,0,25500);//reset
memset(visited,0,2500);//reset
printf("\n %d %s",visited[2300],pa... |
```
memset(visited,0,2500);//reset
```
Visited is an array of integers, so this should be
```
memset(visited, 0, 2500 * sizeof(int))
```
|
I thought I know everything about global variables but now I can not solve that. I deleted some of codes.
```
int counter;//global variable for increase or decrease
int main(){
fun();
}
void fun(){
counter=999;
sad();
}
void sad(){
printf("Counter is %d\n",counter);
}
```
Output is 0. Why?
|
Your code has undefined behavior. Bothfunandsadlack prototypes, and your code calls them before they are declared. Therefore, the the compiler assumes that both these functions return anint. Since the functions are actuallyvoid, this results in undefined behavior.
Once you add prototypes, your coderuns perfectly.
``... |
I'm trying to read two variables inside a struct but I'm facing some problems using scanf. Here is the code:
```
typedef struct {
int pc;
char* label;
} sb;
```
... and here is the instantiation of the struct:
```
sb input;
fscanf (in, "%s%d", input.label, &(input.pc));
printf ("%s %d\n", input.label, input... |
The main problem is that you have not actually allocated any storage in the structure for the label. One solution is to change the declaration to:
```
typedef struct {
int pc;
char label[80];
} sb;
```
But please be aware that code is now dangerous because it reads into the buffer without putting any limits... |
Closed. This question needs to be morefocused. It is not currently accepting answers.Want to improve this question?Update the question so it focuses on one problem only byediting this post.Closed9 years ago.Improve this question
How can I get specific length of integer value from user? I have a piece of code for crea... |
Try taking the input as a character array and then apply strlen
```
pin = scanf("%s",pin_buffer);
len = strlen(pin);
```
then check if len == 4 or not and display the message accordigly!
|
This question already has answers here:Replacement for <conio.h> in Linux(2 answers)Closed9 years ago.
My program is compiling on Windows without problems. On windows i'm usingconio.hon linux i'm using replacemententer link description here. My first error:typedef enum {FALSE=0x00, TRUE=0xff} BOOL;and error:
```
typ... |
The typedef clashes with some other header that #defines FALSE or TRUE.
|
I have an AST consumer that get all the TagDecl which are structure with
```
clang::TagDecl::isStruct()
```
How to get members of the structure (declaration, type) in an array like the FunctionDecl class:
```
clang::FunctionDecl::getParamDecl(unsigned i)
```
Or in any other ways?
|
TheTagDeclmust be cast to aRecordDeclthat have the methods to get the members / fields information.
```
clang::TagDecl*t;
clang::RecordDecl*r;
clang::RecordDecl::field_iterator jt;
for(jt = r->field_begin(); jt != r->field_end();++jt)
{
std::cout << jt->getType().getAsString() << " " << jt->getNameAsString() << ... |
I'm very new to coding in C, and I'm working on calculating the CDF for a chi-square distribution given a value and the degrees of freedom. Is there a function or a library that does this or will I need to write this code myself?
Any help would be appreciated
|
If I am right you can use the GNU Scientific Library. Look for the functiongsl_ran_chisq, which returns a random value from a Chi-square distribution provided a number of degrees of freedom.
You can check the C functions related to chi-square and many other distributions on thislink. Simply install the library. Link ... |
I have a function in my code that uses a seed to get a predictable (based on the seed) set of random numbers.
```
$seed = 1234;
mt_srand($seed);
echo mt_rand(0,10);
echo mt_rand(0,10);
echo mt_rand(0,10);
echo mt_rand(0,10);
```
Is it necessary to call mt_srand() at the end of my function to reset it back to a rand... |
Yes. The state ofmt_rand()is global — if your function sets it to a fixed value, it will stay in that state after your function exits. While it's not ideal to callmt_srand(), as that would disrupt any other function that's trying to set a fixed seed, it's still preferable to leaving the random number generator in a no... |
Is it safe to have one thread modify an atomic unit (e.g. a char) while the other only reads it?
In an environment that permits this of course, like freertos.
I have been given some code that does just this, it uses a bool (defined as char) as a semaphore, I'm not sure why they didnt use a semaphore just for claritys... |
Its safe If:
1.Your processors reads a character in single instruction(which is very likely)
2.Your Processor architecture is not such that while executing a instruction external interrupt can change control flow.
3.Point 2 is vaild only if your variable is updated through ISR
|
I have a array declared as
```
char **a;
```
I am reading from a byte file, and saving the information in the array
Here is the part where I have a question about
```
//Allocate memory is not shown here
fp = fopen(file, "rb");
for (i = 0; i < LN; i++){
for (j = 0; j < SN; j++)
bytesread = fread(&a[... |
You are printing the address of the item. Change your printf to
```
printf("%d \n", a[(int)i][(int)j]);
```
|
i came across a bit of code which says
```
int fd = open(fn, flags, 0);
if (fd < 0 && errno != EMLINK)
...
```
flagsis eitherO_RDONLYorO_RDONLY|O_NOFOLLOW
IEEE Std 1003.1, 2013 (SUSv4) has just
[EMLINK]
Too many links. An attempt was made to have the link count of a single file exceed {LINK_MAX}.{LINK_MAX}
Maxim... |
Good question. WhenO_NOFOLLOWwas added, they chose to reuse an existing error code rather than make up a new one.EMLINKin this case signifies that the file is a symlink and is returned on FreeBSD. Linux and Darwin returnELOOPrather thanEMLINK, while NetBSD usesEFTYPE.
My manpages sayO_NOFOLLOWis a FreeBSD extension s... |
can you define function pointer return integer pointer?
answer is yes. and it should be like this---->
```
integer*(*function)();
```
and my question is , can you define function pointer return function pointer?
if answer is no! teach me please.
if answer is yes, tell me how please.
|
Of course you can. The easiest and most readible way is to have an intermediatetypedef, something like this:
```
typedef int* (*pFunc)(void);
```
and then it's simply:
```
typedef pFunc (*pFuncRetFunc)(void);
```
|
I've written the following shell script to compile and execute a c program and then to do some other operations.
```
#!/bin/sh
#
#FIRST SCRIPT
#
clear
echo "-----STARTING COMPILATION-----"
#echo $1
name=$1
#echo $name
find . -iname $name -maxdepth 1 -exec cp {} $name \;
new_file="tempwithfile.adb"
cp $name $new_file... |
As Manül said, you need to return a value from the main() function in the C code.
Then you can do this in the script:
```
./a.out
if [ $? -ne 0 ]
...
```
|
I am using gdb in order to debug my code, still a beginnerI wanted to know how to get the actual addressFor example, given the following assembly code:cmp %eax, 0x4(%rbp,%rbx,4)
I want to know what is being compared with %eax, in other words i want to know what is in: 0x4(%rbp,%rbx,4)
|
If you don't know at&t syntax, switch gdb to intel syntax usingset disassembly-flavor intel. Then you will see this expression is reallyrbp+rbx*4+4. Then read gdb help and you will find thex(examine memory) command and that you can access registers using$prefix. Putting all this together, you should typex $rbp+$rbx*4+... |
I would need to run bitwise operations (and, or, xor, shifts, sets, etc..) on arrays of bits. So far I have used the 128 bit type to do so, but now I have met the need to work with bigger arrays. After a bit of search I found that CFBitVector and vBigNum in the Accelerate Framework could store this big numbers, but it... |
You can use regular arrays and interpret them as bit arrays. Let's say you use an array of chars, so every element has 8 bits. If you want to access bit 231, you will find it in 231/8=28th element of the array (the 231%8=7th bit of that array). This is easy when you deal with individual bits. If you use masks and shif... |
I am given a task which is as follows:
User enters a string of symbols which can be only < (less), > (greater) or = (equal) and string ends with semicolon. The task is to generate numbers between those symbols while the very first number is 1. An example: if user enters <>>>=<; the program should generate numbers acco... |
sizeof(simboliai)returns size of the pointer (usually 4) not the actual length of allocated array. You need to keep track of that separately. For example, in another variable.
|
I'm usingsetrlimitto put a limit to the niceness of my program when it runs like a proccess, but it's not working.
```
int main()
{
struct rlimit limit;
getrlimit(RLIMIT_NICE, &limit);
limit.rlim_max = 30;
limit.rlim_cur = 15;
setrlimit(RLIMIT_NICE, &limit)
while(1)
sleep(1);
retur... |
if you're on linux, please check if
```
ulimit -e
```
returns0. This is set on my machine:
```
$ ulimit -e
...
scheduling priority (-e) 0
```
this means, non-root users are only allowed to decrease nice value by this limit. you should be able to modify this limit via/etc/security/limits.confif you have... |
I've imported and created a bridging header for some old C source code to Swift. The function signature looks like so:
```
struct Message prattle_parse_message(char *line);
```
The swift declaration for it is:
```
func prattle_parse_message(line: CMutablePointer<CChar>) -> Message
```
However, I'm not sure how to ... |
Thisshouldbe it...
```
var data = inString.dataUsingEncoding(encoding, allowsLossyConversion: allow)
var ccharstr = CChar[](count:data.length, repeatedValue:CChar(0))
data.getBytes(&ccharstr length:data.length)
ccharstr.append(CChar(0))
var message = prattle_parse_message(&ccharstr)
```
Can't test the last... |
I have a Intel Core i5-2450m (2 physical processors and 4 logical processors) and I want to find a way to count logical and physical cores on AMD and Intel CPUs.
But, after some searches I noticed something strange. Instead of returning 4 logical units, my code give me 16.
```
static int8_t LogicalProcCount(void)
{
... |
CPUID.1:EBX[23:16]represents themaximum numberof addressable IDs (initial APIC ID) that can be assigned to logical processors in a physical package.
Source.
So 16 has nothing to do with the actual number of your logical CPUs. On my machineCPUID.1:EBX[23:16]also returns 16, though it has 8 logical CPUs.
Sample code ... |
This question already has answers here:How to repeat a char using printf?(13 answers)Closed9 years ago.
I need to make a program that prints square with x width and y height with #'s.
how can I print multiple #'s ?
```
{
while (ysize > 0)
{
printf("%0*%d\n", xsize,0);
ysize--;
}
}
```
... |
You can, use a function which prints out a line of # of size x, and call that function y times.
```
void printline(int size){
int i;
for(i=0;i<size;i++){
putchar('#');
}
putchar('\n');
}
```
This function prints x #s in a line and then moves the cursor to the next line.
|
I'm very new to coding in C, and I'm working on calculating the CDF for a chi-square distribution given a value and the degrees of freedom. Is there a function or a library that does this or will I need to write this code myself?
Any help would be appreciated
|
If I am right you can use the GNU Scientific Library. Look for the functiongsl_ran_chisq, which returns a random value from a Chi-square distribution provided a number of degrees of freedom.
You can check the C functions related to chi-square and many other distributions on thislink. Simply install the library. Link ... |
I have a function in my code that uses a seed to get a predictable (based on the seed) set of random numbers.
```
$seed = 1234;
mt_srand($seed);
echo mt_rand(0,10);
echo mt_rand(0,10);
echo mt_rand(0,10);
echo mt_rand(0,10);
```
Is it necessary to call mt_srand() at the end of my function to reset it back to a rand... |
Yes. The state ofmt_rand()is global — if your function sets it to a fixed value, it will stay in that state after your function exits. While it's not ideal to callmt_srand(), as that would disrupt any other function that's trying to set a fixed seed, it's still preferable to leaving the random number generator in a no... |
Is it safe to have one thread modify an atomic unit (e.g. a char) while the other only reads it?
In an environment that permits this of course, like freertos.
I have been given some code that does just this, it uses a bool (defined as char) as a semaphore, I'm not sure why they didnt use a semaphore just for claritys... |
Its safe If:
1.Your processors reads a character in single instruction(which is very likely)
2.Your Processor architecture is not such that while executing a instruction external interrupt can change control flow.
3.Point 2 is vaild only if your variable is updated through ISR
|
I have a array declared as
```
char **a;
```
I am reading from a byte file, and saving the information in the array
Here is the part where I have a question about
```
//Allocate memory is not shown here
fp = fopen(file, "rb");
for (i = 0; i < LN; i++){
for (j = 0; j < SN; j++)
bytesread = fread(&a[... |
You are printing the address of the item. Change your printf to
```
printf("%d \n", a[(int)i][(int)j]);
```
|
i came across a bit of code which says
```
int fd = open(fn, flags, 0);
if (fd < 0 && errno != EMLINK)
...
```
flagsis eitherO_RDONLYorO_RDONLY|O_NOFOLLOW
IEEE Std 1003.1, 2013 (SUSv4) has just
[EMLINK]
Too many links. An attempt was made to have the link count of a single file exceed {LINK_MAX}.{LINK_MAX}
Maxim... |
Good question. WhenO_NOFOLLOWwas added, they chose to reuse an existing error code rather than make up a new one.EMLINKin this case signifies that the file is a symlink and is returned on FreeBSD. Linux and Darwin returnELOOPrather thanEMLINK, while NetBSD usesEFTYPE.
My manpages sayO_NOFOLLOWis a FreeBSD extension s... |
Is it possible, for a pure C shared library, to break the ABI compatibility while API compatibility is not broken?
Also, if one writes a library A which provides all the API functions of an existing library B, with some additional API functions, is library A ABI compatible with library B?
|
You can have different calling conventions in two libraries implementing the same API, if that answers your first question.
For the second question: You could change e.g. a structure pointer to a pointer to another structure in the declaration of a function. According to the standard they have to have the same repres... |
I'm trying to print only a certain numbers of bytes of a string with printf of C. I'm working with Nasm assembler. The problem is that i can't use for example "%.5s", because the number of bytes I need to print changes.I have something like this:
```
extern printf
section .data
format: db "%s",10,0
msg:... |
"*printf("(%.s)", n, string);" in assembly:
```
...
format: db "%.*s",10,0
n: dd 5
...
push msg
push dword [n]
push format
call printf
add esp,12 ; 4 * count of pushes
```
Consider the "reverse" order of the pushes.
BTW: You forgot the last 0 in your msg.
|
I added a flag (CONFIG_FLAG=y) in versatile_defconfig
This flag is defined in Kconfig somewhere in drivers directory
after updating the .config as follows
```
make ARCH=arm versatile_defconfig
```
I cannot find the above flag in .config
and when I search CONFIG_FLAG in menuconfig as follows
```
make ARCH=arm men... |
Finally, I had to go into the Kconfig and enable it there by default..it works but I don't know how good this solution is.
|
I'm reading a book about C programming, and I'm not sure whether there is an error in the book or not. Its about arrays and has the following array example:
Then it says:
The following statements sets all the elements in row 2 of array to zero:for( column = 0; column <= 3; column++)
a[ 2 ][ column ] = 0;The prece... |
C usesrow-major orderand zero-based indexing to reference array indices. The description you've provided of what is in the book is consistent with this.
|
How can I get directory name if I know it's inode number? Need the code. Thanks.
the below code passed dir_name by.., then I got it's i-node number, but what I also want is the directory name.
```
/*child stat*/
stat(dir_name, &sb);
if (stat(dir_name, &sb) == -1) {
perror("stat");
exit(EXIT_FAILURE);
}
child... |
Unless you have an index mapping inodes to names, you will have to recursively walk the directory structure until you find a name with the inode you're looking for (which you may not find).
If one part of your program already knows the name of the directory, you should find a way to pass it into your code.
|
In C, is there a way to query numa node info of network interface?
My system is ubuntu 14.04.
Right now, I can only get it via doing the following in bash:
cat /sys/class/net/[device_name]/device/numa_node
Thanks a lot,
|
There is thelibnumaapi whichnumactluses.
http://developer.amd.com/wordpress/media/2012/10/LibNUMA-WP-fv1.pdf
Though you might bee making more work for yourself as sysfs has already
organized this for you. In the kernel you can get the numa_node off struct device which is embedded in struct pci_dev. The sysfs accesso... |
I have this code:
```
const int a = 2;
const int arr[] = {
1,a,3,4
};
```
But it gives me this error:
source.c:6:3: error: initializer element is not constant
How can I add a constant to an array?
|
const int is not considered a constant.
You will have to use the actual number or define it.
```
#define FOUR 4
const int arr[] = {
1,FOUR,3,4
};
```
Using compound literals, it is possible to initialize it with variables:
```
const int value = 2 ;
const int *array[] = { &(int){1} , &value , &(int){3} , &(in... |
I'm reading a book about C programming, and I'm not sure whether there is an error in the book or not. Its about arrays and has the following array example:
Then it says:
The following statements sets all the elements in row 2 of array to zero:for( column = 0; column <= 3; column++)
a[ 2 ][ column ] = 0;The prece... |
C usesrow-major orderand zero-based indexing to reference array indices. The description you've provided of what is in the book is consistent with this.
|
How can I get directory name if I know it's inode number? Need the code. Thanks.
the below code passed dir_name by.., then I got it's i-node number, but what I also want is the directory name.
```
/*child stat*/
stat(dir_name, &sb);
if (stat(dir_name, &sb) == -1) {
perror("stat");
exit(EXIT_FAILURE);
}
child... |
Unless you have an index mapping inodes to names, you will have to recursively walk the directory structure until you find a name with the inode you're looking for (which you may not find).
If one part of your program already knows the name of the directory, you should find a way to pass it into your code.
|
In C, is there a way to query numa node info of network interface?
My system is ubuntu 14.04.
Right now, I can only get it via doing the following in bash:
cat /sys/class/net/[device_name]/device/numa_node
Thanks a lot,
|
There is thelibnumaapi whichnumactluses.
http://developer.amd.com/wordpress/media/2012/10/LibNUMA-WP-fv1.pdf
Though you might bee making more work for yourself as sysfs has already
organized this for you. In the kernel you can get the numa_node off struct device which is embedded in struct pci_dev. The sysfs accesso... |
I have this code:
```
const int a = 2;
const int arr[] = {
1,a,3,4
};
```
But it gives me this error:
source.c:6:3: error: initializer element is not constant
How can I add a constant to an array?
|
const int is not considered a constant.
You will have to use the actual number or define it.
```
#define FOUR 4
const int arr[] = {
1,FOUR,3,4
};
```
Using compound literals, it is possible to initialize it with variables:
```
const int value = 2 ;
const int *array[] = { &(int){1} , &value , &(int){3} , &(in... |
I have the following situation:
```
NSData *audioData = [NSData dataWithContentOfFile:[fileURL path] options:0 error:nil];
```
I need to send this audioData to the server using a method that accepts as input parameterpj_str_t value;
So I did:
```
unsigned char *getBytes = (unsigned char*)[audioData bytes]; //here ... |
Beware that audio data can contain 0's and the pj_str(char *) function you're using will mistake them for the end of the string. Try this:
```
pj_str_t string;
pj_strset(&string, getBytes, [audioData length]);
```
|
This question already has answers here:Why Isn't My Floating Point Values Printing Properly?(4 answers)Closed4 years ago.
I'm new to C and I tried following:
```
float f = 0x41933333;
```
this should give me the float number:18.4but when I look into the memory I find the hex value:
```
66 26 83 4e
```
which is as... |
0x41933333is an integer constant. When assigned to afloat, the integer is converted. If you need a hexadecimal floating point constant, you have to use that notation explicitly:
```
0x0.933333P4
```
or something vaguely similar — I've only made a casual guess at what the correct value is, but the0xprefix and thePe... |
What about using anstd::vector<char>orstd::vector<unsigned char>as aFILE*argument when invoking a C function that expects to receive a pointer to a file ?
Personally I can't recall any object or element from the standard library that can be used as a C style file.
Why I want to do this:
get out the user space as so... |
On some platforms, the standard library contains functions, which can be used for that purpose. For example, on Linux the following two functions are available:
fmemopen: Create aFILE*from a char buffer.fopencookie: Create aFILE*with custom functions.
According to the linked man pages,fmemopenis part of POSIX-2008 a... |
Closed. This question needsdetails or clarity. It is not currently accepting answers.Want to improve this question?Add details and clarify the problem byediting this post.Closed9 years ago.Improve this question
Which function in the C library copies the zero bytes(\x00) into the stack, leading to a buffer overflow?
|
There is no such standard function. C doesn't even specify that there should be a stack.
Ifyou happen to be on a stack machine, and are willing to make assumptions about the stack's layout, you can certainly usememset()to write 0-bytes into stack memory.
|
```
if (pid==0)
{
//child
}
else
{
//parent
...
}
```
Why is the 'else' part necessary? isn't it implied that we are in the parent ?
|
isn't it implied that we are in the parent ?
No.After afork()call, there aretwoprocesses that run from exactly that same point in the code. Only one is the parent. The code you put in theelseblock is runonlyby the parent, just as the code inside theifblock is runonlyby the child. Code that comes after the entireif/el... |
I know there is a problem but I can't understand why. I'm a beginner. Thanks for the help !
```
int main()
{
int a = 5;
int* p = &a;
void* p2 = p;
printf("%d", (int)(*p2) );
return 0;
}
```
I also have a problem with this:
```
int main ()
{
int a[3] = {1,2,3};
int *p = a;
if(++p == ++a)
... |
In the first code,(int)(*p2)is wrong because you can't defer avoidpointer. You first need cast it toint*and only then defer it:*(int*)p2
In the second code, you can't do++abecauseais a constant(the pointer to the array is constant, not the data in the array) so you can't change it's value.
|
When I write Doxygen comments (in C file) I would like an asterisk to be automatically inserted on new line (either with theocommand or just ↩ ).
Like this example :
```
/**
* My Doxygen comment being written
```
And when I hit ↩
```
/**
* My Doxygen comment bein written
*
^
cursor is here
```
I have Dox... |
You need this in your~/.vimrc:
```
filetype plugin indent on
```
I don't know about DoxygenToolkit.vim, I have never used it. The above is all it takes to enable the described behaviour in my 7.x Vims.
You can find mycommented ~/.vimrconline. Nothing too fancy in there, just what I use every day on half a dozen dif... |
Closed. This question needs to be morefocused. It is not currently accepting answers.Want to improve this question?Update the question so it focuses on one problem only byediting this post.Closed5 years ago.Improve this question
I was asked by an interviewer to write code to print a semicolon without using a semicolo... |
Try this code :
```
int main()
{
if(printf("%c",59)) //59 is ascii value of semicolon
{}
}
```
|
Thegcc docs for cppexplain about the#ifdirective:
[...] and logical operations (&& and ||). The latter two obey the usual short-circuiting rules of standard C.
What does that mean? There is no evaluation of expressions during preprocessing, so how can it be short-circuited?
|
Very simple: undefined macros have numeric value zero, and division by zero is illegal.
```
#if FIXEDSIZE && CHUNKSIZE/FIXEDSIZE > 42
#define USE_CELLPOOL
#endif
```
#ifdoes evaluate the rest of its line as an integer constant expression. Your linked documentation begins:
The ‘#if’ directive allows you to test t... |
I am trying to initialize values to a structure using another structure through this code:
```
struct freq
{
char temp[20];
int count=0;
};
struct test
{
char input[100];
struct freq words[20];
int len;
}testdb[1] =
{
{ "ram is playing.he likes playing", { { "ram", 1 }, { "is", 1 }, {"playing... |
You have an error in the first struct. I assume you are writing in C. C doesn't have default values for struct members.
This compiles perfectly:
```
struct freq
{
char temp[20];
int count;
};
struct test
{
char input[100];
struct freq words[20];
int len;
}testdb[1] =
{
{ "ram is playing.... |
I included:
```
#include <sched.h>
#define _GNU_SOURCE
```
Then in my code I have written (brief mention):
```
cpu_set_t set;
CPU_ZERO(&set);
CPU_SET(proc_num, &set);
if (sched_setaffinity(gettid(), sizeof(cpu_set_t), &set))
{
perror("sched_setaffinity");
return NULL;
}
```
But when I compile I find
... |
You need to place
```
#define _GNU_SOURCE
```
at leastbefore
```
#include <sched.h>
```
as the define steers what the file included shall provide.
More on this onthe related man-page here.
Update:
To make sure everything is set as needed, place the#defineat the very beginning of your source files, that is bef... |
How can I restart the function after x seconds again? What can I add toreturn void();?
```
void sendSMS(){
// send the message
sms.beginSMS(remoteNumber);
sms.print(txtMsg);
sms.endSMS();
Serial.println("\nCOMPLETE!\n");
return void();
}
```
|
if you want to re-launch yoursendSMSfunction after waited x seconds, use this :
```
int time = x;
sleep(x);
sendSMS();
```
but, don't do it into yoursendSMSfunction because there will be infinite loop...
if you want only wait, don't use last linesendSMS()
eger x saniye sonra, yenidensendSMSislemeyi yapmak istiyor... |
Closed. This question needs to be morefocused. It is not currently accepting answers.Want to improve this question?Update the question so it focuses on one problem only byediting this post.Closed5 years ago.Improve this question
I was asked by an interviewer to write code to print a semicolon without using a semicolo... |
Try this code :
```
int main()
{
if(printf("%c",59)) //59 is ascii value of semicolon
{}
}
```
|
Thegcc docs for cppexplain about the#ifdirective:
[...] and logical operations (&& and ||). The latter two obey the usual short-circuiting rules of standard C.
What does that mean? There is no evaluation of expressions during preprocessing, so how can it be short-circuited?
|
Very simple: undefined macros have numeric value zero, and division by zero is illegal.
```
#if FIXEDSIZE && CHUNKSIZE/FIXEDSIZE > 42
#define USE_CELLPOOL
#endif
```
#ifdoes evaluate the rest of its line as an integer constant expression. Your linked documentation begins:
The ‘#if’ directive allows you to test t... |
I am trying to initialize values to a structure using another structure through this code:
```
struct freq
{
char temp[20];
int count=0;
};
struct test
{
char input[100];
struct freq words[20];
int len;
}testdb[1] =
{
{ "ram is playing.he likes playing", { { "ram", 1 }, { "is", 1 }, {"playing... |
You have an error in the first struct. I assume you are writing in C. C doesn't have default values for struct members.
This compiles perfectly:
```
struct freq
{
char temp[20];
int count;
};
struct test
{
char input[100];
struct freq words[20];
int len;
}testdb[1] =
{
{ "ram is playing.... |
I included:
```
#include <sched.h>
#define _GNU_SOURCE
```
Then in my code I have written (brief mention):
```
cpu_set_t set;
CPU_ZERO(&set);
CPU_SET(proc_num, &set);
if (sched_setaffinity(gettid(), sizeof(cpu_set_t), &set))
{
perror("sched_setaffinity");
return NULL;
}
```
But when I compile I find
... |
You need to place
```
#define _GNU_SOURCE
```
at leastbefore
```
#include <sched.h>
```
as the define steers what the file included shall provide.
More on this onthe related man-page here.
Update:
To make sure everything is set as needed, place the#defineat the very beginning of your source files, that is bef... |
How can I restart the function after x seconds again? What can I add toreturn void();?
```
void sendSMS(){
// send the message
sms.beginSMS(remoteNumber);
sms.print(txtMsg);
sms.endSMS();
Serial.println("\nCOMPLETE!\n");
return void();
}
```
|
if you want to re-launch yoursendSMSfunction after waited x seconds, use this :
```
int time = x;
sleep(x);
sendSMS();
```
but, don't do it into yoursendSMSfunction because there will be infinite loop...
if you want only wait, don't use last linesendSMS()
eger x saniye sonra, yenidensendSMSislemeyi yapmak istiyor... |
The code given below is giving undefined behaviour, sometimes the code runs well, but sometimes it gives amunmap_chunkerror.
```
char *str = "hello world";
if(str != NULL) free(str)
```
Is there something wrong I am doing in the above code ?
Also how to avoidduplicate free? How do I check if the variable has some m... |
Typically the string literal ("hello world") will be stored in the data section, in a read-only page.
So you can not free them.
Also how to avoid duplicate free ?
free() will free pointed memory but will not make pointer as NULL.After every free() make pointer as NULL.
```
if(str != NULL)
{
free(str);
str = NULL... |
Closed. This question needs to be morefocused. It is not currently accepting answers.Want to improve this question?Update the question so it focuses on one problem only byediting this post.Closed9 years ago.Improve this question
I am running a c program that includes the statement :
```
#include <stdio.h>
#include <... |
what will be the output of printf(“%d”,“Hello”+1);?
Others claimed that it will "print the address of the string plus one". Thatmay or may not be true.The reason for this is thatyour code invokes undefined behavior,because you are printing an object of typechar *with a format specifier suited forintonly.
So, the com... |
I am trying to define a function which will be used as the thread-start-routine argument topthread_create. I wrote this:
```
4 void *(*Func)(void*)
5 {
6 pthread_exit(EXIT_SUCCESS);
7 }
```
But GCC prints out an error to line 5:
```
error： expected 「=」, 「,」, 「;」, 「asm」 or 「__attribute__」 before 「{」 token
`... |
The problem isn'tpthread_create,
```
void *(*Func)(void*)
{
pthread_exit(EXIT_SUCCESS);
}
```
is not a valid function definition. It's actually the signature of the function pointer&func. You probably want:
```
void* func(void* parameter)
{
pthread_exit(EXIT_SUCCESS);
}
```
|
When I compile the following code (with -Wall), I get no warnings because I cast the*(str)++to void type. However, if I do not cast that operation tovoidtype, the follow warning is put:warning: value computed is not used [-Wunused-value]Is this thecorrectway to get rid of compiler warnings?
```
#include <stdio.h>
st... |
The correct way to get rid of those compilers warnings is to simply dostr++;
|
I'm trying to paint a Picture Box over Static Control, yet the image is not appearing.
The image do exist at the location.
Here is my code :
```
HWND hwn = CreateWindow(TEXT("static"), NULL, WS_CHILD | WS_VISIBLE, 5, 10, 470, 100, hwnd, NULL, NULL, NULL);
HBITMAP hBmp = (HBITMAP)LoadImage(NULL, "D:\\Pic.bmp", I... |
You need SS_BITMAP style when creating the static control.
|
I am trying to compare the current time to the date modified time of a file and am experiencing a strange issue. I have a struct tm * which holds the time the file was modified, but this is changed to the current date after I call time(NULL).
My code:
```
printf("month: %d\n", tmst->tm_mon);
time_t curTime = time(... |
From the documentation:
The returned value points to an internal object whose validity or value may be altered by any subsequent call to gmtime or localtime.
Read documentation.
Documentation tells you how functions work.
(Thatlocaltimereturns a pointer is a big clue: who do you think frees the pointee? :D)
|
The & operator deals with the binary format of a decimal number. So10 & 9 = 8because
```
1010 (10)
1001 (9)
=====
1000 (8)
```
This previous example runs fine. But when I try to do010 & 010I expect the result to be 10. However I get 8. Can anyone explain to me why this is happening ?
|
Because a number that starts with a0is considered as being octal, not binary.
10is considereddecimal, because it's default. So the10 & 9 = 8test is resolved in decimal.
When it starts with a0, it's consideredoctal. So010 & 010is resolved in octal, as (in decimal):8 & 8.
0xis considered ashexadecimal.
And asOli Cha... |
If I have a static variablemy_varin the first.c file and pointer ptr_my_var which points to this variable, is it normal to access and change the variablemy_varusing theptr_my_varpointer from another compilation unit?
```
// first.c
...
static float my_var;
float *ptr_my_var = &my_var;
...
// second.c
...
extern flo... |
This is widely recognized as very bad programming practice *).
The whole purpose with declaring the variable as static is that you want to reduce the scope of the variable, making it private to the module it exists in. This is the C way of achievingprivate encapsulation, one of the corner stones of object-oriented pr... |
This question already has answers here:How to find an average date/time in the array of DateTime values(8 answers)Closed9 years ago.
I need to calculate the average the following observed dates:
```
1/7/2010
15/7/2011
17/6/2012
3/7/2013
```
How can I do that in asp.net or any other language. If there is any formula... |
You need to convert it to Ticks (this will convert it toSystem.Int64) and then do the average of them all.
See the following answer:https://stackoverflow.com/a/16683441/643761
|
Is there a way to call C routines from Swift?
A lot of iOS / Apple libraries are C only and I'd still like to be able to call those.
For example, I'd like to be able to call the objc runtime libraries from swift.
In particular, how do you bridge iOS C headers?
|
Yes, you can of course interact with Apple's C libraries.Hereis explained how.
Basically, the C types, C pointers, etc., are translated into Swift objects, for example a Cintin Swift is aCInt.
I've built a tiny example, for another question, which can be used as a little explanation, on how to bridge between C and S... |
When I attempt to#include "postgres.h", I get this errorIntelliSense: cannot open source file "postgres.h".
I have attempted to add to the Include Directories by adding this to the end of the field:$(pathContainingHeaderFile). The error remains when attempting to#include "postgres.h"
If I#include "pathContainingHead... |
You should just append; pathContainingHeaderFileto the Include Directories i.e. omit the$(and)parts. Remove giving the path in the#includeline and it should work fine.
|
This question already has answers here:What are scanf("%*s") and scanf("%*d") format identifiers?(5 answers)Closed9 years ago.
I have a gotten a C program, where one of the line having:
```
scanf("%d%*c%d", &x, &y);
```
What is the meaning of%*c?
|
scanf reads data from stdin and then it stores that data into the parameters pointed according to the format (in your case the parameters are&xand&y).
*indicates that the data is to be read from the stream but ignored (i.e. it is not stored in the location pointed by an parameter).
In your case%*cmeans that the func... |
I need an event which handles clicks on main window of my program.
I usedbutton-press-eventbut when i click on my window nothing happens.
I'm designing my GUI usingGlade Interface Designer.
please explain for me whenbutton-press-eventwill be called in gtk+ & is it the event i need or not?
|
Check you've got the button press event mask set for the window under the
Window Properties - Common tab in glade
|
This question already has answers here:"register" keyword in C?(19 answers)Closed9 years ago.
I was reading some gstreamer code and fell on this line
```
register int i;
```
Does anyone know what theregisterkeyword does ?
|
Another SO questionhas already answered this.
Answer From Brian Knoblauch:
It's a hint to the compiler that the variable will be heavily used and
that you recommend it be kept in a processor register if possible.Most modern compilers do that automatically, and are better at picking
them than us humans. :-)
So, ... |
My function gets aFILE*to read from, and it needs to read starting from some non-negative offset.
I could usefseek(file, offset, SEEK_SET), but it fails onstdin, for instance.
How can I determine iffseekworks? If it doesn't, I could read and discardoffsetbytes.
And is there a way to read (and discard) fromFILEwithou... |
You can test if fseek works on that stream, by callingfseek( file, offset, SEEK_SET)and on error, checking thaterrno == EBADFwhich is returned to say "The stream specified is not a seekable stream".
I think you need to read and discard, with a buffer, but if it can just be pagesize bytes and you keep a count of bytes... |
Say I need to find the euclidean distance from one (x,y) coordinate to every coordinate in an array of million coordinates and then select the coordinate with the smallest distance.
At present I loop though the million element array, calculate distance keeping track of the minimum. Is there a way I could do it differ... |
You can improve your algorithm significantly by using a more complex data structure for instance ak-d tree. Still if what you expect to do is to simply search once for the nearest neighbour, you can not possibly perform better than iterating over all points.
What youcando, though is optimize the function that compute... |
This question already has answers here:What happens if I define a 0-size array in C/C++?(8 answers)Closed9 years ago.
Me and a friend of mine are arguing about that so we thought
here we can get an appropriate answer, with the corresponding explanation.int a[0];isa[0]an array and does it have any advantages?
(I didn... |
As a standalone stack variable, it is not useful. However, as the last member of a struct, it can be used as a variable length array and doing this used to be a common technique. For example:
```
struct foo {
int a[0];
};
struct foo* bar = malloc( sizeof *bar + 10 * sizeof *bar->a );
/* now you can (possibly) us... |
I have a daemon that generates 15 - 20GB of logging each day. I want to use syslog (rsyslogd) to log all the messages. It is possible to redirect these messages to a file and not be printed /var/log/syslog?
I created a rule in /etc/rsyslogd/50-myprogram.conf that contains:
```
!MYPROGRAM
*.* /var/local/myprogram... |
Try this:
```
if $programname == 'myprogram' then /var/local/myprogram/myprogarm.log
```
|
I have some code that a program generated for me, and I really do not understandwhyit does what it does. The language is plain C, and a struct is generated.
.h-file:
```
struct X_IMPL {
sint32 y;
};
struct X {
struct X_IMPL * IMPL;
};
```
.c-file:
```
#define _my_y self->IMPL->y
sint32 do_something(struct ... |
It is just a matter of preferences, as you can do that in many ways, this one is not that sheer. On the first line, where the define is, it assigns nothing but define a macro for accessing a struct pointer through a struct pointer.
|
This question already has answers here:How to find an average date/time in the array of DateTime values(8 answers)Closed9 years ago.
I need to calculate the average the following observed dates:
```
1/7/2010
15/7/2011
17/6/2012
3/7/2013
```
How can I do that in asp.net or any other language. If there is any formula... |
You need to convert it to Ticks (this will convert it toSystem.Int64) and then do the average of them all.
See the following answer:https://stackoverflow.com/a/16683441/643761
|
Is there a way to call C routines from Swift?
A lot of iOS / Apple libraries are C only and I'd still like to be able to call those.
For example, I'd like to be able to call the objc runtime libraries from swift.
In particular, how do you bridge iOS C headers?
|
Yes, you can of course interact with Apple's C libraries.Hereis explained how.
Basically, the C types, C pointers, etc., are translated into Swift objects, for example a Cintin Swift is aCInt.
I've built a tiny example, for another question, which can be used as a little explanation, on how to bridge between C and S... |
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