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SYSCALL

Section: Linux Programmer's Manual (2)
Updated: 2007-07-26
Index Return to Main Contents

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NAME

syscall - indirect system call  

SYNOPSIS

#define _GNU_SOURCE         /* See feature_test_macros(7) */
#include <unistd.h>
#include <sys/syscall.h>   /* For SYS_xxx definitions */

int syscall(int number, ...);

 

DESCRIPTION

syscall() performs the system call whose assembly language interface has the specified number with the specified arguments. Symbolic constants for system calls can be found in the header file <sys/syscall.h>.  

RETURN VALUE

The return value is defined by the system call being invoked. In general, a 0 return value indicates success. A -1 return value indicates an error, and an error code is stored in errno.  

NOTES

syscall() first appeared in 4BSD.  

EXAMPLE

#define _GNU_SOURCE
#include <unistd.h>
#include <sys/syscall.h>
#include <sys/types.h>

int
main(int argc, char *argv[])
{
    pid_t tid;

    tid = syscall(SYS_gettid);
}

 

SEE ALSO

_syscall(2), intro(2), syscalls(2)  

COLOPHON

This page is part of release 3.35 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://man7.org/linux/man-pages/.

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Index

NAME

SYNOPSIS

DESCRIPTION

RETURN VALUE

NOTES

EXAMPLE

SEE ALSO

COLOPHON

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