Name

syscall — indirect system call

Synopsis

#define _GNU_SOURCE         /* or _BSD_SOURCE or _SVID_SOURCE */
#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

intro(2), _syscall(2), syscalls(2)

COLOPHON

This page is part of release 2.79 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.


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    (#)syscall.2 8.1 (Berkeley) 6/16/93


2002-03-20  Christoph Hellwig <hchinfradead.org>
- adopted for Linux