NAME

       syscall, __syscall — indirect system call

LIBRARY

       Standard C Library (libc, -lc)

SYNOPSIS

       #include <sys/syscall.h>
       #include <unistd.h>

       int
       syscall(int number, ...);

       off_t
       __syscall(quad_t number, ...);

DESCRIPTION

       The  syscall()  function  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>.  The __syscall() form should be used when one or more  of  the  arguments  is  a  64-bit
       argument to ensure that argument alignment is correct.  This system call is useful for testing new system
       calls that do not have entries in the C library.

RETURN VALUES

       The  return  values are 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.

HISTORY

       The syscall() function appeared in 4.0BSD.

BUGS

       There is no way to simulate system calls that have multiple return values such as pipe(2).

Debian                                            June 16, 1993                                       SYSCALL(2)