1.\" $NetBSD: syscall.2,v 1.4 1995/02/27 12:38:53 cgd Exp $ 2.\" 3.\" Copyright (c) 1980, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)syscall.2 8.1 (Berkeley) 6/16/93 35.\" 36.Dd June 23, 2008 37.Dt SYSCALL 2 38.Os BSD 4 39.Sh NAME 40.Nm syscall 41.Nd indirect system call 42.Sh SYNOPSIS 43.Fd #include <sys/syscall.h> 44.Fd #include <unistd.h> 45.Ft int 46.Fn syscall "int number" "..." 47.Sh DESCRIPTION 48.Fn syscall 49performs the system call whose assembly language 50interface has the specified 51.Fa number 52with the specified arguments. 53Symbolic constants for system calls can be found in the header file 54.Ao Pa sys/syscall.h Ac . 55This function is useful for testing new system calls that 56do not have entries in the C library. 57.Sh RETURN VALUES 58The return values are defined by the system call being invoked. 59In general, a 0 return value indicates success. 60A -1 return value indicates an error, 61and an error code is stored in 62.Va errno . 63.Sh BUGS 64There is no way to simulate system calls that have multiple return values 65such as 66.Xr pipe 2 . 67.Sh HISTORY 68The 69.Fn syscall 70function call appeared in 71.Bx 4.0 . 72