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 16, 1993 37.Dt SYSCALL 2 38.Os BSD 4 39.Sh NAME 40.Nm syscall , 41.Nm __syscall 42.Nd indirect system call 43.Sh SYNOPSIS 44.Fd #include <sys/syscall.h> 45.Fd #include <unistd.h> 46.Ft int 47.Fn syscall "int number" "..." 48.Ft int 49.Fn __syscall "quad_t number" "..." 50.Sh DESCRIPTION 51.Fn Syscall 52performs the system call whose assembly language 53interface has the specified 54.Fa number 55with the specified arguments. 56Symbolic constants for system calls can be found in the header file 57.Ao Pa sys/syscall.h Ac . 58The 59.Nm __syscall 60form should be used when one or more of the parameters is a 6164-bit argument to ensure that argument alignment is correct. 62This system call is useful for testing new system calls that 63do not have entries in the C library. 64.Sh RETURN VALUES 65The return values are defined by the system call being invoked. 66In general, a 0 return value indicates success. 67A -1 return value indicates an error, 68and an error code is stored in 69.Va errno . 70.Sh BUGS 71There is no way to simulate system calls that have multiple return values 72such as 73.Xr pipe 2 . 74.Sh HISTORY 75The 76.Fn syscall 77function call appeared in 78.Bx 4.0 . 79