[unix-history] / usr / src / lib / libc / sys / syscall.2

.\" Copyright (c) 1980 Regents of the University of California.
.\" All rights reserved.  The Berkeley software License Agreement
.\" specifies the terms and conditions for redistribution.
.\"
.\"	@(#)syscall.2	6.1 (Berkeley) %G%
.\"
.TH SYSCALL 2 ""
.UC 4
.SH NAME
syscall \- indirect system call
.SH SYNOPSIS
.nf
.BR "syscall(number, arg, ...)" \  \  (VAX-11)
.fi
.SH DESCRIPTION
.I Syscall
performs the system call whose assembly language
interface has the specified
.I number,
register arguments
.I r0
and
.I r1
and further arguments
.IR arg .
.PP
The r0 value of the system call is returned.
.SH DIAGNOSTICS
When the C-bit is set,
.I syscall
returns \-1 and sets the
external variable 
.I errno
(see
.IR intro (2)).
.SH BUGS
There is no way to simulate system calls
such as
.IR pipe (2),
which return values in register r1.
Commit	Line	Data
695ad0b4 KM	1	.\" Copyright (c) 1980 Regents of the University of California.
	2	.\" All rights reserved. The Berkeley software License Agreement
	3	.\" specifies the terms and conditions for redistribution.
	4	.\"
f9effee3	5	.\" @(#)syscall.2 6.1 (Berkeley) %G%
695ad0b4	6	.\"
f9effee3	7	.TH SYSCALL 2 ""
695ad0b4 KM	8	.UC 4
	9	.SH NAME
	10	syscall \- indirect system call
	11	.SH SYNOPSIS
	12	.nf
695ad0b4 KM	13	.BR "syscall(number, arg, ...)" \ \ (VAX-11)
	14	.fi
	15	.SH DESCRIPTION
	16	.I Syscall
	17	performs the system call whose assembly language
	18	interface has the specified
	19	.I number,
	20	register arguments
	21	.I r0
	22	and
	23	.I r1
92a92bd0	24	and further arguments
695ad0b4 KM	25	.IR arg .
	26	.PP
	27	The r0 value of the system call is returned.
	28	.SH DIAGNOSTICS
	29	When the C-bit is set,
	30	.I syscall
	31	returns \-1 and sets the
	32	external variable
	33	.I errno
	34	(see
	35	.IR intro (2)).
	36	.SH BUGS
	37	There is no way to simulate system calls
	38	such as
	39	.IR pipe (2),
	40	which return values in register r1.