xref: /csrg-svn/lib/libc/sys/syscall.2 (revision 47208)
1*47208Scael.\" Copyright (c) 1980, 1991 Regents of the University of California.
2*47208Scael.\" All rights reserved.
320095Smckusick.\"
4*47208Scael.\" %sccs.include.redist.man%
520095Smckusick.\"
6*47208Scael.\"     @(#)syscall.2	6.3 (Berkeley) 03/10/91
7*47208Scael.\"
8*47208Scael.Dd
9*47208Scael.Dt SYSCALL 2
10*47208Scael.Os BSD 4
11*47208Scael.Sh NAME
12*47208Scael.Nm syscall
13*47208Scael.Nd indirect system call
14*47208Scael.Sh SYNOPSIS
15*47208Scael.Fd #include <unistd.h>
16*47208Scael.Fd #include <sys/syscall.h>
17*47208Scael.Ft int
18*47208Scael.Fn syscall "int number" "..."
19*47208Scael.Sh DESCRIPTION
20*47208Scael.Fn Syscall
2120095Smckusickperforms the system call whose assembly language
2220095Smckusickinterface has the specified
23*47208Scael.Fa number
24*47208Scaelwith the specified arguments.
2527109SmckusickSymbolic constants for system calls can be found in the header file
26*47208Scael.Ao Pa syscall.h Ac .
27*47208Scael.Pp
28*47208Scael.Sh RETURN VALUES
2920095SmckusickThe r0 value of the system call is returned.
3020095SmckusickWhen the C-bit is set,
31*47208Scael.Fn syscall
32*47208Scaelreturns -1 and sets the
3320095Smckusickexternal variable
34*47208Scael.Va errno
3520095Smckusick(see
36*47208Scael.Xr intro 2 ) .
37*47208Scael.Sh BUGS
3820095SmckusickThere is no way to simulate system calls
3920095Smckusicksuch as
40*47208Scael.Xr pipe 2 .
41*47208Scael.Sh HISTORY
42*47208ScaelThe
43*47208Scael.Nm
44*47208Scaelfunction call appeared in
45*47208Scael.Bx 4.0 .
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