.\" Copyright (c) 1990, 1991 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" %sccs.include.redist.man%
.\"
.\"     @(#)system.3	6.4 (Berkeley) %G%
.\"
.Dd 
.Dt SYSTEM 3
.Os
.Sh NAME
.Nm system
.Nd pass a command to the shell
.Sh SYNOPSIS
.Fd #include <stdlib.h>
.Ft int
.Fn system "const char *string"
.Sh DESCRIPTION
The
.Fn system
function
hands the argument
.Fa string
to the command interpreter
.Xr sh 1 .
The calling process waits for the shell
to finish executing the command,
ignoring
.Dv SIGINT
and
.Dv SIGQUIT ,
and blocking
.Dv SIGCHLD .
.Pp
If
.Fa string
is a
.Dv NULL
pointer,
.Fn system
will return non-zero if the command interpreter
.Xr sh 1
is available, and zero if it is not.
.Pp
The
.Fn system
function
returns the exit status of the shell, or \-1 if the
.Xr wait 3
for the shell failed.
A return value of 127 means the execution of the shell
failed.
.Sh SEE ALSO
.Xr sh 1 ,
.Xr execve 2 ,
.Xr wait 2 ,
.Xr popen 3
.Sh STANDARDS
The
.Fn system
function
conforms to
.St -ansiC .