Manual page for system(3S)
system - issue a shell command
SYNOPSIS
#include <stdlib.h>
int system(const char *string);
MT-LEVEL
MT-Safe
DESCRIPTION
system()
causes the
string
to be given to the shell
as input, as if the string had been typed as a command
at a terminal.
The invoker waits until the shell has
completed, then returns the exit status of the shell
in the format specified by
waitpid.2
If string is a
null pointer,
system()
checks if the shell
exists and is executable. If the shell is available,
system()
returns non-zero; otherwise it returns zero.
- Solaris
-
system()
uses
/usr/bin/sh
(see
sh.1
- XPG4
-
system()
uses the XPG4-compliant shell
/usr/bin/ksh
(see
ksh.1
RETURN VALUES
system()
forks to create a child process that in turn
execs
the shell
in order to execute
string.
If the
fork()
or
exec()
fails,
system()
returns a value of
-1
and sets
errno.
ERRORS
system()
fails if one or more of the following are true:
- EAGAIN
-
The system-imposed limit on the total number of processes under execution by
a single user would be exceeded.
- EINTR
-
system()
was interrupted by a signal.
- ENOMEM
-
The new process requires more memory than is available.
SEE ALSO
ksh.1
sh.1
useradd.1m
exec.2
fork.2
setuid.2
waitpid.2
xpg4.5
NOTES
system()
will fail to execute
setuid()
or
setgid()
if either the uid or gid of the application's owner/group is less than 100.
(see
useradd.1m
and
setuid.2
Created by unroff & hp-tools.
© by Hans-Peter Bischof. All Rights Reserved (1997).
Last modified 21/April/97
