SYSTEM(3) NEWLIB SYSTEM(3)NAME
2.45 `system'--execute command string
SYNOPSIS
#include <stdlib.h>
int system(char *S);
int _system_r(void *REENT, char *S);
DESCRIPTION
Use `system' to pass a command string `*S' to `/bin/sh' on your system,
and wait for it to finish executing.
Use "`system(NULL)'" to test whether your system has `/bin/sh'
available.
The alternate function `_system_r' is a reentrant version. The
extra argument REENT is a pointer to a reentrancy structure.
RETURNS
`system(NULL)' returns a non-zero value if `/bin/sh' is available, and
`0' if it is not.
With a command argument, the result of `system' is the exit status
returned by `/bin/sh'.
PORTABILITY
ANSI C requires `system', but leaves the nature and effects of a com‐
mand processor undefined. ANSI C does, however, specify that `sys‐
tem(NULL)' return zero or nonzero to report on the existence of a com‐
mand processor.
POSIX.2 requires `system', and requires that it invoke a `sh'.
Where `sh' is found is left unspecified.
Supporting OS subroutines required: `_exit', `_execve', `_fork_r',
`_wait_r'.
SEE ALSOsystem is part of the library. The full documentation for is main‐
tained as a Texinfo manual. If info and are properly installed at your
site, the command
info
will give you access to the complete manual.
NEWLIB April 2010 SYSTEM(3)
