system(3C) Standard C Library Functions system(3C)NAMEsystem - issue a shell command
SYNOPSIS
#include <stdlib.h>
int system(const char *string);
DESCRIPTION
The system() function causes string to be given to the shell as input,
as if 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(3C).
If string is a null pointer, system() checks if the shell exists and is
executable. If the shell is available, system() returns a non-zero
value; otherwise, it returns 0. The standard to which the caller con‐
forms determines which shell is used. See standards(5).
RETURN VALUES
The system() function executes vfork(2) to create a child process that
in turn invokes one of the exec family of functions (see exec(2)) on
the shell to execute string. If vfork() or the exec function fails,
system() returns −1 and sets errno to indicate the error.
ERRORS
The system() function fails if:
EAGAIN The system-imposed limit on the total number of pro‐
cesses under execution by a single user would be
exceeded.
EINTR The system() function was interrupted by a signal.
ENOMEM The new process requires more memory than is available.
USAGE
The system() function manipulates the signal handlers for SIGINT,
SIGQUIT, and SIGCHLD. It is therefore not safe to call system() in a
multithreaded process, since some other thread that manipulates these
signal handlers and a thread that concurrently calls system() can
interfere with each other in a destructive manner. If, however, no
such other thread is active, system() can safely be called concurrently
from multiple threads. See popen(3C) for an alternative to system()
that is thread-safe.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │Standard │
├─────────────────────────────┼─────────────────────────────┤
│MT-Level │Unsafe │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOksh(1), sh(1), exec(2), vfork(2), popen(3C), waitpid(3C),
attributes(5), standards(5)SunOS 5.10 18 Dec 2003 system(3C)
