SYSTEM(3S)                           SysV                           SYSTEM(3S)



NAME
     system - issue a shell command

SYNOPSIS
     #include <stdlib.h>

     int system(string)
     const char *string;

DESCRIPTION
     The system function causes the string pointed to by string to be given to
     the command processor (sh(1)) as input, as if the string had been typed
     as a command at a terminal.  If string is a null pointer, system returns
     1 to indicate that a command processor is available.

     If system cannot exec /bin/sh, it tries to exec /com/sh.  If either exec
     is successful, the current process waits until the shell has completed,
     then returns the exit status of the shell. Execution of the current
     process is suspended until the shell exits.

FILES
     /bin/sh
     /com/sh

DIAGNOSTICS
     system returns 1 if given a null pointer.  If string is not null, system
     returns the exit status of the shell upon successful completion.
     Otherwise, it returns a negative number and sets errno to indicate the
     error.

     system forks to create a child process that in turn exec's /bin/sh (or
     /com/sh) in order to execute string.  If the fork or exec fails, system
     returns a negative value and sets errno.

ERRORS
     If the system function fails, errno is set to one of the following
     values:

     [EAGAIN]  The system-imposed limit on the total number of processes under
               execution, system-wide or by a single user ID, would be
               exceeded.

     [EINTR]   The system function was interrupted by a signal which was
               caught.

     [ENOMEM]  There is not enough space left for this process.

NOTES
     system was formerly declared in the header file stdio.h.

SEE ALSO
     exec(2), fork(2).  exit(2), wait(2)
     sh(1) in the SysV Command Reference.
     sh in the Aegis Command Reference.