Standard C Library Functions                           system(3C)

NAME
     system - 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 ter-
     minal. 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, sys-
     tem() returns a non-zero value; otherwise, it returns 0.  If
     the  application  is standard-conforming (see standards(5)),
     system() uses /usr/bin/ksh (see ksh(1)); otherwise  system()
     uses /usr/bin/sh (see sh(1)).

RETURN VALUES
     The system() function forks 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(2) 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
           processes  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  avail-
           able.

USAGE
     The system() function will fail to execute setuid() or  set-
     gid()  if  either  the  UID  or  GID  of  the  application's
     owner/group is less than 100. See useradd(1M) and setuid(2).

     The system() function is implemented using  vfork(2),  which
     is much less likely to fail due to resource constraints than
     fork(2).

SunOS 5.8           Last change: 12 Oct 1999                    1

Standard C Library Functions                           system(3C)

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | MT-Level                    | Unsafe                      |
    |_____________________________|_____________________________|

SEE ALSO
     ksh(1), sh(1),  useradd(1M),  exec(2),  fork(2),  setuid(2),
     vfork(2), waitpid(2), attributes(5), standards(5)

SunOS 5.8           Last change: 12 Oct 1999                    2