system(3,F)                 AIX Technical Reference                 system(3,F)



-------------------------------------------------------------------------------
system



PURPOSE

Runs a shell command.

LIBRARY

Standard C Library (libc.a)

SYNTAX

#include <stdio.h>

int system (string)
char *string;

DESCRIPTION

The system subroutine passes the string parameter to the sh command as input.
Then sh interprets string as a command and runs it.

The system subroutine invokes the runl system call to create a child process to
run /bin/sh, which interprets the shell command contained in the string
parameter.  The current process waits until the shell has completed, then
returns the exit status of the shell.

Note:  The system subroutine runs only sh shell commands (also called Bourne
       shell commands).  The results are unpredictable if the string parameter
       is not a valid sh shell command.

RETURN VALUE

The system subroutine is implemented using runl and waitpid.  If either fails,
a value of -1 is returned and errno is set to indicate the error.

FILE

/bin/sh

ERROR CONDITIONS

The system subroutine fails if one or more of the following are true:

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





Processed November 7, 1990        system(3,F)                                 1

system(3,F)                 AIX Technical Reference                 system(3,F)



EINTR     The system subroutine was interrupted by a signal.

ENOMEM    Insufficient storage space is available.

RELATED INFORMATION

In this book:  "exit, _exit,"  "run: runl, runv, runle, runve, runlp, runvp,"
and "wait, waitpid."

The sh command in AIX Operating System Commands Reference.













































Processed November 7, 1990        system(3,F)                                 2