SYSTEM(3S-SVR4)     RISC/os Reference Manual      SYSTEM(3S-SVR4)



NAME
     system - issue a shell command

SYNOPSIS
     #include <stdlib.h>

     int system (const char *string);

DESCRIPTION
     system causes the string to be given to the shell [see
     sh(1)] as input, as if the string had been typed as a com-
     mand at a terminal.  The current process waits until the
     shell has completed, then returns the exit status of the
     shell in the format specified by waitpid.

     If string is a NULL pointer, system checks if /sbin/sh
     exists and is executable.  If /sbin/sh is available, system
     returns non-zero; otherwise it returns zero.

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

     EAGAIN      The system-imposed limit on the total number of
                 processes under execution by a single user would
                 be exceeded.

     EINTR       system was interrupted by a signal.

     ENOMEM      The new process requires more memory than is
                 allowed by the system-imposed maximum MAXMEM.

SEE ALSO
     exec(2), waitpid(3C).
     sh(1) in the User's Reference Manual.

DIAGNOSTICS
     system forks to create a child process that in turn execs
     /sbin/sh in order to execute string.  If the fork or exec
     fails, system returns a value of -1 and sets errno.

















                        Printed 11/19/92                   Page 1