setpgid(2P)                                           setpgid(2P)



     NAME
          setpgid - set process group ID for job control

     SYNOPSIS
          int setpgid(pid, pgid)
          pid_t pid, pgid;

     DESCRIPTION
          setpgid is used to join an existing process group or to
          create a new process group within the session of the calling
          process.  The process group ID  of a session group leader
          cannot be changed.  The process group ID of the process
          specified by pid is set to pgid.  If pid or pgid is 0, the
          process ID of the calling process is used.

     RETURN VALUE
          On successful completion, setpgid returns a value of 0.
          Otherwise, a value of -1 is returned and errno is set to in-
          dicate the error.

     ERRORS
          If any of the following conditions occur, setpgid returns -1
          and sets errno to the corresponding value:

          [EACCESS]     pid matches the process ID of a child process
                        of the calling process and the child has suc-
                        cessfully executed one of the exec functions.

          [EINVAL]      The value of pgid is less than 0 or exceeds
                        {PID_MAX}.

          [EPERM]       The process indicated by pid is a session
                        group leader.

                        The value of pid is valid but matches the pro-

                        cess ID of a child of the calling process and

                        the child process is not in the same session

                        as the calling process.  The value of pgid

                        does not match the process ID of the process

                        indicated by pid and there is no process with

                        a process group ID that matches the value of

                        pgid in the same session as the calling pro-

                        cess.


          [ESRCH]       pid does not match the process ID of the cal-

                        ling process or of a child process of the cal-

                        ling process.


     SEE ALSO

          exec(2), getpgrp(2), setsid(2P), tcsetpgrp(3P).






     April, 1990                                                     1