SETPGRP(S)               XENIX System V                SETPGRP(S)



     Name
          setpgrp - Sets process group ID.

     Syntax
          int setpgrp ()

     Description
          setpgrp sets the process group ID of the calling process to
          the process ID of the calling process and returns the new
          process group ID.

          There are many ramifications to be considered before
          invoking setpgrp. When a process is made a process group
          leader with setpgrp, the terminal that controlled the
          process that issued the setpgrp statement is lost as the
          controlling terminal for the new process group.  The new
          process group takes as its controlling terminal the next
          terminal it opens that is not already open. All child
          processes of the new process group leader are controlled by
          the new controlling terminal.

          The controlling terminal is responsible for signals (INTR,
          KILL, EOF) sent to the process group leader and it child
          processes.  If there is no controlling terminal, it becomes
          more difficult to interrupt a process.

          As an example, setpgrp is used to separate daemon processes
          from controlling terminals so that they may not be
          interrupted from any terminal by a KILL or INTR signal.

     Return Value
          setpgrp returns the value of the new process group ID.

     See Also
          exec(S), fork(S), getpid(S), intro(S), kill(S), signal(S),
          termio(M)



















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