HPUX DetachPids[3]

 Tcl_DetachPids(3)                   Tcl                   Tcl_DetachPids(3)

 Tcl Library Procedures                               Tcl Library Procedures





 ___________________________________________________________________________

 NAME
      Tcl_DetachPids, Tcl_ReapDetachedProcs  -  manage  child  processes  in
      background

 SYNOPSIS
      #include <tcl.h>

      Tcl_DetachPids(numPids, pidPtr)

      Tcl_ReapDetachedProcs()                                                  |

 ARGUMENTS
      int   numPids      (in)      Number of process ids  contained  in  the
                                   array pointed to by pidPtr.

      int   *pidPtr      (in)       Address  of  array  containing   numPids
                                   process ids.
 ___________________________________________________________________________


 DESCRIPTION
      Tcl_DetachPids  and  Tcl_ReapDetachedProcs  provide  a  mechanism  for  |
      managing   subprocesses   that   are  running  in  background.   These  |
      procedures are needed because the parent of a process must  eventually  |
      invoke  the  waitpid kernel call (or one of a few other similar kernel  |
      calls) to wait for the child to exit.  Until the parent waits for  the  |
      child, the child's state cannot be completely reclaimed by the system.  |
      If a parent continually creates children and doesn't wait on them, the  |
      system's  process  table  will  eventually  overflow,  even if all the  |
      children have exited.                                                   |

      Tcl_DetachPids may be called to ask Tcl to take responsibility for one  |
      or  more processes whose process ids are contained in the pidPtr array  |
      passed as argument.  The caller presumably has started these processes  |
      running  in  background  and  doesn't  want  to have to deal with them  |
      again.                                                                  |

      Tcl_ReapDetachedProcs invokes the waitpid kernel call on each  of  the  |
      background  processes  so  that  its state can be cleaned up if it has  |
      exited.  If  the  process  hasn't  exited  yet,  Tcl_ReapDetachedProcs  |
      doesn't  wait for it to exit;  it will check again the next time it is  |
      invoked.  Tcl automatically calls Tcl_ReapDetachedProcs each time  the  |
      exec  command is executed, so in most cases it isn't necessary for any  |
      code outside of Tcl to invoke Tcl_ReapDetachedProcs.  However, if  you  |
      call Tcl_DetachPids in situations where the exec command may never get  |
      executed, you may wish to call Tcl_ReapDetachedProcs from time to time  |
      so that background processes can be cleaned up.                         |



                                    - 1 -        Formatted:  August 11, 1996






 Tcl_DetachPids(3)                   Tcl                   Tcl_DetachPids(3)

 Tcl Library Procedures                               Tcl Library Procedures





 KEYWORDS
      background, child, detach, process, wait


















































                                    - 2 -        Formatted:  August 11, 1996