ipcs(1)                                                             ipcs(1)




 NAME
      ipcs - report status of interprocess communication facilities

 SYNOPSIS
      ipcs [-mqs] [-abcopt] [-C corefile] [-N namelist]

 DESCRIPTION
      ipcs displays certain information about active interprocess
      communication facilities.  With no options, ipcs displays information
      in short format for the message queues, shared memory segments, and
      semaphores that are currently active in the system.

    Options
      The following options restrict the display to the corresponding
      facilities.

           (none)         This is equivalent to -mqs.

           -m             Display information about active shared memory
                          segments.

           -q             Display information about active message queues.

           -s             Display information about active semaphores.

      The following options add columns of data to the display.  See "Column
      Description" below.

           (none)         Display default columns: for all facilities: T,
                          ID, KEY, MODE, OWNER, GROUP.

           -a             Display all columns, as appropriate.  This is
                          equivalent to -bcopt.

           -b             Display largest-allowable-size information: for
                          message queues: QBYTES; for shared memory
                          segments: SEGSZ; for semaphores: NSEMS.

           -c             Display creator's login name and group name: for
                          all facilities: CREATOR, CGROUP.

           -o             Display information on outstanding usage: for
                          message queues: CBYTES, QNUM; for shared memory
                          segments: NATTCH.

           -p             Display process number information: for message
                          queues: LSPID, LRPID; for shared memory segments:
                          CPID, LPID.

           -t             Display time information: for all facilities:
                          CTIME; for message queues: STIME, RTIME; for



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                          shared memory segments: ATIME, DTIME; for
                          semaphores: OTIME.

      The following options redefine the sources of information.

           -C corefile    Use file corefile in place of /dev/kmem.

           -N namelist    Use file namelist in place of /stand/vmunix.

    Column Descriptions
      The column headings and the meaning of the columns in an ipcs listing
      are given below.  The columns are printed from left to right in the
      order shown below.

           T         Facility type:

                          m    Shared memory segment
                          q    Message queue
                          s    Semaphore

           ID        The identifier for the facility entry.

           KEY       The key used as an argument to msgget(), semget(), or
                     shmget() to create the facility entry.  (Note: The key
                     of a shared memory segment is changed to IPC_PRIVATE
                     when the segment has been removed until all processes
                     attached to the segment detach it.)

           MODE      The facility access modes and flags: The mode consists
                     of 11 characters that are interpreted as follows:

                     The first two characters can be:

                          R    A process is waiting on a msgrcv().
                          S    A process is waiting on a msgsnd().
                          D    The associated shared memory segment has been
                               removed.  It will disappear when the last
                               process attached to the segment detaches it.
                          C    The associated shared memory segment is to be
                               cleared when the first attach is executed.
                          -    The corresponding special flag is not set.

                     The next 9 characters are interpreted as three sets of
                     three characters each.  The first set refers to the
                     owner's permissions, the next to permissions of others
                     in the group of the facility entry, and the last to all
                     others.

                     Within each set, the first character indicates
                     permission to read, the second character indicates
                     permission to write or alter the facility entry, and



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                     the last character is currently unused.

                          r    Read permission is granted.
                          w    Write permission is granted.
                          a    Alter permission is granted.
                          -    The indicated permission is not granted.

           OWNER     The login name of the owner of the facility entry.

           GROUP     The group name of the group of the owner of the
                     facility entry.

           CREATOR   The login name of the creator of the facility entry.

           CGROUP    The group name of the group of the creator of the
                     facility entry.

           CBYTES    The number of bytes in messages currently outstanding
                     on the associated message queue.

           QNUM      The number of messages currently outstanding on the
                     associated message queue.

           QBYTES    The maximum number of bytes allowed in messages
                     outstanding on the associated message queue.

           LSPID     The process ID of the last process to send a message to
                     the associated message queue.

           LRPID     The process ID of the last process to receive a message
                     from the associated message queue.

           STIME     The time the last msgsnd() message was sent to the
                     associated message queue.

           RTIME     The time the last msgrcv() message was received from
                     the associated message queue.

           CTIME     The time when the associated facility entry was created
                     or changed.

           NATTCH    The number of processes attached to the associated
                     shared memory segment.

           SEGSZ     The size of the associated shared memory segment.

           CPID      The process ID of the creating process of the shared
                     memory segment.

           LPID      The process ID of the last process to attach or detach
                     the shared memory segment.



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           ATIME     The time the last shmat() attach was completed to the
                     associated shared memory segment.

           DTIME     The time the last shmdt() detach was completed on the
                     associated shared memory segment.

           NSEMS     The number of semaphores in the set associated with the
                     semaphore entry.

           OTIME     The time the last semop() semaphore operation was
                     completed on the set associated with the semaphore
                     entry.

 WARNINGS
      ipcs produces only an approximate indication of actual system status
      because system processes are continually changing while ipcs is
      acquiring the requested information.

      Do not rely on the exact field widths and spacing of the output, as
      these will vary depending on the system, the release of HP-UX, and the
      data to be displayed.

 FILES
      /dev/kmem           Kernel virtual memory
      /etc/group          Group names
      /etc/passwd         User names
      /stand/vmunix       System namelist

 SEE ALSO
      msgop(2), semop(2), shmop(2).

 STANDARDS CONFORMANCE
      ipcs: SVID2, SVID3





















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