<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> <!--Converted with LaTeX2HTML 96.1-c (Feb 29, 1996) by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds --> <HTML> <HEAD> <TITLE>The ipcs Command</TITLE> <META NAME="description" CONTENT="The ipcs Command"> <META NAME="keywords" CONTENT="lpg"> <META NAME="resource-type" CONTENT="document"> <META NAME="distribution" CONTENT="global"> <LINK REL=STYLESHEET HREF="lpg.css"> </HEAD> <BODY LANG="EN"> <A NAME="tex2html685" HREF="node26.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="/icons//next_motif.gif"></A> <A NAME="tex2html683" HREF="node22.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="/icons//up_motif.gif"></A> <A NAME="tex2html677" HREF="node24.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="/icons//previous_motif.gif"></A> <A NAME="tex2html687" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="/icons//contents_motif.gif"></A> <BR> <B> Next:</B> <A NAME="tex2html686" HREF="node26.html">The ipcrm Command</A> <B>Up:</B> <A NAME="tex2html684" HREF="node22.html">6.4.1 Fundamental Concepts</A> <B> Previous:</B> <A NAME="tex2html678" HREF="node24.html">IPC Keys</A> <BR> <P> <H3><A NAME="SECTION00741300000000000000">The <TT>ipcs</TT> Command</A></H3> <P> The <TT>ipcs</TT> command can be used to obtain the status of all System V IPC objects. The Linux version of this tool was also authored by <EM>Krishna Balasubramanian</EM>. <P> <P> <HR><PRE>ipcs -q: Show only message queues ipcs -s: Show only semaphores ipcs -m: Show only shared memory ipcs --help: Additional arguments</PRE> <HR>By default, all three categories of objects are shown. Consider the following sample output of <TT>ipcs</TT>: <P> <P> <HR><PRE>------ Shared Memory Segments -------- shmid owner perms bytes nattch status ------ Semaphore Arrays -------- semid owner perms nsems status ------ Message Queues -------- msqid owner perms used-bytes messages 0 root 660 5 1</PRE> <HR>Here we see a single message queue which has an identifier of ``0''. It is owned by the user <EM>root</EM>, and has octal permissions of <TT>660</TT>, or <TT>-rw-rw--</TT>. There is one message in the queue, and that message has a total size of 5 bytes. <P> The <TT>ipcs</TT> command is a very powerful tool which provides a peek into the kernel's storage mechanisms for IPC objects. Learn it, use it, revere it. <P> <BR> <HR> <P><ADDRESS> <I>Converted on: <BR> Fri Mar 29 14:43:04 EST 1996</I> </ADDRESS> </BODY> </HTML>
