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<HTML><!--Distributed by F --><HEAD><TITLE>[Chapter 39] 39.6 lastcomm: What Commands Are Running and How Long Do They Take?</TITLE><METANAME="DC.title"CONTENT="UNIX Power Tools"><METANAME="DC.creator"CONTENT="Jerry Peek, Tim O'Reilly &amp; Mike Loukides"><METANAME="DC.publisher"CONTENT="O'Reilly &amp; Associates, Inc."><METANAME="DC.date"CONTENT="1998-08-04T21:50:15Z"><METANAME="DC.type"CONTENT="Text.Monograph"><METANAME="DC.format"CONTENT="text/html"SCHEME="MIME"><METANAME="DC.source"CONTENT="1-56592-260-3"SCHEME="ISBN"><METANAME="DC.language"CONTENT="en-US"><METANAME="generator"CONTENT="Jade 1.1/O'Reilly DocBook 3.0 to HTML 4.0"><LINKREV="made"HREF="mailto:online-books@oreilly.com"TITLE="Online Books Comments"><LINKREL="up"HREF="ch39_01.htm"TITLE="39. Time and Performance"><LINKREL="prev"HREF="ch39_05.htm"TITLE="39.5 Why Is the System So Slow? "><LINKREL="next"HREF="ch39_07.htm"TITLE="39.7 Checking System Load: uptime "></HEAD><BODYBGCOLOR="#FFFFFF"TEXT="#000000"><DIVCLASS="htmlnav"><H1><IMGSRC="gifs/smbanner.gif"ALT="UNIX Power Tools"USEMAP="#srchmap"BORDER="0"></H1><MAPNAME="srchmap"><AREASHAPE="RECT"COORDS="0,0,466,58"HREF="index.htm"ALT="UNIX Power Tools"><AREASHAPE="RECT"COORDS="467,0,514,18"HREF="jobjects/fsearch.htm"ALT="Search this book"></MAP><TABLEWIDTH="515"BORDER="0"CELLSPACING="0"CELLPADDING="0"><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch39_05.htm"TITLE="39.5 Why Is the System So Slow? "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 39.5 Why Is the System So Slow? "BORDER="0"></A></TD><TDALIGN="CENTER"VALIGN="TOP"WIDTH="171"><B><FONTFACE="ARIEL,HELVETICA,HELV,SANSERIF"SIZE="-1">Chapter 39<BR>Time and Performance</FONT></B></TD><TDALIGN="RIGHT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch39_07.htm"TITLE="39.7 Checking System Load: uptime "><IMGSRC="gifs/txtnexta.gif"SRC="gifs/txtnexta.gif"ALT="Next: 39.7 Checking System Load: uptime "BORDER="0"></A></TD></TR></TABLE>&nbsp;<HRALIGN="LEFT"WIDTH="515"TITLE="footer"></DIV><DIVCLASS="SECT1"><H2CLASS="sect1"><ACLASS="title"NAME="UPT-ART-1950">39.6 lastcomm: What Commands Are Running and How Long Do They Take?</A></H2><PCLASS="para"><ACLASS="indexterm"NAME="AUTOID-43863"></A><ACLASS="indexterm"NAME="AUTOID-43866"></A>When you're debugging a problem with a program, trying to figureout why your CPU usage bill is so high, or curious what commandssomeone (including yourself) is running, the <EMCLASS="emphasis">lastcomm</EM> commandon Berkeley-like UNIXes can help (if your computer has its processaccounting system running, that is).Here's an example that lists the user <EMCLASS="emphasis">lesleys</EM>:</P><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">% <CODECLASS="userinput"><B>date</B></CODE>Mon Sep  4 16:38:13 EDT 1995% <CODECLASS="userinput"><B>lastcomm lesleys</B></CODE>emacs          lesleys  ttyp1      1.41 secs Wed Sep  4 16:28cat          X lesleys  ttyp1      0.06 secs Wed Sep  4 16:37stty           lesleys  ttypa      0.02 secs Wed Sep  4 16:36tset           lesleys  ttypa      0.12 secs Wed Sep  4 16:36sed            lesleys  ttypa      0.02 secs Wed Sep  4 16:36hostname       lesleys  ttypa      0.00 secs Wed Sep  4 16:36quota          lesleys  ttypa      0.16 secs Wed Sep  4 16:35   ...</PRE></BLOCKQUOTE></P><PCLASS="para">The processes are listed in the order completed, most-recent first.The <CODECLASS="literal">emacs</CODE> process on the<SPANCLASS="link">tty <CODECLASS="literal">ttyp1</CODE> (<ACLASS="linkend"HREF="ch03_08.htm"TITLE="What tty Am I On? ">3.8</A>)</SPAN>started tenminutes ago and took 1.41 seconds of CPU time.Sometime while <EMCLASS="emphasis">emacs</EM> was on ttyp1, <EMCLASS="emphasis">lesleys</EM> ran <EMCLASS="emphasis">cat</EM>and killed it (the <CODECLASS="literal">X</CODE> shows that).Because <EMCLASS="emphasis">emacs</EM> ran on the same terminal as <EMCLASS="emphasis">cat</EM> but finishedlater, Lesley might have<SPANCLASS="link">stopped <EMCLASS="emphasis">emacs</EM> (with CTRL-z) (<ACLASS="linkend"HREF="ch12_01.htm#UPT-ART-0439"TITLE="Job Control: Work Faster, Stop Runaway Jobs ">12.1</A>)</SPAN>to run <EMCLASS="emphasis">cat</EM>.The processes on <CODECLASS="literal">ttypa</CODE> are the ones run from her <EMCLASS="emphasis">.cshrc</EM>and <EMCLASS="emphasis">.login</EM> files (though you can't tell that from <EMCLASS="emphasis">lastcomm</EM>).You don't see the login shell for <CODECLASS="literal">ttypa</CODE> (<EMCLASS="emphasis">csh</EM>) here becauseit hasn't terminated yet; it'll be listed after Lesley logs out of ttypa.</P><PCLASS="para"><EMCLASS="emphasis">lastcomm</EM> can do more.See its manual page.</P><PCLASS="para">Here's a hint: on a busy system with lots of users and commands being logged,<EMCLASS="emphasis">lastcomm</EM> is pretty slow.If you pipe the output or redirect it into a file, like this:</P><PCLASS="para"><TABLECLASS="screen.co"BORDER="1"><TR><THVALIGN="TOP"><PRECLASS="calloutlist">&#13;<ACLASS="co"HREF="ch13_09.htm"TITLE="13.9 Send Output Two or More Places with tee ">tee</A> &#13;</PRE></TH><TDVALIGN="TOP"><PRECLASS="screen">% <CODECLASS="userinput"><B>lastcomm lesleys &gt; lesley.cmds &amp;</B></CODE>% <CODECLASS="userinput"><B>cat lesley.cmds</B></CODE>   <ICLASS="lineannotation">...nothing...</I>% <CODECLASS="userinput"><B>lastcomm lesleys | tee lesley.cmds</B></CODE>   <ICLASS="lineannotation">...nothing...</I></PRE></TD></TR></TABLE></P><PCLASS="para"><ACLASS="indexterm"NAME="AUTOID-43906"></A>then the <EMCLASS="emphasis">lastcomm</EM> output may be written to the file or pipe in big chunksinstead of line-by-line.That can make it look as if nothing's happening.If you can tie up a terminal while <EMCLASS="emphasis">lastcomm</EM> runs, there are twoworkarounds.If you're using a window system or terminal emulator with a &quot;log to file&quot;command, use it while <EMCLASS="emphasis">lastcomm</EM> runs.Otherwise, to copy the output to a file,start<SPANCLASS="link"><EMCLASS="emphasis">script</EM> (<ACLASS="linkend"HREF="ch51_05.htm"TITLE="Copy What You Do with script ">51.5</A>)</SPAN>and then run <EMCLASS="emphasis">lastcomm</EM>:</P><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">% <CODECLASS="userinput"><B>script lesley.cmds</B></CODE>Script started, file is lesley.cmds% <CODECLASS="userinput"><B>lastcomm lesleys</B></CODE>emacs          lesleys  ttyp1      1.41 secs Wed Sep  4 16:28cat          X lesleys  ttyp1      0.06 secs Wed Sep  4 16:37   ...% <CODECLASS="userinput"><B>exit</B></CODE>Script done, file is lesley.cmds%</PRE></BLOCKQUOTE></P><PCLASS="para">A final word:<EMCLASS="emphasis">lastcomm</EM> can't give information on commands that are<SPANCLASS="link">built into the shell (<ACLASS="linkend"HREF="ch01_10.htm"TITLE="Internal and External Commands ">1.10</A>)</SPAN>.Those commands are counted as part of the shell's execution time;they'll be in an entry for <EMCLASS="emphasis">csh</EM>, <EMCLASS="emphasis">sh</EM>, etc. after the shellterminates.</P><DIVCLASS="sect1info"><PCLASS="SECT1INFO">- <SPANCLASS="authorinitials">JP</SPAN></P></DIV></DIV><DIVCLASS="htmlnav"><P></P><HRALIGN="LEFT"WIDTH="515"TITLE="footer"><TABLEWIDTH="515"BORDER="0"CELLSPACING="0"CELLPADDING="0"><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch39_05.htm"TITLE="39.5 Why Is the System So Slow? 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