72 lines
1.6 KiB
HTML
72 lines
1.6 KiB
HTML
<HTML>
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<HEAD>
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<TITLE>cron(8)</TITLE>
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</HEAD>
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<BODY>
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<H1>cron(8)</H1>
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<HR>
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<PRE>
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</PRE>
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<H2>NAME</H2><PRE>
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cron - clock daemon
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</PRE>
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<H2>SYNOPSIS</H2><PRE>
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<STRONG>cron</STRONG>
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</PRE>
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<H2>EXAMPLES</H2><PRE>
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<STRONG>/usr/bin/cron</STRONG> # Use absolute path in /<EM>etc</EM>/<EM>rc</EM>
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</PRE>
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<H2>DESCRIPTION</H2><PRE>
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<EM>Cron</EM> is clock daemon. It is typically started up by including the
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command /<EM>usr</EM>/<EM>bin</EM>/<EM>cron</EM> in the /<EM>etc</EM>/<EM>rc</EM> file. Once started, <EM>cron</EM> puts itself
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in the background, so no & is needed. It runs forever, sleeping most of
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the time. Once a minute it wakes up and examines /<EM>usr</EM>/<EM>lib</EM>/<EM>crontab</EM> to see
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if there is any work to do. If there is, the work is done. The entries
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of /<EM>usr</EM>/<EM>lib</EM>/<EM>crontab</EM> contain 6 elements each. Some examples follow:
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<STRONG>Min</STRONG> <STRONG>Hr</STRONG> <STRONG>Dat</STRONG> <STRONG>Mo</STRONG> <STRONG>Day</STRONG> <STRONG>Command</STRONG>
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* * * * * /usr/bin/date >/dev/log #print date every minute
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0 * * * * /usr/bin/date >/dev/log #print date on the hour
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30 4 * * 1-5 /bin/backup /dev/fd1 #do backup Mon-Fri at 0430
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30 19 * * 1,3,5 /etc/backup /dev/fd1 #Mon, Wed, Fri at 1930
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0 9 25 12 * /usr/bin/sing >/dev/log #Xmas morning at 0900 only
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</PRE>
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<H2>SEE ALSO</H2><PRE>
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<STRONG><A HREF="../man1/at.1.html">at(1)</A></STRONG>.
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</PRE>
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</BODY>
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</HTML>
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