Unix Tip: TRIMMING THE LOG

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3016 - May 10, 2010

http://www.ugu.com/sui/ugu/show?tip.today

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

TRIMMING THE LOG

Various unix processes can produce fast growing logs that sometimes need to be trimmed instead of deleted, for reference or troubleshooting. And you likely have no desire to edit the files. Here is a handy ksh script that will quickly trim the log so it keeps recent information and lets you keep as many lines as you think you might need. I call it trimlog:

#! /bin/sh
# trimlog
filesize=`cat $1|wc -l`
trim=`expr $filesize - $2`
if [ $trim -gt 0 ]
then
sed "1,$trim d" $1 > /tmp/$1
mv /tmp/$1 $1
echo $1 trimmed by $trim lines fi

Use it by feeding in the name of the log you want to trim followed by the number of lines you want to keep:

# trimlog oracle_listener.log 10000

Of course you can't use it in the /tmp directory. There are probably newer and more efficient ways to do this, but this works.

--------------------------------------------------------------------------
To Subscribe: http://www.ugu.com/sui/ugu/show?tip.subscribe
To Unsubscribe: http://www.ugu.com/sui/ugu/show?tip.unsubscribe
To Submit A Tip: http://www.ugu.com/sui/ugu/show?tip.today

==========================================================================
DISCLAIMER: All UNIX HOT TIPS ARE OWNED BY THE UNIX GURU UNIVERSE AND ARE
NOT TO BE SOLD, PRINTED OR USED WITHOUT THE WRITTEN CONSENT OF THE UNIX
GURU UNIVERSE. ALL TIPS ARE "USE AT YOUR OWN RISK". UGU ADVISES THAT
ALL TIPS BE TESTED IN A NON-PRODUCTION DEVELOPMENT ENVIRONMENT FIRST.

Unix Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
==========================================================================