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Top Forums Shell Programming and Scripting how to get variable to re-evaluate itself? Post 94706 by frustrated1 on Tuesday 3rd of January 2006 08:45:47 AM
Old 01-03-2006
how to get variable to re-evaluate itself?

Probably a simple one.
Basically I am retrieving a number from a file - setting a variable against it and then incrementing this by 1 and using this as an entry number in a log file for messages. I need the variable to re-evalute itself each time I call it so I get the latest number in the file - how do I do this? my script is basically as follows:

The number within test4.csv is updated every 2 seconds ... so the second time I echo $e I hope to see the latest number incremented by one

#!/usr/bin/ksh

d=`tail -1 test4.csv | cut -f1 -d" "`
e=$((d + 1))

echo e is $e
sleep 3
echo e is $e
sleep 3
 

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PROCESSCSV.PY(1)					      Virtualization Support						  PROCESSCSV.PY(1)

NAME
processcsv.py - process virt-top CSV files SUMMARY
virt-top --csv data.csv processcsv.py < data.csv DESCRIPTION
virt-top is a top(1)-like utility for showing stats of virtualized domains. processcsv.py is a simple Python script that post-processes the output of "virt-top --csv". It is used like this: virt-top --csv data.csv processcsv.py < data.csv The second command will overwrite the following files in the current directory: "global.csv" This contains the global (host) statistics columns from the CSV file. "domainNN.csv" (multiple files) For each libvirt domain ID NN, a file is created containing the per-domain statistics from the CSV file. SEE ALSO
virt-top(1) AUTHORS
Richard W.M. Jones <rjones @ redhat . com> COPYRIGHT
(C) Copyright 2007-2012 Red Hat Inc., Richard W.M. Jones http://libvirt.org/ This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. virt-top-1.0.8 2013-12-29 PROCESSCSV.PY(1)
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