Algorithms, Design, Code and more: Shell

Showing posts with label Shell. Show all posts

Wednesday, January 15, 2014

Mocks for Unit testing Shell Scripts

1. Look at shunit for a sense of what kind of unit testing can be performed for Shell scripts.

2. For mocking up specific steps/ programs in the script, make use of alias.

Within a shell script testScript.sh this would be something as follows:

Friday, May 3, 2013

Php Script To Display Process, Vmstat, Disk Usage, Syslog Of A Linux Server Via A Browser

A Php script that executes some standard shell programs for monitoring resource utilization & processes on a given Linux box. The script directs the output to a web-browser.

Apache web-server should be installed on the server. To run copy the script to the DocumentRoot (/var/www/html). Appropriate execute rights (-rw-x) need to be given to the apache user (which runs this script, but is not the owner) to execute this Php file & to be able to access /var/log/syslog.

Save this file as: showHealth.php in the /var/www/html folder:

<html>
<body>
<script type="text/javascript">

</script>
<div id="outermost">
<div id="mcdetails">
Showing stats from:

<?php
echo shell_exec("ip addr show | grep 'inet' | tail -1");
?>
<br/><br/>Server Date is:
<?php
echo shell_exec("date");
?>
<br/><br/>
</div>
<a href="#" onclick="toggle('vmstat');">-------Vmstat----------</a><br/><br/>
<div id="vmstat" style="display:none">
<?php
$output = shell_exec("vmstat| sed 's/$/<br\/>/g'| sed 's/ /./g'");
echo $output;
?>
</div>
<br/><a href="#" onclick="toggle('df');">-------df -m----------</a><br/><br/>
<div id="df" style="display:none">
<?php
$output = shell_exec("df -m | sed 's/$/<br\/>/g'| sed 's/ /./g'");
echo $output;
?>
</div>
<br/><a href="#" onclick="toggle('ps');">-------ps aux----------</a><br/><br/>
<div id="ps" style="display:none">
<?php
$output = shell_exec("ps aux | sed 's/$/<br\/><br\/>/g'| sed 's/ /./g'");
//$output = shell_exec('ls -l');
echo $output;
?>
</div>
<br/><a href="#" onclick="toggle('syslogdiv');">-------syslog----------</a><br/><br/>

<div id="syslogdiv" style="display:none">
<?php
$output = shell_exec("tail -200 /var/log/syslog | sed 's/$/<br\/>/g' ");
//$output = shell_exec('ls -l');
echo $output;
?>
</div>
</div>
</body>
</html>

Saturday, April 20, 2013

Linux/Unix Shell Function For Date Addition and Subtraction

Here is a small shell script to do date addition and subtraction. This works on the bash shell with GNU Date.

#!/bin/bash

function getPreviousDateTime(){
d1=`date -d "$1" +'%Y-%m-%d %H:%M:%S'`;
secs1=`date -d"$d1" +%s`;
secs2=`expr $secs1 - $2`;

# change to %H:%M:%S if you want the nos. left padded
result=`date -d@"$secs2" +'%Y-%m-%d %-H:%-M:%-S'`;
# return formatted string
echo $result;
}

function getNextDateTime(){
d1=`date -d "$1" +'%Y-%m-%d %H:%M:%S'`;
secs1=`date -d"$d1" +%s`;
secs2=`expr $secs1 + $2`;
result=`date -d@"$secs2" +'%Y-%m-%d %H:%M:%S'`;
# return formatted string
echo $result;
}

# Tests

echo `getPreviousDateTime "2012-04-29 18:00:31" 30`
echo `getPreviousDateTime "2012-04-29 00:00:00" 60`
echo `getPreviousDateTime "2012-04-29 02:00:00" 60`

echo `getNextDateTime "2012-04-29 19:00:00" 60`;
echo `getNextDateTime "2012-04-30 23:59:00" 60`;
echo `getNextDateTime "2012-02-28 23:59:00" 60`;
echo `getNextDateTime "2012-02-28 2:59:00" 60`;