[SOLVED] how to check multiple processes ? bash script...

dlugasx · 06-13-2011, 04:25 PM

Hi Gurus,

I have running license server on my server. Right now I would like to write small status script and check if software is running.

My software include 3 deamons:

1) daemonA
2) daemonB
3) daemonC

My script should check, if each of this deamon is running. If all deamons are running then script should print short output: "License server is running" if one of this daemons is not running, output should "License server is not running".

Is it possible to write small loop to check it ? Let say, loop will take new daemon name from deamons pool and will check if its running. Sometimes I need to check more than three daemons of one Program and I dont know how to write good script for this. Maybe somebody could help me with this loop that in the future I could also use; daemonD, daemonE, daemonF... etc.etc. if all daemons from pool is running then..."Software is running"

Would be great if somebody could help me ?

David the H. · 06-13-2011, 11:48 PM

It should be quite simple to set something like this up. But it would be best if you did most of the work yourself, so you'll learn more.

Start by figuring out how to generate the list of daemons you want using shell commands (do you want it to read from a simple text file, or grab the output from some other program?). Then figure out how to test whether a single daemon is running or not (hint: try grepping ps, or use pgrep). Then, determine how to print a message depending on its status (hint: use an if or case statement).

Once you have the individual steps mapped out, then you can wrap it up in a simple loop to test them all in turn.

Here are a few useful bash scripting references:
http://www.linuxcommand.org/index.php
http://tldp.org/LDP/Bash-Beginners-G...tml/index.html
http://www.tldp.org/LDP/abs/html/index.html
http://www.gnu.org/software/bash/manual/bashref.html
http://wiki.bash-hackers.org/start
http://mywiki.wooledge.org/BashFAQ
http://mywiki.wooledge.org/BashPitfalls

We'll be here to help you out if you encounter any problem points.

Good luck!

PS: Could you please remove or break up the hash lines in you signature? It's causing my browser to side-scroll something terrible. Thanks.

dlugasx · 06-14-2011, 03:35 AM

Code:

sitepoint=`ps aux | grep -v grep | egrep -c 'daemonA|daemonB|daemonC'`
if [ $sitepoint -lt "3" ]; then
 echo "Software is RUNNING"
else
 echio "Software is NOT RUNNING"
fi

I have found this on unix.com forum and works like a charm but I dont understand this line...

Code:

if [ $sitepoint -lt "3" ]; then

what is mean "-lt" from which command is this parameter ?

thanks in advance

mario.almeida · 06-14-2011, 07:27 AM

-lt = less then