shell script problem

tulsi · 03-17-2011, 12:06 AM

Hi Guys,

I write a shell script,its shown in below,

#!/bin/bash

ps -ef | grep -v grep | grep "./server"

if [ $? -eq 1 ]

then

echo " not working"

cd /home/server

nohup ./server > /dev/null 2>&1&

else

echo "its working fine"

fi

when the "server" was stop and i ran the script, its run but after sometime i greped out ps -ef | grep /.server , this process was not running,i am doing couple times, but same result. can you suggest me any problem in the script.

Thanks

corp769 · 03-17-2011, 12:45 AM

First of all, edit your post and put the code in code tags, thanks.

As far as the actual problem, change ./server to server in your grep statement. It should do the trick... If not, let me know.

Josh

jschiwal · 03-17-2011, 01:03 AM

Your script will include the grep line which contains the pattern you are looking for.

Code:

ps -ef | grep server
jschiwal  2714 21717  0 00:44 pts/4    00:00:00 grep server
jschiwal  2786  2535  0 Mar14 ?        00:00:00 kwrapper4 ksmserver
...

You will have other false matches as well.

It would probably be better to check services using it's startup script with a "status" option. If this is a server you wrote yourself. A service usually creates a .pid file the contents of which is the PID of the process. A shell wrapper could echo $$ to a file, and you could use that files value.

You could also use `pidof' to return the pid of a named command.

Code:

jschiwal@qosmio:~> ps -p $(pidof caliber) >/dev/null 2>&1 && echo OK || echo FAILED
FAILED
jschiwal@qosmio:~> ps -p $(pidof calibre) >/dev/null 2>&1 && echo OK || echo FAILED
OK

tulsi · 03-17-2011, 02:19 AM

first of all thanks for your replies,

can you explain pidof command ...

corp769 · 03-17-2011, 02:41 AM

All pidof does is returns the PID of the process you pass to the command.