Need Help / Advice For Creating a Script

carlosinfl · 09-20-2011, 09:30 AM

I have a RHEL 6.1 Linux server running an IBM server side application called Clearquest. My question is I'm being asked to have a script execute the following command every hour and then have it email me the results.

The command is as follows:

Code:

/opt/rational/base/cots/flexlm.11.8/i386_linux2/lmutil lmstat -c ratinoal_redirect.dat -a

Now my question is can I just plug that command in Cron and set it to run every hour or do I need to generate some kind of Bash script and then just tell Cron to run the script every hour? Either way I just need Linux to run that command above every hour and then finally, how would I format my Crontab to also email me the results of running that command?

TB0ne · 09-20-2011, 09:56 AM

Quote:

Originally Posted by carlosinfl

I have a RHEL 6.1 Linux server running an IBM server side application called Clearquest. My question is I'm being asked to have a script execute the following command every hour and then have it email me the results.

The command is as follows:

Code:

/opt/rational/base/cots/flexlm.11.8/i386_linux2/lmutil lmstat -c ratinoal_redirect.dat -a

Now my question is can I just plug that command in Cron and set it to run every hour or do I need to generate some kind of Bash script and then just tell Cron to run the script every hour? Either way I just need Linux to run that command above every hour and then finally, how would I format my Crontab to also email me the results of running that command?

Crontab (by itself) doesn't do anything but run a command when you tell it to...IT won't email you, but a script that you write CAN be run through crontab.

Writing a simple bash script to execute that command, then emailing the result (using mailx, sendemail, or a similar command), is trivial. Put your command on one line, then your mail command on the next. Shove it into cron, and you're done.

carlosinfl · 09-20-2011, 11:09 AM

Thanks. I've never written a script in Bash or anything for that matter so I was wondering how hard would it be to write this script and or how can I figure out what this would look like?

mmrtnt · 09-20-2011, 12:22 PM

A mailer script:

Code:

#!/bin/sh

# mailer.sh
# USAGE: mailer.sh somefilename.txt

SUBJECT="Test Mail"
MAILBODY=`cat $1`
MAILTO="recipient@domain.com"
mail -s "$SUBJECT" "$MAILTO" <<-EOF
$MAILBODY
EOF

And the modified cron:

Code:

/opt/rational/base/cots/flexlm.11.8/i386_linux2/lmutil lmstat -c ratinoal_redirect.dat -a; mailer.sh somefilename.txt

TB0ne · 09-20-2011, 01:01 PM

Quote:

Originally Posted by carlosinfl

Thanks. I've never written a script in Bash or anything for that matter so I was wondering how hard would it be to write this script and or how can I figure out what this would look like?

There are THOUSANDS of shell-scripting tutorials you can find with a quick Google search. Even lots of sample scripts on here, too. Again, not hard to write, you can do it with two lines, one being the command you've already got.

Nominal Animal · 09-20-2011, 01:13 PM

I would personally put everything in the script. (Note that I think you also have a typo in the file name, carlosinfl; shouldn't it be rational_redirect.dat instead?)

Code:

#!/bin/bash

SUBJECT="License report"
RECIPIENT="you@example.com"

/opt/rational/base/cots/flexlm.11.8/i386_linux2/lmutil lmstat -c rational_redirect.dat -a 2>&1 | mail -s "$SUBJECT" "$RECIPIENT" &>/dev/null

In the simplest case, you can just save the above as a script in /etc/cron.hourly. Make sure it is runnable by root (chmod 0755 /etc/cron.hourly/filename). You can even test it immediately using sudo /etc/cron.hourly/filename if you wish.

Nylex · 10-03-2011, 01:30 AM

Quote:

Originally Posted by TB0ne

Crontab (by itself) doesn't do anything but run a command when you tell it to...IT won't email you

Well, cron will email you. From the man page for dcron (found on Slackware at least):

Quote:

It is also common to redirect job output to a file or to /dev/null. If
you do not, and the command generates output on stdout or stderr, that
output will be mailed to the local user whose crontab the job comes from.

Of course, you need sendmail (or possibly another MTA) set up for this..