Running a command via cron vs manual

[Mark Cook]

I was wondering why a script would run sucessfully if ran from the command line, however, the same script scheduled in cron dose not produce the same results if any at all. I have a script named "ck_syslog.sh" which checks syslog.log for certain keywords. If any of the defined key words are found, then it sends me an e-mail with the results. This works everytime running from the command line, however, if I schedule it using cron I have never received the proper resluts. Any suggestions? Thanks, in advacne, for everyone's/anyone's help!!! Mark

[A. Clay Stephenson]

It's really very simple. The environment under cron is very sparse. Your script neets to
set and export PATH and any other variables you might need. (e.g. SHLIB_PATH, ORACLE_HOME,
ORACLE_SID, etc.) Typically all you need is PATH.

[James R. Ferguson · Accepted solution]

Hi Mark:

The environment which is provided to cron does not include the environmental variables you have when you have logged-in (for instance) and therefore sourced your $HOME profile.

Environmental variables can be embedded in your script as necessary, or they can be specified and exported or file-sourced in a crontab entry in one of the following ways:

0 1 * * * (V=x;export V;/home/my/script)

0 1 * * * (. /home/my/.env /home/my/script)

0 1 * * * su -c -c /home/my/script

...JRF...

[Mark Cook]

First off, thanks A.Clay Stephenson & James Ferguson for both of your quick replies. When I look at other scripts they may have the following:
PATH=/usr/bin:/usr/sbin:/sbin:/usr/omni/bin:/opt/omni/bin:/usr/local/bin
Is this what you are refering to and if so, can you please indicate why this is necessary. I have certain scripts currently in cron that work to succession without this type of entry. Thanks again gentlemen!

[A. Clay Stephenson]

You are on the right track. You need to add a
couple of lines much like this to your script:
PATH=/usr/bin:/usr/local/bin:/opt/omni/bin
export PATH
You may need other directories as well depending on where the executables are located.

You can get a clear idea of what is going on by creating a small script, 'my.sh'.
#!/usr/bin/sh
echo "Path = ${PATH}" > /tmp/path.txt

chmod 755 my.sh
Execute my.sh from the shell and examine /tmp/path.txt.
Next create a crontab entry to execute my.sh
and examine /tmp/path.txt again. I think that you will find that the PATH's are vastly different.

Clay

[Mark Cook]

Thanks again...I will do that and if you don't ever hear from me again, then you know it worked. Thanks for your time and efforts!