Cron send email with STDERR but NOT STDOUT?

email scripting cron stderr
g33kz0r picture g33kz0r · Sep 8, 2009 · Viewed 26.6k times · Source

I have some python scripts that run on a daily basis in cron. How can I have cron send me an email ONLY WHEN THERE IS STDERR OUTPUT from my script? I want to be able to mail multiple recipients, and set the subject line individually for each cron entry.

I tried this:

./prog > /dev/null | mail . . .

but it didn't work -- I still receive blank emails when there is no STDERR. Do I need to do this in the script itself?

Sorry if this seems basic, I have googled a lot but can't seem to find this answered succintly.

Answer

Shizzmo picture Shizzmo · Sep 8, 2009

For cron you don't need to pipe through mail. The cron daemon will automatically mail any output of your command to you. Your crontab entry should look like:

# every minute
* * * * * ./prog >/dev/null

If there is no STDERR output, you won't get any mail.

Related questions

Shell script to send email

I am on linux machine and I monitor a process usage. Most of the time I will be away from my system and I have access to internet on my device. So I planned to write a shell-script that can …

Read More
Send mail from a Windows script

I would like to send mail from a script on a Windows Server 2003 Standard Edition. I think the server setup is pretty much out of the box. The mail server is an Exchange one, and when you're on the internal …

Read More
How to validate an email address in JavaScript

Is there a regular expression to validate an email address in JavaScript?

Read More