I set up a cron job and want to prove to my professor that it is working. Is there a log file that records that it actually took place?

I'm looking in the /var/log/cron file and it does not seem to have recorded it, although I know it took place.

HK

/var/log/cronlog should show if the cron job was initiated but it won't give you any details of what that job did. That is to say it is simply a log for cron scheduling not for the jobs themselves.

When creating a job you want to get better logging for you should just add it to the crontab with redirect statements:

1 * * * * myscript.sh >>/somelogdir/myscript.log 2>&1

Where myscript and somelogdir are the names you choose. The above will send any output of myscript.sh to somelogdir/myscript.log and also redirect any errors to that same log. Of course if the script had no output or errors you wouldn't see anything in the log. You can modify the script by doing things like:

date
echo "Now running something"

These statements would display the screen when run from the command line but when run from cron (using the above redirect) would go to the logfile you'd created.

Thanks for your help!

Alternatively, if you have a MTA (mail transport agent) like sendmail or postfix running, you can make
cron mail the output and error messages back to either the user that submitted the cron jobs (default) or to
a random mail address (by adding "MAILTO=someone@somewhere" at the top of the crontab settings).