UNIX for Dummies Questions & Answers

Okay. I hadn't read that requirement. I would do something like:-

Code:

su username -c "crontab -l > /tmp/my_cron
echo "0 * * * * /path/to/myscript.sh" >> /tmp/my_cron
crontab /tmp/my_cron"

This switches to the non-root account to do the work. The user would have to be allowed to use crontab and not be locked into an application menu else you might get very odd results.




Robin

I think the approach is OK. Maybe thread-o/p is trying to set up a mechanism to deploy a cron job for a lot of systems: think, for instance, of a database backup script to be run as the DBA user. If i had to create such a system i would write exactly such a (postinstall-) script and put it into a package, along with the script to be called from cron itself.

For cron to become aware of the changed crontab you just need to send it a HUP signal:

Code:

echo "0 * * * * /path/to/myscript.sh 2>/dev/null 1>/dev/null " >> /var/spool/cron/crontabs/username
kill -1 $(cat /var/run/crond.pid)

but even if this works i'd still prefer rbatte1's solution because this will work even when the involved path for the crontabs and/or the location of the PID-file changes with different cron-implementations.

Btw.: i suggest to add redirections to /dev/null (or designated log files) otherwise cron would start to mail stray output to the user. Another thing: check if the user is allowed to have a crontab. In most implementations there is a file /etc/cron.allow and another file /etc/cron.deny.

I hope this helps.

bakunin

Thank you very much guys for sharing your thoughts. This time I am using Rbatte1's solution.

Cheer.