From: Florian Frank <flori@...>
Date: 2004-11-11T23:09:08+09:00
Subject: Re: Writing a looping, low-configuration script in Ruby

On 2004-11-11 22:44:51 +0900, Francis Hwang wrote:
> So then I was thinking: Can I have a config that automatically edits
> the crontab? Has anybody used Ruby to programmatically edit a crontab?
> I suppose the brute force way to do it is to call "crontab -e" and
> send the various keystrokes to stdin, but I wonder if anybody knows of
> a less duct-tapey way.

You can install a new crontab with
$ crontab filename
or
$ crontab -
for stdin input.

You can output the current crontab of $USER with
$ crontab -l > filename

Of course you can do this in a ruby script, too. In this case you should
perhaps use a lock file.

If you only want to run a script every 30 minutes with cron, you
can add a line like
*/30 * * * *    /path/to/script.rb
to your crontab. This is actually one of the main reasons to install
something like cron.

-- 
Florian Frank