Re: [gentoo-user] crontab questions

[Michael Orlitzky <michael@orlitzky.com>]

On 12/11/2012 04:15 PM, Grant wrote:
> Is there a way to remove "Cron <root@hostname>" from the subject line of
> crontab mail without piping each cron job to 'mail'?
> 
> I set 'usermod -c hostname root' on each of my systems so that the From:
> line displays "hostname" for crontab mail.  This works on each system
> except the mail server itself which still shows "Cron Daemon".  Can
> crontab mail from the mail server be made to display From: "hostname"
> like the other systems?
> 
> I'm not completely clear on how cronbase works.  Can this crontab be
> integrated into the system crontab via cronbase or should it be run as a
> separate user crontab for root?
> 
> 0 4 * * * layman -NS && eix-sync -n && eix-remote update -n
> 15 4 * * * emerge -pvDuN world
> 20 4 * * * eclean -C distfiles
> 30 4 * * * eclean -C packages
> 40 4 * * * eix-test-obsolete
> 45 4 * * * revdep-rebuild -ip
> 

If your goal is to run these each one after the other, you can simply
stick a shell script in /etc/cron.daily that executes them in order.

The default crontab runs any executable files in,

  * /etc/cron.daily
  * /etc/cron.hourly
  * /etc/cron.monthly
  * /etc/cron.weekly

at roughly the time specified in /etc/crontab. If any of those
directories contain scripts, they're run in "alphabetical" order, i.e.
how `ls` would sort them.

To fix the Subject/From headers, try,

  http://www.postfix.org/header_checks.5.html

I've never had to use them myself, but I think the REPLACE action will
do what you want. The alternative is to replace the sendmail binary with
something that executes e.g.,

  sed -e 's/Subject: Cron <[^>]> /Subject: /g' | /the/actual/sendmail

Both feel a little dirty, but the header checks are less likely to break
something assuming that they will work on a client-provided From header.