We maintain multiple repositories, many of which have the same rpms repeated in different locations. In order to save space we use hardlinking extensively. The hardlink command does an ok job of finding things to link, but we are only really interested in rpms and don't want repomod.xml or comps getting linked so I wrote a little python script to hard link all the rpms based on a checksum. The script is over at my github. hardlink_rpms
Our aliases are spammed like any other account, but filtering on them would require making a real account. I wanted to be able to filter aliases without creating accounts for everything. My first solution was to create an account and filter on that one, then using $original_local_part I could forward to a filtered alias. This works but if someone discovers the filtered alias, they can bypass the filtering.
We are using gnarwl for vacation notification and I would like gnarwl to only reply if the current time is in the vacationStart vacationEnd window.
Here is the queryfilter to do that using the following information:
$recepient - receiver of the message
$time - current time in seconds since the epoch
I often use dd to copy large files or make images from hard drives. It's annoying to watch something without any progress indicator, so I use the little known kill switch on dd.
From the man page:
Sending a USR1 signal to a running ‘dd’ process makes it print I/O statistics to standard error and then resume copying.
$ dd if=/dev/zero of=/dev/null& pid=$!