postrm is in mcollective-plugins-registration-monitor 0.0.0~git20120105.9b90c2b-0ubuntu2.
This file is a maintainer script. It is executed when installing (*inst) or removing (*rm) the package.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 | #!/bin/sh -e
if [ -f "/etc/mcollective/server.cfg" ]
then
invoke-rc.d mcollective restart
fi
|