postrm is in cron-apt 0.12.0.
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 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | #!/bin/sh -e
# Cron-apt postrm script using debconf
# Written by Ola Lundqvist <opal@debian.org>
case "$1" in
    purge)
        if [ -d /var/log/cron-apt ] ; then
	    rm -Rf /var/log/cron-apt
	fi
    ;;
    remove|upgrade|failed-upgrade|abort-install|abort-upgrade|disappear)
    
    ;;
    
    *)
        echo "postrm called with unknown argument \`$1'" >&2
        exit 0
    ;;
esac
exit 0
 |