postrm is in cloud-initramfs-dyn-netconf 0.40ubuntu1.
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 | #!/bin/sh
set -e
case "$1" in
remove|purge)
dpkg-trigger update-initramfs;;
*) exit 0;;
esac
exit 0
# vi: ts=4 noexpandtab
|