postinst is in biosdevname 0.4.1-0ubuntu10.
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  | #!/bin/sh
set -e
case "$1" in
    configure)
        update-initramfs -u
        ;;
    abort-upgrade|abort-deconfigure|abort-remove)
        ;;
    *)
        echo "$0 called with unknown argument \`$1'" 1>&2
        exit 1
        ;;
esac
exit 0
 |