postinst is in pmount 0.9.23-3build1.
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 25 26 27 28 29 30 31 32 33 34 35 36 37  | #! /bin/sh
set -e
case "$1" in
    configure)
	[ -e /media ] || mkdir /media
	# confine pmount/pumount execution to $GROUP members
	for prog in /usr/bin/pmount /usr/bin/pumount; do
	    if ! dpkg-statoverride --list $prog > /dev/null; then
                if ! getent group plugdev > /dev/null; then
                    addgroup --quiet --system plugdev || true
                fi
                chown root:plugdev $prog
                chmod 4754 $prog
	    fi
	done
        # Clean up pmount stamps in lock directories (bug from < 0.8 packages,
        # see #302174)
        if [ -d /var/lock/pmount ]; then
            find /var/lock/pmount/ -name .created_by_pmount -exec rm -f '{}' \;
        fi
	;;
    abort-upgrade|abort-remove|abort-deconfigure)
	;;
    *)
        echo "postinst called with unknown argument \`$1'" >&2
        exit 1
	;;
esac
exit 0
 |