postinst is in libpam-poldi 0.4.2+git20151221.338f78b-1.
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  | #! /bin/sh
set -e
case "$1" in
    configure)
	if ! [ -e /var/log/poldi ]; then
	    touch /var/log/poldi
	    chown root:adm /var/log/poldi
	    chmod 0640 /var/log/poldi
	fi
    ;;
    abort-upgrade|abort-remove|abort-deconfigure)
    ;;
    *)
        echo "postinst called with unknown argument \`$1'" >&2
        exit 1
    ;;
esac
exit 0
 |