postinst is in distmp3 0.1.9.ds1-4.4.
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  | #!/bin/sh
set -e
# XXX
export in_postinst=1
USER=distmp3
# Debconf notice
. /usr/share/debconf/confmodule
if test "$1" = configure; then
  if getent passwd distmp3 > /dev/null; then
    echo "$USER user exists already, not adding."
  else
    echo "Adding a $USER user..."
    adduser --quiet --system --home /nonexistent --disabled-password \
            --no-create-home --group distmp3
  fi
  chown $USER:$USER /var/run/distmp3
fi
# Automatically added by dh_installinit
if [ -x "/etc/init.d/distmp3" ]; then
	if [ ! -e "/etc/init/distmp3.conf" ]; then
		update-rc.d distmp3 defaults >/dev/null
	fi
	invoke-rc.d distmp3 start || exit $?
fi
# End automatically added section
db_stop
 |