#!/bin/sh
#
# fetchmail	This shell script takes care of starting and stopping
#		fetchmail.
#
# chkconfig: 2345 81 45
# description: The Fetchmail daemons allows to retrieve mail using various
#	       mail protocols and route them to the local MTA just as if
#	       the mail was sent directly to the local MTA. This is
#	       specially useful on intermittent dial-up connections.
# processname: fetchmail
# config: /etc/fetchmailrc
# author[s]:
#	Andrea Sterbini	<a .sterbini@itelcad.it>
#	ObiTuarY <obituary @freshmeat.net>

. /etc/rc.d/init.d/functions

# Source networking configuration.
. /etc/sysconfig/network

# Check that networking is up.
if [ ${NETWORKING} = "no" ]
then
	exit 0
fi 
    
# See how we were called.
case "$1" in
  start)
	if [ -s /etc/fetchmailrc ]; then
		echo -n "Loading fetchmail: "
		daemon /usr/bin/fetchmail -f /etc/fetchmailrc
		echo
		touch /var/lock/subsys/fetchmail
	else
		exit 1
	fi
	;;
  stop)	
	echo -n "Shutting down fetchmail: "
	/usr/bin/fetchmail -q >/dev/null 2>&1 && echo fetchmail
#	killproc fetchmail
	rm -f /var/lock/subsys/fetchmail
	;;
  status)
        status fetchmail
        ;;
  restart|reload)
        $0 stop
        $0 start
        ;; 
	*)
	echo "Usage: fetchmail {start|stop|status|restart|reload}"
	exit 1
esac

exit 0

# === End of File ===
</obituary></a>

First thing, you need a file with all of your list names – this works:

ls /usr/local/mailman/lists | cat > lists.txt ## This is where mailman is located on FreeBSD

Next, download mailman-subscribers.py to your home directory.

Finally, you need to create a shell script (i.e. getallsubscribers.sh) and paste the following (substitute the [[bracketed text]] with the info for your system):

while read line
do
 echo $line | cat >> listsAndMembers.csv
  ~/mailman-subscribers.py -c [[your.mailman.host]] $line [[listAdminPassword]] | cat >> listsAndMembers.csv
  echo | cat >> listsAndMembers.csv
  echo | cat >> listsAndMembers.csv
done < lists.txt

chmod +x getallsubscribers.sh
./getallsubscribers.sh

That's it. You should have a single file with all of your lists and their subscribers.

edit: It came up later that it would be nice to get a list of who from each domain was subscribed. This regex will turn up the listname and name/email for each subscriber in the .csv

(?:.*(?:gmail\.com)"|^[^"].*$)