--- /dev/null
+#!/usr/bin/ruby1.9.1
+
+require 'json'
+
+db = ENV['MOCK_MAILMAN_DB']
+
+lists = JSON.load(File.read(db))
+if ARGV[0] != '-f'
+ $stderr.puts "Bad call"
+ exit 1
+else
+ emails = (ARGV[1] == '-' ? $stdin : File.open(ARGV[1])).read.split
+ lists[ARGV[2]] = (lists[ARGV[2]] || []) - emails
+end
+File.open(db, 'w') { |f| f.write(JSON.dump(lists)) }