#!/usr/local/bin/python
# -*- Mode: Python -*-

import os
import sys

known_hosts = os.path.join (os.environ['HOME'], '.ssh/known_hosts')

looking_for = sys.argv[1].split('@')[1].lower()

f0 = open (known_hosts, 'rb')
f1 = open (known_hosts + '.tmp', 'wb')

while 1:
    line = f0.readline()
    if not line:
        break
    else:
        names = line.split()[0].lower().split(',')
        if looking_for not in names:
            f1.write (line)
        else:
            print 'forgetting %r\n' % (line[:-1])

os.rename (known_hosts + '.tmp', known_hosts)