#!/usr/bin/python
#
# An example from Sean Reifschneider's Python Tutorial at Linux Expo 98.
#
# Copyright (c) 1998 Sean Reifschneider, tummy.com, ltd. 
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
#
# You can contact Sean Reifschneider at 
#	P.O. Box 270624, 
#	Fort Collins, CO USA 80527-0624, 
# or at jafo-gpl@tummy.com
#
#  Ping a list of machines, send e-mail when they aren't reachable.

import os
import re

hostList = [ '127.0.0.1', 'www.tummy.com', 'foo.bar.com' ]
mailTo = 'changemenow@localhost'		#  Mail error reports to

pingRegex = r'.*(?P<trans>\d+)\s+packets transmitted.*\s+' + \
		r'(?P<recv>\d+)\s+packets received.*\s+' + \
		r'(?P<loss>\d+)% packet loss'

for host in hostList:
	ping = os.popen('ping -c 3 -i 1 ' + host + ' 2>&1')
	data = ping.read()

	match = re.match(pingRegex, data, re.DOTALL)
	if match:
		print '%s:\t%s transmitted, %s received, %s%% lost' % ( host,
				match.group('trans'), match.group('recv'), match.group('loss') )
		if match.group('loss') != '0':
			os.system('mail -s \'Ping failure: %s\' %s </dev/null >/dev/null'
					% ( host, mailTo ))
	else:
		print host + ':\tPING ERROR'
		os.system('mail -s \'Ping ERROR: %s\' %s </dev/null >/dev/null'
				% ( host, mailTo ))