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#!/usr/bin/python
# Copyright (C) 2008 Manu Garg.
# Author: Manu Garg <manugarg@gmail.com>
#
# pacparser is a library that provides methods to parse proxy auto-config
# (PAC) files. Please read README file included with this package for more
# information about this library.
#
# pacparser is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
# pacparser 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
# Lesser General Public License for more details.
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
# USA
"""
This script demonstrates how python web clients can use
proxy auto-config (PAC) files for proxy configuration using pacparser.
It take a PAC file and an url as arguments, fetches the URL using the
proxy as determined by PAC file and URL and returns the retrieved webpage.
"""
__author__ = 'manugarg@gmail.com (Manu Garg)'
__copyright__ = 'Copyright (C) 2008 Manu Garg'
__license__ = 'LGPL'
import pacparser
import socket
import sys
import urllib
def fetch_url_using_pac(pac, url):
try:
proxy_string = pacparser.just_find_proxy(pac, url)
except:
sys.stderr.write('could not determine proxy using Pacfile\n')
return None
proxylist = proxy_string.split(";")
proxies = None # Dictionary to be passed to urlopen method of urllib
while proxylist:
proxy = proxylist.pop(0).strip()
if 'DIRECT' in proxy:
proxies = {}
break
if proxy[0:5].upper() == 'PROXY':
proxy = proxy[6:].strip()
if isproxyalive(proxy):
proxies = {'http': 'http://%s' % proxy}
break
try:
sys.stderr.write('trying to fetch the page using proxy %s\n' % proxy)
response = urllib.urlopen(url, proxies=proxies)
except Exception, e:
sys.stderr.write('could not fetch webpage %s using proxy %s\n' %
(url, proxies))
sys.stderr.write(str(e)+'\n')
return None
return response
def isproxyalive(proxy):
host_port = proxy.split(":")
if len(host_port) != 2:
sys.stderr.write('proxy host is not defined as host:port\n')
return False
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.settimeout(10)
try:
s.connect((host_port[0], int(host_port[1])))
except Exception, e:
sys.stderr.write('proxy %s is not accessible\n' % proxy)
sys.stderr.write(str(e)+'\n')
return False
s.close()
return True
def main():
if len(sys.argv) != 3:
print('Not enough arguments')
print('Usage:\n%s <pacfile> <url>' % sys.argv[0])
return None
pacfile = sys.argv[1]
url = sys.argv[2]
response = fetch_url_using_pac(pacfile, url)
if response:
print(response.read())
else:
sys.stderr.write('URL %s could not be retrieved using PAC file %s.' %
(url, pacfile))
if __name__ == '__main__':
main()
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