#!/usr/bin/env python
#
# Copyright (c) 2006-2007, Hans Meine <hans_meine@gmx.net>
#  All rights reserved.
#
# This is licensed according to the new BSD license.
# Please send patches / comments, I would be happy about any feedback.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# * Redistributions of source code must retain the above copyright
#   notice, this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
#   documentation and/or other materials provided with the distribution.
#
# * Neither the name of the University of Hamburg nor the names of its
#   contributors may be used to endorse or promote products derived from
#   this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.

import sys, re, urlparse, urllib, getopt

endChars = ' ,;\t<>"\''
url_re = re.compile(r'(((http|https|ftp|gopher|mailto):[^%s]+|(www|ftp)\.[-a-z0-9._]+)[^%s):]+)|href="([^"]+)"' % (endChars, endChars), re.I)

def usage():
	print "USAGE:", sys.argv[0], "[-b base_url] <filename> .."
	print "  extracts URLS from one or more files and dumps them to stdout."
	print "Options:\n  -b: specify base URL for relative-to-absolute link conversion."

base= ""

options, files = getopt.getopt(sys.argv[1:], "b:")
for option, value in options:
	if option == "-h" or option == "-?":
		usage()
		sys.exit(0)
	elif option == "-b":
		base = value

if len(files) < 1:
	files = ["-"]

def scanFile(f, base = base):
	for ma in url_re.finditer(f.read()):
		if ma.group(1):
			print ma.group(1)
		else:
			print urlparse.urljoin(base, ma.group(5))

for filename in files:
	if filename == "-":
		scanFile(sys.stdin)
	elif url_re.match(filename):
		scanFile(urllib.urlopen(filename), filename)
	else:
		scanFile(file(filename))