summaryrefslogtreecommitdiffstats
path: root/Lib/urllib.py
blob: 422cb9ebb644c73c092d6a3a047607c4d7cea808 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
# Open an arbitrary URL
#
# See the following document for more info on URLs:
# "Names and Addresses, URIs, URLs, URNs, URCs", at
# http://www.w3.org/pub/WWW/Addressing/Overview.html
#
# See also the HTTP spec (from which the error codes are derived):
# "HTTP - Hypertext Transfer Protocol", at
# http://www.w3.org/pub/WWW/Protocols/
#
# Related standards and specs:
# - RFC1808: the "relative URL" spec. (authoritative status)
# - RFC1738 - the "URL standard". (authoritative status)
# - RFC1630 - the "URI spec". (informational status)
#
# The object returned by URLopener().open(file) will differ per
# protocol.  All you know is that is has methods read(), readline(),
# readlines(), fileno(), close() and info().  The read*(), fileno()
# and close() methods work like those of open files. 
# The info() method returns a mimetools.Message object which can be
# used to query various info about the object, if available.
# (mimetools.Message objects are queried with the getheader() method.)

import string
import socket
import os
import sys


__version__ = '1.8'

MAXFTPCACHE = 10		# Trim the ftp cache beyond this size

# Helper for non-unix systems
if os.name == 'mac':
	from macurl2path import url2pathname, pathname2url
elif os.name == 'nt':    
	from nturl2path import url2pathname, pathname2url 
else:
	def url2pathname(pathname):
		return pathname
	def pathname2url(pathname):
		return pathname

# This really consists of two pieces:
# (1) a class which handles opening of all sorts of URLs
#     (plus assorted utilities etc.)
# (2) a set of functions for parsing URLs
# XXX Should these be separated out into different modules?


# Shortcut for basic usage
_urlopener = None
def urlopen(url, data=None):
	global _urlopener
	if not _urlopener:
		_urlopener = FancyURLopener()
	if data is None:
		return _urlopener.open(url)
	else:
		return _urlopener.open(url, data)
def urlretrieve(url, filename=None):
	global _urlopener
	if not _urlopener:
		_urlopener = FancyURLopener()
	if filename:
	    return _urlopener.retrieve(url, filename)
	else:
	    return _urlopener.retrieve(url)
def urlcleanup():
	if _urlopener:
		_urlopener.cleanup()


# Class to open URLs.
# This is a class rather than just a subroutine because we may need
# more than one set of global protocol-specific options.
# Note -- this is a base class for those who don't want the
# automatic handling of errors type 302 (relocated) and 401
# (authorization needed).
ftpcache = {}
class URLopener:

	__tempfiles = []

	# Constructor
	def __init__(self, proxies=None):
		if proxies is None:
			proxies = getproxies()
		self.proxies = proxies
		server_version = "Python-urllib/%s" % __version__
		self.addheaders = [('User-agent', server_version)]
		self.__tempfiles = []
		self.tempcache = None
		# Undocumented feature: if you assign {} to tempcache,
		# it is used to cache files retrieved with
		# self.retrieve().  This is not enabled by default
		# since it does not work for changing documents (and I
		# haven't got the logic to check expiration headers
		# yet).
		self.ftpcache = ftpcache
		# Undocumented feature: you can use a different
		# ftp cache by assigning to the .ftpcache member;
		# in case you want logically independent URL openers

	def __del__(self):
		self.close()

	def close(self):
		self.cleanup()

	def cleanup(self):
		if self.__tempfiles:
			import os
			for file in self.__tempfiles:
				try:
					os.unlink(file)
				except os.error:
					pass
		URLopener.__tempfiles = []
		self.tempcache = None

	# Add a header to be used by the HTTP interface only
	# e.g. u.addheader('Accept', 'sound/basic')
	def addheader(self, *args):
		self.addheaders.append(args)

	# External interface
	# Use URLopener().open(file) instead of open(file, 'r')
	def open(self, fullurl, data=None):
		fullurl = unwrap(fullurl)
		type, url = splittype(fullurl)
 		if not type: type = 'file'
		self.openedurl = '%s:%s' % (type, url)
		if self.proxies.has_key(type):
			proxy = self.proxies[type]
			type, proxy = splittype(proxy)
			host, selector = splithost(proxy)
			url = (host, fullurl) # Signal special case to open_*()
		name = 'open_' + type
		if '-' in name:
		        # replace - with _
			name = string.join(string.split(name, '-'), '_')
		if not hasattr(self, name):
			if data is None:
				return self.open_unknown(fullurl)
			else:
				return self.open_unknown(fullurl, data)
		try:
			if data is None:
				return getattr(self, name)(url)
			else:
				return getattr(self, name)(url, data)
		except socket.error, msg:
			raise IOError, ('socket error', msg), sys.exc_info()[2]

	# Overridable interface to open unknown URL type
	def open_unknown(self, fullurl, data=None):
		type, url = splittype(fullurl)
		raise IOError, ('url error', 'unknown url type', type)

	# External interface
	# retrieve(url) returns (filename, None) for a local object
	# or (tempfilename, headers) for a remote object
	def retrieve(self, url, filename=None):
		if self.tempcache and self.tempcache.has_key(url):
			return self.tempcache[url]
		url1 = unwrap(url)
		self.openedurl = url1
		if self.tempcache and self.tempcache.has_key(url1):
			self.tempcache[url] = self.tempcache[url1]
			return self.tempcache[url1]
		type, url1 = splittype(url1)
		if not filename and (not type or type == 'file'):
			try:
				fp = self.open_local_file(url1)
				del fp
				return url2pathname(splithost(url1)[1]), None
			except IOError, msg:
				pass
		fp = self.open(url)
		headers = fp.info()
		if not filename:
		    import tempfile
		    filename = tempfile.mktemp()
		    self.__tempfiles.append(filename)
		result = filename, headers
		if self.tempcache is not None:
			self.tempcache[url] = result
		tfp = open(filename, 'wb')
		bs = 1024*8
		block = fp.read(bs)
		while block:
			tfp.write(block)
			block = fp.read(bs)
		fp.close()
		tfp.close()
		del fp
		del tfp
		return result

	# Each method named open_<type> knows how to open that type of URL

	# Use HTTP protocol
	def open_http(self, url, data=None):
		import httplib
		if type(url) is type(""):
			host, selector = splithost(url)
			user_passwd, host = splituser(host)
			realhost = host
		else:
			host, selector = url
			urltype, rest = splittype(selector)
			user_passwd = None
			if string.lower(urltype) != 'http':
			    realhost = None
			else:
			    realhost, rest = splithost(rest)
			    user_passwd, realhost = splituser(realhost)
			    if user_passwd:
				selector = "%s://%s%s" % (urltype,
							  realhost, rest)
			#print "proxy via http:", host, selector
		if not host: raise IOError, ('http error', 'no host given')
		if user_passwd:
			import base64
			auth = string.strip(base64.encodestring(user_passwd))
		else:
			auth = None
		h = httplib.HTTP(host)
		if data is not None:
			h.putrequest('POST', selector)
			h.putheader('Content-type',
				    'application/x-www-form-urlencoded')
			h.putheader('Content-length', '%d' % len(data))
		else:
			h.putrequest('GET', selector)
		if auth: h.putheader('Authorization', 'Basic %s' % auth)
		if realhost: h.putheader('Host', realhost)
		for args in self.addheaders: apply(h.putheader, args)
		h.endheaders()
		if data is not None:
			h.send(data + '\r\n')
		errcode, errmsg, headers = h.getreply()
		fp = h.getfile()
		if errcode == 200:
			return addinfourl(fp, headers, self.openedurl)
		else:
			return self.http_error(url,
					       fp, errcode, errmsg, headers)

	# Handle http errors.
	# Derived class can override this, or provide specific handlers
	# named http_error_DDD where DDD is the 3-digit error code
	def http_error(self, url, fp, errcode, errmsg, headers):
		# First check if there's a specific handler for this error
		name = 'http_error_%d' % errcode
		if hasattr(self, name):
			method = getattr(self, name)
			result = method(url, fp, errcode, errmsg, headers)
			if result: return result
		return self.http_error_default(
			url, fp, errcode, errmsg, headers)

	# Default http error handler: close the connection and raises IOError
	def http_error_default(self, url, fp, errcode, errmsg, headers):
		void = fp.read()
		fp.close()
		raise IOError, ('http error', errcode, errmsg, headers)

	# Use Gopher protocol
	def open_gopher(self, url):
		import gopherlib
		host, selector = splithost(url)
		if not host: raise IOError, ('gopher error', 'no host given')
		type, selector = splitgophertype(selector)
		selector, query = splitquery(selector)
		selector = unquote(selector)
		if query:
			query = unquote(query)
			fp = gopherlib.send_query(selector, query, host)
		else:
			fp = gopherlib.send_selector(selector, host)
		return addinfourl(fp, noheaders(), self.openedurl)

	# Use local file or FTP depending on form of URL
	def open_file(self, url):
	    if url[:2] == '//' and url[2:3] != '/':
		return self.open_ftp(url)
	    else:
		return self.open_local_file(url)

	# Use local file
	def open_local_file(self, url):
		host, file = splithost(url)
		if not host:
			return addinfourl(
				open(url2pathname(file), 'rb'),
				noheaders(), 'file:'+file)
		host, port = splitport(host)
		if not port and socket.gethostbyname(host) in (
			  localhost(), thishost()):
			file = unquote(file)
			return addinfourl(
				open(url2pathname(file), 'rb'),
				noheaders(), 'file:'+file)
		raise IOError, ('local file error', 'not on local host')

	# Use FTP protocol
	def open_ftp(self, url):
		host, path = splithost(url)
		if not host: raise IOError, ('ftp error', 'no host given')
		host, port = splitport(host)
		user, host = splituser(host)
		if user: user, passwd = splitpasswd(user)
		else: passwd = None
		host = socket.gethostbyname(host)
		if not port:
			import ftplib
			port = ftplib.FTP_PORT
		path, attrs = splitattr(path)
		dirs = string.splitfields(path, '/')
		dirs, file = dirs[:-1], dirs[-1]
		if dirs and not dirs[0]: dirs = dirs[1:]
		key = (user, host, port, string.joinfields(dirs, '/'))
		if len(self.ftpcache) > MAXFTPCACHE:
			# Prune the cache, rather arbitrarily
			for k in self.ftpcache.keys():
				if k != key:
					v = self.ftpcache[k]
					del self.ftpcache[k]
					v.close()
		try:
			if not self.ftpcache.has_key(key):
				self.ftpcache[key] = \
						   ftpwrapper(user, passwd,
							      host, port, dirs)
			if not file: type = 'D'
			else: type = 'I'
			for attr in attrs:
				attr, value = splitvalue(attr)
				if string.lower(attr) == 'type' and \
				   value in ('a', 'A', 'i', 'I', 'd', 'D'):
					type = string.upper(value)
			return addinfourl(
				self.ftpcache[key].retrfile(file, type),
				noheaders(), self.openedurl)
		except ftperrors(), msg:
			raise IOError, ('ftp error', msg), sys.exc_info()[2]


# Derived class with handlers for errors we can handle (perhaps)
class FancyURLopener(URLopener):

	def __init__(self, *args):
		apply(URLopener.__init__, (self,) + args)
		self.auth_cache = {}

	# Default error handling -- don't raise an exception
	def http_error_default(self, url, fp, errcode, errmsg, headers):
	    return addinfourl(fp, headers, self.openedurl)

	# Error 302 -- relocated (temporarily)
	def http_error_302(self, url, fp, errcode, errmsg, headers):
		# XXX The server can force infinite recursion here!
		if headers.has_key('location'):
			newurl = headers['location']
		elif headers.has_key('uri'):
			newurl = headers['uri']
		else:
			return
		void = fp.read()
		fp.close()
		return self.open(newurl)

	# Error 301 -- also relocated (permanently)
	http_error_301 = http_error_302

	# Error 401 -- authentication required
	# See this URL for a description of the basic authentication scheme:
	# http://www.ics.uci.edu/pub/ietf/http/draft-ietf-http-v10-spec-00.txt
	def http_error_401(self, url, fp, errcode, errmsg, headers):
		if headers.has_key('www-authenticate'):
			stuff = headers['www-authenticate']
			import re
			match = re.match(
			    '[ \t]*([^ \t]+)[ \t]+realm="([^"]*)"', stuff)
			if match:
			        scheme, realm = match.group()
				if string.lower(scheme) == 'basic':
					return self.retry_http_basic_auth(
						url, realm)

	def retry_http_basic_auth(self, url, realm):
		host, selector = splithost(url)
		i = string.find(host, '@') + 1
		host = host[i:]
		user, passwd = self.get_user_passwd(host, realm, i)
		if not (user or passwd): return None
		host = user + ':' + passwd + '@' + host
		newurl = '//' + host + selector
		return self.open_http(newurl)

	def get_user_passwd(self, host, realm, clear_cache = 0):
		key = realm + '@' + string.lower(host)
		if self.auth_cache.has_key(key):
			if clear_cache:
				del self.auth_cache[key]
			else:
				return self.auth_cache[key]
		user, passwd = self.prompt_user_passwd(host, realm)
		if user or passwd: self.auth_cache[key] = (user, passwd)
		return user, passwd

	def prompt_user_passwd(self, host, realm):
		# Override this in a GUI environment!
		try:
			user = raw_input("Enter username for %s at %s: " %
					 (realm, host))
			self.echo_off()
			try:
				passwd = raw_input(
				  "Enter password for %s in %s at %s: " %
				  (user, realm, host))
			finally:
				self.echo_on()
			return user, passwd
		except KeyboardInterrupt:
			return None, None

	def echo_off(self):
		import os
		os.system("stty -echo")

	def echo_on(self):
		import os
		print
		os.system("stty echo")


# Utility functions

# Return the IP address of the magic hostname 'localhost'
_localhost = None
def localhost():
	global _localhost
	if not _localhost:
		_localhost = socket.gethostbyname('localhost')
	return _localhost

# Return the IP address of the current host
_thishost = None
def thishost():
	global _thishost
	if not _thishost:
		_thishost = socket.gethostbyname(socket.gethostname())
	return _thishost

# Return the set of errors raised by the FTP class
_ftperrors = None
def ftperrors():
	global _ftperrors
	if not _ftperrors:
		import ftplib
		_ftperrors = ftplib.all_errors
	return _ftperrors

# Return an empty mimetools.Message object
_noheaders = None
def noheaders():
	global _noheaders
	if not _noheaders:
		import mimetools
		import StringIO
		_noheaders = mimetools.Message(StringIO.StringIO(), 0)
		_noheaders.fp.close()	# Recycle file descriptor
	return _noheaders


# Utility classes

# Class used by open_ftp() for cache of open FTP connections
class ftpwrapper:
	def __init__(self, user, passwd, host, port, dirs):
		self.user = unquote(user or '')
		self.passwd = unquote(passwd or '')
		self.host = host
		self.port = port
		self.dirs = []
		for dir in dirs:
			self.dirs.append(unquote(dir))
		self.init()
	def init(self):
		import ftplib
		self.ftp = ftplib.FTP()
		self.ftp.connect(self.host, self.port)
		self.ftp.login(self.user, self.passwd)
		for dir in self.dirs:
			self.ftp.cwd(dir)
	def retrfile(self, file, type):
		import ftplib
		if type in ('d', 'D'): cmd = 'TYPE A'; isdir = 1
		else: cmd = 'TYPE ' + type; isdir = 0
		try:
			self.ftp.voidcmd(cmd)
		except ftplib.all_errors:
			self.init()
			self.ftp.voidcmd(cmd)
		conn = None
		if file and not isdir:
			try:
				cmd = 'RETR ' + file
				conn = self.ftp.transfercmd(cmd)
			except ftplib.error_perm, reason:
				if reason[:3] != '550':
					raise IOError, ('ftp error', reason), \
					      sys.exc_info()[2]
		if not conn:
			# Try a directory listing
			if file: cmd = 'LIST ' + file
			else: cmd = 'LIST'
			conn = self.ftp.transfercmd(cmd)
		return addclosehook(conn.makefile('rb'), self.endtransfer)
	def endtransfer(self):
		try:
			self.ftp.voidresp()
		except ftperrors():
			pass
	def close(self):
		try:
			self.ftp.close()
		except ftperrors():
			pass

# Base class for addinfo and addclosehook
class addbase:
	def __init__(self, fp):
		self.fp = fp
		self.read = self.fp.read
		self.readline = self.fp.readline
		self.readlines = self.fp.readlines
		self.fileno = self.fp.fileno
	def __repr__(self):
		return '<%s at %s whose fp = %s>' % (
			  self.__class__.__name__, `id(self)`, `self.fp`)
	def close(self):
		self.read = None
		self.readline = None
		self.readlines = None
		self.fileno = None
		if self.fp: self.fp.close()
		self.fp = None

# Class to add a close hook to an open file
class addclosehook(addbase):
	def __init__(self, fp, closehook, *hookargs):
		addbase.__init__(self, fp)
		self.closehook = closehook
		self.hookargs = hookargs
	def close(self):
		if self.closehook:
			apply(self.closehook, self.hookargs)
			self.closehook = None
			self.hookargs = None
		addbase.close(self)

# class to add an info() method to an open file
class addinfo(addbase):
	def __init__(self, fp, headers):
		addbase.__init__(self, fp)
		self.headers = headers
	def info(self):
		return self.headers

# class to add info() and geturl() methods to an open file
class addinfourl(addbase):
	def __init__(self, fp, headers, url):
		addbase.__init__(self, fp)
		self.headers = headers
		self.url = url
	def info(self):
		return self.headers
	def geturl(self):
		return self.url


# Utility to combine a URL with a base URL to form a new URL

def basejoin(base, url):
	type, path = splittype(url)
	if type:
		# if url is complete (i.e., it contains a type), return it
		return url
	host, path = splithost(path)
	type, basepath = splittype(base) # inherit type from base
	if host:
		# if url contains host, just inherit type
		if type: return type + '://' + host + path
		else:
			# no type inherited, so url must have started with //
			# just return it
			return url
	host, basepath = splithost(basepath) # inherit host
	basepath, basetag = splittag(basepath) # remove extraneuous cruft
	basepath, basequery = splitquery(basepath) # idem
	if path[:1] != '/':
		# non-absolute path name
		if path[:1] in ('#', '?'):
			# path is just a tag or query, attach to basepath
			i = len(basepath)
		else:
			# else replace last component
			i = string.rfind(basepath, '/')
		if i < 0:
			# basepath not absolute
			if host:
				# host present, make absolute
				basepath = '/'
			else:
				# else keep non-absolute
				basepath = ''
		else:
			# remove last file component
			basepath = basepath[:i+1]
		# Interpret ../ (important because of symlinks)
		while basepath and path[:3] == '../':
			path = path[3:]
			i = string.rfind(basepath[:-1], '/')
			if i > 0:
				basepath = basepath[:i+1]
			elif i == 0:
				basepath = '/'
				break
			else:
				basepath = ''
			
		path = basepath + path
	if type and host: return type + '://' + host + path
	elif type: return type + ':' + path
	elif host: return '//' + host + path # don't know what this means
	else: return path


# Utilities to parse URLs (most of these return None for missing parts):
# unwrap('<URL:type://host/path>') --> 'type://host/path'
# splittype('type:opaquestring') --> 'type', 'opaquestring'
# splithost('//host[:port]/path') --> 'host[:port]', '/path'
# splituser('user[:passwd]@host[:port]') --> 'user[:passwd]', 'host[:port]'
# splitpasswd('user:passwd') -> 'user', 'passwd'
# splitport('host:port') --> 'host', 'port'
# splitquery('/path?query') --> '/path', 'query'
# splittag('/path#tag') --> '/path', 'tag'
# splitattr('/path;attr1=value1;attr2=value2;...') ->
#   '/path', ['attr1=value1', 'attr2=value2', ...]
# splitvalue('attr=value') --> 'attr', 'value'
# splitgophertype('/Xselector') --> 'X', 'selector'
# unquote('abc%20def') -> 'abc def'
# quote('abc def') -> 'abc%20def')

def unwrap(url):
	url = string.strip(url)
	if url[:1] == '<' and url[-1:] == '>':
		url = string.strip(url[1:-1])
	if url[:4] == 'URL:': url = string.strip(url[4:])
	return url

_typeprog = None
def splittype(url):
	global _typeprog
	if _typeprog is None:
	    import re
	    _typeprog = re.compile('^([^/:]+):')

        match = _typeprog.match(url)
	if match:
		scheme = match.group(1)
		return scheme, url[len(scheme) + 1:]
	return None, url

_hostprog = None
def splithost(url):
	global _hostprog
	if _hostprog is None:
	    import re
	    _hostprog = re.compile('^//([^/]+)(.*)$')

        match = _hostprog.match(url) 
	if match: return match.group(1, 2)
	return None, url

_userprog = None
def splituser(host):
	global _userprog
	if _userprog is None:
	    import re
	    _userprog = re.compile('^([^@]*)@(.*)$')

        match = _userprog.match(host)
	if match: return match.group(1, 2)
	return None, host

_passwdprog = None
def splitpasswd(user):
	global _passwdprog
	if _passwdprog is None:
	    import re
	    _passwdprog = re.compile('^([^:]*):(.*)$')

        match = _passwdprog.match(user)
	if match: return match.group(1, 2)
	return user, None

_portprog = None
def splitport(host):
	global _portprog
	if _portprog is None:
	    import re
	    _portprog = re.compile('^(.*):([0-9]+)$')

        match = _portprog.match(host)
	if match: return match.group(1, 2)
	return host, None

# Split host and port, returning numeric port.
# Return given default port if no ':' found; defaults to -1.
# Return numerical port if a valid number are found after ':'.
# Return None if ':' but not a valid number.
_nportprog = None
def splitnport(host, defport=-1):
	global _nportprog
	if _nportprog is None:
	    import re
	    _nportprog = re.compile('^(.*):(.*)$')
	    
        match = _nportprog.match(host)
	if match:
	    host, port = match.group(1, 2)
	    try:
		if not port: raise string.atoi_error, "no digits"
		nport = string.atoi(port)
	    except string.atoi_error:
		nport = None
	    return host, nport
	return host, defport

_queryprog = None
def splitquery(url):
	global _queryprog
	if _queryprog is None:
	    import re
	    _queryprog = re.compile('^(.*)\?([^?]*)$')

        match = _queryprog.match(url)
	if match: return match.group(1, 2)
	return url, None

_tagprog = None
def splittag(url):
	global _tagprog
	if _tagprog is None:
	    import re
	    _tagprog = re.compile('^(.*)#([^#]*)$')
	    
        match = _tagprog.match(url)
	if match: return match.group(1, 2)
	return url, None

def splitattr(url):
	words = string.splitfields(url, ';')
	return words[0], words[1:]

_valueprog = None
def splitvalue(attr):
	global _valueprog
	if _valueprog is None:
	    import re
	    _valueprog = re.compile('^([^=]*)=(.*)$')

        match = _valueprog.match(attr)
	if match: return match.group(1, 2)
	return attr, None

def splitgophertype(selector):
	if selector[:1] == '/' and selector[1:2]:
		return selector[1], selector[2:]
	return None, selector

_quoteprog = None
def unquote(s):
	global _quoteprog
	if _quoteprog is None:
	    import re
	    _quoteprog = re.compile('%[0-9a-fA-F][0-9a-fA-F]')
	    
	i = 0
	n = len(s)
	res = []
	while 0 <= i < n:
		match = _quoteprog.search(s, i)
		if not match:
			res.append(s[i:])
			break
		j = match.start(0)
		res.append(s[i:j] + chr(string.atoi(s[j+1:j+3], 16)))
		i = j+3
	return string.joinfields(res, '')

def unquote_plus(s):
    if '+' in s:
	# replace '+' with ' '
	s = string.join(string.split(s, '+'), ' ')
    return unquote(s)

always_safe = string.letters + string.digits + '_,.-'
def quote(s, safe = '/'):
	safe = always_safe + safe
	res = []
	for c in s:
		if c in safe:
			res.append(c)
		else:
			res.append('%%%02x' % ord(c))
	return string.joinfields(res, '')

def quote_plus(s, safe = '/'):
    if ' ' in s:
	# replace ' ' with '+'
	s = string.join(string.split(s, ' '), '+')
	return quote(s, safe + '+')
    else:
	return quote(s, safe)


# Proxy handling
def getproxies():
	"""Return a dictionary of protocol scheme -> proxy server URL mappings.

	Scan the environment for variables named <scheme>_proxy;
	this seems to be the standard convention.  If you need a
	different way, you can pass a proxies dictionary to the
	[Fancy]URLopener constructor.

	"""
	proxies = {}
	for name, value in os.environ.items():
		name = string.lower(name)
		if value and name[-6:] == '_proxy':
			proxies[name[:-6]] = value
	return proxies


# Test and time quote() and unquote()
def test1():
	import time
	s = ''
	for i in range(256): s = s + chr(i)
	s = s*4
	t0 = time.time()
	qs = quote(s)
	uqs = unquote(qs)
	t1 = time.time()
	if uqs != s:
		print 'Wrong!'
	print `s`
	print `qs`
	print `uqs`
	print round(t1 - t0, 3), 'sec'


# Test program
def test():
	import sys
	args = sys.argv[1:]
	if not args:
		args = [
			'/etc/passwd',
			'file:/etc/passwd',
			'file://localhost/etc/passwd',
			'ftp://ftp.python.org/etc/passwd',
			'gopher://gopher.micro.umn.edu/1/',
			'http://www.python.org/index.html',
			]
	try:
		for url in args:
			print '-'*10, url, '-'*10
			fn, h = urlretrieve(url)
			print fn, h
			if h:
				print '======'
				for k in h.keys(): print k + ':', h[k]
				print '======'
			fp = open(fn, 'rb')
			data = fp.read()
			del fp
			if '\r' in data:
			    table = string.maketrans("", "")
			    data = string.translate(data, table, "\r")
			print data
			fn, h = None, None
		print '-'*40
	finally:
		urlcleanup()

# Run test program when run as a script
if __name__ == '__main__':
	test1()
	test()