Towards a standard access mechanism for URLs.
diff --git a/Lib/gopherlib.py b/Lib/gopherlib.py
new file mode 100644
index 0000000..71413ba
--- /dev/null
+++ b/Lib/gopherlib.py
@@ -0,0 +1,195 @@
+# Gopher protocol client interface
+
+import string
+
+# Default selector, host and port
+DEF_SELECTOR = '1/'
+DEF_HOST = 'gopher.micro.umn.edu'
+DEF_PORT = 70
+
+# Recognized file types
+A_TEXT = '0'
+A_MENU = '1'
+A_CSO = '2'
+A_ERROR = '3'
+A_MACBINHEX = '4'
+A_PCBINHEX = '5'
+A_UUENCODED = '6'
+A_INDEX = '7'
+A_TELNET = '8'
+A_BINARY = '9'
+A_DUPLICATE = '+'
+A_SOUND = 's'
+A_EVENT = 'e'
+A_CALENDAR = 'c'
+A_HTML = 'h'
+A_TN3270 = 'T'
+A_MIME = 'M'
+A_IMAGE = 'I'
+A_WHOIS = 'w'
+A_QUERY = 'q'
+A_GIF = 'g'
+A_HTML = 'h' # HTML file
+A_WWW = 'w' # WWW address
+A_PLUS_IMAGE = ':'
+A_PLUS_MOVIE = ';'
+A_PLUS_SOUND = '<'
+
+
+# Function mapping all file types to strings; unknown types become TYPE='x'
+_names = dir()
+_type_to_name_map = None
+def type_to_name(gtype):
+ global _type_to_name_map
+ if not _type_to_name_map:
+ for name in _names:
+ if name[:2] == 'A_':
+ _type_to_name_map[eval(name)] = name[2:]
+ if _type_to_name_map.has_key(gtype):
+ return _type_to_name_map[gtype]
+ return 'TYPE=' + `gtype`
+
+# Names for characters and strings
+CRLF = '\r\n'
+TAB = '\t'
+
+# Send a selector to a given host and port, return a file with the reply
+def send_selector(selector, host, *args):
+ import socket
+ import string
+ if args:
+ if args[1:]: raise TypeError, 'too many args'
+ port = args[0]
+ else:
+ port = None
+ i = string.find(host, ':')
+ if i >= 0:
+ host, port = host[:i], string.atoi(host[i+1:])
+ if not port:
+ port = DEF_PORT
+ elif type(port) == type(''):
+ port = string.atoi(port)
+ s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+ s.connect(host, port)
+ s.send(selector + CRLF)
+ s.shutdown(1)
+ return s.makefile('r')
+
+# Send a selector and a query string
+def send_query(selector, query, host, *args):
+ return apply(send_selector, (selector + '\t' + query, host) + args)
+
+# The following functions interpret the data returned by the gopher
+# server according to the expected type, e.g. textfile or directory
+
+# Get a directory in the form of a list of entries
+def get_directory(f):
+ import string
+ list = []
+ while 1:
+ line = f.readline()
+ if not line:
+ print '(Unexpected EOF from server)'
+ break
+ if line[-2:] == CRLF:
+ line = line[:-2]
+ elif line[-1:] in CRLF:
+ line = line[:-1]
+ if line == '.':
+ break
+ if not line:
+ print '(Empty line from server)'
+ continue
+ gtype = line[0]
+ parts = string.splitfields(line[1:], TAB)
+ if len(parts) < 4:
+ print '(Bad line from server:', `line`, ')'
+ continue
+ if len(parts) > 4:
+ if parts[4:] != ['+']:
+ print '(Extra info from server:', parts[4:], ')'
+ else:
+ parts.append('')
+ parts.insert(0, gtype)
+ list.append(parts)
+ return list
+
+# Get a text file as a list of lines, with trailing CRLF stripped
+def get_textfile(f):
+ list = []
+ get_alt_textfile(f, list.append)
+ return list
+
+# Get a text file and pass each line to a function, with trailing CRLF stripped
+def get_alt_textfile(f, func):
+ while 1:
+ line = f.readline()
+ if not line:
+ print '(Unexpected EOF from server)'
+ break
+ if line[-2:] == CRLF:
+ line = line[:-2]
+ elif line[-1:] in CRLF:
+ line = line[:-1]
+ if line == '.':
+ break
+ if line[:2] == '..':
+ line = line[1:]
+ func(line)
+
+# Get a binary file as one solid data block
+def get_binary(f):
+ data = f.read()
+ return data
+
+# Get a binary file and pass each block to a function
+def get_alt_binary(f, func, blocksize):
+ while 1:
+ data = f.read(blocksize)
+ if not data:
+ break
+ func(data)
+
+# Trivial test program
+def test():
+ import sys
+ import getopt
+ opts, args = getopt.getopt(sys.argv[1:], '')
+ selector = DEF_SELECTOR
+ type = selector[0]
+ host = DEF_HOST
+ port = DEF_PORT
+ if args:
+ host = args[0]
+ args = args[1:]
+ if args:
+ type = args[0]
+ args = args[1:]
+ if len(type) > 1:
+ type, selector = type[0], type
+ else:
+ selector = ''
+ if args:
+ selector = args[0]
+ args = args[1:]
+ query = ''
+ if args:
+ query = args[0]
+ args = args[1:]
+ if type == A_INDEX:
+ f = send_query(selector, query, host)
+ else:
+ f = send_selector(selector, host)
+ if type == A_TEXT:
+ list = get_textfile(f)
+ for item in list: print item
+ elif type in (A_MENU, A_INDEX):
+ list = get_directory(f)
+ for item in list: print item
+ else:
+ data = get_binary(f)
+ print 'binary data:', len(data), 'bytes:', `data[:100]`[:40]
+
+# Run the test when run as script
+if __name__ == '__main__':
+ test()
diff --git a/Lib/httplib.py b/Lib/httplib.py
new file mode 100644
index 0000000..ea6e565
--- /dev/null
+++ b/Lib/httplib.py
@@ -0,0 +1,129 @@
+# HTTP client class
+#
+# See the following document for a tentative protocol description:
+# Hypertext Transfer Protocol (HTTP) Tim Berners-Lee, CERN
+# Internet Draft 5 Nov 1993
+# draft-ietf-iiir-http-00.txt Expires 5 May 1994
+#
+# Example:
+#
+# >>> from httplib import HTTP
+# >>> h = HTTP('www.cwi.nl')
+# >>> h.putreqest('GET', '/index.html')
+# >>> h.putheader('Accept', 'text/html')
+# >>> h.putheader('Accept', 'text/plain')
+# >>> errcode, errmsg, headers = h.getreply()
+# >>> if errcode == 200:
+# ... f = h.getfile()
+# ... print f.read() # Print the raw HTML
+# ...
+# <TITLE>Home Page of CWI, Amsterdam</TITLE>
+# [...many more lines...]
+# >>>
+#
+# Note that an HTTP object is used for a single request -- to issue a
+# second request to the same server, you create a new HTTP object.
+# (This is in accordance with the protocol, which uses a new TCP
+# connection for each request.)
+
+
+import os
+import socket
+import string
+import regex
+import regsub
+import rfc822
+
+HTTP_VERSION = 'HTTP/1.0'
+HTTP_PORT = 80
+
+replypat = regsub.gsub('\\.', '\\\\.', HTTP_VERSION) + \
+ '[ \t]+\([0-9][0-9][0-9]\)\(.*\)'
+replyprog = regex.compile(replypat)
+
+class HTTP:
+
+ def __init__(self, *args):
+ self.debuglevel = 0
+ if args: apply(self.connect, args)
+
+ def set_debuglevel(self, debuglevel):
+ self.debuglevel = debuglevel
+
+ def connect(self, host, *args):
+ if args:
+ if args[1:]: raise TypeError, 'too many args'
+ port = args[0]
+ else:
+ i = string.find(host, ':')
+ if i >= 0:
+ host, port = host[:i], host[i+1:]
+ try: port = string.atoi(port)
+ except string.atoi_error: port = None
+ if not port: port = HTTP_PORT
+ self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+ if self.debuglevel > 0: print 'connect:', (host, port)
+ self.sock.connect(host, port)
+
+ def send(self, str):
+ if self.debuglevel > 0: print 'send:', `str`
+ self.sock.send(str)
+
+ def putrequest(self, request, selector):
+ str = '%s %s %s\r\n' % (request, selector, HTTP_VERSION)
+ self.send(str)
+
+ def putheader(self, header, *args):
+ str = '%s: %s\r\n' % (header, string.joinfields(args,'\r\n\t'))
+ self.send(str)
+
+ def endheaders(self):
+ self.send('\r\n')
+
+ def endrequest(self):
+ if self.debuglevel > 0: print 'shutdown: 1'
+ self.sock.shutdown(1)
+
+ def getreply(self):
+ self.endrequest()
+ self.file = self.sock.makefile('r')
+ line = self.file.readline()
+ if self.debuglevel > 0: print 'reply:', `line`
+ if replyprog.match(line) < 0:
+ self.headers = None
+ return -1, line, self.headers
+ errcode, errmsg = replyprog.group(1, 2)
+ errcode = string.atoi(errcode)
+ errmsg = string.strip(errmsg)
+ self.headers = rfc822.Message(self.file)
+ return errcode, errmsg, self.headers
+
+ def getfile(self):
+ return self.file
+
+
+def test():
+ import sys
+ import getopt
+ opts, args = getopt.getopt(sys.argv[1:], 'd')
+ dl = 0
+ for o, a in opts:
+ if o == '-d': dl = dl + 1
+ host = 'www.cwi.nl:80'
+ selector = '/index.html'
+ if args[0:]: host = args[0]
+ if args[1:]: selector = args[1]
+ h = HTTP()
+ h.set_debuglevel(dl)
+ h.connect(host)
+ h.putrequest('GET', selector)
+ errcode, errmsg, headers = h.getreply()
+ print 'errcode =', errcode
+ print 'headers =', headers
+ print 'errmsg =', errmsg
+ if headers:
+ for header in headers.headers: print string.strip(header)
+ print h.getfile().read()
+
+if __name__ == '__main__':
+ test()
diff --git a/Lib/urlopen.py b/Lib/urlopen.py
new file mode 100755
index 0000000..c24b3f9
--- /dev/null
+++ b/Lib/urlopen.py
@@ -0,0 +1,222 @@
+# Open an arbitrary URL
+#
+# See the following document for a tentative description of URLs:
+# Uniform Resource Locators Tim Berners-Lee
+# INTERNET DRAFT CERN
+# IETF URL Working Group 14 July 1993
+# draft-ietf-uri-url-01.txt
+#
+# The object returned by urlopen() will differ per protocol.
+# All you know is that is has methods read(), fileno(), close() and info().
+# The read(), fileno() and close() methods work like those of open files.
+# The info() method returns an rfc822.Message object which can be
+# used to query various info about the object, if available.
+# (rfc822.Message objects are queried with the getheader() method.)
+
+import socket
+import regex
+import regsub
+import string
+import rfc822
+import ftplib
+
+
+# External interface -- use urlopen(file) as if it were open(file, 'r')
+def urlopen(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:])
+ type, url = splittype(url)
+ if not type: type = 'file'
+ type = regsub.gsub('-', '_', type)
+ try:
+ func = eval('open_' + type)
+ except NameError:
+ raise IOError, ('url error', 'unknown url type', type)
+ try:
+ return func(url)
+ except socket.error, msg:
+ raise IOError, ('socket error', msg)
+
+
+# Each routine of the form open_<type> knows how to open that type of URL
+
+# Use HTTP protocol
+def open_http(url):
+ import httplib
+ host, selector = splithost(url)
+ h = httplib.HTTP(host)
+ h.putrequest('GET', selector)
+ errcode, errmsg, headers = h.getreply()
+ if errcode == 200: return makefile(h.getfile(), headers)
+ else: raise IOError, ('http error', errcode, errmsg, headers)
+
+# Empty rfc822.Message object
+noheaders = rfc822.Message(open('/dev/null', 'r'))
+noheaders.fp.close() # Recycle file descriptor
+
+# Use Gopher protocol
+def open_gopher(url):
+ import gopherlib
+ host, selector = splithost(url)
+ type, selector = splitgophertype(selector)
+ selector, query = splitquery(selector)
+ if query: fp = gopherlib.send_query(selector, query, host)
+ else: fp = gopherlib.send_selector(selector, host)
+ return makefile(fp, noheaders)
+
+# Use local file or FTP depending on form of URL
+localhost = socket.gethostbyname('localhost')
+thishost = socket.gethostbyname(socket.gethostname())
+def open_file(url):
+ host, file = splithost(url)
+ if not host: return makefile(open(file, 'r'), noheaders)
+ host, port = splitport(host)
+ if not port and socket.gethostbyname(host) in (localhost, thishost):
+ try: fp = open(file, 'r')
+ except IOError: fp = None
+ if fp: return makefile(fp, noheaders)
+ return open_ftp(url)
+
+# Use FTP protocol
+ftpcache = {}
+ftperrors = (ftplib.error_reply,
+ ftplib.error_temp,
+ ftplib.error_perm,
+ ftplib.error_proto)
+def open_ftp(url):
+ host, file = splithost(url)
+ host, port = splitport(host)
+ host = socket.gethostbyname(host)
+ if not port: port = ftplib.FTP_PORT
+ key = (host, port)
+ try:
+ if not ftpcache.has_key(key):
+ ftpcache[key] = ftpwrapper(host, port)
+ return makefile(ftpcache[key].retrfile(file), noheaders)
+ except ftperrors, msg:
+ raise IOError, ('ftp error', msg)
+
+
+# Utility classes
+
+# Class used to add an info() method to a file object
+class makefile:
+ def __init__(self, fp, headers):
+ self.fp = fp
+ self.headers = headers
+ self.read = self.fp.read
+ self.fileno = self.fp.fileno
+ self.close = self.fp.close
+ def info(self):
+ return self.headers
+
+# Class used by open_ftp() for cache of open FTP connections
+class ftpwrapper:
+ def __init__(self, host, port):
+ self.host = host
+ self.port = port
+ self.init()
+ def init(self):
+ self.ftp = ftplib.FTP()
+ self.ftp.connect(self.host, self.port)
+ self.ftp.login()
+ def retrfile(self, file):
+ try:
+ self.ftp.voidcmd('TYPE I')
+ except ftplib.all_errors:
+ self.init()
+ self.ftp.voidcmd('TYPE I')
+ conn = None
+ if file:
+ try:
+ cmd = 'RETR ' + file
+ conn = self.ftp.transfercmd(cmd)
+ except ftplib.error_perm, reason:
+ if reason[:3] != '550':
+ raise IOError, ('ftp error', reason)
+ if not conn:
+ # Try a directory listing
+ if file: cmd = 'NLST ' + file
+ else: cmd = 'NLST'
+ conn = self.ftp.transfercmd(cmd)
+ return fakefile(self.ftp, conn)
+
+# Class used by ftpwrapper to handle response when transfer is complete
+class fakefile:
+ def __init__(self, ftp, conn):
+ self.ftp = ftp
+ self.conn = conn
+ self.fp = self.conn.makefile('r')
+ self.read = self.fp.read
+ self.fileno = self.fp.fileno
+ def __del__(self):
+ self.close()
+ def close(self):
+ self.conn = None
+ self.fp = None
+ self.read = None
+ if self.ftp: self.ftp.voidresp()
+ self.ftp = None
+
+
+# Utilities to split url parts into components:
+# splittype('type:opaquestring') --> 'type', 'opaquestring'
+# splithost('//host[:port]/path') --> 'host[:port]', '/path'
+# splitport('host:port') --> 'host', 'port'
+# splitquery('/path?query') --> '/path', 'query'
+# splittag('/path#tag') --> '/path', 'tag'
+# splitgophertype('/Xselector') --> 'X', 'selector'
+
+typeprog = regex.compile('^\([^/:]+\):\(.*\)$')
+def splittype(url):
+ if typeprog.match(url) >= 0: return typeprog.group(1, 2)
+ return None, url
+
+hostprog = regex.compile('^//\([^/]+\)\(.*\)$')
+def splithost(url):
+ if hostprog.match(url) >= 0: return hostprog.group(1, 2)
+ return None, url
+
+portprog = regex.compile('^\(.*\):\([0-9]+\)$')
+def splitport(host):
+ if portprog.match(host) >= 0: return portprog.group(1, 2)
+ return host, None
+
+queryprog = regex.compile('^\(.*\)\?\([^?]*\)$')
+def splitquery(url):
+ if queryprog.match(url) >= 0: return queryprog.group(1, 2)
+ return url, None
+
+tagprog = regex.compile('^\(.*\)#\([^#]*\)$')
+def splittag(url):
+ if tagprog.match(url) >= 0: return tagprog.group(1, 2)
+ return url, None
+
+def splitgophertype(selector):
+ if selector[:1] == '/' and selector[1:2]:
+ return selector[1], selector[2:]
+ return None, selector
+
+
+# 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.cwi.nl/etc/passwd',
+ 'gopher://gopher.cwi.nl/11/',
+ 'http://www.cwi.nl/index.html',
+ ]
+ for arg in args:
+ print '-'*10, arg, '-'*10
+ print regsub.gsub('\r', '', urlopen(arg).read())
+ print '-'*40
+
+# Run test program when run as a script
+if __name__ == '__main__':
+ test()