Lib/gopherlib.py

   1 """Gopher protocol client interface."""
   2
   3 __all__ = ["send_selector","send_query"]
   4
   5 import warnings
   6 warnings.warn("the gopherlib module is deprecated", DeprecationWarning,
   7               stacklevel=2)
   8
   9 # Default selector, host and port
  10 DEF_SELECTOR = '1/'
  11 DEF_HOST     = 'gopher.micro.umn.edu'
  12 DEF_PORT     = 70
  13
  14 # Recognized file types
  15 A_TEXT       = '0'
  16 A_MENU       = '1'
  17 A_CSO        = '2'
  18 A_ERROR      = '3'
  19 A_MACBINHEX  = '4'
  20 A_PCBINHEX   = '5'
  21 A_UUENCODED  = '6'
  22 A_INDEX      = '7'
  23 A_TELNET     = '8'
  24 A_BINARY     = '9'
  25 A_DUPLICATE  = '+'
  26 A_SOUND      = 's'
  27 A_EVENT      = 'e'
  28 A_CALENDAR   = 'c'
  29 A_HTML       = 'h'
  30 A_TN3270     = 'T'
  31 A_MIME       = 'M'
  32 A_IMAGE      = 'I'
  33 A_WHOIS      = 'w'
  34 A_QUERY      = 'q'
  35 A_GIF        = 'g'
  36 A_HTML       = 'h'          # HTML file
  37 A_WWW        = 'w'          # WWW address
  38 A_PLUS_IMAGE = ':'
  39 A_PLUS_MOVIE = ';'
  40 A_PLUS_SOUND = '<'
  41
  42
  43 _names = dir()
  44 _type_to_name_map = {}
  45 def type_to_name(gtype):
  46     """Map all file types to strings; unknown types become TYPE='x'."""
  47     global _type_to_name_map
  48     if _type_to_name_map=={}:
  49         for name in _names:
  50             if name[:2] == 'A_':
  51                 _type_to_name_map[eval(name)] = name[2:]
  52     if gtype in _type_to_name_map:
  53         return _type_to_name_map[gtype]
  54     return 'TYPE=%r' % (gtype,)
  55
  56 # Names for characters and strings
  57 CRLF = '\r\n'
  58 TAB = '\t'
  59
  60 def send_selector(selector, host, port = 0):
  61     """Send a selector to a given host and port, return a file with the reply."""
  62     import socket
  63     if not port:
  64         i = host.find(':')
  65         if i >= 0:
  66             host, port = host[:i], int(host[i+1:])
  67     if not port:
  68         port = DEF_PORT
  69     elif type(port) == type(''):
  70         port = int(port)
  71     s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
  72     s.connect((host, port))
  73     s.sendall(selector + CRLF)
  74     s.shutdown(1)
  75     return s.makefile('rb')
  76
  77 def send_query(selector, query, host, port = 0):
  78     """Send a selector and a query string."""
  79     return send_selector(selector + '\t' + query, host, port)
  80
  81 def path_to_selector(path):
  82     """Takes a path as returned by urlparse and returns the appropriate selector."""
  83     if path=="/":
  84         return "/"
  85     else:
  86         return path[2:] # Cuts initial slash and data type identifier
  87
  88 def path_to_datatype_name(path):
  89     """Takes a path as returned by urlparse and maps it to a string.
  90     See section 3.4 of RFC 1738 for details."""
  91     if path=="/":
  92         # No way to tell, although "INDEX" is likely
  93         return "TYPE='unknown'"
  94     else:
  95         return type_to_name(path[1])
  96
  97 # The following functions interpret the data returned by the gopher
  98 # server according to the expected type, e.g. textfile or directory
  99
 100 def get_directory(f):
 101     """Get a directory in the form of a list of entries."""
 102     entries = []
 103     while 1:
 104         line = f.readline()
 105         if not line:
 106             print '(Unexpected EOF from server)'
 107             break
 108         if line[-2:] == CRLF:
 109             line = line[:-2]
 110         elif line[-1:] in CRLF:
 111             line = line[:-1]
 112         if line == '.':
 113             break
 114         if not line:
 115             print '(Empty line from server)'
 116             continue
 117         gtype = line[0]
 118         parts = line[1:].split(TAB)
 119         if len(parts) < 4:
 120             print '(Bad line from server: %r)' % (line,)
 121             continue
 122         if len(parts) > 4:
 123             if parts[4:] != ['+']:
 124                 print '(Extra info from server:',
 125                 print parts[4:], ')'
 126         else:
 127             parts.append('')
 128         parts.insert(0, gtype)
 129         entries.append(parts)
 130     return entries
 131
 132 def get_textfile(f):
 133     """Get a text file as a list of lines, with trailing CRLF stripped."""
 134     lines = []
 135     get_alt_textfile(f, lines.append)
 136     return lines
 137
 138 def get_alt_textfile(f, func):
 139     """Get a text file and pass each line to a function, with trailing CRLF stripped."""
 140     while 1:
 141         line = f.readline()
 142         if not line:
 143             print '(Unexpected EOF from server)'
 144             break
 145         if line[-2:] == CRLF:
 146             line = line[:-2]
 147         elif line[-1:] in CRLF:
 148             line = line[:-1]
 149         if line == '.':
 150             break
 151         if line[:2] == '..':
 152             line = line[1:]
 153         func(line)
 154
 155 def get_binary(f):
 156     """Get a binary file as one solid data block."""
 157     data = f.read()
 158     return data
 159
 160 def get_alt_binary(f, func, blocksize):
 161     """Get a binary file and pass each block to a function."""
 162     while 1:
 163         data = f.read(blocksize)
 164         if not data:
 165             break
 166         func(data)
 167
 168 def test():
 169     """Trivial test program."""
 170     import sys
 171     import getopt
 172     opts, args = getopt.getopt(sys.argv[1:], '')
 173     selector = DEF_SELECTOR
 174     type = selector[0]
 175     host = DEF_HOST
 176     if args:
 177         host = args[0]
 178         args = args[1:]
 179     if args:
 180         type = args[0]
 181         args = args[1:]
 182         if len(type) > 1:
 183             type, selector = type[0], type
 184         else:
 185             selector = ''
 186             if args:
 187                 selector = args[0]
 188                 args = args[1:]
 189         query = ''
 190         if args:
 191             query = args[0]
 192             args = args[1:]
 193     if type == A_INDEX:
 194         f = send_query(selector, query, host)
 195     else:
 196         f = send_selector(selector, host)
 197     if type == A_TEXT:
 198         lines = get_textfile(f)
 199         for item in lines: print item
 200     elif type in (A_MENU, A_INDEX):
 201         entries = get_directory(f)
 202         for item in entries: print item
 203     else:
 204         data = get_binary(f)
 205         print 'binary data:', len(data), 'bytes:', repr(data[:100])[:40]
 206
 207 # Run the test when run as script
 208 if __name__ == '__main__':
 209     test()