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
|
# 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 = {}
def type_to_name(gtype):
global _type_to_name_map
if _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, port = 0):
import socket
import string
if not port:
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('rb')
# Send a selector and a query string
def send_query(selector, query, host, port = 0):
return send_selector(selector + '\t' + query, host, port)
# Takes a path as returned by urlparse and returns the appropriate selector
def path_to_selector(path):
if path=="/":
return "/"
else:
return path[2:] # Cuts initial slash and data type identifier
# Takes a path as returned by urlparse and maps it to a string
# See section 3.4 of RFC 1738 for details
def path_to_datatype_name(path):
if path=="/":
# No way to tell, although "INDEX" is likely
return "TYPE='unknown'"
else:
return type_to_name(path[1])
# 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:',
print 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()
|
