Initial revision
diff --git a/Demo/sockets/gopher.py b/Demo/sockets/gopher.py
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+++ b/Demo/sockets/gopher.py
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+#! /usr/local/bin/python
+
+# A simple gopher client.
+#
+# Usage: gopher [ [selector] host [port] ]
+
+import string
+import sys
+import os
+import socket
+
+# Default selector, host and port
+DEF_SELECTOR = ''
+DEF_HOST = 'gopher.micro.umn.edu'
+DEF_PORT = 70
+
+# Recognized file types
+T_TEXTFILE = '0'
+T_MENU = '1'
+T_CSO = '2'
+T_ERROR = '3'
+T_BINHEX = '4'
+T_DOS = '5'
+T_UUENCODE = '6'
+T_SEARCH = '7'
+T_TELNET = '8'
+T_BINARY = '9'
+T_REDUNDANT = '+'
+T_SOUND = 's'
+
+# Dictionary mapping types to strings
+typename = {'0': '<TEXT>', '1': '<DIR>', '2': '<CSO>', '3': '<ERROR>', \
+ '4': '<BINHEX>', '5': '<DOS>', '6': '<UUENCODE>', '7': '<SEARCH>', \
+ '8': '<TELNET>', '9': '<BINARY>', '+': '<REDUNDANT>', 's': '<SOUND>'}
+
+# Oft-used characters and strings
+CRLF = '\r\n'
+TAB = '\t'
+
+# Open a TCP connection to a given host and port
+def open_socket(host, port):
+ if type(port) == type(''):
+ port = string.atoi(port)
+ s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+ s.connect((host, port))
+ return s
+
+# Send a selector to a given host and port, return a file with the reply
+def send_request(selector, host, port):
+ s = open_socket(host, port)
+ s.send(selector + CRLF)
+ s.shutdown(1)
+ return s.makefile('r')
+
+# Get a menu in the form of a list of entries
+def get_menu(selector, host, port):
+ f = send_request(selector, host, port)
+ 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
+ typechar = line[0]
+ parts = string.splitfields(line[1:], TAB)
+ if len(parts) < 4:
+ print '(Bad line from server:', `line`, ')'
+ continue
+ if len(parts) > 4:
+ print '(Extra info from server:', parts[4:], ')'
+ parts.insert(0, typechar)
+ list.append(parts)
+ f.close()
+ return list
+
+# Get a text file as a list of lines, with trailing CRLF stripped
+def get_textfile(selector, host, port):
+ list = []
+ get_alt_textfile(selector, host, port, list.append)
+ return list
+
+# Get a text file and pass each line to a function, with trailing CRLF stripped
+def get_alt_textfile(selector, host, port, func):
+ f = send_request(selector, host, port)
+ 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)
+ f.close()
+
+# Get a binary file as one solid data block
+def get_binary(selector, host, port):
+ f = send_request(selector, host, port)
+ data = f.read()
+ f.close()
+ return data
+
+# Get a binary file and pass each block to a function
+def get_alt_binary(selector, host, port, func, blocksize):
+ f = send_request(selector, host, port)
+ while 1:
+ data = f.read(blocksize)
+ if not data:
+ break
+ func(data)
+
+# A *very* simple interactive browser
+
+# Browser main command, has default arguments
+def browser(*args):
+ selector = DEF_SELECTOR
+ host = DEF_HOST
+ port = DEF_PORT
+ n = len(args)
+ if n > 0 and args[0]:
+ selector = args[0]
+ if n > 1 and args[1]:
+ host = args[1]
+ if n > 2 and args[2]:
+ port = args[2]
+ if n > 3:
+ raise RuntimeError, 'too many args'
+ try:
+ browse_menu(selector, host, port)
+ except socket.error, msg:
+ print 'Socket error:', msg
+ sys.exit(1)
+ except KeyboardInterrupt:
+ print '\n[Goodbye]'
+
+# Browse a menu
+def browse_menu(selector, host, port):
+ list = get_menu(selector, host, port)
+ while 1:
+ print '----- MENU -----'
+ print 'Selector:', `selector`
+ print 'Host:', host, ' Port:', port
+ print
+ for i in range(len(list)):
+ item = list[i]
+ typechar, description = item[0], item[1]
+ print string.rjust(`i+1`, 3) + ':', description,
+ if typename.has_key(typechar):
+ print typename[typechar]
+ else:
+ print '<TYPE=' + `typechar` + '>'
+ print
+ while 1:
+ try:
+ str = raw_input('Choice [CR == up a level]: ')
+ except EOFError:
+ print
+ return
+ if not str:
+ return
+ try:
+ choice = string.atoi(str)
+ except string.atoi_error:
+ print 'Choice must be a number; try again:'
+ continue
+ if not 0 < choice <= len(list):
+ print 'Choice out of range; try again:'
+ continue
+ break
+ item = list[choice-1]
+ typechar = item[0]
+ [i_selector, i_host, i_port] = item[2:5]
+ if typebrowser.has_key(typechar):
+ browserfunc = typebrowser[typechar]
+ try:
+ browserfunc(i_selector, i_host, i_port)
+ except (IOError, socket.error):
+ print '***', sys.exc_type, ':', sys.exc_value
+ else:
+ print 'Unsupported object type'
+
+# Browse a text file
+def browse_textfile(selector, host, port):
+ x = None
+ try:
+ p = os.popen('${PAGER-more}', 'w')
+ x = SaveLines().init(p)
+ get_alt_textfile(selector, host, port, x.writeln)
+ except IOError, msg:
+ print 'IOError:', msg
+ if x:
+ x.close()
+ f = open_savefile()
+ if not f:
+ return
+ x = SaveLines().init(f)
+ try:
+ get_alt_textfile(selector, host, port, x.writeln)
+ print 'Done.'
+ except IOError, msg:
+ print 'IOError:', msg
+ x.close()
+
+# Browse a search index
+def browse_search(selector, host, port):
+ while 1:
+ print '----- SEARCH -----'
+ print 'Selector:', `selector`
+ print 'Host:', host, ' Port:', port
+ print
+ try:
+ query = raw_input('Query [CR == up a level]: ')
+ except EOFError:
+ print
+ break
+ query = string.strip(query)
+ if not query:
+ break
+ if '\t' in query:
+ print 'Sorry, queries cannot contain tabs'
+ continue
+ browse_menu(selector + TAB + query, host, port)
+
+# "Browse" telnet-based information, i.e. open a telnet session
+def browse_telnet(selector, host, port):
+ if selector:
+ print 'Log in as', `selector`
+ if type(port) <> type(''):
+ port = `port`
+ sts = os.system('set -x; exec telnet ' + host + ' ' + port)
+ if sts:
+ print 'Exit status:', sts
+
+# "Browse" a binary file, i.e. save it to a file
+def browse_binary(selector, host, port):
+ f = open_savefile()
+ if not f:
+ return
+ x = SaveWithProgress().init(f)
+ get_alt_binary(selector, host, port, x.write, 8*1024)
+ x.close()
+
+# "Browse" a sound file, i.e. play it or save it
+def browse_sound(selector, host, port):
+ browse_binary(selector, host, port)
+
+# Dictionary mapping types to browser functions
+typebrowser = {'0': browse_textfile, '1': browse_menu, \
+ '4': browse_binary, '5': browse_binary, '6': browse_textfile, \
+ '7': browse_search, \
+ '8': browse_telnet, '9': browse_binary, 's': browse_sound}
+
+# Class used to save lines, appending a newline to each line
+class SaveLines:
+ def init(self, f):
+ self.f = f
+ return self
+ def writeln(self, line):
+ self.f.write(line + '\n')
+ def close(self):
+ sts = self.f.close()
+ if sts:
+ print 'Exit status:', sts
+
+# Class used to save data while showing progress
+class SaveWithProgress:
+ def init(self, f):
+ self.f = f
+ return self
+ def write(self, data):
+ sys.stdout.write('#')
+ sys.stdout.flush()
+ self.f.write(data)
+ def close(self):
+ print
+ sts = self.f.close()
+ if sts:
+ print 'Exit status:', sts
+
+# Ask for and open a save file, or return None if not to save
+def open_savefile():
+ try:
+ savefile = raw_input( \
+ 'Save as file [CR == don\'t save; |pipeline or ~user/... OK]: ')
+ except EOFError:
+ print
+ return None
+ savefile = string.strip(savefile)
+ if not savefile:
+ return None
+ if savefile[0] == '|':
+ cmd = string.strip(savefile[1:])
+ try:
+ p = os.popen(cmd, 'w')
+ except IOError, msg:
+ print `cmd`, ':', msg
+ return None
+ print 'Piping through', `cmd`, '...'
+ return p
+ if savefile[0] == '~':
+ savefile = os.path.expanduser(savefile)
+ try:
+ f = open(savefile, 'w')
+ except IOError, msg:
+ print `savefile`, ':', msg
+ return None
+ print 'Saving to', `savefile`, '...'
+ return f
+
+# Test program
+def test():
+ if sys.argv[4:]:
+ print 'usage: gopher [ [selector] host [port] ]'
+ sys.exit(2)
+ elif sys.argv[3:]:
+ browser(sys.argv[1], sys.argv[2], sys.argv[3])
+ elif sys.argv[2:]:
+ try:
+ port = string.atoi(sys.argv[2])
+ selector = ''
+ host = sys.argv[1]
+ except string.atoi_error:
+ selector = sys.argv[1]
+ host = sys.argv[2]
+ port = ''
+ browser(selector, host, port)
+ elif sys.argv[1:]:
+ browser('', sys.argv[1])
+ else:
+ browser()
+
+# Call the test program as a main program
+test()