|
| 1 | +#! /usr/local/bin/python |
| 2 | + |
| 3 | +# A simple gopher client. |
| 4 | +# |
| 5 | +# Usage: gopher [ [selector] host [port] ] |
| 6 | + |
| 7 | +import string |
| 8 | +import sys |
| 9 | +import os |
| 10 | +import socket |
| 11 | + |
| 12 | +# Default selector, host and port |
| 13 | +DEF_SELECTOR = '' |
| 14 | +DEF_HOST = 'gopher.micro.umn.edu' |
| 15 | +DEF_PORT = 70 |
| 16 | + |
| 17 | +# Recognized file types |
| 18 | +T_TEXTFILE = '0' |
| 19 | +T_MENU = '1' |
| 20 | +T_CSO = '2' |
| 21 | +T_ERROR = '3' |
| 22 | +T_BINHEX = '4' |
| 23 | +T_DOS = '5' |
| 24 | +T_UUENCODE = '6' |
| 25 | +T_SEARCH = '7' |
| 26 | +T_TELNET = '8' |
| 27 | +T_BINARY = '9' |
| 28 | +T_REDUNDANT = '+' |
| 29 | +T_SOUND = 's' |
| 30 | + |
| 31 | +# Dictionary mapping types to strings |
| 32 | +typename = {'0': '<TEXT>', '1': '<DIR>', '2': '<CSO>', '3': '<ERROR>', \ |
| 33 | + '4': '<BINHEX>', '5': '<DOS>', '6': '<UUENCODE>', '7': '<SEARCH>', \ |
| 34 | + '8': '<TELNET>', '9': '<BINARY>', '+': '<REDUNDANT>', 's': '<SOUND>'} |
| 35 | + |
| 36 | +# Oft-used characters and strings |
| 37 | +CRLF = '\r\n' |
| 38 | +TAB = '\t' |
| 39 | + |
| 40 | +# Open a TCP connection to a given host and port |
| 41 | +def open_socket(host, port): |
| 42 | + if type(port) == type(''): |
| 43 | + port = string.atoi(port) |
| 44 | + s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) |
| 45 | + s.connect((host, port)) |
| 46 | + return s |
| 47 | + |
| 48 | +# Send a selector to a given host and port, return a file with the reply |
| 49 | +def send_request(selector, host, port): |
| 50 | + s = open_socket(host, port) |
| 51 | + s.send(selector + CRLF) |
| 52 | + s.shutdown(1) |
| 53 | + return s.makefile('r') |
| 54 | + |
| 55 | +# Get a menu in the form of a list of entries |
| 56 | +def get_menu(selector, host, port): |
| 57 | + f = send_request(selector, host, port) |
| 58 | + list = [] |
| 59 | + while 1: |
| 60 | + line = f.readline() |
| 61 | + if not line: |
| 62 | + print '(Unexpected EOF from server)' |
| 63 | + break |
| 64 | + if line[-2:] == CRLF: |
| 65 | + line = line[:-2] |
| 66 | + elif line[-1:] in CRLF: |
| 67 | + line = line[:-1] |
| 68 | + if line == '.': |
| 69 | + break |
| 70 | + if not line: |
| 71 | + print '(Empty line from server)' |
| 72 | + continue |
| 73 | + typechar = line[0] |
| 74 | + parts = string.splitfields(line[1:], TAB) |
| 75 | + if len(parts) < 4: |
| 76 | + print '(Bad line from server:', `line`, ')' |
| 77 | + continue |
| 78 | + if len(parts) > 4: |
| 79 | + print '(Extra info from server:', parts[4:], ')' |
| 80 | + parts.insert(0, typechar) |
| 81 | + list.append(parts) |
| 82 | + f.close() |
| 83 | + return list |
| 84 | + |
| 85 | +# Get a text file as a list of lines, with trailing CRLF stripped |
| 86 | +def get_textfile(selector, host, port): |
| 87 | + list = [] |
| 88 | + get_alt_textfile(selector, host, port, list.append) |
| 89 | + return list |
| 90 | + |
| 91 | +# Get a text file and pass each line to a function, with trailing CRLF stripped |
| 92 | +def get_alt_textfile(selector, host, port, func): |
| 93 | + f = send_request(selector, host, port) |
| 94 | + while 1: |
| 95 | + line = f.readline() |
| 96 | + if not line: |
| 97 | + print '(Unexpected EOF from server)' |
| 98 | + break |
| 99 | + if line[-2:] == CRLF: |
| 100 | + line = line[:-2] |
| 101 | + elif line[-1:] in CRLF: |
| 102 | + line = line[:-1] |
| 103 | + if line == '.': |
| 104 | + break |
| 105 | + if line[:2] == '..': |
| 106 | + line = line[1:] |
| 107 | + func(line) |
| 108 | + f.close() |
| 109 | + |
| 110 | +# Get a binary file as one solid data block |
| 111 | +def get_binary(selector, host, port): |
| 112 | + f = send_request(selector, host, port) |
| 113 | + data = f.read() |
| 114 | + f.close() |
| 115 | + return data |
| 116 | + |
| 117 | +# Get a binary file and pass each block to a function |
| 118 | +def get_alt_binary(selector, host, port, func, blocksize): |
| 119 | + f = send_request(selector, host, port) |
| 120 | + while 1: |
| 121 | + data = f.read(blocksize) |
| 122 | + if not data: |
| 123 | + break |
| 124 | + func(data) |
| 125 | + |
| 126 | +# A *very* simple interactive browser |
| 127 | + |
| 128 | +# Browser main command, has default arguments |
| 129 | +def browser(*args): |
| 130 | + selector = DEF_SELECTOR |
| 131 | + host = DEF_HOST |
| 132 | + port = DEF_PORT |
| 133 | + n = len(args) |
| 134 | + if n > 0 and args[0]: |
| 135 | + selector = args[0] |
| 136 | + if n > 1 and args[1]: |
| 137 | + host = args[1] |
| 138 | + if n > 2 and args[2]: |
| 139 | + port = args[2] |
| 140 | + if n > 3: |
| 141 | + raise RuntimeError, 'too many args' |
| 142 | + try: |
| 143 | + browse_menu(selector, host, port) |
| 144 | + except socket.error, msg: |
| 145 | + print 'Socket error:', msg |
| 146 | + sys.exit(1) |
| 147 | + except KeyboardInterrupt: |
| 148 | + print '\n[Goodbye]' |
| 149 | + |
| 150 | +# Browse a menu |
| 151 | +def browse_menu(selector, host, port): |
| 152 | + list = get_menu(selector, host, port) |
| 153 | + while 1: |
| 154 | + print '----- MENU -----' |
| 155 | + print 'Selector:', `selector` |
| 156 | + print 'Host:', host, ' Port:', port |
| 157 | + print |
| 158 | + for i in range(len(list)): |
| 159 | + item = list[i] |
| 160 | + typechar, description = item[0], item[1] |
| 161 | + print string.rjust(`i+1`, 3) + ':', description, |
| 162 | + if typename.has_key(typechar): |
| 163 | + print typename[typechar] |
| 164 | + else: |
| 165 | + print '<TYPE=' + `typechar` + '>' |
| 166 | + print |
| 167 | + while 1: |
| 168 | + try: |
| 169 | + str = raw_input('Choice [CR == up a level]: ') |
| 170 | + except EOFError: |
| 171 | + print |
| 172 | + return |
| 173 | + if not str: |
| 174 | + return |
| 175 | + try: |
| 176 | + choice = string.atoi(str) |
| 177 | + except string.atoi_error: |
| 178 | + print 'Choice must be a number; try again:' |
| 179 | + continue |
| 180 | + if not 0 < choice <= len(list): |
| 181 | + print 'Choice out of range; try again:' |
| 182 | + continue |
| 183 | + break |
| 184 | + item = list[choice-1] |
| 185 | + typechar = item[0] |
| 186 | + [i_selector, i_host, i_port] = item[2:5] |
| 187 | + if typebrowser.has_key(typechar): |
| 188 | + browserfunc = typebrowser[typechar] |
| 189 | + try: |
| 190 | + browserfunc(i_selector, i_host, i_port) |
| 191 | + except (IOError, socket.error): |
| 192 | + print '***', sys.exc_type, ':', sys.exc_value |
| 193 | + else: |
| 194 | + print 'Unsupported object type' |
| 195 | + |
| 196 | +# Browse a text file |
| 197 | +def browse_textfile(selector, host, port): |
| 198 | + x = None |
| 199 | + try: |
| 200 | + p = os.popen('${PAGER-more}', 'w') |
| 201 | + x = SaveLines().init(p) |
| 202 | + get_alt_textfile(selector, host, port, x.writeln) |
| 203 | + except IOError, msg: |
| 204 | + print 'IOError:', msg |
| 205 | + if x: |
| 206 | + x.close() |
| 207 | + f = open_savefile() |
| 208 | + if not f: |
| 209 | + return |
| 210 | + x = SaveLines().init(f) |
| 211 | + try: |
| 212 | + get_alt_textfile(selector, host, port, x.writeln) |
| 213 | + print 'Done.' |
| 214 | + except IOError, msg: |
| 215 | + print 'IOError:', msg |
| 216 | + x.close() |
| 217 | + |
| 218 | +# Browse a search index |
| 219 | +def browse_search(selector, host, port): |
| 220 | + while 1: |
| 221 | + print '----- SEARCH -----' |
| 222 | + print 'Selector:', `selector` |
| 223 | + print 'Host:', host, ' Port:', port |
| 224 | + print |
| 225 | + try: |
| 226 | + query = raw_input('Query [CR == up a level]: ') |
| 227 | + except EOFError: |
| 228 | + print |
| 229 | + break |
| 230 | + query = string.strip(query) |
| 231 | + if not query: |
| 232 | + break |
| 233 | + if '\t' in query: |
| 234 | + print 'Sorry, queries cannot contain tabs' |
| 235 | + continue |
| 236 | + browse_menu(selector + TAB + query, host, port) |
| 237 | + |
| 238 | +# "Browse" telnet-based information, i.e. open a telnet session |
| 239 | +def browse_telnet(selector, host, port): |
| 240 | + if selector: |
| 241 | + print 'Log in as', `selector` |
| 242 | + if type(port) <> type(''): |
| 243 | + port = `port` |
| 244 | + sts = os.system('set -x; exec telnet ' + host + ' ' + port) |
| 245 | + if sts: |
| 246 | + print 'Exit status:', sts |
| 247 | + |
| 248 | +# "Browse" a binary file, i.e. save it to a file |
| 249 | +def browse_binary(selector, host, port): |
| 250 | + f = open_savefile() |
| 251 | + if not f: |
| 252 | + return |
| 253 | + x = SaveWithProgress().init(f) |
| 254 | + get_alt_binary(selector, host, port, x.write, 8*1024) |
| 255 | + x.close() |
| 256 | + |
| 257 | +# "Browse" a sound file, i.e. play it or save it |
| 258 | +def browse_sound(selector, host, port): |
| 259 | + browse_binary(selector, host, port) |
| 260 | + |
| 261 | +# Dictionary mapping types to browser functions |
| 262 | +typebrowser = {'0': browse_textfile, '1': browse_menu, \ |
| 263 | + '4': browse_binary, '5': browse_binary, '6': browse_textfile, \ |
| 264 | + '7': browse_search, \ |
| 265 | + '8': browse_telnet, '9': browse_binary, 's': browse_sound} |
| 266 | + |
| 267 | +# Class used to save lines, appending a newline to each line |
| 268 | +class SaveLines: |
| 269 | + def init(self, f): |
| 270 | + self.f = f |
| 271 | + return self |
| 272 | + def writeln(self, line): |
| 273 | + self.f.write(line + '\n') |
| 274 | + def close(self): |
| 275 | + sts = self.f.close() |
| 276 | + if sts: |
| 277 | + print 'Exit status:', sts |
| 278 | + |
| 279 | +# Class used to save data while showing progress |
| 280 | +class SaveWithProgress: |
| 281 | + def init(self, f): |
| 282 | + self.f = f |
| 283 | + return self |
| 284 | + def write(self, data): |
| 285 | + sys.stdout.write('#') |
| 286 | + sys.stdout.flush() |
| 287 | + self.f.write(data) |
| 288 | + def close(self): |
| 289 | + print |
| 290 | + sts = self.f.close() |
| 291 | + if sts: |
| 292 | + print 'Exit status:', sts |
| 293 | + |
| 294 | +# Ask for and open a save file, or return None if not to save |
| 295 | +def open_savefile(): |
| 296 | + try: |
| 297 | + savefile = raw_input( \ |
| 298 | + 'Save as file [CR == don\'t save; |pipeline or ~user/... OK]: ') |
| 299 | + except EOFError: |
| 300 | + print |
| 301 | + return None |
| 302 | + savefile = string.strip(savefile) |
| 303 | + if not savefile: |
| 304 | + return None |
| 305 | + if savefile[0] == '|': |
| 306 | + cmd = string.strip(savefile[1:]) |
| 307 | + try: |
| 308 | + p = os.popen(cmd, 'w') |
| 309 | + except IOError, msg: |
| 310 | + print `cmd`, ':', msg |
| 311 | + return None |
| 312 | + print 'Piping through', `cmd`, '...' |
| 313 | + return p |
| 314 | + if savefile[0] == '~': |
| 315 | + savefile = os.path.expanduser(savefile) |
| 316 | + try: |
| 317 | + f = open(savefile, 'w') |
| 318 | + except IOError, msg: |
| 319 | + print `savefile`, ':', msg |
| 320 | + return None |
| 321 | + print 'Saving to', `savefile`, '...' |
| 322 | + return f |
| 323 | + |
| 324 | +# Test program |
| 325 | +def test(): |
| 326 | + if sys.argv[4:]: |
| 327 | + print 'usage: gopher [ [selector] host [port] ]' |
| 328 | + sys.exit(2) |
| 329 | + elif sys.argv[3:]: |
| 330 | + browser(sys.argv[1], sys.argv[2], sys.argv[3]) |
| 331 | + elif sys.argv[2:]: |
| 332 | + try: |
| 333 | + port = string.atoi(sys.argv[2]) |
| 334 | + selector = '' |
| 335 | + host = sys.argv[1] |
| 336 | + except string.atoi_error: |
| 337 | + selector = sys.argv[1] |
| 338 | + host = sys.argv[2] |
| 339 | + port = '' |
| 340 | + browser(selector, host, port) |
| 341 | + elif sys.argv[1:]: |
| 342 | + browser('', sys.argv[1]) |
| 343 | + else: |
| 344 | + browser() |
| 345 | + |
| 346 | +# Call the test program as a main program |
| 347 | +test() |
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