1 """distutils.fancy_getopt 2 3 Wrapper around the standard getopt module that provides the following 4 additional features: 5 * short and long options are tied together 6 * options have help strings, so fancy_getopt could potentially 7 create a complete usage summary 8 * options set attributes of a passed-in object 9 """ 10 11 import sys, string, re 12 import getopt 13 from distutils.errors import * 14 15 # Much like command_re in distutils.core, this is close to but not quite 16 # the same as a Python NAME -- except, in the spirit of most GNU 17 # utilities, we use '-' in place of '_'. (The spirit of LISP lives on!) 18 # The similarities to NAME are again not a coincidence... 19 longopt_pat = r'[a-zA-Z](?:[a-zA-Z0-9-]*)' 20 longopt_re = re.compile(r'^%s$' % longopt_pat) 21 22 # For recognizing "negative alias" options, eg. "quiet=!verbose" 23 neg_alias_re = re.compile("^(%s)=!(%s)$" % (longopt_pat, longopt_pat)) 24 25 # This is used to translate long options to legitimate Python identifiers 26 # (for use as attributes of some object). 27 longopt_xlate = str.maketrans('-', '_') 28 29 class FancyGetopt: 30 """Wrapper around the standard 'getopt()' module that provides some 31 handy extra functionality: 32 * short and long options are tied together 33 * options have help strings, and help text can be assembled 34 from them 35 * options set attributes of a passed-in object 36 * boolean options can have "negative aliases" -- eg. if 37 --quiet is the "negative alias" of --verbose, then "--quiet" 38 on the command line sets 'verbose' to false 39 """ 40 41 def __init__(self, option_table=None): 42 # The option table is (currently) a list of tuples. The 43 # tuples may have 3 or four values: 44 # (long_option, short_option, help_string [, repeatable]) 45 # if an option takes an argument, its long_option should have '=' 46 # appended; short_option should just be a single character, no ':' 47 # in any case. If a long_option doesn't have a corresponding 48 # short_option, short_option should be None. All option tuples 49 # must have long options. 50 self.option_table = option_table 51 52 # 'option_index' maps long option names to entries in the option 53 # table (ie. those 3-tuples). 54 self.option_index = {} 55 if self.option_table: 56 self._build_index() 57 58 # 'alias' records (duh) alias options; {'foo': 'bar'} means 59 # --foo is an alias for --bar 60 self.alias = {} 61 62 # 'negative_alias' keeps track of options that are the boolean 63 # opposite of some other option 64 self.negative_alias = {} 65 66 # These keep track of the information in the option table. We 67 # don't actually populate these structures until we're ready to 68 # parse the command-line, since the 'option_table' passed in here 69 # isn't necessarily the final word. 70 self.short_opts = [] 71 self.long_opts = [] 72 self.short2long = {} 73 self.attr_name = {} 74 self.takes_arg = {} 75 76 # And 'option_order' is filled up in 'getopt()'; it records the 77 # original order of options (and their values) on the command-line, 78 # but expands short options, converts aliases, etc. 79 self.option_order = [] 80 81 def _build_index(self): 82 self.option_index.clear() 83 for option in self.option_table: 84 self.option_index[option[0]] = option 85 86 def set_option_table(self, option_table): 87 self.option_table = option_table 88 self._build_index() 89 90 def add_option(self, long_option, short_option=None, help_string=None): 91 if long_option in self.option_index: 92 raise DistutilsGetoptError( 93 "option conflict: already an option '%s'" % long_option) 94 else: 95 option = (long_option, short_option, help_string) 96 self.option_table.append(option) 97 self.option_index[long_option] = option 98 99 def has_option(self, long_option): 100 """Return true if the option table for this parser has an 101 option with long name 'long_option'.""" 102 return long_option in self.option_index 103 104 def get_attr_name(self, long_option): 105 """Translate long option name 'long_option' to the form it 106 has as an attribute of some object: ie., translate hyphens 107 to underscores.""" 108 return long_option.translate(longopt_xlate) 109 110 def _check_alias_dict(self, aliases, what): 111 assert isinstance(aliases, dict) 112 for (alias, opt) in aliases.items(): 113 if alias not in self.option_index: 114 raise DistutilsGetoptError(("invalid %s '%s': " 115 "option '%s' not defined") % (what, alias, alias)) 116 if opt not in self.option_index: 117 raise DistutilsGetoptError(("invalid %s '%s': " 118 "aliased option '%s' not defined") % (what, alias, opt)) 119 120 def set_aliases(self, alias): 121 """Set the aliases for this option parser.""" 122 self._check_alias_dict(alias, "alias") 123 self.alias = alias 124 125 def set_negative_aliases(self, negative_alias): 126 """Set the negative aliases for this option parser. 127 'negative_alias' should be a dictionary mapping option names to 128 option names, both the key and value must already be defined 129 in the option table.""" 130 self._check_alias_dict(negative_alias, "negative alias") 131 self.negative_alias = negative_alias 132 133 def _grok_option_table(self): 134 """Populate the various data structures that keep tabs on the 135 option table. Called by 'getopt()' before it can do anything 136 worthwhile. 137 """ 138 self.long_opts = [] 139 self.short_opts = [] 140 self.short2long.clear() 141 self.repeat = {} 142 143 for option in self.option_table: 144 if len(option) == 3: 145 long, short, help = option 146 repeat = 0 147 elif len(option) == 4: 148 long, short, help, repeat = option 149 else: 150 # the option table is part of the code, so simply 151 # assert that it is correct 152 raise ValueError("invalid option tuple: %r" % (option,)) 153 154 # Type- and value-check the option names 155 if not isinstance(long, str) or len(long) < 2: 156 raise DistutilsGetoptError(("invalid long option '%s': " 157 "must be a string of length >= 2") % long) 158 159 if (not ((short is None) or 160 (isinstance(short, str) and len(short) == 1))): 161 raise DistutilsGetoptError("invalid short option '%s': " 162 "must a single character or None" % short) 163 164 self.repeat[long] = repeat 165 self.long_opts.append(long) 166 167 if long[-1] == '=': # option takes an argument? 168 if short: short = short + ':' 169 long = long[0:-1] 170 self.takes_arg[long] = 1 171 else: 172 # Is option is a "negative alias" for some other option (eg. 173 # "quiet" == "!verbose")? 174 alias_to = self.negative_alias.get(long) 175 if alias_to is not None: 176 if self.takes_arg[alias_to]: 177 raise DistutilsGetoptError( 178 "invalid negative alias '%s': " 179 "aliased option '%s' takes a value" 180 % (long, alias_to)) 181 182 self.long_opts[-1] = long # XXX redundant?! 183 self.takes_arg[long] = 0 184 185 # If this is an alias option, make sure its "takes arg" flag is 186 # the same as the option it's aliased to. 187 alias_to = self.alias.get(long) 188 if alias_to is not None: 189 if self.takes_arg[long] != self.takes_arg[alias_to]: 190 raise DistutilsGetoptError( 191 "invalid alias '%s': inconsistent with " 192 "aliased option '%s' (one of them takes a value, " 193 "the other doesn't" 194 % (long, alias_to)) 195 196 # Now enforce some bondage on the long option name, so we can 197 # later translate it to an attribute name on some object. Have 198 # to do this a bit late to make sure we've removed any trailing 199 # '='. 200 if not longopt_re.match(long): 201 raise DistutilsGetoptError( 202 "invalid long option name '%s' " 203 "(must be letters, numbers, hyphens only" % long) 204 205 self.attr_name[long] = self.get_attr_name(long) 206 if short: 207 self.short_opts.append(short) 208 self.short2long[short[0]] = long 209 210 def getopt(self, args=None, object=None): 211 """Parse command-line options in args. Store as attributes on object. 212 213 If 'args' is None or not supplied, uses 'sys.argv[1:]'. If 214 'object' is None or not supplied, creates a new OptionDummy 215 object, stores option values there, and returns a tuple (args, 216 object). If 'object' is supplied, it is modified in place and 217 'getopt()' just returns 'args'; in both cases, the returned 218 'args' is a modified copy of the passed-in 'args' list, which 219 is left untouched. 220 """ 221 if args is None: 222 args = sys.argv[1:] 223 if object is None: 224 object = OptionDummy() 225 created_object = True 226 else: 227 created_object = False 228 229 self._grok_option_table() 230 231 short_opts = ' '.join(self.short_opts) 232 try: 233 opts, args = getopt.getopt(args, short_opts, self.long_opts) 234 except getopt.error as msg: 235 raise DistutilsArgError(msg) 236 237 for opt, val in opts: 238 if len(opt) == 2 and opt[0] == '-': # it's a short option 239 opt = self.short2long[opt[1]] 240 else: 241 assert len(opt) > 2 and opt[:2] == '--' 242 opt = opt[2:] 243 244 alias = self.alias.get(opt) 245 if alias: 246 opt = alias 247 248 if not self.takes_arg[opt]: # boolean option? 249 assert val == '', "boolean option can't have value" 250 alias = self.negative_alias.get(opt) 251 if alias: 252 opt = alias 253 val = 0 254 else: 255 val = 1 256 257 attr = self.attr_name[opt] 258 # The only repeating option at the moment is 'verbose'. 259 # It has a negative option -q quiet, which should set verbose = 0. 260 if val and self.repeat.get(attr) is not None: 261 val = getattr(object, attr, 0) + 1 262 setattr(object, attr, val) 263 self.option_order.append((opt, val)) 264 265 # for opts 266 if created_object: 267 return args, object 268 else: 269 return args 270 271 def get_option_order(self): 272 """Returns the list of (option, value) tuples processed by the 273 previous run of 'getopt()'. Raises RuntimeError if 274 'getopt()' hasn't been called yet. 275 """ 276 if self.option_order is None: 277 raise RuntimeError("'getopt()' hasn't been called yet") 278 else: 279 return self.option_order 280 281 def generate_help(self, header=None): 282 """Generate help text (a list of strings, one per suggested line of 283 output) from the option table for this FancyGetopt object. 284 """ 285 # Blithely assume the option table is good: probably wouldn't call 286 # 'generate_help()' unless you've already called 'getopt()'. 287 288 # First pass: determine maximum length of long option names 289 max_opt = 0 290 for option in self.option_table: 291 long = option[0] 292 short = option[1] 293 l = len(long) 294 if long[-1] == '=': 295 l = l - 1 296 if short is not None: 297 l = l + 5 # " (-x)" where short == 'x' 298 if l > max_opt: 299 max_opt = l 300 301 opt_width = max_opt + 2 + 2 + 2 # room for indent + dashes + gutter 302 303 # Typical help block looks like this: 304 # --foo controls foonabulation 305 # Help block for longest option looks like this: 306 # --flimflam set the flim-flam level 307 # and with wrapped text: 308 # --flimflam set the flim-flam level (must be between 309 # 0 and 100, except on Tuesdays) 310 # Options with short names will have the short name shown (but 311 # it doesn't contribute to max_opt): 312 # --foo (-f) controls foonabulation 313 # If adding the short option would make the left column too wide, 314 # we push the explanation off to the next line 315 # --flimflam (-l) 316 # set the flim-flam level 317 # Important parameters: 318 # - 2 spaces before option block start lines 319 # - 2 dashes for each long option name 320 # - min. 2 spaces between option and explanation (gutter) 321 # - 5 characters (incl. space) for short option name 322 323 # Now generate lines of help text. (If 80 columns were good enough 324 # for Jesus, then 78 columns are good enough for me!) 325 line_width = 78 326 text_width = line_width - opt_width 327 big_indent = ' ' * opt_width 328 if header: 329 lines = [header] 330 else: 331 lines = ['Option summary:'] 332 333 for option in self.option_table: 334 long, short, help = option[:3] 335 text = wrap_text(help, text_width) 336 if long[-1] == '=': 337 long = long[0:-1] 338 339 # Case 1: no short option at all (makes life easy) 340 if short is None: 341 if text: 342 lines.append(" --%-*s %s" % (max_opt, long, text[0])) 343 else: 344 lines.append(" --%-*s " % (max_opt, long)) 345 346 # Case 2: we have a short option, so we have to include it 347 # just after the long option 348 else: 349 opt_names = "%s (-%s)" % (long, short) 350 if text: 351 lines.append(" --%-*s %s" % 352 (max_opt, opt_names, text[0])) 353 else: 354 lines.append(" --%-*s" % opt_names) 355 356 for l in text[1:]: 357 lines.append(big_indent + l) 358 return lines 359 360 def print_help(self, header=None, file=None): 361 if file is None: 362 file = sys.stdout 363 for line in self.generate_help(header): 364 file.write(line + "\n") 365 366 367 def fancy_getopt(options, negative_opt, object, args): 368 parser = FancyGetopt(options) 369 parser.set_negative_aliases(negative_opt) 370 return parser.getopt(args, object) 371 372 373 WS_TRANS = {ord(_wschar) : ' ' for _wschar in string.whitespace} 374 375 def wrap_text(text, width): 376 """wrap_text(text : string, width : int) -> [string] 377 378 Split 'text' into multiple lines of no more than 'width' characters 379 each, and return the list of strings that results. 380 """ 381 if text is None: 382 return [] 383 if len(text) <= width: 384 return [text] 385 386 text = text.expandtabs() 387 text = text.translate(WS_TRANS) 388 chunks = re.split(r'( +|-+)', text) 389 chunks = [ch for ch in chunks if ch] # ' - ' results in empty strings 390 lines = [] 391 392 while chunks: 393 cur_line = [] # list of chunks (to-be-joined) 394 cur_len = 0 # length of current line 395 396 while chunks: 397 l = len(chunks[0]) 398 if cur_len + l <= width: # can squeeze (at least) this chunk in 399 cur_line.append(chunks[0]) 400 del chunks[0] 401 cur_len = cur_len + l 402 else: # this line is full 403 # drop last chunk if all space 404 if cur_line and cur_line[-1][0] == ' ': 405 del cur_line[-1] 406 break 407 408 if chunks: # any chunks left to process? 409 # if the current line is still empty, then we had a single 410 # chunk that's too big too fit on a line -- so we break 411 # down and break it up at the line width 412 if cur_len == 0: 413 cur_line.append(chunks[0][0:width]) 414 chunks[0] = chunks[0][width:] 415 416 # all-whitespace chunks at the end of a line can be discarded 417 # (and we know from the re.split above that if a chunk has 418 # *any* whitespace, it is *all* whitespace) 419 if chunks[0][0] == ' ': 420 del chunks[0] 421 422 # and store this line in the list-of-all-lines -- as a single 423 # string, of course! 424 lines.append(''.join(cur_line)) 425 426 return lines 427 428 429 def translate_longopt(opt): 430 """Convert a long option name to a valid Python identifier by 431 changing "-" to "_". 432 """ 433 return opt.translate(longopt_xlate) 434 435 436 class OptionDummy: 437 """Dummy class just used as a place to hold command-line option 438 values as instance attributes.""" 439 440 def __init__(self, options=[]): 441 """Create a new OptionDummy instance. The attributes listed in 442 'options' will be initialized to None.""" 443 for opt in options: 444 setattr(self, opt, None) 445 446 447 if __name__ == "__main__": 448 text = """\ 449 Tra-la-la, supercalifragilisticexpialidocious. 450 How *do* you spell that odd word, anyways? 451 (Someone ask Mary -- she'll know [or she'll 452 say, "How should I know?"].)""" 453 454 for w in (10, 20, 30, 40): 455 print("width: %d" % w) 456 print("\n".join(wrap_text(text, w))) 457 print() 458
