"""distutils.fancy_getopt Wrapper around the standard getopt module that provides the following additional features: * short and long options are tied together * options have help strings, so fancy_getopt could potentially create a complete usage summary * options set attributes of a passed-in object """ # created 1999/03/03, Greg Ward __revision__ = "$Id$" import sys, string, re from types import * import getopt from distutils.errors import * # Much like command_re in distutils.core, this is close to but not quite # the same as a Python NAME -- except, in the spirit of most GNU # utilities, we use '-' in place of '_'. (The spirit of LISP lives on!) # The similarities to NAME are again not a coincidence... longopt_pat = r'[a-zA-Z](?:[a-zA-Z0-9-]*)' longopt_re = re.compile (r'^%s$' % longopt_pat) # For recognizing "negative alias" options, eg. "quiet=!verbose" neg_alias_re = re.compile ("^(%s)=!(%s)$" % (longopt_pat, longopt_pat)) # This is used to translate long options to legitimate Python identifiers # (for use as attributes of some object). longopt_xlate = string.maketrans ('-', '_') # This records (option, value) pairs in the order seen on the command line; # it's close to what getopt.getopt() returns, but with short options # expanded. (Ugh, this module should be OO-ified.) _option_order = None class FancyGetopt: """Wrapper around the standard 'getopt()' module that provides some handy extra functionality: * short and long options are tied together * options have help strings, and help text can be assembled from them * options set attributes of a passed-in object * boolean options can have "negative aliases" -- eg. if --quiet is the "negative alias" of --verbose, then "--quiet" on the command line sets 'verbose' to false """ def __init__ (self, option_table=None): # The option table is (currently) a list of 3-tuples: # (long_option, short_option, help_string) # if an option takes an argument, its long_option should have '=' # appended; short_option should just be a single character, no ':' # in any case. If a long_option doesn't have a corresponding # short_option, short_option should be None. All option tuples # must have long options. self.option_table = option_table # 'option_index' maps long option names to entries in the option # table (ie. those 3-tuples). self.option_index = {} if self.option_table: self._build_index() # 'negative_alias' keeps track of options that are the boolean # opposite of some other option self.negative_alias = {} # These keep track of the information in the option table. We # don't actually populate these structures until we're ready to # parse the command-line, since the 'option_table' passed in here # isn't necessarily the final word. self.short_opts = [] self.long_opts = [] self.short2long = {} self.attr_name = {} self.takes_arg = {} # And 'option_order' is filled up in 'getopt()'; it records the # original order of options (and their values) on the command-line, # but expands short options, converts aliases, etc. self.option_order = [] # __init__ () def _build_index (self): for option in self.option_table: self.option_index[option[0]] = option def set_option_table (self, option_table): self.option_table = option_table self._build_index() def add_option (self, long_option, short_option=None, help_string=None): if self.option_index.has_key(long_option): raise DistutilsGetoptError, \ "option conflict: already an option '%s'" % long_option else: option = (long_option, short_option, help_string) self.option_table.append (option) self.option_index[long_option] = option def has_option (self, long_option): """Return true if the option table for this parser has an option with long name 'long_option'.""" return self.option_index.has_key(long_option) def get_attr_name (self, long_option): """Translate long option name 'long_option' to the form it has as an attribute of some object: ie., translate hyphens to underscores.""" return string.translate (long_option, longopt_xlate) def set_negative_aliases (self, negative_alias): """Set the negative aliases for this option parser. 'negative_alias' should be a dictionary mapping option names to option names, both the key and value must already be defined in the option table.""" assert type(negative_alias) is DictionaryType for (negopt, opt) in negative_alias.items(): if not self.option_index.has_key(negopt): raise DistutilsGetoptError, \ ("invalid negative alias '%s': " "option '%s' not defined") % (negopt, negopt) if not self.option_index.has_key(opt): raise DistutilsGetoptError, \ ("invalid negative alias '%s': " "aliased option '%s' not defined") % (negopt, opt) self.negative_alias = negative_alias def _grok_option_table (self): """Populate the various data structures that keep tabs on the option table. Called by 'getopt()' before it can do anything worthwhile.""" for option in self.option_table: try: (long, short, help) = option except ValueError: raise DistutilsGetoptError, \ "invalid option tuple " + str (option) # Type- and value-check the option names if type(long) is not StringType or len(long) < 2: raise DistutilsGetoptError, \ ("invalid long option '%s': " "must be a string of length >= 2") % long if (not ((short is None) or (type (short) is StringType and len (short) == 1))): raise DistutilsGetoptError, \ ("invalid short option '%s': " "must a single character or None") % short self.long_opts.append (long) if long[-1] == '=': # option takes an argument? if short: short = short + ':' long = long[0:-1] self.takes_arg[long] = 1 else: # Is option is a "negative alias" for some other option (eg. # "quiet" == "!verbose")? alias_to = self.negative_alias.get(long) if alias_to is not None: if self.takes_arg[alias_to]: raise DistutilsGetoptError, \ ("invalid negative alias '%s': " "aliased option '%s' takes a value") % \ (long, alias_to) self.long_opts[-1] = long # XXX redundant?! self.takes_arg[long] = 0 else: self.takes_arg[long] = 0 # Now enforce some bondage on the long option name, so we can # later translate it to an attribute name on some object. Have # to do this a bit late to make sure we've removed any trailing # '='. if not longopt_re.match (long): raise DistutilsGetoptError, \ ("invalid long option name '%s' " + "(must be letters, numbers, hyphens only") % long self.attr_name[long] = self.get_attr_name (long) if short: self.short_opts.append (short) self.short2long[short[0]] = long # for option_table # _grok_option_table() def getopt (self, args=None, object=None): """Parse the command-line options in 'args' and store the results as attributes of 'object'. If 'args' is None or not supplied, uses 'sys.argv[1:]'. If 'object' is None or not supplied, creates a new OptionDummy object, stores option values there, and returns a tuple (args, object). If 'object' is supplied, it is modified in place and 'getopt()' just returns 'args'; in both cases, the returned 'args' is a modified copy of the passed-in 'args' list, which is left untouched.""" if args is None: args = sys.argv[1:] if object is None: object = OptionDummy() created_object = 1 else: created_object = 0 self._grok_option_table() short_opts = string.join (self.short_opts) try: (opts, args) = getopt.getopt (args, short_opts, self.long_opts) except getopt.error, msg: raise DistutilsArgError, msg for (opt, val) in opts: if len (opt) == 2 and opt[0] == '-': # it's a short option opt = self.short2long[opt[1]] elif len (opt) > 2 and opt[0:2] == '--': opt = opt[2:] else: raise DistutilsInternalError, \ "this can't happen: bad option string '%s'" % opt if not self.takes_arg[opt]: # boolean option? if val != '': # shouldn't have a value! raise DistutilsInternalError, \ "this can't happen: bad option value '%s'" % value alias = self.negative_alias.get (opt) if alias: opt = alias val = 0 else: val = 1 attr = self.attr_name[opt] setattr (object, attr, val) self.option_order.append ((opt, val)) # for opts if created_object: return (args, object) else: return args # getopt() def get_option_order (self): """Returns the list of (option, value) tuples processed by the previous run of 'getopt()'. Raises RuntimeError if 'getopt()' hasn't been called yet.""" if self.option_order is None: raise RuntimeError, "'getopt()' hasn't been called yet" else: return self.option_order def generate_help (header=None): """Generate help text (a list of strings, one per suggested line of output) from the option table for this FancyGetopt object.""" # Blithely assume the option table is good: probably wouldn't call # 'generate_help()' unless you've already called 'getopt()'. # First pass: determine maximum length of long option names max_opt = 0 for option in self.option_table: long = option[0] short = option[1] l = len (long) if long[-1] == '=': l = l - 1 if short is not None: l = l + 5 # " (-x)" where short == 'x' if l > max_opt: max_opt = l opt_width = max_opt + 2 + 2 + 2 # room for indent + dashes + gutter # Typical help block looks like this: # --foo controls foonabulation # Help block for longest option looks like this: # --flimflam set the flim-flam level # and with wrapped text: # --flimflam set the flim-flam level (must be between # 0 and 100, except on Tuesdays) # Options with short names will have the short name shown (but # it doesn't contribute to max_opt): # --foo (-f) controls foonabulation # If adding the short option would make the left column too wide, # we push the explanation off to the next line # --flimflam (-l) # set the flim-flam level # Important parameters: # - 2 spaces before option block start lines # - 2 dashes for each long option name # - min. 2 spaces between option and explanation (gutter) # - 5 characters (incl. space) for short option name # Now generate lines of help text. (If 80 columns were good enough # for Jesus, then 78 columns are good enough for me!) line_width = 78 text_width = line_width - opt_width big_indent = ' ' * opt_width if header: lines = [header] else: lines = ['Option summary:'] for (long,short,help) in self.option_table: text = wrap_text (help, text_width) if long[-1] == '=': long = long[0:-1] # Case 1: no short option at all (makes life easy) if short is None: if text: lines.append (" --%-*s %s" % (max_opt, long, text[0])) else: lines.append (" --%-*s " % (max_opt, long)) for l in text[1:]: lines.append (big_indent + l) # Case 2: we have a short option, so we have to include it # just after the long option else: opt_names = "%s (-%s)" % (long, short) if text: lines.append (" --%-*s %s" % (max_opt, opt_names, text[0])) else: lines.append (" --%-*s" % opt_names) # for self.option_table return lines # generate_help () def print_help (self, file=None, header=None): if file is None: file = sys.stdout for line in self.generate_help (header): file.write (line + "\n") # print_help () # class FancyGetopt def fancy_getopt (options, negative_opt, object, args): parser = FancyGetopt (options) parser.set_negative_aliases (negative_opt) return parser.getopt (args, object) WS_TRANS = string.maketrans (string.whitespace, ' ' * len (string.whitespace)) def wrap_text (text, width): if text is None: return [] if len (text) <= width: return [text] text = string.expandtabs (text) text = string.translate (text, WS_TRANS) chunks = re.split (r'( +|-+)', text) chunks = filter (None, chunks) # ' - ' results in empty strings lines = [] while chunks: cur_line = [] # list of chunks (to-be-joined) cur_len = 0 # length of current line while chunks: l = len (chunks[0]) if cur_len + l <= width: # can squeeze (at least) this chunk in cur_line.append (chunks[0]) del chunks[0] cur_len = cur_len + l else: # this line is full # drop last chunk if all space if cur_line and cur_line[-1][0] == ' ': del cur_line[-1] break if chunks: # any chunks left to process? # if the current line is still empty, then we had a single # chunk that's too big too fit on a line -- so we break # down and break it up at the line width if cur_len == 0: cur_line.append (chunks[0][0:width]) chunks[0] = chunks[0][width:] # all-whitespace chunks at the end of a line can be discarded # (and we know from the re.split above that if a chunk has # *any* whitespace, it is *all* whitespace) if chunks[0][0] == ' ': del chunks[0] # and store this line in the list-of-all-lines -- as a single # string, of course! lines.append (string.join (cur_line, '')) # while chunks return lines # wrap_text () class OptionDummy: """Dummy class just used as a place to hold command-line option values as instance attributes.""" pass if __name__ == "__main__": text = """\ Tra-la-la, supercalifragilisticexpialidocious. How *do* you spell that odd word, anyways? (Someone ask Mary -- she'll know [or she'll say, "How should I know?"].)""" for w in (10, 20, 30, 40): print "width: %d" % w print string.join (wrap_text (text, w), "\n") print