docutils/frontend.py

   1 # $Id$
   2 # Author: David Goodger <goodger@python.org>
   3 # Copyright: This module has been placed in the public domain.
   4
   5 """
   6 Command-line and common processing for Docutils front-end tools.
   7
   8 Exports the following classes:
   9
  10 * `OptionParser`: Standard Docutils command-line processing.
  11 * `Option`: Customized version of `optparse.Option`; validation support.
  12 * `Values`: Runtime settings; objects are simple structs
  13   (``object.attribute``).  Supports cumulative list settings (attributes).
  14 * `ConfigParser`: Standard Docutils config file processing.
  15
  16 Also exports the following functions:
  17
  18 * Option callbacks: `store_multiple`, `read_config_file`.
  19 * Setting validators: `validate_encoding`,
  20   `validate_encoding_error_handler`,
  21   `validate_encoding_and_error_handler`, `validate_boolean`,
  22   `validate_threshold`, `validate_colon_separated_string_list`,
  23   `validate_dependency_file`.
  24 * `make_paths_absolute`.
  25 * SettingSpec manipulation: `filter_settings_spec`.
  26 """
  27
  28 __docformat__ = 'reStructuredText'
  29
  30 import os
  31 import os.path
  32 import sys
  33 import warnings
  34 import ConfigParser as CP
  35 import codecs
  36 import optparse
  37 from optparse import SUPPRESS_HELP
  38 import docutils
  39 import docutils.utils
  40 import docutils.nodes
  41 from docutils.error_reporting import locale_encoding, ErrorOutput, ErrorString
  42
  43
  44 def store_multiple(option, opt, value, parser, *args, **kwargs):
  45     """
  46     Store multiple values in `parser.values`.  (Option callback.)
  47
  48     Store `None` for each attribute named in `args`, and store the value for
  49     each key (attribute name) in `kwargs`.
  50     """
  51     for attribute in args:
  52         setattr(parser.values, attribute, None)
  53     for key, value in kwargs.items():
  54         setattr(parser.values, key, value)
  55
  56 def read_config_file(option, opt, value, parser):
  57     """
  58     Read a configuration file during option processing.  (Option callback.)
  59     """
  60     try:
  61         new_settings = parser.get_config_file_settings(value)
  62     except ValueError, error:
  63         parser.error(error)
  64     parser.values.update(new_settings, parser)
  65
  66 def validate_encoding(setting, value, option_parser,
  67                       config_parser=None, config_section=None):
  68     try:
  69         codecs.lookup(value)
  70     except LookupError:
  71         raise (LookupError('setting "%s": unknown encoding: "%s"'
  72                            % (setting, value)),
  73                None, sys.exc_info()[2])
  74     return value
  75
  76 def validate_encoding_error_handler(setting, value, option_parser,
  77                                     config_parser=None, config_section=None):
  78     try:
  79         codecs.lookup_error(value)
  80     except LookupError:
  81         raise (LookupError(
  82             'unknown encoding error handler: "%s" (choices: '
  83             '"strict", "ignore", "replace", "backslashreplace", '
  84             '"xmlcharrefreplace", and possibly others; see documentation for '
  85             'the Python ``codecs`` module)' % value),
  86                None, sys.exc_info()[2])
  87     return value
  88
  89 def validate_encoding_and_error_handler(
  90     setting, value, option_parser, config_parser=None, config_section=None):
  91     """
  92     Side-effect: if an error handler is included in the value, it is inserted
  93     into the appropriate place as if it was a separate setting/option.
  94     """
  95     if ':' in value:
  96         encoding, handler = value.split(':')
  97         validate_encoding_error_handler(
  98             setting + '_error_handler', handler, option_parser,
  99             config_parser, config_section)
 100         if config_parser:
 101             config_parser.set(config_section, setting + '_error_handler',
 102                               handler)
 103         else:
 104             setattr(option_parser.values, setting + '_error_handler', handler)
 105     else:
 106         encoding = value
 107     validate_encoding(setting, encoding, option_parser,
 108                       config_parser, config_section)
 109     return encoding
 110
 111 def validate_boolean(setting, value, option_parser,
 112                      config_parser=None, config_section=None):
 113     if isinstance(value, unicode):
 114         try:
 115             return option_parser.booleans[value.strip().lower()]
 116         except KeyError:
 117             raise (LookupError('unknown boolean value: "%s"' % value),
 118                    None, sys.exc_info()[2])
 119     return value
 120
 121 def validate_nonnegative_int(setting, value, option_parser,
 122                              config_parser=None, config_section=None):
 123     value = int(value)
 124     if value < 0:
 125         raise ValueError('negative value; must be positive or zero')
 126     return value
 127
 128 def validate_threshold(setting, value, option_parser,
 129                        config_parser=None, config_section=None):
 130     try:
 131         return int(value)
 132     except ValueError:
 133         try:
 134             return option_parser.thresholds[value.lower()]
 135         except (KeyError, AttributeError):
 136             raise (LookupError('unknown threshold: %r.' % value),
 137                    None, sys.exc_info[2])
 138
 139 def validate_colon_separated_string_list(
 140     setting, value, option_parser, config_parser=None, config_section=None):
 141     if isinstance(value, unicode):
 142         value = value.split(':')
 143     else:
 144         last = value.pop()
 145         value.extend(last.split(':'))
 146     return value
 147
 148 def validate_url_trailing_slash(
 149     setting, value, option_parser, config_parser=None, config_section=None):
 150     if not value:
 151         return './'
 152     elif value.endswith('/'):
 153         return value
 154     else:
 155         return value + '/'
 156
 157 def validate_dependency_file(setting, value, option_parser,
 158                              config_parser=None, config_section=None):
 159     try:
 160         return docutils.utils.DependencyList(value)
 161     except IOError:
 162         return docutils.utils.DependencyList(None)
 163
 164 def validate_strip_class(setting, value, option_parser,
 165                          config_parser=None, config_section=None):
 166     # convert to list:
 167     if isinstance(value, unicode):
 168         value = [value]
 169     class_values = filter(None, [v.strip() for v in value.pop().split(',')])
 170     # validate:
 171     for class_value in class_values:
 172         normalized = docutils.nodes.make_id(class_value)
 173         if class_value != normalized:
 174             raise ValueError('invalid class value %r (perhaps %r?)'
 175                              % (class_value, normalized))
 176     value.extend(class_values)
 177     return value
 178
 179 def make_paths_absolute(pathdict, keys, base_path=None):
 180     """
 181     Interpret filesystem path settings relative to the `base_path` given.
 182
 183     Paths are values in `pathdict` whose keys are in `keys`.  Get `keys` from
 184     `OptionParser.relative_path_settings`.
 185     """
 186     if base_path is None:
 187         base_path = os.getcwd()
 188     for key in keys:
 189         if key in pathdict:
 190             value = pathdict[key]
 191             if isinstance(value, list):
 192                 value = [make_one_path_absolute(base_path, path)
 193                          for path in value]
 194             elif value:
 195                 value = make_one_path_absolute(base_path, value)
 196             pathdict[key] = value
 197
 198 def make_one_path_absolute(base_path, path):
 199     return os.path.abspath(os.path.join(base_path, path))
 200
 201 def filter_settings_spec(settings_spec, *exclude, **replace):
 202     """Return a copy of `settings_spec` excluding/replacing some settings.
 203
 204     `settings_spec` is a tuple of configuration settings with a structure
 205     described for docutils.SettingsSpec.settings_spec.
 206
 207     Optional positional arguments are names of to-be-excluded settings.
 208     Keyword arguments are option specification replacements.
 209     (See the html4strict writer for an example.)
 210     """
 211     settings = list(settings_spec)
 212     # every third item is a sequence of option tuples
 213     for i in range(2, len(settings), 3):
 214         newopts = []
 215         for opt_spec in settings[i]:
 216             # opt_spec is ("<help>", [<option strings>], {<keyword args>})
 217             opt_name = [opt_string[2:].replace('-', '_')
 218                         for opt_string in opt_spec[1]
 219                             if opt_string.startswith('--')
 220                        ][0]
 221             if opt_name in exclude:
 222                 continue
 223             if opt_name in replace.keys():
 224                 newopts.append(replace[opt_name])
 225             else:
 226                 newopts.append(opt_spec)
 227         settings[i] = tuple(newopts)
 228     return tuple(settings)
 229
 230
 231 class Values(optparse.Values):
 232
 233     """
 234     Updates list attributes by extension rather than by replacement.
 235     Works in conjunction with the `OptionParser.lists` instance attribute.
 236     """
 237
 238     def __init__(self, *args, **kwargs):
 239         optparse.Values.__init__(self, *args, **kwargs)
 240         if (not hasattr(self, 'record_dependencies')
 241             or self.record_dependencies is None):
 242             # Set up dependency list, in case it is needed.
 243             self.record_dependencies = docutils.utils.DependencyList()
 244
 245     def update(self, other_dict, option_parser):
 246         if isinstance(other_dict, Values):
 247             other_dict = other_dict.__dict__
 248         other_dict = other_dict.copy()
 249         for setting in option_parser.lists.keys():
 250             if (hasattr(self, setting) and setting in other_dict):
 251                 value = getattr(self, setting)
 252                 if value:
 253                     value += other_dict[setting]
 254                     del other_dict[setting]
 255         self._update_loose(other_dict)
 256
 257     def copy(self):
 258         """Return a shallow copy of `self`."""
 259         return self.__class__(defaults=self.__dict__)
 260
 261
 262 class Option(optparse.Option):
 263
 264     ATTRS = optparse.Option.ATTRS + ['validator', 'overrides']
 265
 266     def process(self, opt, value, values, parser):
 267         """
 268         Call the validator function on applicable settings and
 269         evaluate the 'overrides' option.
 270         Extends `optparse.Option.process`.
 271         """
 272         result = optparse.Option.process(self, opt, value, values, parser)
 273         setting = self.dest
 274         if setting:
 275             if self.validator:
 276                 value = getattr(values, setting)
 277                 try:
 278                     new_value = self.validator(setting, value, parser)
 279                 except Exception, error:
 280                     raise (optparse.OptionValueError(
 281                         'Error in option "%s":\n    %s'
 282                         % (opt, ErrorString(error))),
 283                            None, sys.exc_info()[2])
 284                 setattr(values, setting, new_value)
 285             if self.overrides:
 286                 setattr(values, self.overrides, None)
 287         return result
 288
 289
 290 class OptionParser(optparse.OptionParser, docutils.SettingsSpec):
 291
 292     """
 293     Parser for command-line and library use.  The `settings_spec`
 294     specification here and in other Docutils components are merged to build
 295     the set of command-line options and runtime settings for this process.
 296
 297     Common settings (defined below) and component-specific settings must not
 298     conflict.  Short options are reserved for common settings, and components
 299     are restrict to using long options.
 300     """
 301
 302     standard_config_files = [
 303         '/etc/docutils.conf',           # system-wide
 304         './docutils.conf',              # project-specific
 305         '~/.docutils']                  # user-specific
 306     """Docutils configuration files, using ConfigParser syntax.  Filenames
 307     will be tilde-expanded later.  Later files override earlier ones."""
 308
 309     threshold_choices = 'info 1 warning 2 error 3 severe 4 none 5'.split()
 310     """Possible inputs for for --report and --halt threshold values."""
 311
 312     thresholds = {'info': 1, 'warning': 2, 'error': 3, 'severe': 4, 'none': 5}
 313     """Lookup table for --report and --halt threshold values."""
 314
 315     booleans={'1': 1, 'on': 1, 'yes': 1, 'true': 1,
 316               '0': 0, 'off': 0, 'no': 0, 'false': 0, '': 0}
 317     """Lookup table for boolean configuration file settings."""
 318
 319     default_error_encoding = getattr(sys.stderr, 'encoding',
 320                                      None) or locale_encoding or 'ascii'
 321
 322     default_error_encoding_error_handler = 'backslashreplace'
 323
 324     settings_spec = (
 325         'General Docutils Options',
 326         None,
 327         (('Specify the document title as metadata.',
 328           ['--title'], {}),
 329          ('Include a "Generated by Docutils" credit and link.',
 330           ['--generator', '-g'], {'action': 'store_true',
 331                                   'validator': validate_boolean}),
 332          ('Do not include a generator credit.',
 333           ['--no-generator'], {'action': 'store_false', 'dest': 'generator'}),
 334          ('Include the date at the end of the document (UTC).',
 335           ['--date', '-d'], {'action': 'store_const', 'const': '%Y-%m-%d',
 336                              'dest': 'datestamp'}),
 337          ('Include the time & date (UTC).',
 338           ['--time', '-t'], {'action': 'store_const',
 339                              'const': '%Y-%m-%d %H:%M UTC',
 340                              'dest': 'datestamp'}),
 341          ('Do not include a datestamp of any kind.',
 342           ['--no-datestamp'], {'action': 'store_const', 'const': None,
 343                                'dest': 'datestamp'}),
 344          ('Include a "View document source" link.',
 345           ['--source-link', '-s'], {'action': 'store_true',
 346                                     'validator': validate_boolean}),
 347          ('Use <URL> for a source link; implies --source-link.',
 348           ['--source-url'], {'metavar': '<URL>'}),
 349          ('Do not include a "View document source" link.',
 350           ['--no-source-link'],
 351           {'action': 'callback', 'callback': store_multiple,
 352            'callback_args': ('source_link', 'source_url')}),
 353          ('Link from section headers to TOC entries.  (default)',
 354           ['--toc-entry-backlinks'],
 355           {'dest': 'toc_backlinks', 'action': 'store_const', 'const': 'entry',
 356            'default': 'entry'}),
 357          ('Link from section headers to the top of the TOC.',
 358           ['--toc-top-backlinks'],
 359           {'dest': 'toc_backlinks', 'action': 'store_const', 'const': 'top'}),
 360          ('Disable backlinks to the table of contents.',
 361           ['--no-toc-backlinks'],
 362           {'dest': 'toc_backlinks', 'action': 'store_false'}),
 363          ('Link from footnotes/citations to references. (default)',
 364           ['--footnote-backlinks'],
 365           {'action': 'store_true', 'default': 1,
 366            'validator': validate_boolean}),
 367          ('Disable backlinks from footnotes and citations.',
 368           ['--no-footnote-backlinks'],
 369           {'dest': 'footnote_backlinks', 'action': 'store_false'}),
 370          ('Enable section numbering by Docutils.  (default)',
 371           ['--section-numbering'],
 372           {'action': 'store_true', 'dest': 'sectnum_xform',
 373            'default': 1, 'validator': validate_boolean}),
 374          ('Disable section numbering by Docutils.',
 375           ['--no-section-numbering'],
 376           {'action': 'store_false', 'dest': 'sectnum_xform'}),
 377          ('Remove comment elements from the document tree.',
 378           ['--strip-comments'],
 379           {'action': 'store_true', 'validator': validate_boolean}),
 380          ('Leave comment elements in the document tree. (default)',
 381           ['--leave-comments'],
 382           {'action': 'store_false', 'dest': 'strip_comments'}),
 383          ('Remove all elements with classes="<class>" from the document tree. '
 384           'Warning: potentially dangerous; use with caution. '
 385           '(Multiple-use option.)',
 386           ['--strip-elements-with-class'],
 387           {'action': 'append', 'dest': 'strip_elements_with_classes',
 388            'metavar': '<class>', 'validator': validate_strip_class}),
 389          ('Remove all classes="<class>" attributes from elements in the '
 390           'document tree. Warning: potentially dangerous; use with caution. '
 391           '(Multiple-use option.)',
 392           ['--strip-class'],
 393           {'action': 'append', 'dest': 'strip_classes',
 394            'metavar': '<class>', 'validator': validate_strip_class}),
 395          ('Report system messages at or higher than <level>: "info" or "1", '
 396           '"warning"/"2" (default), "error"/"3", "severe"/"4", "none"/"5"',
 397           ['--report', '-r'], {'choices': threshold_choices, 'default': 2,
 398                                'dest': 'report_level', 'metavar': '<level>',
 399                                'validator': validate_threshold}),
 400          ('Report all system messages.  (Same as "--report=1".)',
 401           ['--verbose', '-v'], {'action': 'store_const', 'const': 1,
 402                                 'dest': 'report_level'}),
 403          ('Report no system messages.  (Same as "--report=5".)',
 404           ['--quiet', '-q'], {'action': 'store_const', 'const': 5,
 405                               'dest': 'report_level'}),
 406          ('Halt execution at system messages at or above <level>.  '
 407           'Levels as in --report.  Default: 4 (severe).',
 408           ['--halt'], {'choices': threshold_choices, 'dest': 'halt_level',
 409                        'default': 4, 'metavar': '<level>',
 410                        'validator': validate_threshold}),
 411          ('Halt at the slightest problem.  Same as "--halt=info".',
 412           ['--strict'], {'action': 'store_const', 'const': 1,
 413                          'dest': 'halt_level'}),
 414          ('Enable a non-zero exit status for non-halting system messages at '
 415           'or above <level>.  Default: 5 (disabled).',
 416           ['--exit-status'], {'choices': threshold_choices,
 417                               'dest': 'exit_status_level',
 418                               'default': 5, 'metavar': '<level>',
 419                               'validator': validate_threshold}),
 420          ('Enable debug-level system messages and diagnostics.',
 421           ['--debug'], {'action': 'store_true', 'validator': validate_boolean}),
 422          ('Disable debug output.  (default)',
 423           ['--no-debug'], {'action': 'store_false', 'dest': 'debug'}),
 424          ('Send the output of system messages to <file>.',
 425           ['--warnings'], {'dest': 'warning_stream', 'metavar': '<file>'}),
 426          ('Enable Python tracebacks when Docutils is halted.',
 427           ['--traceback'], {'action': 'store_true', 'default': None,
 428                             'validator': validate_boolean}),
 429          ('Disable Python tracebacks.  (default)',
 430           ['--no-traceback'], {'dest': 'traceback', 'action': 'store_false'}),
 431          ('Specify the encoding and optionally the '
 432           'error handler of input text.  Default: <locale-dependent>:strict.',
 433           ['--input-encoding', '-i'],
 434           {'metavar': '<name[:handler]>',
 435            'validator': validate_encoding_and_error_handler}),
 436          ('Specify the error handler for undecodable characters.  '
 437           'Choices: "strict" (default), "ignore", and "replace".',
 438           ['--input-encoding-error-handler'],
 439           {'default': 'strict', 'validator': validate_encoding_error_handler}),
 440          ('Specify the text encoding and optionally the error handler for '
 441           'output.  Default: UTF-8:strict.',
 442           ['--output-encoding', '-o'],
 443           {'metavar': '<name[:handler]>', 'default': 'utf-8',
 444            'validator': validate_encoding_and_error_handler}),
 445          ('Specify error handler for unencodable output characters; '
 446           '"strict" (default), "ignore", "replace", '
 447           '"xmlcharrefreplace", "backslashreplace".',
 448           ['--output-encoding-error-handler'],
 449           {'default': 'strict', 'validator': validate_encoding_error_handler}),
 450          ('Specify text encoding and error handler for error output.  '
 451           'Default: %s:%s.'
 452           % (default_error_encoding, default_error_encoding_error_handler),
 453           ['--error-encoding', '-e'],
 454           {'metavar': '<name[:handler]>', 'default': default_error_encoding,
 455            'validator': validate_encoding_and_error_handler}),
 456          ('Specify the error handler for unencodable characters in '
 457           'error output.  Default: %s.'
 458           % default_error_encoding_error_handler,
 459           ['--error-encoding-error-handler'],
 460           {'default': default_error_encoding_error_handler,
 461            'validator': validate_encoding_error_handler}),
 462          ('Specify the language (as BCP 47 language tag).  Default: en.',
 463           ['--language', '-l'], {'dest': 'language_code', 'default': 'en',
 464                                  'metavar': '<name>'}),
 465          ('Write output file dependencies to <file>.',
 466           ['--record-dependencies'],
 467           {'metavar': '<file>', 'validator': validate_dependency_file,
 468            'default': None}),           # default set in Values class
 469          ('Read configuration settings from <file>, if it exists.',
 470           ['--config'], {'metavar': '<file>', 'type': 'string',
 471                          'action': 'callback', 'callback': read_config_file}),
 472          ("Show this program's version number and exit.",
 473           ['--version', '-V'], {'action': 'version'}),
 474          ('Show this help message and exit.',
 475           ['--help', '-h'], {'action': 'help'}),
 476          # Typically not useful for non-programmatical use:
 477          (SUPPRESS_HELP, ['--id-prefix'], {'default': ''}),
 478          (SUPPRESS_HELP, ['--auto-id-prefix'], {'default': 'id'}),
 479          # Hidden options, for development use only:
 480          (SUPPRESS_HELP, ['--dump-settings'], {'action': 'store_true'}),
 481          (SUPPRESS_HELP, ['--dump-internals'], {'action': 'store_true'}),
 482          (SUPPRESS_HELP, ['--dump-transforms'], {'action': 'store_true'}),
 483          (SUPPRESS_HELP, ['--dump-pseudo-xml'], {'action': 'store_true'}),
 484          (SUPPRESS_HELP, ['--expose-internal-attribute'],
 485           {'action': 'append', 'dest': 'expose_internals',
 486            'validator': validate_colon_separated_string_list}),
 487          (SUPPRESS_HELP, ['--strict-visitor'], {'action': 'store_true'}),
 488          ))
 489     """Runtime settings and command-line options common to all Docutils front
 490     ends.  Setting specs specific to individual Docutils components are also
 491     used (see `populate_from_components()`)."""
 492
 493     settings_defaults = {'_disable_config': None,
 494                          '_source': None,
 495                          '_destination': None,
 496                          '_config_files': None}
 497     """Defaults for settings that don't have command-line option equivalents."""
 498
 499     relative_path_settings = ('warning_stream',)
 500
 501     config_section = 'general'
 502
 503     version_template = ('%%prog (Docutils %s [%s], Python %s, on %s)'
 504                         % (docutils.__version__, docutils.__version_details__,
 505                            sys.version.split()[0], sys.platform))
 506     """Default version message."""
 507
 508     def __init__(self, components=(), defaults=None, read_config_files=None,
 509                  *args, **kwargs):
 510         """
 511         `components` is a list of Docutils components each containing a
 512         ``.settings_spec`` attribute.  `defaults` is a mapping of setting
 513         default overrides.
 514         """
 515
 516         self.lists = {}
 517         """Set of list-type settings."""
 518
 519         self.config_files = []
 520         """List of paths of applied configuration files."""
 521
 522         optparse.OptionParser.__init__(
 523             self, option_class=Option, add_help_option=None,
 524             formatter=optparse.TitledHelpFormatter(width=78),
 525             *args, **kwargs)
 526         if not self.version:
 527             self.version = self.version_template
 528         # Make an instance copy (it will be modified):
 529         self.relative_path_settings = list(self.relative_path_settings)
 530         self.components = (self,) + tuple(components)
 531         self.populate_from_components(self.components)
 532         self.set_defaults_from_dict(defaults or {})
 533         if read_config_files and not self.defaults['_disable_config']:
 534             try:
 535                 config_settings = self.get_standard_config_settings()
 536             except ValueError, error:
 537                 self.error(error)
 538             self.set_defaults_from_dict(config_settings.__dict__)
 539
 540     def populate_from_components(self, components):
 541         """
 542         For each component, first populate from the `SettingsSpec.settings_spec`
 543         structure, then from the `SettingsSpec.settings_defaults` dictionary.
 544         After all components have been processed, check for and populate from
 545         each component's `SettingsSpec.settings_default_overrides` dictionary.
 546         """
 547         for component in components:
 548             if component is None:
 549                 continue
 550             settings_spec = component.settings_spec
 551             self.relative_path_settings.extend(
 552                 component.relative_path_settings)
 553             for i in range(0, len(settings_spec), 3):
 554                 title, description, option_spec = settings_spec[i:i+3]
 555                 if title:
 556                     group = optparse.OptionGroup(self, title, description)
 557                     self.add_option_group(group)
 558                 else:
 559                     group = self        # single options
 560                 for (help_text, option_strings, kwargs) in option_spec:
 561                     option = group.add_option(help=help_text, *option_strings,
 562                                               **kwargs)
 563                     if kwargs.get('action') == 'append':
 564                         self.lists[option.dest] = 1
 565                 if component.settings_defaults:
 566                     self.defaults.update(component.settings_defaults)
 567         for component in components:
 568             if component and component.settings_default_overrides:
 569                 self.defaults.update(component.settings_default_overrides)
 570
 571     def get_standard_config_files(self):
 572         """Return list of config files, from environment or standard."""
 573         try:
 574             config_files = os.environ['DOCUTILSCONFIG'].split(os.pathsep)
 575         except KeyError:
 576             config_files = self.standard_config_files
 577
 578         # If 'HOME' is not set, expandvars() requires the 'pwd' module which is
 579         # not available under certain environments, for example, within
 580         # mod_python.  The publisher ends up in here, and we need to publish
 581         # from within mod_python.  Therefore we need to avoid expanding when we
 582         # are in those environments.
 583         expand = os.path.expanduser
 584         if 'HOME' not in os.environ:
 585             try:
 586                 import pwd
 587             except ImportError:
 588                 expand = lambda x: x
 589         return [expand(f) for f in config_files if f.strip()]
 590
 591     def get_standard_config_settings(self):
 592         settings = Values()
 593         for filename in self.get_standard_config_files():
 594             settings.update(self.get_config_file_settings(filename), self)
 595         return settings
 596
 597     def get_config_file_settings(self, config_file):
 598         """Returns a dictionary containing appropriate config file settings."""
 599         parser = ConfigParser()
 600         parser.read(config_file, self)
 601         self.config_files.extend(parser._files)
 602         base_path = os.path.dirname(config_file)
 603         applied = {}
 604         settings = Values()
 605         for component in self.components:
 606             if not component:
 607                 continue
 608             for section in (tuple(component.config_section_dependencies or ())
 609                             + (component.config_section,)):
 610                 if section in applied:
 611                     continue
 612                 applied[section] = 1
 613                 settings.update(parser.get_section(section), self)
 614         make_paths_absolute(
 615             settings.__dict__, self.relative_path_settings, base_path)
 616         return settings.__dict__
 617
 618     def check_values(self, values, args):
 619         """Store positional arguments as runtime settings."""
 620         values._source, values._destination = self.check_args(args)
 621         make_paths_absolute(values.__dict__, self.relative_path_settings,
 622                             os.getcwd())
 623         values._config_files = self.config_files
 624         return values
 625
 626     def check_args(self, args):
 627         source = destination = None
 628         if args:
 629             source = args.pop(0)
 630             if source == '-':           # means stdin
 631                 source = None
 632         if args:
 633             destination = args.pop(0)
 634             if destination == '-':      # means stdout
 635                 destination = None
 636         if args:
 637             self.error('Maximum 2 arguments allowed.')
 638         if source and source == destination:
 639             self.error('Do not specify the same file for both source and '
 640                        'destination.  It will clobber the source file.')
 641         return source, destination
 642
 643     def set_defaults_from_dict(self, defaults):
 644         self.defaults.update(defaults)
 645
 646     def get_default_values(self):
 647         """Needed to get custom `Values` instances."""
 648         defaults = Values(self.defaults)
 649         defaults._config_files = self.config_files
 650         return defaults
 651
 652     def get_option_by_dest(self, dest):
 653         """
 654         Get an option by its dest.
 655
 656         If you're supplying a dest which is shared by several options,
 657         it is undefined which option of those is returned.
 658
 659         A KeyError is raised if there is no option with the supplied
 660         dest.
 661         """
 662         for group in self.option_groups + [self]:
 663             for option in group.option_list:
 664                 if option.dest == dest:
 665                     return option
 666         raise KeyError('No option with dest == %r.' % dest)
 667
 668
 669 class ConfigParser(CP.RawConfigParser):
 670
 671     old_settings = {
 672         'pep_stylesheet': ('pep_html writer', 'stylesheet'),
 673         'pep_stylesheet_path': ('pep_html writer', 'stylesheet_path'),
 674         'pep_template': ('pep_html writer', 'template')}
 675     """{old setting: (new section, new setting)} mapping, used by
 676     `handle_old_config`, to convert settings from the old [options] section."""
 677
 678     old_warning = """
 679 The "[option]" section is deprecated.  Support for old-format configuration
 680 files may be removed in a future Docutils release.  Please revise your
 681 configuration files.  See <http://docutils.sf.net/docs/user/config.html>,
 682 section "Old-Format Configuration Files".
 683 """
 684
 685     not_utf8_error = """\
 686 Unable to read configuration file "%s": content not encoded as UTF-8.
 687 Skipping "%s" configuration file.
 688 """
 689
 690     def __init__(self, *args, **kwargs):
 691         CP.RawConfigParser.__init__(self, *args, **kwargs)
 692
 693         self._files = []
 694         """List of paths of configuration files read."""
 695
 696         self._stderr = ErrorOutput()
 697         """Wrapper around sys.stderr catching en-/decoding errors"""
 698
 699     def read(self, filenames, option_parser):
 700         if type(filenames) in (str, unicode):
 701             filenames = [filenames]
 702         for filename in filenames:
 703             try:
 704                 # Config files must be UTF-8-encoded:
 705                 fp = codecs.open(filename, 'r', 'utf-8')
 706             except IOError:
 707                 continue
 708             try:
 709                 if sys.version_info < (3,2):
 710                     CP.RawConfigParser.readfp(self, fp, filename)
 711                 else:
 712                     CP.RawConfigParser.read_file(self, fp, filename)
 713             except UnicodeDecodeError:
 714                 self._stderr.write(self.not_utf8_error % (filename, filename))
 715                 fp.close()
 716                 continue
 717             fp.close()
 718             self._files.append(filename)
 719             if self.has_section('options'):
 720                 self.handle_old_config(filename)
 721             self.validate_settings(filename, option_parser)
 722
 723     def handle_old_config(self, filename):
 724         warnings.warn_explicit(self.old_warning, ConfigDeprecationWarning,
 725                                filename, 0)
 726         options = self.get_section('options')
 727         if not self.has_section('general'):
 728             self.add_section('general')
 729         for key, value in options.items():
 730             if key in self.old_settings:
 731                 section, setting = self.old_settings[key]
 732                 if not self.has_section(section):
 733                     self.add_section(section)
 734             else:
 735                 section = 'general'
 736                 setting = key
 737             if not self.has_option(section, setting):
 738                 self.set(section, setting, value)
 739         self.remove_section('options')
 740
 741     def validate_settings(self, filename, option_parser):
 742         """
 743         Call the validator function and implement overrides on all applicable
 744         settings.
 745         """
 746         for section in self.sections():
 747             for setting in self.options(section):
 748                 try:
 749                     option = option_parser.get_option_by_dest(setting)
 750                 except KeyError:
 751                     continue
 752                 if option.validator:
 753                     value = self.get(section, setting)
 754                     try:
 755                         new_value = option.validator(
 756                             setting, value, option_parser,
 757                             config_parser=self, config_section=section)
 758                     except Exception, error:
 759                         raise (ValueError(
 760                             'Error in config file "%s", section "[%s]":\n'
 761                             '    %s\n'
 762                             '        %s = %s'
 763                             % (filename, section, ErrorString(error),
 764                                setting, value)), None, sys.exc_info()[2])
 765                     self.set(section, setting, new_value)
 766                 if option.overrides:
 767                     self.set(section, option.overrides, None)
 768
 769     def optionxform(self, optionstr):
 770         """
 771         Transform '-' to '_' so the cmdline form of option names can be used.
 772         """
 773         return optionstr.lower().replace('-', '_')
 774
 775     def get_section(self, section):
 776         """
 777         Return a given section as a dictionary (empty if the section
 778         doesn't exist).
 779         """
 780         section_dict = {}
 781         if self.has_section(section):
 782             for option in self.options(section):
 783                 section_dict[option] = self.get(section, option)
 784         return section_dict
 785
 786
 787 class ConfigDeprecationWarning(DeprecationWarning):
 788     """Warning for deprecated configuration file features."""