scripts/dtrx

#!/usr/bin/env python
#
# dtrx -- Intelligently extract various archive types.
# Copyright (c) 2006, 2007 Brett Smith <brettcsmith@brettcsmith.org>.
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 3 of the License, or (at your
# option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
# Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, 5th Floor, Boston, MA, 02111.

import errno
import logging
import mimetypes
import optparse
import os
import re
import stat
import subprocess
import sys
import tempfile
import textwrap
import traceback

VERSION = "5.0"
VERSION_BANNER = """dtrx version %s
Copyright (c) 2006, 2007 Brett Smith <brettcsmith@brettcsmith.org>

This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3 of the License, or (at your
option) any later version.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
Public License for more details.""" % (VERSION,)

MATCHING_DIRECTORY = 1
ONE_ENTRY = 2
BOMB = 3
EMPTY = 4
ONE_ENTRY_KNOWN = 5

EXTRACT_HERE = 1
EXTRACT_WRAP = 2
EXTRACT_RENAME = 3

RECURSE_ALWAYS = 1
RECURSE_ONCE = 2
RECURSE_NOT_NOW = 3
RECURSE_NEVER = 4

mimetypes.encodings_map.setdefault('.bz2', 'bzip2')
mimetypes.types_map.setdefault('.gem', 'x-ruby-gem')

logger = logging.getLogger('dtrx-log')

def run_command(command, description, stdout=None, stderr=None, stdin=None):
    process = subprocess.Popen(command, stdin=stdin, stdout=stdout,
                               stderr=stderr)
    status = process.wait()
    for pipe in (process.stdout, process.stderr):
        try:
            pipe.close()
        except AttributeError:
            pass
    if status != 0:
        return ("%s error: '%s' returned status code %s" %
                (description, ' '.join(command), status))
    return None

class FilenameChecker(object):
    def __init__(self, original_name):
        self.original_name = original_name

    def is_free(self, filename):
        return not os.path.exists(filename)

    def check(self):
        for suffix in [''] + ['.%s' % (x,) for x in range(1, 10)]:
            filename = '%s%s' % (self.original_name, suffix)
            if self.is_free(filename):
                return filename
        raise ValueError("all alternatives for name %s taken" %
                         (self.original_name,))
        

class DirectoryChecker(FilenameChecker):
    def is_free(self, filename):
        try:
            os.mkdir(filename)
        except OSError, error:
            if error.errno == errno.EEXIST:
                return False
            raise
        return True


class ExtractorError(Exception):
    pass


class BaseExtractor(object):
    decoders = {'bzip2': 'bzcat', 'gzip': 'zcat', 'compress': 'zcat'}

    name_checker = DirectoryChecker

    def __init__(self, filename, encoding):
        if encoding and (not self.decoders.has_key(encoding)):
            raise ValueError("unrecognized encoding %s" % (encoding,))
        self.filename = os.path.realpath(filename)
        self.encoding = encoding
        self.included_archives = []
        self.target = None
        self.content_type = None
        self.content_name = None
        self.pipes = []
        try:
            self.archive = open(filename, 'r')
        except (IOError, OSError), error:
            raise ExtractorError("could not open %s: %s" %
                                 (filename, error.strerror))
        if encoding:
            self.pipe([self.decoders[encoding]], "decoding")
        self.prepare()

    def pipe(self, command, description="extraction"):
        self.pipes.append((command, description))

    def run_pipes(self, final_stdout=None):
        if final_stdout is None:
            # FIXME: Buffering this might be dumb.
            final_stdout = tempfile.TemporaryFile()
        if not self.pipes:
            return
        num_pipes = len(self.pipes)
        last_pipe = num_pipes - 1
        processes = []
        for index, command in enumerate([pipe[0] for pipe in self.pipes]):
            if index == 0:
                stdin = self.archive
            else:
                stdin = processes[-1].stdout
            if index == last_pipe:
                stdout = final_stdout
            else:
                stdout = subprocess.PIPE
            processes.append(subprocess.Popen(command, stdin=stdin,
                                              stdout=stdout,
                                              stderr=subprocess.PIPE))
        exit_codes = [pipe.wait() for pipe in processes]
        self.archive.close()
        for index in range(last_pipe):
            processes[index].stdout.close()
            processes[index].stderr.close()
        for index, status in enumerate(exit_codes):
            if status != 0:
                raise ExtractorError("%s error: '%s' returned status code %s" %
                                     (self.pipes[index][1],
                                      ' '.join(self.pipes[index][0]), status))
        self.archive = final_stdout
    
    def prepare(self):
        pass

    def check_included_archives(self, filenames):
        for filename in filenames:
            if (ExtractorBuilder.try_by_mimetype(filename)[0] or
                ExtractorBuilder.try_by_extension(filename)[0]):
                self.included_archives.append(filename)

    def check_contents(self):
        filenames = os.listdir('.')
        if not filenames:
            self.content_type = EMPTY
        elif len(filenames) == 1:
            if self.basename() == filenames[0]:
                self.content_type = MATCHING_DIRECTORY
            else:
                self.content_type = ONE_ENTRY
            self.content_name = filenames[0]
            if os.path.isdir(filenames[0]):
                self.content_name += '/'
        else:
            self.content_type = BOMB
        self.check_included_archives(filenames)

    def basename(self):
        pieces = os.path.basename(self.filename).split('.')
        extension = '.' + pieces[-1]
        if mimetypes.encodings_map.has_key(extension):
            pieces.pop()
            extension = '.' + pieces[-1]
        if (mimetypes.types_map.has_key(extension) or
            mimetypes.common_types.has_key(extension) or
            mimetypes.suffix_map.has_key(extension)):
            pieces.pop()
        return '.'.join(pieces)

    def extract(self):
        self.target = tempfile.mkdtemp(prefix='.dtrx-', dir='.')
        old_path = os.path.realpath(os.curdir)
        os.chdir(self.target)
        try:
            self.archive.seek(0, 0)
            self.extract_archive()
            self.check_contents()
        except ExtractorError:
            os.chdir(old_path)
            subprocess.call(['rm', '-rf', self.target])
            raise
        os.chdir(old_path)

    def get_filenames(self):
        self.run_pipes()
        self.archive.seek(0, 0)
        while True:
            line = self.archive.readline()
            if not line:
                self.archive.close()
                return
            yield line.rstrip('\n')
    

class CompressionExtractor(BaseExtractor):
    name_checker = FilenameChecker

    def basename(self):
        pieces = os.path.basename(self.filename).split('.')
        extension = '.' + pieces[-1]
        if mimetypes.encodings_map.has_key(extension):
            pieces.pop()
        return '.'.join(pieces)

    def get_filenames(self):
        yield self.basename()

    def extract(self):
        self.content_type = ONE_ENTRY_KNOWN
        self.content_name = self.basename()
        output_fd, self.target = tempfile.mkstemp(prefix='.dtrx-', dir='.')
        self.run_pipes(output_fd)
        os.close(output_fd)
        

class TarExtractor(BaseExtractor):
    def get_filenames(self):
        self.pipe(['tar', '-t'], "listing")
        return BaseExtractor.get_filenames(self)

    def extract_archive(self): 
        self.pipe(['tar', '-x'])
        self.run_pipes()
        
        
class ZipExtractor(BaseExtractor):
    def __init__(self, filename, encoding):
        BaseExtractor.__init__(self, '/dev/null', None)
        self.filename = os.path.realpath(filename)

    def get_filenames(self):
        self.pipe(['zipinfo', '-1', self.filename], "listing")
        return BaseExtractor.get_filenames(self)

    def extract_archive(self):
        self.pipe(['unzip', '-q', self.filename])
        self.run_pipes()


class CpioExtractor(BaseExtractor):
    def get_filenames(self):
        self.pipe(['cpio', '-t'], "listing")
        return BaseExtractor.get_filenames(self)

    def extract_archive(self):
        self.pipe(['cpio', '-i', '--make-directories',
                   '--no-absolute-filenames'])
        self.run_pipes()


class RPMExtractor(CpioExtractor):
    def prepare(self):
        self.pipe(['rpm2cpio', '-'], "rpm2cpio")

    def basename(self):
        pieces = os.path.basename(self.filename).split('.')
        if len(pieces) == 1:
            return pieces[0]
        elif pieces[-1] != 'rpm':
            return BaseExtractor.basename(self)
        pieces.pop()
        if len(pieces) == 1:
            return pieces[0]
        elif len(pieces[-1]) < 8:
            pieces.pop()
        return '.'.join(pieces)

    def check_contents(self):
        self.check_included_archives(os.listdir('.'))
        self.content_type = BOMB


class DebExtractor(TarExtractor):
    def prepare(self):
        self.pipe(['ar', 'p', self.filename, 'data.tar.gz'],
                  "data.tar.gz extraction")
        self.pipe(['zcat'], "data.tar.gz decompression")

    def basename(self):
        pieces = os.path.basename(self.filename).split('_')
        if len(pieces) == 1:
            return pieces[0]
        last_piece = pieces.pop()
        if (len(last_piece) > 10) or (not last_piece.endswith('.deb')):
            return BaseExtractor.basename(self)
        return '_'.join(pieces)

    def check_contents(self):
        self.check_included_archives(os.listdir('.'))
        self.content_type = BOMB


class DebMetadataExtractor(DebExtractor):
    def prepare(self):
        self.pipe(['ar', 'p', self.filename, 'control.tar.gz'],
                  "control.tar.gz extraction")
        self.pipe(['zcat'], "control.tar.gz decompression")


class GemExtractor(TarExtractor):
    def prepare(self):
        self.pipe(['tar', '-xO', 'data.tar.gz'], "data.tar.gz extraction")
        self.pipe(['zcat'], "data.tar.gz decompression")

    def check_contents(self):
        self.check_included_archives(os.listdir('.'))
        self.content_type = BOMB


class GemMetadataExtractor(CompressionExtractor):
    def prepare(self):
        self.pipe(['tar', '-xO', 'metadata.gz'], "metadata.gz extraction")
        self.pipe(['zcat'], "metadata.gz decompression")

    def basename(self):
        return os.path.basename(self.filename) + '-metadata.txt'


class SevenExtractor(BaseExtractor):
    border_re = re.compile('^[- ]+$')

    def __init__(self, filename, encoding):
        BaseExtractor.__init__(self, '/dev/null', None)
        self.filename = os.path.realpath(filename)

    def get_filenames(self):
        self.pipe(['7z', 'l', self.filename], "listing")
        self.run_pipes()
        self.archive.seek(0, 0)
        fn_index = None
        for line in self.archive:
            if self.border_re.match(line):
                if fn_index is not None:
                    break
                else:
                    fn_index = line.rindex(' ') + 1
            elif fn_index is not None:
                yield line[fn_index:-1]
        self.archive.close()

    def extract_archive(self):
        self.pipe(['7z', 'x', self.filename])
        self.run_pipes()
        

class BaseHandler(object):
    def __init__(self, extractor, options):
        self.extractor = extractor
        self.options = options
        self.target = None

    def handle(self):
        command = 'find'
        status = subprocess.call(['find', self.extractor.target, '-type', 'd',
                                  '-exec', 'chmod', 'u+rwx', '{}', ';'])
        if status == 0:
            command = 'chmod'
            status = subprocess.call(['chmod', '-R', 'u+rwX',
                                      self.extractor.target])
        if status != 0:
            return "%s returned with exit status %s" % (command, status)
        return self.organize()


# The "where to extract" table, with options and archive types.
# This dictates the contents of each can_handle method.
#
#         Flat           Overwrite            None
# File    basename       basename             FilenameChecked
# Match   .              .                    tempdir + checked
# Bomb    .              basename             DirectoryChecked

class FlatHandler(BaseHandler):
    def can_handle(contents, options):
        return ((options.flat and (contents != ONE_ENTRY_KNOWN)) or
                (options.overwrite and (contents == MATCHING_DIRECTORY)))
    can_handle = staticmethod(can_handle)

    def organize(self):
        self.target = '.'
        for curdir, dirs, filenames in os.walk(self.extractor.target,
                                               topdown=False):
            path_parts = curdir.split(os.sep)
            if path_parts[0] == '.':
                del path_parts[1]
            else:
                del path_parts[0]
            newdir = os.path.join(*path_parts)
            if not os.path.isdir(newdir):
                os.makedirs(newdir)
            for filename in filenames:
                os.rename(os.path.join(curdir, filename),
                          os.path.join(newdir, filename))
            os.rmdir(curdir)


class OverwriteHandler(BaseHandler):
    def can_handle(contents, options):
        return ((options.flat and (contents == ONE_ENTRY_KNOWN)) or
                (options.overwrite and (contents != MATCHING_DIRECTORY)))
    can_handle = staticmethod(can_handle)

    def organize(self):
        self.target = self.extractor.basename()
        result = run_command(['rm', '-rf', self.target],
                             "removing %s to overwrite" % (self.target,))
        if result is None:
            os.rename(self.extractor.target, self.target)
        return result
        

class MatchHandler(BaseHandler):
    def can_handle(contents, options):
        return ((contents == MATCHING_DIRECTORY) or
                ((contents == ONE_ENTRY) and
                 options.one_entry_policy.ok_for_match()))
    can_handle = staticmethod(can_handle)

    def organize(self):
        if self.options.one_entry_policy == EXTRACT_HERE:
            destination = self.extractor.content_name.rstrip('/')
        else:
            destination = self.extractor.basename()
        self.target = self.extractor.name_checker(destination).check()
        if os.path.isdir(self.extractor.target):
            os.rename(os.path.join(self.extractor.target,
                                   os.listdir(self.extractor.target)[0]),
                      self.target)
            os.rmdir(self.extractor.target)
        else:
            os.rename(self.extractor.target, self.target)


class EmptyHandler(object):
    def can_handle(contents, options):
        return contents == EMPTY
    can_handle = staticmethod(can_handle)

    def __init__(self, extractor, options): pass
    def handle(self): pass


class BombHandler(BaseHandler):
    def can_handle(contents, options):
        return True
    can_handle = staticmethod(can_handle)

    def organize(self):
        basename = self.extractor.basename()
        self.target = self.extractor.name_checker(basename).check()
        os.rename(self.extractor.target, self.target)

        
class BasePolicy(object):
    def __init__(self, options):
        self.current_policy = None
        if options.batch:
            self.permanent_policy = self.answers['']
        else:
            self.permanent_policy = None

    def ask_question(self, question):
        question = textwrap.wrap(question) + self.choices
        while True:
            print "\n".join(question)
            try:
                answer = raw_input(self.prompt)
            except EOFError:
                return self.answers['']
            try:
                return self.answers[answer.lower()]
            except KeyError:
                print

    def __cmp__(self, other):
        return cmp(self.current_policy, other)
    

class OneEntryPolicy(BasePolicy):
    answers = {'h': EXTRACT_HERE, 'i': EXTRACT_WRAP, 'r': EXTRACT_RENAME,
               '': EXTRACT_WRAP}
    choices = ["You can:",
               " * extract it Inside another directory",
               " * extract it and Rename the directory",
               " * extract it Here"]
    prompt = "What do you want to do?  (I/r/h) "

    def prep(self, archive_filename, entry_name):
        question = ("%s contains one entry: %s." %
                    (archive_filename, entry_name))
        self.current_policy = (self.permanent_policy or
                               self.ask_question(question))

    def ok_for_match(self):
        return self.current_policy in (EXTRACT_RENAME, EXTRACT_HERE)


class RecursionPolicy(BasePolicy):
    answers = {'o': RECURSE_ONCE, 'a': RECURSE_ALWAYS, 'n': RECURSE_NOT_NOW,
               'v': RECURSE_NEVER, '': RECURSE_NOT_NOW}
    choices = ["You can:",
               " * Always extract included archives",
               " * extract included archives this Once",
               " * choose Not to extract included archives",
               " * neVer extract included archives"]
    prompt = "What do you want to do?  (a/o/N/v) "

    def __init__(self, options):
        BasePolicy.__init__(self, options)
        if options.show_list:
            self.permanent_policy = RECURSE_NEVER
        elif options.recursive:
            self.permanent_policy = RECURSE_ALWAYS

    def prep(self, current_filename, included_archives):
        archive_count = len(included_archives)
        if (self.permanent_policy is not None) or (archive_count == 0):
            self.current_policy = self.permanent_policy or RECURSE_NOT_NOW
            return
        elif archive_count > 1:
            question = ("%s contains %s other archive files." %
                        (current_filename, archive_count))
        else:
            question = ("%s contains another archive: %s." %
                        (current_filename, included_archives[0]))
        self.current_policy = self.ask_question(question)
        if self.current_policy in (RECURSE_ALWAYS, RECURSE_NEVER):
            self.permanent_policy = self.current_policy

    def ok_to_recurse(self):
        return self.current_policy in (RECURSE_ALWAYS, RECURSE_ONCE)
            

class ExtractorBuilder(object):
    extractor_map = {'tar': (TarExtractor, None),
                     'zip': (ZipExtractor, None),
                     'deb': (DebExtractor, DebMetadataExtractor),
                     'rpm': (RPMExtractor, None),
                     'cpio': (CpioExtractor, None),
                     'gem': (GemExtractor, GemMetadataExtractor),
                     'compress': (CompressionExtractor, None),
                     '7z': (SevenExtractor, None)}

    mimetype_map = {}
    for mapping in (('tar', 'x-tar'),
                    ('zip', 'x-msdos-program', 'zip'),
                    ('deb', 'x-debian-package'),
                    ('rpm', 'x-redhat-package-manager', 'x-rpm'),
                    ('cpio', 'x-cpio'),
                    ('gem', 'x-ruby-gem'),
                    ('7z', 'x-7z-compressed')):
        for mimetype in mapping[1:]:
            if '/' not in mimetype:
                mimetype = 'application/' + mimetype
            mimetype_map[mimetype] = mapping[0]

    magic_mime_map = {}
    for mapping in (('deb', 'Debian binary package'),
                    ('cpio', 'cpio archive'),
                    ('tar', 'POSIX tar archive'),
                    ('zip', 'Zip archive'),
                    ('rpm', 'RPM'),
                    ('7z', '7-zip archive')):
        for pattern in mapping[1:]:
            magic_mime_map[re.compile(pattern)] = mapping[0]
    
    magic_encoding_map = {}
    for mapping in (('bzip2', 'bzip2 compressed'),
                    ('gzip', 'gzip compressed')):
        for pattern in mapping[1:]:
            magic_encoding_map[re.compile(pattern)] = mapping[0]

    extension_map = {}
    for mapping in (('tar', 'bzip2', 'tar.bz2'),
                    ('tar', 'gzip', 'tar.gz', 'tgz'),
                    ('tar', None, 'tar'),
                    ('zip', None, 'zip', 'exe'),
                    ('deb', None, 'deb'),
                    ('rpm', None, 'rpm'),
                    ('cpio', None, 'cpio'),
                    ('gem', None, 'gem'),
                    ('compress', None, 'gz', 'bz2'),
                    ('7z', None, '7z')):
        for extension in mapping[2:]:
            extension_map[extension] = mapping[:2]

    def __init__(self, filename, options):
        self.filename = filename
        self.options = options

    def build_extractor(self, archive_type, encoding):
        extractors = self.extractor_map[archive_type]
        if self.options.metadata and (extractors[1] is not None):
            extractor = extractors[1]
        else:
            extractor = extractors[0]
        return extractor(self.filename, encoding)

    def get_extractor(self):
        for func_name in ('mimetype', 'extension', 'magic'):
            archive_type, encoding = \
                          getattr(self, 'try_by_' + func_name)(self.filename)
            logger.debug("%s extractor is %s, %s" %
                         (func_name, archive_type, encoding))
            if archive_type is not None:
                yield self.build_extractor(archive_type, encoding)

    def try_by_mimetype(cls, filename):
        mimetype, encoding = mimetypes.guess_type(filename)
        try:
            return cls.mimetype_map[mimetype], encoding
        except KeyError:
            if encoding:
                return 'compress', encoding
        return None, None
    try_by_mimetype = classmethod(try_by_mimetype)

    def try_by_magic(cls, filename):
        process = subprocess.Popen(['file', '-z', filename],
                                   stdout=subprocess.PIPE)
        status = process.wait()
        if status != 0:
            return None, None
        output = process.stdout.readline()
        process.stdout.close()
        if output.startswith('%s: ' % filename):
            output = output[len(filename) + 2:]
        results = [None, None]
        for index, mapping in enumerate((cls.magic_mime_map,
                                         cls.magic_encoding_map)):
            for regexp, result in mapping.items():
                if regexp.search(output):
                    results[index] = result
                    break
        return results
    try_by_magic = classmethod(try_by_magic)

    def try_by_extension(cls, filename):
        parts = filename.rsplit('.', 2)[1:]
        while parts:
            try:
                return cls.extension_map['.'.join(parts)]
            except KeyError:
                del parts[0]
        return [None, None]
    try_by_extension = classmethod(try_by_extension)


class BaseAction(object):
    def __init__(self, options, filenames):
        self.options = options
        self.filenames = filenames
        self.target = None
        
    def report(self, function, *args):
        try:
            error = function(*args)
        except (ExtractorError, IOError, OSError), exception:
            error = str(exception)
            logger.debug(''.join(traceback.format_exception(*sys.exc_info())))
        if error:
            logger.info("%s: %s", self.current_filename, error)
            return False
        return True


class ExtractionAction(BaseAction):
    handlers = [FlatHandler, OverwriteHandler, MatchHandler, EmptyHandler,
                BombHandler]

    def get_handler(self, extractor):
        if extractor.content_type == ONE_ENTRY:
            self.options.one_entry_policy.prep(self.current_filename,
                                               extractor.content_name)
        for handler in self.handlers:
            if handler.can_handle(extractor.content_type, self.options):
                self.current_handler = handler(extractor, self.options)
                break

    def run(self, filename, extractor):
        self.current_filename = filename
        success = (self.report(extractor.extract) and
                   self.report(self.get_handler, extractor) and
                   self.report(self.current_handler.handle))
        if success:
            self.target = self.current_handler.target
        return success


class ListAction(BaseAction):
    def __init__(self, options, filenames):
        BaseAction.__init__(self, options, filenames)

    def get_list(self, extractor):
        # Note: The reason I'm getting all the filenames up front is
        # because if we run into trouble partway through the archive, we'll
        # try another extractor.  So before we display anything we have to
        # be sure this one is successful.  We maybe don't have to be quite
        # this conservative but this is the easy way out for now.
        self.filelist = list(extractor.get_filenames())

    def show_list(self, filename):
        if len(self.filenames) != 1:
            if filename != self.filenames[0]:
                print
            print "%s:" % (filename,)
        print '\n'.join(self.filelist)

    def run(self, filename, extractor):
        self.current_filename = filename
        return (self.report(self.get_list, extractor) and
                self.report(self.show_list, filename))


class ExtractorApplication(object):
    def __init__(self, arguments):
        self.parse_options(arguments)
        self.setup_logger()
        self.successes = []
        self.failures = []

    def parse_options(self, arguments):
        parser = optparse.OptionParser(
            usage="%prog [options] archive [archive2 ...]",
            description="Intelligent archive extractor",
            version=VERSION_BANNER
            )
        parser.add_option('-r', '--recursive', dest='recursive',
                          action='store_true', default=False,
                          help='extract archives contained in the ones listed')
        parser.add_option('-q', '--quiet', dest='quiet',
                          action='count', default=3,
                          help='suppress warning/error messages')
        parser.add_option('-v', '--verbose', dest='verbose',
                          action='count', default=0,
                          help='be verbose/print debugging information')
        parser.add_option('-o', '--overwrite', dest='overwrite',
                          action='store_true', default=False,
                          help='overwrite any existing target directory')
        parser.add_option('-f', '--flat', '--no-directory', dest='flat',
                          action='store_true', default=False,
                          help="don't put contents in their own directory")
        parser.add_option('-l', '-t', '--list', '--table', dest='show_list',
                          action='store_true', default=False,
                          help="list contents of archives on standard output")
        parser.add_option('-n', '--noninteractive', dest='batch',
                          action='store_true', default=False,
                          help="don't ask how to handle special cases")
        parser.add_option('-m', '--metadata', dest='metadata',
                          action='store_true', default=False,
                          help="extract metadata from a .deb/.gem/etc.")
        self.options, filenames = parser.parse_args(arguments)
        if not filenames:
            parser.error("you did not list any archives")
        self.options.one_entry_policy = OneEntryPolicy(self.options)
        self.options.recursion_policy = RecursionPolicy(self.options)
        self.archives = {os.path.realpath(os.curdir): filenames}

    def setup_logger(self):
        # WARNING is the default.
        log_level = (10 * (self.options.quiet - self.options.verbose))
        logging.getLogger().setLevel(log_level)
        handler = logging.StreamHandler()
        handler.setLevel(log_level)
        formatter = logging.Formatter("dtrx: %(levelname)s: %(message)s")
        handler.setFormatter(formatter)
        logger.addHandler(handler)
        logger.debug("logger is set up")

    def recurse(self, filename, extractor, action):
        archives = extractor.included_archives
        self.options.recursion_policy.prep(filename, archives)
        if self.options.recursion_policy.ok_to_recurse():
            for filename in archives:
                tail_path, basename = os.path.split(filename)
                directory = os.path.join(self.current_directory,
                                         action.target, tail_path)
                self.archives.setdefault(directory, []).append(basename)

    def run(self):
        if self.options.show_list:
            action = ListAction
        else:
            action = ExtractionAction
        action = action(self.options, self.archives.values()[0])
        while self.archives:
            self.current_directory, self.filenames = self.archives.popitem()
            os.chdir(self.current_directory)
            for filename in self.filenames:
                builder = ExtractorBuilder(filename, self.options)
                for extractor in builder.get_extractor():
                    if action.run(filename, extractor):
                        self.successes.append(filename)
                        self.recurse(filename, extractor, action)
                        break
                else:
                    logger.error("%s: could not find a way to extract this" %
                                 (filename,))
                    self.failures.append(filename)
            self.options.one_entry_policy.permanent_policy = EXTRACT_WRAP
        if self.failures:
            return 1
        return 0


if __name__ == '__main__':
    app = ExtractorApplication(sys.argv[1:])
    sys.exit(app.run())