scripts/x

Sun, 31 Dec 2006 19:27:23 -0500

author
brett
date
Sun, 31 Dec 2006 19:27:23 -0500
branch
trunk
changeset 16
29794d4d41aa
parent 15
28dbd52a8bb8
child 17
481a2b4be471
permissions
-rwxr-xr-x

[svn] There's now an entirely new object hierarchy for handlers, because the
number of corner cases, switches, etc. was starting to get out of hand.
This makes it easier to tell what's going on in a given case.

#!/usr/bin/env python
#
# x -- Intelligently extract various archive types.
# Copyright (c) 2006 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 2 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 stat
import subprocess
import sys
import tempfile

from cStringIO import StringIO

VERSION = "2.1"
VERSION_BANNER = """x version %s
Copyright (c) 2006 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 2 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_DIRECTORY = 2
BOMB = 3
EMPTY = 4
COMPRESSED = 5

mimetypes.encodings_map.setdefault('.bz2', 'bzip2')
mimetypes.types_map['.exe'] = 'application/x-msdos-program'

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=None):
        if filename is None:
            filename = self.original_name
        return self._is_free(filename)

    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 ProcessStreamer(object):
    def __init__(self, command, stdin, description="checking contents",
                 stderr=None):
        self.process = subprocess.Popen(command, bufsize=1, stdin=stdin,
                                        stdout=subprocess.PIPE, stderr=stderr)
        self.command = ' '.join(command)
        self.description = description

    def __iter__(self):
        return self

    def next(self):
        line = self.process.stdout.readline()
        if line:
            return line.rstrip('\n')
        else:
            raise StopIteration

    def stop(self):
        while self.process.stdout.readline():
            pass
        self.process.stdout.close()
        status = self.process.wait()
        if status != 0:
            raise ExtractorError("%s error: '%s' returned status code %s" %
                                 (self.description, self.command, status))
        try:
            self.process.stderr.close()
        except AttributeError:
            pass
    

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

    name_checker = DirectoryChecker

    def __init__(self, filename, mimetype, encoding):
        if encoding and (not self.decoders.has_key(encoding)):
            raise ValueError("unrecognized encoding %s" % (encoding,))
        self.filename = os.path.realpath(filename)
        self.mimetype = mimetype
        self.encoding = encoding
        self.included_archives = []
        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 run(self, command, description="extraction", stdout=None, stderr=None,
            stdin=None):
        error = run_command(command, description, stdout, stderr, stdin)
        if error:
            raise ExtractorError(error)

    def pipe(self, command, description, stderr=None):
        output = tempfile.TemporaryFile()
        self.run(command, description, output, stderr, self.archive)
        self.archive.close()
        self.archive = output
        self.archive.flush()
    
    def prepare(self):
        pass

    def check_contents(self):
        archive_type = None
        filenames = self.get_filenames()
        try:
            filename = filenames.next()
            if extractor_map.has_key(mimetypes.guess_type(filename)[0]):
                self.included_archives.append(filename)
            first_part = filename.split('/', 1)[0] + '/'
        except StopIteration:
            filenames.stop()
            return EMPTY
        for filename in filenames:
            if extractor_map.has_key(mimetypes.guess_type(filename)[0]):
                self.included_archives.append(filename)
            if (archive_type is None) and (not filename.startswith(first_part)):
                archive_type = BOMB
        filenames.stop()
        if archive_type:
            return archive_type
        if self.basename() == first_part[:-1]:
            return MATCHING_DIRECTORY
        return first_part

    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, path):
        old_path = os.path.realpath(os.curdir)
        os.chdir(path)
        self.archive.seek(0, 0)
        self.extract_archive()
        os.chdir(old_path)
    

class TarExtractor(BaseExtractor):
    def get_filenames(self):
        self.archive.seek(0, 0)
        return ProcessStreamer(['tar', '-t'], self.archive)

    def extract_archive(self): 
        self.run(['tar', '-x'], stdin=self.archive)
        
        
class ZipExtractor(BaseExtractor):
    def __init__(self, filename, mimetype, encoding):
        self.filename = os.path.realpath(filename)
        self.mimetype = mimetype
        self.encoding = encoding
        self.included_archives = []
        self.archive = StringIO()

    def get_filenames(self):
        self.archive.seek(0, 0)
        return ProcessStreamer(['zipinfo', '-1', self.filename], None)

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


class CpioExtractor(BaseExtractor):
    def get_filenames(self):
        self.archive.seek(0, 0)
        return ProcessStreamer(['cpio', '-t'], self.archive,
                               stderr=subprocess.PIPE)

    def extract_archive(self):
        self.run(['cpio', '-i', '--make-directories',
                  '--no-absolute-filenames'],
                 stderr=subprocess.PIPE, stdin=self.archive)


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):
        CpioExtractor.check_contents(self)
        return BOMB


class DebExtractor(TarExtractor):
    def prepare(self):
        self.pipe(['ar', 'p', self.filename, 'data.tar.gz'],
                  "data.tar.gz extraction")
        self.archive.seek(0, 0)
        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):
        TarExtractor.check_contents(self)
        return BOMB
        

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 check_contents(self):
        return COMPRESSED

    def extract(self, path):
        output = open(path, 'w')
        self.run(['cat'], "output write", stdin=self.archive, stdout=output)
        output.close()
        

class BaseHandler(object):
    def __init__(self, extractor, contents, options):
        self.logger = logging.getLogger('x-log')
        self.extractor = extractor
        self.contents = contents
        self.options = options

##     def extract(self):
##         raise NotImplementedError
##         checker = self.extractor.name_checker(self.extractor.basename())
##         if self.options.flat:
##             self.target = '.'
##             return self.do_extract('.')
##         elif self.options.overwrite or checker.is_free():
##             self.target = self.extractor.basename()
##             return self.overwrite()
##         else:
##             self.target = checker.check()
##             return self.safe_extract()

    def extract(self):
        try:
            self.extractor.extract(self.target)
        except ExtractorError, error:
            return str(error)
        
    def cleanup(self):
        raise NotImplementedError
        if self.options.flat:
            self.cleanup_files()
        else:
            self.cleanup_directory()

    def cleanup_files(self):
        for filename in self.extractor.get_filenames():
            stat_info = os.stat(filename)
            perms = stat.S_IRUSR | stat.S_IWUSR
            if stat.S_ISDIR(stat_info.st_mode):
                perms |= stat.S_IXUSR
            os.chmod(filename, stat_info.st_mode | perms)

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


# 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 != COMPRESSED)) or
                (options.overwrite and (contents == MATCHING_DIRECTORY)))
    can_handle = staticmethod(can_handle)

    target = '.'
    cleanup = BaseHandler.cleanup_files


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

    def __init__(self, extractor, contents, options):
        BaseHandler.__init__(self, extractor, contents, options)
        self.target = self.extractor.basename()

    cleanup = BaseHandler.cleanup_directory
        

class MatchHandler(BaseHandler):
    def can_handle(contents, options):
        return contents == MATCHING_DIRECTORY
    can_handle = staticmethod(can_handle)

    def extract(self):
        basename = self.extractor.basename()
        self.target = tempfile.mkdtemp()
        result = BaseHandler.extract(self)
        if result is None:
            tempdir = self.target
            checker = self.extractor.name_checker(basename)
            self.target = checker.check()
            os.rename(os.path.join(tempdir, basename), self.target)
            os.rmdir(tempdir)
        return result

    cleanup = BaseHandler.cleanup_directory


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

    def __init__(self, extractor, contents, options): pass
    def extract(self): pass
    def cleanup(self): pass


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

    def __init__(self, extractor, contents, options):
        BaseHandler.__init__(self, extractor, contents, options)
        checker = self.extractor.name_checker(self.extractor.basename())
        self.target = checker.check()

    cleanup = BaseHandler.cleanup_directory

        
## class BombHandler(BaseHandler):
##     def safe_extract(self):
##         return self.do_extract(self.target)

##     def overwrite(self):
##         self.target = self.extractor.basename()
##         return self.do_extract(self.target)


extractor_map = {'application/x-tar': TarExtractor,
                 'application/zip': ZipExtractor,
                 'application/x-msdos-program': ZipExtractor,
                 'application/x-debian-package': DebExtractor,
                 'application/x-redhat-package-manager': RPMExtractor,
                 'application/x-rpm': RPMExtractor,
                 'application/x-cpio': CpioExtractor}

handlers = [FlatHandler, OverwriteHandler, MatchHandler, EmptyHandler,
            BombHandler]

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('-n', '--noninteractive', dest='batch',
##                           action='store_true', default=False,
##                           help="don't ask how to handle special cases")
        self.options, filenames = parser.parse_args(arguments)
        if not filenames:
            parser.error("you did not list any archives")
        self.archives = {os.path.realpath(os.curdir): filenames}

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

    def get_extractor(self):
        mimetype, encoding = mimetypes.guess_type(self.current_filename)
        try:
            extractor = extractor_map[mimetype]
        except KeyError:
            if encoding:
                extractor = CompressionExtractor
                contents = COMPRESSED
            else:
                return "not a known archive type"
        try:
            self.current_extractor = extractor(self.current_filename, mimetype,
                                               encoding)
            content = self.current_extractor.check_contents()
            for handler in handlers:
                if handler.can_handle(content, self.options):
                    self.current_handler = handler(self.current_extractor,
                                                   content, self.options)
                    break
        except ExtractorError, error:
            return str(error)

    def recurse(self):
        if not self.options.recursive:
            return
        for filename in self.current_extractor.included_archives:
            tail_path, basename = os.path.split(filename)
            directory = os.path.join(self.current_directory,
                                     self.current_handler.target, tail_path)
            self.archives.setdefault(directory, []).append(basename)

    def report(self, function, *args):
        error = function(*args)
        if error:
            self.logger.error("%s: %s", self.current_filename, error)
            return False
        return True

    def run(self):
        while self.archives:
            self.current_directory, filenames = self.archives.popitem()
            for filename in filenames:
                os.chdir(self.current_directory)
                self.current_filename = filename
                self.cleanup_actions = []
                success = self.report(self.get_extractor)
                if success:
                    for name in 'extract', 'cleanup':
                        success = (self.report(getattr(self.current_handler,
                                                       name)) and success)
                    self.recurse()
                if success:
                    self.successes.append(self.current_filename)
                else:
                    self.failures.append(self.current_filename)
        if self.failures:
            return 1
        return 0


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

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