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# DebFile: a Python representation of Debian .deb binary packages.
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# Copyright (C) 2007 Stefano Zacchiroli <zack@debian.org>
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# Copyright (C) 2007 Filippo Giunchedi <filippo@debian.org>
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful, but
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# WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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# General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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from arfile import ArFile, ArError
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from changelog import Changelog
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from deb822 import Deb822
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DATA_PART = 'data.tar.gz'
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CTRL_PART = 'control.tar.gz'
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INFO_PART = 'debian-binary'
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MAINT_SCRIPTS = ['preinst', 'postinst', 'prerm', 'postrm', 'config']
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CONTROL_FILE = 'control'
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CHANGELOG_NATIVE = 'usr/share/doc/%s/changelog.gz' # with package stem
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CHANGELOG_DEBIAN = 'usr/share/doc/%s/changelog.Debian.gz'
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class DebError(ArError):
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class DebPart(object):
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"""'Part' of a .deb binary package.
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A .deb package is considered as made of 2 parts: a 'data' part
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(corresponding to the 'data.tar.gz' archive embedded in a .deb) and a
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'control' part (the 'control.tar.gz' archive). Each of them is represented
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by an instance of this class.
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When referring to file members of the underlying .tar.gz archive, file
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names can be specified in one of 3 formats "file", "./file", "/file". In
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all cases the file is considered relative to the root of the archive. For
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the control part the preferred mechanism is the first one (as in
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deb.control.get_content('control') ); for the data part the preferred
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mechanism is the third one (as in deb.data.get_file('/etc/vim/vimrc') ).
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def __init__(self, member):
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self.__member = member # arfile.ArMember file member
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"""Return a TarFile object corresponding to this part of a .deb
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if self.__tgz is None:
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gz = gzip.GzipFile(fileobj=self.__member, mode='r')
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self.__tgz = tarfile.TarFile(fileobj=gz, mode='r')
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def __normalize_member(fname):
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""" try (not so hard) to obtain a member file name in a form relative
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to the .tar.gz root and with no heading '.' """
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if fname.startswith('./'):
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elif fname.startswith('/'):
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# XXX in some of the following methods, compatibility among >= 2.5 and <<
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# 2.5 python versions had to be taken into account. TarFile << 2.5 indeed
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# was buggied and returned member file names with an heading './' only for
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# the *first* file member. TarFile >= 2.5 fixed this and has the heading
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# './' for all file members.
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def has_file(self, fname):
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"""Check if this part contains a given file name."""
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fname = DebPart.__normalize_member(fname)
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names = self.tgz().getnames()
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return (('./' + fname in names) \
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or (fname in names)) # XXX python << 2.5 TarFile compatibility
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def get_file(self, fname):
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"""Return a file object corresponding to a given file name."""
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fname = DebPart.__normalize_member(fname)
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return (self.tgz().extractfile('./' + fname))
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except KeyError: # XXX python << 2.5 TarFile compatibility
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return (self.tgz().extractfile(fname))
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def get_content(self, fname):
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"""Return the string content of a given file, or None (e.g. for
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f = self.get_file(fname)
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if f: # can be None for non regular or link files
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# container emulation
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return iter(self.tgz().getnames())
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def __contains__(self, fname):
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return self.has_file(fname)
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def __getitem__(self, fname):
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return self.get_content(fname)
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class DebData(DebPart):
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class DebControl(DebPart):
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""" Return a dictionary of maintainer scripts (postinst, prerm, ...)
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mapping script names to script text. """
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for fname in MAINT_SCRIPTS:
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if self.has_file(fname):
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scripts[fname] = self.get_content(fname)
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def debcontrol(self):
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""" Return the debian/control as a Deb822 (a Debian-specific dict-like
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For a string representation of debian/control try
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.get_content('control') """
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return Deb822(self.get_content(CONTROL_FILE))
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""" Return a dictionary mapping filenames (of the data part) to
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md5sums. Fails if the control part does not contain a 'md5sum' file.
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Keys of the returned dictionary are the left-hand side values of lines
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in the md5sums member of control.tar.gz, usually file names relative to
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the file system root (without heading '/' or './'). """
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if not self.has_file(MD5_FILE):
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raise DebError("'%s' file not found, can't list MD5 sums" %
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md5_file = self.get_file(MD5_FILE)
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for line in md5_file.readlines():
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# we need to support spaces in filenames, .split() is not enough
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md5, fname = line.rstrip('\r\n').split(None, 1)
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class DebFile(ArFile):
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"""Representation of a .deb file (a Debian binary package)
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DebFile objects have the following (read-only) properties:
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- version debian .deb file format version (not related with the
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contained package version), 2.0 at the time of writing
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for all .deb packages in the Debian archive
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- data DebPart object corresponding to the data.tar.gz
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archive contained in the .deb file
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- control DebPart object corresponding to the control.tar.gz
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archive contained in the .deb file
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def __init__(self, filename=None, mode='r', fileobj=None):
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ArFile.__init__(self, filename, mode, fileobj)
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required_names = set([INFO_PART, CTRL_PART, DATA_PART])
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actual_names = set(self.getnames())
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if not (required_names <= actual_names):
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"the following required .deb members are missing: " \
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+ string.join(required_names - actual_names))
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self.__parts[CTRL_PART] = DebControl(self.getmember(CTRL_PART))
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self.__parts[DATA_PART] = DebData(self.getmember(DATA_PART))
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self.__pkgname = None # updated lazily by __updatePkgName
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f = self.getmember(INFO_PART)
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self.__version = f.read().strip()
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def __updatePkgName(self):
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self.__pkgname = self.debcontrol()['package']
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version = property(lambda self: self.__version)
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data = property(lambda self: self.__parts[DATA_PART])
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control = property(lambda self: self.__parts[CTRL_PART])
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# proxy methods for the appropriate parts
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def debcontrol(self):
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""" See .control.debcontrol() """
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return self.control.debcontrol()
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""" See .control.scripts() """
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return self.control.scripts()
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""" See .control.md5sums() """
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return self.control.md5sums()
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""" Return a Changelog object for the changelog.Debian.gz of the
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present .deb package. Return None if no changelog can be found. """
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if self.__pkgname is None:
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self.__updatePkgName()
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for fname in [ CHANGELOG_DEBIAN % self.__pkgname,
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CHANGELOG_NATIVE % self.__pkgname ]:
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if self.data.has_file(fname):
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gz = gzip.GzipFile(fileobj=self.data.get_file(fname))
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raw_changelog = gz.read()
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return Changelog(raw_changelog)
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if __name__ == '__main__':
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deb = DebFile(filename=sys.argv[1])
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tgz = deb.control.tgz()
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print tgz.getmember('control')
added
removed
debian_bundle/debfile.py
