~azzar1/unity/add-show-desktop-key

# IVLE - Informatics Virtual Learning Environment

# Copyright (C) 2007-2008 The University of Melbourne

#

# 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 St, Fifth Floor, Boston, MA  02110-1301  USA

# Module: common.zip

# Author: Matt Giuca

# Date: 17/1/2008

# ZIP function wrappers. Provides easy methods for reading and writing zip

# files for the purpose of the IVLE file browser.

import os

import os.path

import zipfile

from common import studpath

def make_zip(basepath, paths, file):

    """Zips up a bunch of files on the student file space and writes it as

    a zip file.

    basepath: Path relative to student home. All file paths will be made

    relative to this path, such that unzipping the file in this path will

    place the files back in their original places.

    paths: List of paths relative to basepath. These are the files to be

    zipped. All paths must be relative.

    file: Either a filename to write to, or a file-like object.

    Throws an OSError if one or more of the files cannot be read. This error

    will be thrown before any writing takes place.

    """

    # First make sure all the files are valid

    newpaths = []       # Store tuples of (path, localpath)

    for path in paths:

        if len(path) == 0 or path[0] == os.sep:

            raise OSError("ZIP: Invalid path")

        else:

            # Relative to req.path

            relpath = os.path.join(basepath, path)

        _, r = studpath.url_to_local(relpath)

        if r is None:

            raise OSError("ZIP: Invalid path")

        if not os.access(r, os.R_OK):

            raise OSError("ZIP: Could not access a file")

        newpaths.append((path, r))

    # Now open the zip file and write each path to it

    zip = zipfile.ZipFile(file, 'w')

    for (path, localpath) in newpaths:

        if os.path.isdir(localpath):

            # Walk the directory tree

            if len(localpath) > 0 and localpath[-1] != os.sep:

                localpath += os.sep

            def error(err):

                raise OSError("ZIP: Could not access a file")

            for (dirpath, dirnames, filenames) in \

                os.walk(localpath, onerror=error):

                # Do not traverse into .svn directories

                try:

                    dirnames.remove(".svn")

                except ValueError:

                    pass

                # dirpath is local. Make arc_dirpath, relative to root

                arc_dirpath = os.path.join(path, dirpath[len(localpath):])

                for filename in filenames:

                    zip.write(os.path.join(dirpath, filename),

                                os.path.join(arc_dirpath, filename))

        else:

            zip.write(localpath, path)

    zip.close()

def unzip(path, file):

    """Unzips a zip file (or file-like object) into a path.

    Note: All files go directly into the path. To avoid having a "zip bomb"

    situation, the zip file should have a single directory in it with all the

    files.

    """

    zip = zipfile.ZipFile(file, 'r')

    # First test the zip file

    if zip.testzip() is not None:

        raise OSError("ZIP: Bad zip file")

    for filename in zip.namelist():

        # Work out the name of this file on the local file system, and make

        # sure it is valid

        relpath = os.path.join(path, filename)

        _, localpath = studpath.url_to_local(relpath)

        if localpath is None:

            raise OSError("ZIP: Permission denied")

        # Create directory for filename

        (file_dir, _) = os.path.split(localpath)

        if not os.path.exists(file_dir):

            os.makedirs(file_dir)

        if filename.endswith(os.sep):

            # Is a directory make the directory

            if not os.path.exists(localpath):

                os.mkdir(localpath)

        else:

            filedata = zip.read(filename)

            f = open(localpath, 'w')

            f.write(filedata)

            f.close()