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# IVLE - Informatics Virtual Learning Environment
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# Copyright (C) 2007-2008 The University of Melbourne
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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 2 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,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU 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, write to the Free Software
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# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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# Contains common utility functions.
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# Also initialises mime types library. You must import util before using
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# Python's builtin mimetypes module to make sure local settings are applied.
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class IVLEError(Exception):
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This is the "standard" exception class for IVLE errors.
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It is the ONLY exception which should propagate to the top - it will then
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be displayed to the user as an HTTP error with the given code.
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All other exceptions are considered IVLE bugs and should not occur
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(they will display a traceback).
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This error should not be raised directly. Call req.throw_error.
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def __init__(self, httpcode, message=None):
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self.httpcode = httpcode
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self.message = message
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self.args = (httpcode, message)
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class IVLEJailError(Exception):
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This exception indicates an error that occurred inside an IVLE CGI script
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inside the jail. It should never be raised directly - only by the
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Information will be retrieved from it, and then treated as a normal
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def __init__(self, type_str, message, info):
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self.type_str = type_str
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self.message = message
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class FakeObject(object):
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""" A representation of an object that can't be Pickled """
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def __init__(self, type, name, attrib={}):
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return "<Fake %s %s>"%(self.type, self.name)
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"""Given a path relative to the IVLE root, makes the path relative to the
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site root using conf.root_dir. This path can be used in URLs sent to the
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return os.path.join(conf.root_dir, path)
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def make_local_path(path):
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"""Given a path relative to the IVLE root, on the local file system, makes
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the path relative to the root using conf.ivle_install_dir. This path can
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be used in reading files from the local file system."""
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return os.path.join(conf.ivle_install_dir, 'www', path)
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def unmake_path(path):
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"""Given a path relative to the site root, makes the path relative to the
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IVLE root by removing conf.root_dir if it appears at the beginning. If it
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does not appear at the beginning, returns path unchanged. Also normalises
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path = os.path.normpath(path)
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root = os.path.normpath(conf.root_dir)
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if path.startswith(root):
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path = path[len(root):]
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# Take out the slash as well
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if len(path) > 0 and path[0] == os.sep:
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def split_path(path):
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"""Given a path, returns a tuple consisting of the top-level directory in
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the path, and the rest of the path. Note that both items in the tuple will
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NOT begin with a slash, regardless of whether the original path did. Also
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Always returns a pair of strings, except for one special case, in which
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the path is completely empty (or just a single slash). In this case the
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return value will be (None, ''). But still always returns a pair.
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>>> split_path("home")
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>>> split_path("home/docs/files")
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('home', 'docs/files')
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>>> split_path("//home/docs/files")
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('', 'home/docs/files')
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path = os.path.normpath(path)
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# Ignore the opening slash
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if path.startswith(os.sep):
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path = path[len(os.sep):]
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if path == '' or path == '.':
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splitpath = path.split(os.sep, 1)
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if len(splitpath) == 1:
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return (splitpath[0], '')
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return tuple(splitpath)
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def open_exercise_file(exercisename):
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"""Given an exercise name, opens the corresponding XML file for reading.
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Returns None if the exercise file was not found.
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(For tutorials / worksheets).
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# First normalise the path
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exercisename = os.path.normpath(exercisename)
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# Now if it begins with ".." or separator, then it's illegal
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if exercisename.startswith("..") or exercisename.startswith(os.sep):
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exercisefile = os.path.join(conf.exercises_base, exercisename)
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return open(exercisefile)
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except (TypeError, IOError): # TypeError if exercisefile == None
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# Initialise mime types library
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for (ext, mimetype) in conf.mimetypes.additional_mime_types.items():
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mimetypes.add_type(mimetype, ext)
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def nice_filetype(filename):
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"""Given a filename or basename, returns a "friendly" name for that
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eg. nice_mimetype("file.py") == "Python source code".
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nice_filetype("file.bzg") == "BZG file".
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nice_filetype("directory/") == "Directory".
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if filename[-1] == os.sep:
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return conf.mimetypes.nice_mimetypes[
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mimetypes.guess_type(filename)[0]]
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filename = os.path.basename(filename)
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return filename[filename.rindex('.')+1:].upper() + " file"
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def send_terms_of_service(req):
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Sends the Terms of Service document to the req object.
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This consults conf to find out where the TOS is located on disk, and sends
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that. If it isn't found, it sends a generic message explaining to admins
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how to create a real one.
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req.sendfile(conf.tos_path)
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"""<h1>Terms of Service</h1>
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<p><b>*** SAMPLE ONLY ***</b></p>
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<p>This is the text of the IVLE Terms of Service.</p>
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<p>The administrator should create a license file with an appropriate
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"Terms of Service" license for your organisation.</p>
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<h2>Instructions for Administrators</h2>
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<p>You are seeing this message because you have not configured a Terms of
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Service document.</p>
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<p>When you configured IVLE, you specified a path to the Terms of Service
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document (this is found in <b><tt>lib/conf/conf.py</tt></b> under
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"<tt>tos_path</tt>").</p>
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<p>Create a file at this location; an HTML file with the appropriately-worded
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<p>This should be a normal XHTML file, except it should not contain
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<tt>html</tt>, <tt>head</tt> or <tt>body</tt> elements - it should
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just be the contents of a body element (IVLE will wrap it accordingly).</p>
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<p>This will automatically be used as the license text instead of this
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placeholder text.</p>
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def parse_iso8601(str):
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"""Parses ISO8601 string into a datetime object."""
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# FIXME: Terrific hack that means we only accept the format that is
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# produced by json.js module when it encodes date objects.
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return datetime.datetime.strptime(str, "%Y-%m-%dT%H:%M:%SZ")
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def incomplete_utf8_sequence(byteseq):
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Given a UTF-8-encoded byte sequence (str), returns the number of bytes at
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the end of the string which comprise an incomplete UTF-8 character
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If the string is empty or ends with a complete character OR INVALID
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Otherwise, returns 1-3 indicating the number of bytes in the final
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incomplete (but valid) character sequence.
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Does not check any bytes before the final sequence for correctness.
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>>> incomplete_utf8_sequence("")
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>>> incomplete_utf8_sequence("xy")
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>>> incomplete_utf8_sequence("xy\xc3\xbc")
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>>> incomplete_utf8_sequence("\xc3")
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>>> incomplete_utf8_sequence("\xbc\xc3")
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>>> incomplete_utf8_sequence("xy\xbc\xc3")
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>>> incomplete_utf8_sequence("xy\xe0\xa0")
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>>> incomplete_utf8_sequence("xy\xf4")
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>>> incomplete_utf8_sequence("xy\xf4\x8f")
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>>> incomplete_utf8_sequence("xy\xf4\x8f\xa0")
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for b in byteseq[::-1]:
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# 0xxxxxxx (single-byte character)
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elif b & 0xc0 == 0x80:
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# 10xxxxxx (subsequent byte)
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elif b & 0xe0 == 0xc0:
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# 110xxxxx (start of 2-byte sequence)
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elif b & 0xf0 == 0xe0:
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# 1110xxxx (start of 3-byte sequence)
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elif b & 0xf8 == 0xf0:
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# 11110xxx (start of 4-byte sequence)
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# Seen too many "subsequent bytes", invalid
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# We never saw a "first byte", invalid
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# We now know expect and count
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# Complete, or we saw an invalid sequence
added
removed
lib/common/util.py
