# Copyright (C) 2005, Giovanni Bajo
# Based on previous work under copyright (c) 2002 McMillan Enterprises, Inc.
#
# 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, Fifth Floor, Boston, MA 02110-1301, USA
_orig_open = open
class _BkFile:
def __init__(self, file, mode, bufsize):
import os
self.__filename = file
self.__backup = file + '~'
try:
os.unlink(self.__backup)
except os.error:
pass
try:
os.rename(file, self.__backup)
except os.error:
self.__backup = None
self.__file = _orig_open(file, mode, bufsize)
self.closed = self.__file.closed
self.fileno = self.__file.fileno
self.flush = self.__file.flush
self.isatty = self.__file.isatty
self.mode = self.__file.mode
self.name = self.__file.name
self.read = self.__file.read
self.readinto = self.__file.readinto
self.readline = self.__file.readline
self.readlines = self.__file.readlines
self.seek = self.__file.seek
self.softspace = self.__file.softspace
self.tell = self.__file.tell
self.truncate = self.__file.truncate
self.write = self.__file.write
self.writelines = self.__file.writelines
def close(self):
self.__file.close()
if self.__backup is None:
return
try:
from cmp import do_cmp
except:
from filecmp import cmp
do_cmp = cmp
# don't use cmp.cmp because of NFS bugs :-( and
# anyway, the stat mtime values differ so do_cmp will
# most likely be called anyway
if do_cmp(self.__backup, self.__filename):
import os
os.unlink(self.__filename)
os.rename(self.__backup, self.__filename)
def open(file, mode = 'r', bufsize = -1):
if 'w' not in mode:
return _orig_open(file, mode, bufsize)
return _BkFile(file, mode, bufsize)
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