# Copyright (C) 2006 Canonical Ltd
#
# 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
"""Utilities for distinguishing binary files from text files"""
from itertools import chain
from bzrlib.errors import BinaryFile
from bzrlib.iterablefile import IterableFile
from bzrlib.osutils import file_iterator
def text_file(input):
"""Produce a file iterator that is guaranteed to be text, without seeking.
BinaryFile is raised if the file contains a NUL in the first 1024 bytes.
"""
first_chunk = input.read(1024)
if '\x00' in first_chunk:
raise BinaryFile()
return IterableFile(chain((first_chunk,), file_iterator(input)))
def check_text_lines(lines):
"""Raise BinaryFile if the supplied lines contain NULs.
Only the first 1024 characters are checked.
"""
f = IterableFile(lines)
if '\x00' in f.read(1024):
raise BinaryFile()
def check_text_path(path):
"""Check whether the supplied path is a text, not binary file.
Raise BinaryFile if a NUL occurs in the first 1024 bytes.
"""
f = open(path, 'rb')
try:
text_file(f)
finally:
f.close()
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