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#!/usr/bin/python
# Copyright 2011-2012 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
import io
import optparse
import os
import stat
import sys
CONTENT_ENCODING = "utf_8"
FS_ENCODING = "utf_8"
try:
import magic
except ImportError:
magic = None
else:
try:
magic.MIME_TYPE
except AttributeError:
# magic module seems to be broken
magic = None
class IsTextFile(object):
def __init__(self):
if magic is not None:
self._call = self._is_text_magic
self._m = magic.open(magic.MIME_TYPE)
self._m.load()
else:
self._call = self._is_text_encoding
self._encoding = CONTENT_ENCODING
def __call__(self, filename):
"""
Returns True if the given file is a text file, and False otherwise.
"""
return self._call(filename)
def _is_text_magic(self, filename):
mime_type = self._m.file(filename)
return mime_type.startswith("text/")
def _is_text_encoding(self, filename):
try:
for line in io.open(filename, mode='r', encoding=self._encoding):
pass
except UnicodeDecodeError:
return False
return True
def chpath_inplace(filename, is_text_file, old, new):
"""
Returns True if any modifications were made, and False otherwise.
"""
modified = False
orig_stat = os.lstat(filename)
try:
f = io.open(filename, buffering=0, mode='r+b')
except IOError:
try:
orig_mode = stat.S_IMODE(os.lstat(filename).st_mode)
except OSError as e:
sys.stderr.write("%s: %s\n" % (e, filename))
return
temp_mode = 0o200 | orig_mode
os.chmod(filename, temp_mode)
try:
f = io.open(filename, buffering=0, mode='r+b')
finally:
os.chmod(filename, orig_mode)
len_old = len(old)
len_new = len(new)
matched_byte_count = 0
while True:
in_byte = f.read(1)
if not in_byte:
break
if in_byte == old[matched_byte_count]:
matched_byte_count += 1
if matched_byte_count == len_old:
modified = True
matched_byte_count = 0
end_position = f.tell()
start_position = end_position - len_old
if not is_text_file:
# search backwards for leading slashes written by
# a previous invocation of this tool
num_to_write = len_old
f.seek(start_position - 1)
while True:
if f.read(1) != b'/':
break
num_to_write += 1
f.seek(f.tell() - 2)
# pad with as many leading slashes as necessary
while num_to_write > len_new:
f.write(b'/')
num_to_write -= 1
f.write(new)
else:
remainder = f.read()
f.seek(start_position)
f.write(new)
if remainder:
f.write(remainder)
f.truncate()
f.seek(start_position + len_new)
elif matched_byte_count > 0:
# back up an try to start a new match after
# the first byte of the previous partial match
f.seek(f.tell() - matched_byte_count)
matched_byte_count = 0
f.close()
if modified:
if sys.hexversion >= 0x3030000:
orig_mtime = orig_stat.st_mtime_ns
os.utime(filename, ns=(orig_mtime, orig_mtime))
else:
orig_mtime = orig_stat[stat.ST_MTIME]
os.utime(filename, (orig_mtime, orig_mtime))
return modified
def chpath_inplace_symlink(filename, st, old, new):
target = os.readlink(filename)
if target.startswith(old):
new_target = new + target[len(old):]
os.unlink(filename)
os.symlink(new_target, filename)
os.lchown(filename, st.st_uid, st.st_gid)
def main(argv):
usage = "%s [options] <location> <old> <new>" % (os.path.basename(argv[0],))
parser = optparse.OptionParser(usage=usage)
options, args = parser.parse_args(argv[1:])
if len(args) != 3:
parser.error("3 args required, got %s" % (len(args),))
location, old, new = args
is_text_file = IsTextFile()
if not isinstance(location, bytes):
location = location.encode(FS_ENCODING)
if not isinstance(old, bytes):
old = old.encode(FS_ENCODING)
if not isinstance(new, bytes):
new = new.encode(FS_ENCODING)
st = os.lstat(location)
if stat.S_ISDIR(st.st_mode):
for parent, dirs, files in os.walk(location):
for filename in files:
filename = os.path.join(parent, filename)
try:
st = os.lstat(filename)
except OSError:
pass
else:
if stat.S_ISREG(st.st_mode):
chpath_inplace(filename,
is_text_file(filename), old, new)
elif stat.S_ISLNK(st.st_mode):
chpath_inplace_symlink(filename, st, old, new)
elif stat.S_ISREG(st.st_mode):
chpath_inplace(location,
is_text_file(location), old, new)
elif stat.S_ISLNK(st.st_mode):
chpath_inplace_symlink(location, st, old, new)
return os.EX_OK
if __name__ == "__main__":
sys.exit(main(sys.argv))
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