/usr/lib/python2.7/encodings/utf_8_sig.py is in python2.7-minimal 2.7.3-0ubuntu3.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 | """ Python 'utf-8-sig' Codec
This work similar to UTF-8 with the following changes:
* On encoding/writing a UTF-8 encoded BOM will be prepended/written as the
first three bytes.
* On decoding/reading if the first three bytes are a UTF-8 encoded BOM, these
bytes will be skipped.
"""
import codecs
### Codec APIs
def encode(input, errors='strict'):
return (codecs.BOM_UTF8 + codecs.utf_8_encode(input, errors)[0], len(input))
def decode(input, errors='strict'):
prefix = 0
if input[:3] == codecs.BOM_UTF8:
input = input[3:]
prefix = 3
(output, consumed) = codecs.utf_8_decode(input, errors, True)
return (output, consumed+prefix)
class IncrementalEncoder(codecs.IncrementalEncoder):
def __init__(self, errors='strict'):
codecs.IncrementalEncoder.__init__(self, errors)
self.first = 1
def encode(self, input, final=False):
if self.first:
self.first = 0
return codecs.BOM_UTF8 + codecs.utf_8_encode(input, self.errors)[0]
else:
return codecs.utf_8_encode(input, self.errors)[0]
def reset(self):
codecs.IncrementalEncoder.reset(self)
self.first = 1
def getstate(self):
return self.first
def setstate(self, state):
self.first = state
class IncrementalDecoder(codecs.BufferedIncrementalDecoder):
def __init__(self, errors='strict'):
codecs.BufferedIncrementalDecoder.__init__(self, errors)
self.first = True
def _buffer_decode(self, input, errors, final):
if self.first:
if len(input) < 3:
if codecs.BOM_UTF8.startswith(input):
# not enough data to decide if this really is a BOM
# => try again on the next call
return (u"", 0)
else:
self.first = None
else:
self.first = None
if input[:3] == codecs.BOM_UTF8:
(output, consumed) = codecs.utf_8_decode(input[3:], errors, final)
return (output, consumed+3)
return codecs.utf_8_decode(input, errors, final)
def reset(self):
codecs.BufferedIncrementalDecoder.reset(self)
self.first = True
class StreamWriter(codecs.StreamWriter):
def reset(self):
codecs.StreamWriter.reset(self)
try:
del self.encode
except AttributeError:
pass
def encode(self, input, errors='strict'):
self.encode = codecs.utf_8_encode
return encode(input, errors)
class StreamReader(codecs.StreamReader):
def reset(self):
codecs.StreamReader.reset(self)
try:
del self.decode
except AttributeError:
pass
def decode(self, input, errors='strict'):
if len(input) < 3:
if codecs.BOM_UTF8.startswith(input):
# not enough data to decide if this is a BOM
# => try again on the next call
return (u"", 0)
elif input[:3] == codecs.BOM_UTF8:
self.decode = codecs.utf_8_decode
(output, consumed) = codecs.utf_8_decode(input[3:],errors)
return (output, consumed+3)
# (else) no BOM present
self.decode = codecs.utf_8_decode
return codecs.utf_8_decode(input, errors)
### encodings module API
def getregentry():
return codecs.CodecInfo(
name='utf-8-sig',
encode=encode,
decode=decode,
incrementalencoder=IncrementalEncoder,
incrementaldecoder=IncrementalDecoder,
streamreader=StreamReader,
streamwriter=StreamWriter,
)
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