sigilplugins/imagecrunch/PIL/TarIO.py

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2019-08-03 07:49:15 +00:00
#
# The Python Imaging Library.
# $Id$
#
# read files from within a tar file
#
# History:
# 95-06-18 fl Created
# 96-05-28 fl Open files in binary mode
#
# Copyright (c) Secret Labs AB 1997.
# Copyright (c) Fredrik Lundh 1995-96.
#
# See the README file for information on usage and redistribution.
#
from . import ContainerIO
##
# A file object that provides read access to a given member of a TAR
# file.
class TarIO(ContainerIO.ContainerIO):
def __init__(self, tarfile, file):
"""
Create file object.
:param tarfile: Name of TAR file.
:param file: Name of member file.
"""
fh = open(tarfile, "rb")
while True:
s = fh.read(512)
if len(s) != 512:
raise IOError("unexpected end of tar file")
name = s[:100].decode('utf-8')
i = name.find('\0')
if i == 0:
raise IOError("cannot find subfile")
if i > 0:
name = name[:i]
size = int(s[124:135], 8)
if file == name:
break
fh.seek((size + 511) & (~511), 1)
# Open region
ContainerIO.ContainerIO.__init__(self, fh, fh.tell(), size)