74 lines
1.7 KiB
Python
74 lines
1.7 KiB
Python
#
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# The Python Imaging Library.
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# $Id$
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#
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# read files from within a tar file
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#
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# History:
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# 95-06-18 fl Created
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# 96-05-28 fl Open files in binary mode
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#
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# Copyright (c) Secret Labs AB 1997.
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# Copyright (c) Fredrik Lundh 1995-96.
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#
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# See the README file for information on usage and redistribution.
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#
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from __future__ import annotations
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import io
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from types import TracebackType
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from . import ContainerIO
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class TarIO(ContainerIO.ContainerIO[bytes]):
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"""A file object that provides read access to a given member of a TAR file."""
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def __init__(self, tarfile: str, file: str) -> None:
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"""
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Create file object.
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:param tarfile: Name of TAR file.
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:param file: Name of member file.
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"""
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self.fh = open(tarfile, "rb")
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while True:
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s = self.fh.read(512)
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if len(s) != 512:
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msg = "unexpected end of tar file"
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raise OSError(msg)
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name = s[:100].decode("utf-8")
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i = name.find("\0")
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if i == 0:
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msg = "cannot find subfile"
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raise OSError(msg)
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if i > 0:
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name = name[:i]
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size = int(s[124:135], 8)
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if file == name:
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break
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self.fh.seek((size + 511) & (~511), io.SEEK_CUR)
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# Open region
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super().__init__(self.fh, self.fh.tell(), size)
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# Context manager support
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def __enter__(self) -> TarIO:
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return self
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def __exit__(
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self,
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exc_type: type[BaseException] | None,
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exc_val: BaseException | None,
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exc_tb: TracebackType | None,
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) -> None:
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self.close()
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def close(self) -> None:
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self.fh.close()
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