tar.extractall()无法识别意外的EOF

Question

Python tarfile库没有检测到损坏的tar.

user@host$ wc -c good.tar
143360 good.tar

user@host$ head -c 130000 good.tar > cut.tar

user@host$ tar -tf cut.tar 
...
tar: Unexpected EOF in archive
tar: Error is not recoverable: exiting now

非常好,命令行工具可识别意外的EOF.

user@host$ python
Python 2.7.6 (default, Mar 22 2014, 22:59:56) 
>>> import tarfile
>>> tar=tarfile.open('cut.tar')
>>> tar.extractall()

不太好.Python库对文件进行解码,但不会引发任何异常.

如何使用Python库检测意外的EOF？我想避开subprocess模块.

该参数errorlevel没有帮助.我试过errorlevel = 1和errorlevel = 2.

Answer 1

我写了一个工作.它适用于我的tar文件.我想它不支持所有类型的对象都可以存储在tar文件中.

# -*- coding: utf-8 -*-
from __future__ import absolute_import, division, unicode_literals, print_function
import os
import tarfile

class TarfileWhichRaisesOnEOF(tarfile.TarFile):
    def extractall(self, path=".", members=None):
        super(TarfileWhichRaisesOnEOF, self).extractall(path, members)
        if members is None:
            members = self

        for tarinfo in members:
            if not tarinfo.isfile():
                continue
            file=os.path.join(path, tarinfo.name)
            size_real=os.path.getsize(file)
            if size_real!=tarinfo.size:
                raise tarfile.ExtractError('Extracting %s: Size does not match. According to tarinfo %s and on disk %s' % (
                    tarinfo, tarinfo.size, size_real))