CODEWITHSUNDEEP
javapythonpython-2.7maven-assembly-plugin
inanutshellus
inanutshellus

Reputation: 10001

python tarfile.py "file could not be opened successfully"

I have a tarball that I can't open using python:

>>> import tarfile
>>> tarfile.open('/tmp/bad.tar.gz')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "tarfile.py", line 1672, in open
    raise ReadError("file could not be opened successfully")
tarfile.ReadError: file could not be opened successfully

but I'm able to extract the file with no problem on the command line.

$ tar -xzvf /tmp/bad.tar.gz

I've traced the python tarfile code, and there's a function "nti" where they're converting bytes. It gets to this line:

obj.uid = nti(buf[108:116])

and blows up. These bits (for the UID) coming through as eight spaces. Not sure where to go from here...

Upvotes: 2

Views: 4325

Answers (1)

inanutshellus
inanutshellus

Reputation: 10001

Honestly it looks like the bug is in tarfile.py's nti function:

n = int(nts(s) or "0", 8)

The fall-through logic (or "0") is not working because s is spaces, not None, so int() blows up.

I copied tarfile.py from /var/lib/python2.7/ and wrapped that particular line with a try/catch, which fixed me up:

    try:
        obj.uid = nti(buf[108:116])
    except InvalidHeaderError:
        obj.uid = 0

It's a hack solution, though. Really I'd prefer that the python folk took a look at it and fixed the "or "0" logic.

Update

Turns out the tarball was created by the maven-assembly-plugin in a Java 6 project that had just been upgraded to Java 7. The issue was resolved by upgrading the maven-assembly-plugin to 2.5.3.

Upvotes: 1

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