Selective extraction bug

[Ryan Ulch]

If you attempt to selectively extract files from an archive, and it is listed more than once, then you get a very misleading error message. It wasn’t super obvious that a file was listed twice when I first encountered the problem since I was using wildcards but I believe that goes through shell expansion so obviously nothing to do with tar on that end.

 

$ ls

test.sh

 

$ cat test.sh

set -x

 

touch testFile

tar -tf test.tar.gz

tar -czvf test.tar.gz testFile

tar -xz -f test.tar.gz testFile

tar -xz -f test.tar.gz testFile testFile

 

 

$ ./test.sh

++ touch testFile

++ tar -czvf test.tar.gz testFile

testFile

++ tar -tf test.tar.gz

testFile

++ tar -xz -f test.tar.gz testFile

++ tar -xz -f test.tar.gz testFile testFile

tar: testFile: Not found in archive

tar: Exiting with failure status due to previous errors

 

You can see that I create a file, then archive it, then confirm it’s in the archive, then selectively extract it with the file only listed once and it works fine, but if I listed the file twice, it fails with:

“tar: testFile: Not found in archive”

 

I downloaded the latest tar source from a mirror and built it to see if it’s present in the latest release:

 

$ tar --version

tar (GNU tar) 1.32

Copyright (C) 2019 Free Software Foundation, Inc.

License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.

This is free software: you are free to change and redistribute it.

There is NO WARRANTY, to the extent permitted by law.

 

Written by John Gilmore and Jay Fenlason.

 

I don’t mind if you think this should be an error in the first place, but the misleading error message is the worst part of it. Perhaps there’s an internal reason for this, but I figured I would report it.

 

Thanks,

Ryan