[Bug-tar] feature request / request to add into head version

[Zoubek Ondřej]

Dear sirs,

I have added --only-first-file option to tar utility, version 1.19-3 
obtained from my kubuntu repository as current version and sending its diff.

Its purpose is to extract only first file from archive (typically read 
from stdin) and die just after extracting it and not flushing input pipe 
(change to sys_drain_input_pipe() function).

It is intended to be used when you need only one file to extract and 
archive is too large to be scanned for it. Some utility which feeds tar 
should seek or skip number of blocks obtained by --block-number during 
archive creating.

This option is used for fast obtaining one file from backup.
I have also made a patch to gzip to make seekable 100% compatible files 
with option --seekable (synchronization point from which can be file 
read every ~2MB of zipped stream).

In attachement I am including the diff from 1.19 to 1.19-3 and my diff 
from 1.19-3. My changes are about 5 lines at all.

Best regards,
Ondrej

tar_1.19-3.diff.gz
Description: application/gzip

tar_1.19-3-zuban.diff.gz
Description: application/gzip