Re: [Bug-tar] Fwd: bug in GnuTar

[Jean-Louis Martineau]

> touch 1
> tar cz 1 > file.tgz
> ls -al file.tgz
-rw-rw-r-- 1 martinea martinea 10240 Nov 23 07:32 file.tgz
> dd if=file.tgz count=1 bs=108 > a.tgz
> gunzip -t -v a.tgz
a.tgz:   OK

Why the file is 10k in size? Why tar pad with zeros a compressed output?
The first 108 bytes are the compressed tar file followed by zeros.

> tar c 1 | gzip > file.tgz
> ls -al file.tgz
-rw-rw-r-- 1 martinea martinea 108 Nov 23 07:45 file.tgz

Only 108 bytes.

Jean-Louis



Tim Kientzle wrote:
> Sergey Poznyakoff wrote:
> > Vitaly V. Ch <address@hidden> ha escrit:
> >
> > > On some machines run under slackware 10.2 next test always fail:
> > >
> > > for ((i=0;i<1000;i++)); do echo $i >$i; tar cz $i >>file.tgz; done;
> > > gzip -t -v file.tgz
> >
> > It should have failed. You cannot glue together two compressed files and
> > expect the result to be a valid compressed file.
>
> That doesn't quite explain why his second example always
> works for him, though:
>
> > but following test always success on all machines:
> >
> >  for ((i=0;i<1000;i++)); do echo $i >$i; tar c $i | gzip >>file.tgz;
> > done; gzip -t -v file.tgz
>
> It does sound as though tar is exiting before the child
> gzip under some circumstances.
>
> Tim Kientzle