Thanks for looking after this.
I worked from the wikipedia description which was lazier than reading the
rfc.
On Mon, Jun 4, 2012 at 6:47 PM, bill lam <bbill....@gmail.com> wrote:
> tar.ijs works correctly with files created by linux tar. Files
> created from 7z give different format for count and checksum fields,
> may be it interprets RFC in a different way. I also tested that
> linux tar accetp tar files created from 7z. To fix this, please try
> replace the 2 lines in both tarf and tarx to
>
> count=. 8#._48+a.i. ' '-.~ ({.~ i.&null) 12{.124}.d
> assert. (chksum{d) =&((0&".)@:({.~ i.&null)) (getchk d)
>
> Пнд, 04 Июн 2012, Robert Cyr писал(а):
> > File archiving, compressing etc. are fascinating fields, and as
> > Wikipedia indicates, the checksum for the header block should
> > normally be at offset 148, size 8 . It is " 6247" in my
> > 'HlpDict.tar' file before transfer to my iPad using iTunes.
> >
> > In 'tart':
> > The checksum is " 6247" (4 leading blanks), and chksum{d
> > correctly reads it.
> > But getchk d returns "006247 " (2 trailing blanks)
> >
> > The problem shows up in line 11 of 'tart'
> >
> >
> > Sent from my iPad
> >
> > On 2012-06-04, at 09:36, Eric Iverson <eric.b.iver...@gmail.com> wrote:
> >
> > > That blows my theory of a problem in J tar create. Probably a
> difference
> > > between my interpretation of the tar file spec and 7-zip. Although not
> the
> > > same, not that J tar exctract works on the addons tar of the
> dictionary.
> > >
> > > Perhaps you already ave, but it would be helpful if you could document
> > > exactly what bytes the 7-zip has for its checksum and what bytes J tar
> x
> > > things it should have.
> > >
> > > On Mon, Jun 4, 2012 at 9:28 AM, Robert Cyr <robert....@gmail.com>
> wrote:
> > >
> > >> The file was created with 7-Zip on a 64-bit vista pc.
> > >>
> > >> Sent from my iPad
> > >>
> > >> On 2012-06-04, at 08:56, Eric Iverson <eric.b.iver...@gmail.com>
> wrote:
> > >>
> > >>> I haven't had a chance to look at this, but if there is a big I
> expect it
> > >>> is in tar create. Most of the testing was done with tar 'x' (that is,
> > >>> extract). Quite a few addons, with quite a range of files and folder
> > >>> structures extract successfully.
> > >>>
> > >>> Can you confirm that the problem you found was with a file that the
> J tar
> > >>> created, rather than a file created by standard unix tar.
> > >>>
> > >>> If the bug is in J tar create checksum then it is probably easy to
> figure
> > >>> out the fix.
> > >>>
> > >>> On Sun, Jun 3, 2012 at 3:00 PM, Robert Cyr <robert....@gmail.com>
> wrote:
> > >>>
> > >>>> tar defines a var named checksum and uses a function named getchk.
> > >>>>
> > >>>> The 4 (out of 8) leading chars of checksum{d are '0', whereas the 4
> > >>>> leading chars of getchk d are ' '. The other 4 are ok.
> > >>>>
> > >>>> This leads to an assertion failure.
> > >>>>
> > >>>> Sent from my iPad
> > >>>>
> ----------------------------------------------------------------------
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> > >>>>
> > >>>
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>
> --
> regards,
> ====================================================
> GPG key 1024D/4434BAB3 2008-08-24
> gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3
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