[Insight-users] installation problem

[Luis Ibanez]

Hi Murthy,

It is very likely that you are inadvertedly calling
the SunOS version of "tar" and not GNU tar.

The SunOS 'tar' version is incompatible with GNU tar
and it doesn't respect POSIX standards.

---

Please double check the path of your "tar" utility.

You can do this with:

    which  tar

check also that you don't have any aliases to "tar"

--

Here is what the man page of GNU "tar" says:

"Checksuming problems:

SunOS and HP-UX 'tar' fail to accept archives created using GNU 'tar'
and containing non-ASCII file names, that is, file names having
characters with the eight bit set, because they use signed checksums,
while GNU 'tar' uses unsigned checksums while creating archives, as per
POSIX standards. On reading, GNU 'tar' computes both checksums and
accepts any. It is somewhat worrying that a lot of people may go around
doing backup of their files using faulty (or at leaset non-standard)
software, not learning about it until it's time to restore their missing
files with an incompatible file extractor, or vice versa.

GNU 'tar' compute checksums both ways, and accept any on read, so GNU
tar can read Sun tapes even with their wrong checksums. GNU 'tar'
produces the standard cheksum, however, raising incompatibilities with
Sun. That is to say, GNU 'tar' has not been modified to _produce_
incorrect archives to be read by buggy 'tar''s. I'be been told that more
recent Sun 'tar' now read standard archives, so maybe Sun did a similar
patch, arter all ?

The story seems to be that when Sun first imported 'tar' sources on
their system, tey recompiled it wihout realizing that the checksums were
computed differently, because of a change in the default signing of
'char's in their compiler. So they started computing checksums wrongly.
When they later realized their mistake, they merely decided to stay
compatible with it, and with temselves afterwards. Presumably, but I
don't really know, HP-UX has chosen that their 'tar' archives to be
compatible with Sun's. The current standards do not favor Sun 'tar'
format. In any case, it now falls on the shoulders of SunOS and HP-UX
users to get a 'tar' able to read the good archives they receive."

-----------------


Nifty story...

Regards,


    Luis


--------------------------
DAKSHINA VALIVETI wrote:
> Hi Luis,
>      I am typing 'tar -xvf InsightToolkit-1.6.0.tar'
> after I unzip the file using 'gunzip' command.
> I am working on SunOS Release 5.8 Generic_117000-03.
> And my tar version is 'tar (GNU tar) 1.13.19'.
> 
> When I untar the packet, the process unpacks some
> blocks and then stops with a comment:
> "tar: directory checksum error"
> I downloaded thrice to see if there is any
> downloading problem. But I came across the same
> problem again. Please help.
> 
> Thank you.
> Murthy.
> 
> 
>