gunzip incompatible

[Muthiah Annamalai]

Thomas Weber wrote:
> On 28/01/08 13:45 -0500, John W. Eaton wrote:
>   
>> On 28-Jan-2008, Mats Hedlund wrote:
>>
>> | In matlab, this works for unzipping an ODF spreadsheet: gunzip('file.ods').
>> | In octave, it does not, replying with 'unknown file format'.
>> | Any thoughts on this and ways to fix it?
>>
>> Octave's gunzip function is just a .m file.  It ultimately calls
>> another function called unpack to do the work.  I think the problem is
>> that gunzip is leaving it up to unpack to determine which
>> uncompression utility to use, when it should probably be forcing it to
>> use gzip.  It would be great if someone could have a look at this
>> problem and propose a patch.  Similar changes would likely be
>> appropriate for the bunzip2, untar, and unzip functions.
>>     
>
> Well, how do you determine the compressing algorithm if not by the
> extension (by the way, .odf can be extracted by unzip, not gunzip)?
>
> "file" is highly system-dependant. I guess the only solution would be to
> try all commands on an unknown file type and check their return value -
> bah, that's ugly.
>
> 	Thomas
>   
No I think you could change 'unpack.m' and allow a 4th argument that can 
be used
as a fallback.

Otherwise, we could somehow make unpack to figure out who called it, i.e 
tar, gzip, etc,
and do the appropriate fallback method.

-Muthu