On 9 Jul 2009, at 10:32, Dr. David Kirkby wrote:

>
> Ralf Hemmecke wrote:
>> Thanks. That makes sense.
>>
>> But as you see, some people (me) ask why these .tar files are not
>> zipped. I guess, a small note on the webpage would clarify that.
>>
>> """
>> The .tar files below contain collections of .spkg files (which are
>> basically .tar.bz2 files).
>> """
>>
>> Or you put somewhere on that page a link to a .txt file that lists  
>> the
>> contents of the .tar file. Some project add a manifest.txt file to  
>> the
>> distribution.
>>
>> Just my 1/2 cents.
>>
>> Ralf
>
> I would agree with Ralf. The fact the file is already compressed is  
> not
> obvious. In fact, since some of it is not compressed, and each .spkg
> must have some overhead in compression, has anyone ever tried
> compressing the tar file? It might save a few bytes, and reduce
> confusion. (I'm aware it could also increase the size by compressing
> compressed files.) No I have not tried it myself - perhaps I will  
> later.
>

I have tried compressing the sage.*.tar files using gzip and bzip2.   
The compression is insignificant, at least when using the default  
compression levels.

  % ls -l *tar*
-rw-r--r--   1 XXX   staff  215244800 Jun 19 08:46 sage-4.0.2.tar
-rw-r--r--   1 XXX   staff  214183786 Jun 19 08:46 sage-4.0.2.tar.gz
-rw-r--r--   1 XXX   staff  215169684 Jun 19 08:46 sage-4.0.2.tar.bz2

But, there is the big advantage that if you have a compressed file you  
are alerted right away if the file is corrupt.  I have had more than  
one occurrence where the tar file was bad, and only found there was a  
problem after several hours of compilation attempt ended in failure.

I would prefer that the tar ball was compressed with gzip, so I can  
know right away whether it is good or bad.  gzip is a better choice  
than bzip2, as it results in slightly smaller file sizes, and it is  
much, much quicker to compress the file, at least on my ancient PPC  
machine.

--
Kevin Horton
Ottawa, Canada




--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to 
[email protected]
For more options, visit this group at http://groups.google.com/group/sage-devel
URLs: http://www.sagemath.org
-~----------~----~----~----~------~----~------~--~---

Reply via email to