Re: github port group

>
> On Apr 22, 2012, at 16:21, Joshua Root wrote:
>
>> On 2012-4-23 06:51 , Ryan Schmidt wrote:
>>> No, I'm trying to protect against the gzip compression of the tar archive varying from generation to generation. gzip compression uses entropy -- random numbers. If you have two identical tar archives, and gzip compress them with the same settings, the resulting gzip files will not be byte for byte identical, and thus they'll have different checksums:
>>>
>>> $ sha1sum *.tar
>>> 92bfe8b02b49b977a18c9f8e8d301a0ef159fe51  1.tar
>>> 92bfe8b02b49b977a18c9f8e8d301a0ef159fe51  2.tar
>>> $ gzip 1.tar
>>> $ gzip 2.tar
>>> $ sha1sum *.tar.gz
>>> 39c6beda6851d98295f770a11b8ea122647ae4c8  1.tar.gz
>>> 7a95ea746e698d367ec155e4387972051e1a2e38  2.tar.gz
>>> $
>>
>> Nonsense. The gzip files in the above example differ because they
>> contain files with different names.
>
> Oh. Well, here's a test with the same file names:
>
> $ sha1sum */file.tar
> 92bfe8b02b49b977a18c9f8e8d301a0ef159fe51  1/file.tar
> 92bfe8b02b49b977a18c9f8e8d301a0ef159fe51  2/file.tar
> $ gzip 1/file.tar
> $ gzip 2/file.tar
> $ sha1sum */file.tar.gz
> 238d08d9c64af0622abdd6a074b5c3c0b784a238  1/file.tar.gz
> e398dbc43e65f5bb165876bcb1819b302fe251fd  2/file.tar.gz
> $