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Re: [OCLUG-Tech] tarball differences

Hi John,
You might get some value from creating a verbose listing from each tarball, dump to file, sort so they are in the same order, and then compare the two files.

"tar -tzf ..." lists the files in the tarball, add v to it for the verbose listing with date and size and maybe more.

Rob

 
--
Rob Echlin, B. Eng.
613-266-8311 -  Ottawa, ON
http://talksoftware.wordpress.com/



----- Original Message -----
> From: John C Nash <nashjc [ at ] uottawa [ dot ] ca>
> To: Rick <graham [ dot ] rick [ at ] gmail [ dot ] com>
> Cc: linux <linux [ at ] lists [ dot ] oclug [ dot ] on [ dot ] ca>
> Sent: Wednesday, August 31, 2011 1:04:19 PM
> Subject: Re: [OCLUG-Tech] tarball differences
> 
>T hanks. That makes sense.
> 
> Best, JN
> 
> 
> On 08/31/2011 12:51 PM, Rick wrote:
>>  According to the spec that bite is the first byte of the modification
>>  time field.
>> 
>>  --
>>  MTIME (Modification TIME)
>>      This gives the most recent modification time of the original file
>>  being compressed. The time is in Unix format, i.e., seconds since
>>  00:00:00 GMT, Jan. 1, 1970. (Note that this may cause problems for
>>  MS-DOS and other systems that use local rather than Universal time.)
>>  If the compressed data did not come from a file, MTIME is set to the
>>  time at which compression started. MTIME = 0 means no time stamp is
>>  available.
>>  --
>> 
>>  see: http://www.gzip.org/zlib/rfc-gzip.html#file-format
>> 
>>  On Wed, Aug 31, 2011 at 12:35 PM, John C Nash <nashjc [ at ] uottawa [ dot ] ca> 
> wrote:
>>>  In preparing a backup script for my server, I wanted to tar a 
> directory, e.g.,
>>> 
>>>   tar czvf mydir.tar.gz /path-to-mydir/
>>> 
>>>  and compare it with the "last" versions e.g., 
> last/mydir.tar.gz
>>> 
>>>  Even when no changes made, if I do
>>> 
>>>   cmp mydir.tar.gz last/mydir.tar.gz
>>> 
>>>  I get
>>> 
>>>   mydir.tar.gz last/mydir.tar.gz differ: byte 5, line 1
>>> 
>>>  This doesn't happen with zip, so I have a "sort of" 
> workaround. However, I'm curious to
>>>  the origin of the issue if anyone has ideas.
>>> 
>>>  Cheers,
>>> 
>>>  JN
>>>  _______________________________________________
>>>  Linux mailing list
>>>  Linux [ at ] lists [ dot ] oclug [ dot ] on [ dot ] ca
>>>  http://oclug.on.ca/mailman/listinfo/linux
>>> 
>> 
>> 
>> 
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