----------------------------------------
> From: murth...@hotmail.com
> To: ebl...@redhat.com; cygwin@cygwin.com
> Subject: RE: tar zxvf won't work with Redhat generated compressed tar file
> Date: Mon, 20 Apr 2015 22:00:10 +0000
>
>
>
> ----------------------------------------
>> Date: Mon, 20 Apr 2015 15:16:43 -0600
>> From: ebl...@redhat.com
>> To: cygwin@cygwin.com
>> Subject: Re: tar zxvf won't work with Redhat generated compressed tar file
>>
>> On 04/20/2015 03:08 PM, Murthy Gandikota wrote:
>>
>>>>
>>>>> $ tar xvf mytar.gz
>>>>> tar: This does not look like a tar archive
>>>>> tar: Skipping to next header
>>>>> tar: Exiting with failure status due to previous errors
>>>>
>>>> Then what makes you think it is actually a tar archive?
>>>> What
>>>>
>>>> gunzip> mytar < mytar.gz; file mytar
>>>>
>>>> says?
>>>>
>>
>>> Sorry, didn't notice the top-posting.... here is the output to the command
>>>
>>> mytar: gzip compressed data, last modified: Tue Mar 24 03:50:58 2015, from
>>> Unix
>>
>> Then it looks like you have a DOUBLE-compressed file. That is, someone
>> took a .tar.gz file, and ran THAT through gzip again (which seldom does
>> anything except make a LARGER file - because the first round of
>> compression removed any redundancy). Tar cannot read a
>> double-compressed stream, but breaking things into two steps lets you
>> get back to a single compressed stream, where the tar call then
>> auto-decompresses because you weren't supplying an explicit 'z' the
>> second time around. To prove it, try:
>>
>> gunzip <mytar.gz>mytar
>> tar zxvf mytar
>>
>> and if it still untars with an explicit decompression, then you have
>> proven that your original file was double-compressed. Also, if I'm
>> right about double compression, then mytar.gz would likely be slightly
>> larger than mytar (rather than the usual case of the .gz being
>> noticeably smaller).
>>
>> --
>> Eric Blake eblake redhat com +1-919-301-3266
>> Libvirt virtualization library http://libvirt.org
>>
>
> Yes, Sir. It did untar properly. So the problem is with the server
> compressing during the download (I get the file from a http server)?
> Thanks a lot for your help
> --
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It would be doubly nice if cygwin handled it ;-) It seems gunzip had no problem
recognizing the file as double compressed.
Thanks all for the help.
>
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