---------------------------------------- > Date: Mon, 20 Apr 2015 16:38:49 -0700 > From: garyj...@spocom.com > To: cygwin@cygwin.com > Subject: Re: tar zxvf won't work with Redhat generated compressed tar file > > On 2015-04-20, Murthy Gandikota wrote: > >>>> 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 > >> 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. > > I think you misunderstand. Gunzip decompresses once. As Eric > wrote, tar recognizes compressed files and will decompress them > automatically even without specifying a compression flag such as > 'z'. The second decompression is done by tar, not by gunzip. > > Regards, > Gary >
Got it! Thanks a ton. > -- > Problem reports: http://cygwin.com/problems.html > FAQ: http://cygwin.com/faq/ > Documentation: http://cygwin.com/docs.html > Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple > -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
