Subj : tar.gz files
To   : Thomas W. Mueller
From : Jasen Betts
Date : Sun Jul 01 2001 02:47 am

Hi Thomas.

30-Jun-01 11:24:16, Thomas W. Mueller wrote to Russ Johnson

 TWM> Hello Russ.

 TWM> 28 Jun 01 17:03, you wrote to Maurice Kinal:

 RJ>> I just had a discussion with the author of bbbs. According to
 RJ>> him, the reason you can't use tar.gz as an echomail archiver is
 RJ>> because it can't append to an archive. This makes sense, since
 RJ>> tar is used for writing to tape.

 TWM> That's not quite correct. tar.gz is actually created by two
 TWM> programs, tar and gzip. tar could be used for echomail, but it
 TWM> would be pretty pointless, since it does not compress at all.

:^) so what ? compression is what modems are for :^)

 TWM> That's what it calls gzip for if you call tar with the -z
 TWM> parameter. The resulting tar.gz file can indeed not be appended
 TWM> to without first un-gzip-in it, appending and then gzip-ing it.

Actually it can, I just tested it. you do lose compression efficinecy
compared to a single compression pass though

 TWM> And one last option: You could just use tar and call gzip just
 TWM> before you transfer the file or even just pipe it through gzip
 TWM> when you read it from the disk for transferring

Or just collect the files together and tar.gz them before sending.

 -=> Bye <=-
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 * Origin: Don't look a gift hose in the mouth  -  Helen of Troy (3:640/531.42)

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