Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!ncar!gatech!purdue!haven!adm!smoke!gwyn
From: gwyn@smoke.brl.mil (Doug Gwyn)
Newsgroups: comp.sys.apple2
Subject: Re: .tar
Message-ID: <15293@smoke.brl.mil>
Date: 22 Feb 91 18:16:21 GMT
References: <9102212124.AA24505@apple.com>
Organization: U.S. Army Ballistic Research Laboratory, APG, MD.
Lines: 18

In article <9102212124.AA24505@apple.com> PYC121@URIACC.URI.EDU (Andy Kress) writes:
>    What is it and how do I unpack a file with the .tar extension?  I
> do NOT have access to a unix machine.  I have to unpack it on my GS.
> Is this possible?  Specifically, I wanted to check out emacs for the
> GS which happens to be .tar.Z .  GSHK will take care of the Z but
> what about the tar.  Thanks in advance!

I think you may be able to obtain a free implementation of an archiver
that understands "tar" format from the GNU project, but in any case
the "tar" archive format is really quite simple:  The contained files
are not compressed in any way, and each is preceded by a 512-byte header
the first 100 bytes of which contain the file name in ASCIZ.  The file
size in bytes is contained in the 12 characters of the header starting
at byte number 124 (0 origin).  That is enough information to allow you
to write a little program that unpacks most "tar" archives.  Be sure to
handle errors gracefully and to precreate any subdirectories that you
might need to hold the extracted files, or else you'll have problems
when the first nonexistent directory is encountered in the archive.


Brought to you by Super Global Mega Corp .com