From: Chris Gehlker <gehlker@...>
Date: 2002-01-14T12:08:58+09:00
Subject: Re: Best way for platf. independent compression?

On 1/13/02 1:42 PM, "Massimiliano Mirra" <list@chromatic-harp.com> wrote:

> Currently, rpkg builds packets by tar'ring and gzip'ping the source
> directories through GNU tar.
> 
> However it aims to be entirely Ruby-based or at least platform
> independent out of the box.  If you have any though or warning on the
> following subjects, I'd like to hear them:
> 
> - is GNU tar a reasonable external requirement for this, i.e. is it
> easily available on every platform that Ruby runs on or even
> widespread enough that it is already installed?

On Macs, gnutar will be their if the user installed the optional Developer
Tools. It a pretty safe bet that she did in order to build ruby in the first
place.
> - do backquotes for calling external commands work reliably and
> uniformly across supported platforms?  In other words, will writing
> `tar xcf #{pkgdir}` always do the trick or will it need tweakings
> depending on the platform?

Backquotes work fine but 'tar' is not symlinked to gnutar. Rather it will
invoke BSD tar which, IIRC, needs an explicit z parameter to deal with .tgz
files. So you are better off  with
`tar -xzf #{pkgdir}`
Or
`gnutar xcf #{pkgdir}`

I think the former will work on every BSD.
> - alternatively, is there any reasonable pure Ruby solution?  I have
> seen CompressionR, Rubyzip, and Ruby/zlib in the RAA.  Could someone
> who has used them a bit if not extensively suggest whether the answer
> is among them?
> 
> 
> Massimiliano
> 

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