From: Simon Mullis <simon@...>
Date: 2007-09-28T21:55:30+09:00
Subject: Re: repost: minitar - how to extract only one file from a tar archive as an object

Great! This is exactly what I was looking for!

Thankyou.

SM

On 9/28/07, Raf Coremans <rrafje@gmail.com> wrote:
> 2007/9/28, Simon Mullis <simon@mullis.co.uk>:
> >
> > trying again....
> >
> > ;-)
> >
> > SM
> >
> > ---------- Forwarded message ----------
> > From: Simon Mullis <simon@mullis.co.uk>
> > Date: Sep 27, 2007 4:16 PM
> > Subject: minitar - how to extract only one file from a tar archive as an
> > object
> > To: ruby-talk@ruby-lang.org
> >
> >
> > Ahoy there, fellow rubyphiles...
> >
> > I'm trying to use Archive::Tar::Minitar to extract a single file from
> > a tar archive:
> >
> > "test.tar" contains:
> >
> > ./test/foo
> > ./test/bar
> > ./test/baz
> >
> > <code>
> > # lifted from the minitar source...
> > require 'archive/tar/minitar'
> > include Archive::Tar
> >
> > a = File.open("test.tar", "rb")
> > Minitar::Input.open(a) do |inp|
> >     inp.each do |entry|
> >        inp.extract_entry(".", entry) if entry.full_name =~ /baz/
> >     end
> > end
> > </code>
> >
> > This all works fine, and writes to "./test/baz"
> >
> > But!
> >
> > How could I do the same and create a File object of the extracted
> > file? (i.e. not write anything to disk).
> >
> > (The reason I ask is the file I want is a zip, which lives inside the
> > tar archive and I then want to grab some files from that using the
> > 'rubyzip' gem.)
> >
> > It's quite possible (in fact, more than likely) that I've missed
> > something obvious and there is already a straightforward way to do
> > this.
> >
> > To be honest, a few more examples of minitar in use would be great.
> >
> > Many thanks in advance for any pointers or tips.
> >
> > Cheers!
> >
> > --
> > Simon Mullis
> > _________________
> > simon@mullis.co.uk
> >
> >
>
> Hi,
>
>
> Use entry.read instead of inp.extract_entry; this will not extract the file
> to disk, but returns its contents as a string. And if wanted, you can wrap
> that string in a StringIO to get a file-like object:
>
> require 'archive/tar/minitar'
> include Archive::Tar
>
> require 'stringio'
>
> a = File.open("test.tar", "rb")
> Minitar::Input.open(a) do |inp|
>   inp.each do |entry|
>     if entry.full_name =~ /baz/
>       f = StringIO.new( entry.read)
>       #Do something useful with f
>     end
>   end
> end
>
>
> Regards,
> Raf
>


-- 
Simon Mullis
_________________
simon@mullis.co.uk