Re: Let's discuss big changes in Ruby packaging for squeeze+1

[Lucas Nussbaum <lucas@lucas-nussbaum.net>]

On 22/04/10 at 07:33 -0600, Marcelo E. Magallon wrote:
>  When I was exploring a similar idea, I was thinking of going
>  with:
> 
>  DIR=`basename "$gem" .gem`
>  mkdir "$DIR"
>  tar xOf "$gem" data.tar.gz | tar -C "$DIR" -xzf -

My own implementation:
#!/bin/bash
set -x
set -e
GEM=$1
BASENAME=$(basename $GEM .gem)
TDIR=$(mktemp -d /tmp/gem2tgz.XXXXXX)
mkdir $TDIR/$BASENAME
tar xf $GEM -O data.tar.gz | tar xz -C $TDIR/$BASENAME
tar xf $GEM -O metadata.gz | gunzip > $TDIR/$BASENAME/metadata
# Fix timestamps of files
find $TDIR/$BASENAME -exec touch -m {} \+
tar czf $BASENAME.tgz -C $TDIR $BASENAME
rm -rf $TDIR

>  And using the gem metadata to extract things like the gem name,
>  version, etc.
> 
>  But then I realised that it's better to use Rubygem's library,
>  which allows for something like:
> 
>     require 'rubygems/format'
>     format = Gem::Format.from_file_by_path ARGV.first
>     spec = format.spec
>     puts "Gem: #{spec.name} (#{spec.version})"
>     format.file_entries.each do |entry, data|
>        # entry['path'] is the file's path
>        # entry['mode'] is the file's mode
>        # data contains the actual file data
> 
>        # you only need to add sanity checks and filters here and
>        # write data to entry['path']
>     end
> 
>  It's a real pity that the gem spec does not include the license
>  information in a machine readable format.

The problem with using the gem library is that I usually prefer not to
have it installed, to make it easier to detect usages of "require
'rubygems'". Maybe we should have our own private copy of just
rubygems/format for that.
-- 
| Lucas Nussbaum
| lucas@lucas-nussbaum.net   http://www.lucas-nussbaum.net/ |
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