[Rubygems-developers] Automating gems

Chad Woolley thewoolleyman at gmail.com
Thu Mar 15 05:04:28 EDT 2007

You can create your own implementation of StreamUI. and use that in
place of the default StreamUI in Gem::CommandManager.  That may seem
"messy, but I believe this is the mechanism that was built into
rubygems for doing this, and it works pretty well - except for where
someone forgot to use it - see

For an example of overriding StreamUI to intercept the IO streams,
check out geminstaller.rubyforge.org, and look at gem_runner_proxy,
and enhanced_stream_ui.

-- Chad

On 3/14/07, Patrick Hurley <phurley at gmail.com> wrote:
> Sorry, if I should have been able to find some docs to point me in the
> right direction, but so far here is what I figured out from trial and
> error and some source code reading.
> I want to unpack a gem already on my machine:
> gem unpack a_gem
> Then I want to retrieve the gem spec
> gem specification a_gem
> (then more stuff but this will get me started)
> So far I have the simple code:
> require "rubygems"
> Gem.manage_gems
> if gem = ARGV.first
>   puts "Processing #{gem}"
>   runner = Gem::GemRunner.new
>   puts "Unpack #{gem}"
>   runner.run ['unpack', gem]
>   runner.run(['specification', gem])
> end
> This works; however, the run command displays to the screen. Is there
> an easy way to capture its output? I see there is a default interface
> object, with a method called say I could grab, but that seems pretty
> messy. I could also grab the stdout handle and play games there, but
> again, I feel I am missing something.
> Thanks in advance for your time
> pth
> _______________________________________________
> Rubygems-developers mailing list
> Rubygems-developers at rubyforge.org
> http://rubyforge.org/mailman/listinfo/rubygems-developers

More information about the Rubygems-developers mailing list