From: Lars Haugseth <ruby-talk@...>
Date: 2012-10-04T21:02:42+09:00
Subject: Re: How to get installed module version

On 10/04/2012 12:32 PM, Abhishek K. wrote:
> i am looking something we do in perl and python same way in ruby like
>
> perl -MABC -e 'print "$ABC::VERSION"'
>
> python -c "import MODULE; print (MODULE.__version__)";

List all gems and their version:

$ ruby -e 'puts Gem::Specification.map {|gem| "#{gem.name}: 
#{gem.version}"}'

List all installed versions of a particular gem:

$ ruby -e 'puts Gem::Specification.find_all_by_name("rake").map(&:version)'

-- 
Lars Haugseth