Question

How can I get the version of a gem using just Ruby? I’d rather not use a system call and grep it the shells output like:

`gem search passenger`.scan(/(?:\(|, *)([^,)]*)/).flatten.first
=> "2.2.9"

Can’t I just get it somehow with:

Gem::Version

I just don’t know how to specify the gem I want, like in this case I want to get the Passenger gem’s newest version.

Answer 1

This should help get you on your way. This searches the remote index for the latest version of a specific gem.

$ irb
>> require "rubygems"
>> dep = Gem::Dependency.new "passenger", Gem::Requirement.default
>> Gem::SpecFetcher.fetcher.find_matching dep
=> [[["passenger", #<Gem::Version "2.2.9">, "ruby"], "http://gems.rubyforge.org"]]