Don't reinstall if gem is already installed

Question

How can I prevent gem install to not reinstall a Gem if the same version is already installed?

Answer 1

You can use the --conservative flag with gem install.

gem install sqlite -v 1.3.8 --conservative

It won't install or update any gems that meet the version requirement.

Answer 2

I would go with some bash oneliner:

if ! gem list | grep your_gem_name; then gem install your_gem_name; fi;