Menu
All of your installed gem code will be there, under the gems directory. These paths vary from system to system, and they also depend on how you installed Ruby (rvm is different from Homebrew, which is different from rbenv, and so on). So gem environment will be helpful when you want to know where your gems' code lives.
Almost seems like running 'gem install' adds it to the global available gems (and hence terminal can run the package's commands), whereas adding it to the gemfile and running bundle install only adds it to the application. Similar to npm install --global. that's basically it.
The install command installs local or remote gem into a gem repository. For gems with executables ruby installs a wrapper file into the executable directory by default.
Since your goal is to verify a gem is installed with the correct version, use gem list . You can limit to the specific gem by using gem list data_mapper . To verify that it's installed and working, you'll have to try to require the gem and then use it in your code.
Contrary to all the other posts I suggest NOT using sudo when installing gems.
Instead I recommend you install RVM and start a happy life with portable gem homes and different version of Ruby all living under one roof.
For the uninitiated, from the documentation:
RVM is a command line tool which allows us to easily install, manage and work with multiple ruby environments and sets of gems.
The reason why installing gems with sudo is worse than just gem install is because it installs the gems for ALL USERS as root. This might be fine if you're the only person using the machine, but if you're not it can cause weirdness.
If you decide you want to blow away all your gems and start again it's much easier, and safer, to do so as a non-root user.
If you decide you want to use RVM then using sudo will cause all kinds of weirdness because each Ruby version you install through RVM has its own GEM_HOME.
Also, it's nice if you can make your development environment as close to your production environment as possible, and in production you'll most likely install gems as a non-root user.
You can also install gems in your local environment (without sudo) with
gem install --user-install <gemname>
I recommend that so you don't mess with your system-level configuration even if it's a single-user computer.
You can check where the gems go by looking at gempaths with gem environment. In my case it's "~/.gem/ruby/1.8".
If you need some binaries from local installs added to your path, you can add something to your bashrc like:
if which ruby >/dev/null && which gem >/dev/null; then
PATH="$(ruby -r rubygems -e 'puts Gem.user_dir')/bin:$PATH"
fi
(from http://guides.rubygems.org/faqs/#user-install)
Better yet, put --user-install in your ~/.gemrc file so you don't have to type it every time
gem: --user-install
In case you
add the following to your .bash_profile :
export GEM_HOME=/Users/‹your_user›/.gem
export PATH="$GEM_HOME/bin:$PATH"
Open a new tab in Terminal OR source ~/.bash_profile and you're good to go!
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With