I recommend direnv. It is an environment switcher for the shell.
Before each prompt it checks for the existence of an ".envrc" file in the current and parent directories. If the file exists (and authorized), it is loaded into a bash sub-shell and all exported variables are then captured by direnv and then made available the current shell.
Here is how to use direnv with ruby-install
+ ruby-install
Add this to the ~/.direnvrc
use_ruby() {
local ruby_root=$HOME/.rubies/$1
load_prefix "$ruby_root"
layout_ruby
}
Install ruby-install (brew install ruby-install
) and install a bunch of rubies.
ruby-install ruby 1.9.3
ruby-install ruby 2.0.0
ruby-install ruby 2.2.0
And then make a couple of symlinks for convenience:
ln -s .rubies/1.9 ruby-1.9.3-p*
ln -s .rubies/2.0 ruby-2.0.0
ln -s .rubies/2.2 ruby-2.2.0
And finally in any project's .envrc
:
use ruby 2.0
This will put all gems under the project's .direnv/ruby
directory (makes opening gems easier). bundler will put wrapper binaries in .direnv/bin
(no more bundle exec
!).
+ rbenv
It's also possible to use rbenv by adding the use rbenv
command in any .envrc
file. This will activate rbenv which in turn will put the ruby wrappers in the PATH.
Note that it's not necessary to install rbenv in the .bashrc or .zshrc for this to work.
+ RVM
Here is the most complicated .envrc that I use on ruby projects:
rvm use 1.8.7
layout ruby
PATH_add .direnv/bundler-bin
rvm is used to select the right ruby version for you
layout commands automatically set some of the usual environment variables. For now only the ruby layout exists. What it does is set the GEM_HOME environment variable and it's bin directory to your path. Because it depends on the ruby version, make sure to call it after "rvm". Since each ruby layout directories have their own GEM_HOME, you don't need to use rvm's gemsets.
PATH_add prepends and expands the given relative path. In that case, I use this to segregate the bundler binstubs from my own bin scripts with bundle install --binstubs .direnv/bundler-bin
If you want to find out what those commands exactly do, for now: cat direnv stdlib
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