Following yesterday’s post about using “npm install -g” without root privileges, here are the Python and Ruby counterparts for your beloved OSX or Linux box.

By default, pip install and gem install try to install stuff in /usr/, which requires root privileges. Hence, most users will “naturally” do a sudo to perform the install — which is, in my opinion at least, a very bad idea (do you really want to give root privileges to packages that haven’t been reviewed?). Fortunately, there’s more than the default setting.

Python: pip install --user

With Python 2.6 and later you can avoid “sudoing” your pip install by using the --user argument (thanks @cmdevienne for the tip!). Let’s test this with html-linter:

$ pip install --user html-linter

By default on Linux and OSX (non-framework builds) this will install your package into ~/.local, which is just fine for me. All executables are in ~/.local/bin/, which is included in my $PATH, and all Python libraries are in ~/.local/lib/python2.7/. The world couldn’t be any better.

You can specify a custom destination by setting the PYTHONUSERBASE environment variable:

$ export PYTHONUSERBASE=/myappenv
$ pip install --user html-linter

Of course, you’ll have to add that to your $PATH to make it work. You can add the following lines to your ~/.profile like that:

export PYTHONUSERBASE=/myappenv
PATH="$PYTHONUSERBASE/bin:${PATH}"

The only downside (compared to npm) is that you’ll have to remember to use the --user argument when installing Python packages. If there’s a way to make it the default mode, please let me know.

EDIT: a good workaround is to define a custom pip function in your ~/.bash_aliases (or bashrc, zshrc, whatever), as suggested in comment #1.

Ruby: gem install --user-install

gem’s --user-install argument is quite similar. One good thing is that you can easily make it the default mode:

$ echo "gem: --user-install" >> ~/.gemrc

Now let’s try that with the most valuable gem I know:

$ gem install vimgolf
Fetching: vimgolf-0.4.6.gem (100%)
WARNING:  You don't have /home/kaze/.gem/ruby/1.8/bin in your PATH,
          gem executables will not run.

As you can see, gem installs everything in ~/.gem by default; unfortunately, the file structure does not allow to put executables in the same ~/.local/bin/ directory. Never mind, we’ll add those ~/.gem/ruby/*/bin/ directories to the $PATH manually by adding these lines to the ~/.profile:

for dir in $HOME/.gem/ruby/*; do
  [ -d "$dir/bin" ] && PATH="${dir}/bin:${PATH}"
done

Source your ~/.profile, you’re done.

http://kazhack.org/?post/2014/12/12/pip-gem-install-without-sudo