Add Scripting With RVM as a ruby til

README.md

@@ -10,7 +10,7 @@ smart people at [Hashrocket](http://hashrocket.com/).
 For a steady stream of TILs from a variety of rocketeers, checkout
 [til.hashrocket.com](https://til.hashrocket.com/).
 
-_754 TILs and counting..._
+_755 TILs and counting..._
 
 ---
 
@@ -622,6 +622,7 @@ _754 TILs and counting..._
 - [Returning With Sequel](ruby/returning-with-sequel.md)
 - [Running A Single MiniTest Example](ruby/running-a-single-minitest-example.md)
 - [Safe Navigation Operator](ruby/safe-navigation-operator.md)
+- [Scripting With RVM](ruby/scripting-with-rvm.md)
 - [Scroll To Top Of Page With Capybara](ruby/scroll-to-top-of-page-with-capybara.md)
 - [Set RVM Default Ruby](ruby/set-rvm-default-ruby.md)
 - [Show Public Methods With Pry](ruby/show-public-methods-with-pry.md)

ruby/scripting-with-rvm.md

@@ -0,0 +1,37 @@
+# Scripting With RVM
+
+Because of how [RVM](https://rvm.io/) works under the hood, you have to do a
+couple things to get it to work in a script.
+
+First, you need to ensure that your script is using `bash` instead of `sh`,
+so add this to the top of your scripts:
+
+```bash
+#!/bin/bash
+```
+
+You'll then want to make sure that RVM is sourced. Their
+[docs](https://rvm.io/workflow/scripting) recommend sourcing in a script
+like this:
+
+```bash
+# Load RVM into a shell session *as a function*
+if [[ -s "$HOME/.rvm/scripts/rvm" ]] ; then
+
+  # First try to load from a user install
+  source "$HOME/.rvm/scripts/rvm"
+
+elif [[ -s "/usr/local/rvm/scripts/rvm" ]] ; then
+
+  # Then try to load from a root install
+  source "/usr/local/rvm/scripts/rvm"
+
+else
+
+  printf "ERROR: An RVM installation was not found.\n"
+
+fi
+```
+
+After that, you can utilize any of the capabilities of RVM in your script as
+you'd like.