Add Where Are The Binaries as a zsh til.

README.md

@@ -60,6 +60,7 @@ smart people at [Hashrocket](http://hashrocket.com/).
 
 - [Clear The Screen](zsh/clear-the-screen.md)
 - [Search History](zsh/search-history.md)
+- [Where Are The Binaries?](zsh/where-are-the-binaries.md)
 
 ## About
 

zsh/where-are-the-binaries.md

@@ -0,0 +1,21 @@
+# Where Are The Binaries?
+
+When I want to know where an executable is, I use `which` like so:
+
+```
+$ which rails
+/Users/jbranchaud/.gem/ruby/2.1.4/bin/rails
+```
+
+That is the rails binary on my path that will be used if I enter a rails command.
+
+However, with something like rails, there may be multiple versions on your
+path. If you want to know where all of them are, you can use `where`, like
+so:
+
+```
+$ where rails
+/Users/jbranchaud/.gem/ruby/2.1.4/bin/rails
+/Users/jbranchaud/.rubies/2.1.4/bin/rails
+/usr/bin/rails
+```