what is “$:” in ruby?

Question

Usually be seen in .gemspec file. eg. i18n.gemspec.

$: << File.expand_path(\'../lib\', __FILE__)

Answer 1

$: is the load path and $LOAD_PATH is its alias. When you load/require libraries/files within your ruby application, ruby searches in the directories listed in $: for them. With $: << File.expand_path('../lib', __FILE__) you add a specific directory to the load path.