Ruby: __FILE__, __dir__ and symlinks

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Ruby's __FILE__ keyword returns the path to the current file. On popular for this are Ruby binaries:

#!/usr/bin/env ruby
$LOAD_PATH << File.expand_path('../../lib', __FILE__)
require 'my_cli'!

However, if you create a symlink to this file, this will no longer work. __FILE__ will resolve to the path of the symlink, not to its target.

One solution is to use File.realpath(__FILE__).

In Ruby 2+ you can also use this:

$LOAD_PATH << File.expand_path('../lib', __dir__)

__dir__ is simply a shortcut for File.dirname(File.realpath(__FILE__)).

Tobias Kraze
Last edit
Felix Eschey
Source code in this card is licensed under the MIT License.
Posted by Tobias Kraze to makandra dev (2016-08-23 12:50)