What does $:.push do in ruby?

Question

I found this in Gemspec file of surveyor gem. What does the following line do?

$:.push File.expand_path("../lib", __FILE__)
require "surveyor/version"

Why does the $:.push thing do? To me it looks like its just requires the ../lib/surveyor/version file. if so, can't I just replace that with following one line?

require File.expand_path('../lib/surveyor/version', __FILE__)

Are both these same thing? If not, then what the difference?

Just a side note: `$LOAD_PATH << File.expand_path ...` does the same and looks a bit less obfuscated, IMHO. — Niklas B., Apr 29 '12 at 14:37

score 17 · Accepted Answer · edited Apr 29 '12 at 14:36

17

$: is Ruby's load path, so it's in fact adding the a subfolder /lib of a folder in which __FILE__ resides to this array, so that other files from this gem can be required.

edited Apr 29 '12 at 14:36

Joshua Cheek

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answered Apr 29 '12 at 14:35

Mchl

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Basically a shortcut of having to write the complete path. That explains it. Thanks! – CuriousMind Apr 29 '12 at 14:52
@Gaurish: Not only that. The gem can assume that it is in the load path, in which it will fail to load if you require it by full path, without adding it to the load path. – Niklas B. Apr 29 '12 at 15:15

What does $:.push do in ruby?

1 Answers1