Most efficient way of matching file names with Ruby regex

Question

The method Dir.glob is used for achieving file names that match a certain pattern, but its argument has a Unix-like syntax (e.g., using *, ** as wild cards in a particular way, etc.). Instead, I want to use Ruby (Onigmo) regex for the matching pattern to do the same thing (using its wildcards, quantifiers, anchors, escaped characters, etc). What is the best way to do this?

One simple way that comes to mind is to use Dir.glob to get the list of all existing files in all directories, and filtering them using the regex, but that does not look efficient. Or, is it? Is there a better way?

Answer 1

You could try the Find module in Ruby's standard library.

require 'find'
Find.find(path).grep(/regex/)

The find method returns every path that exists within the path you provide as an argument recursively, pretty much like what you mentioned with Dir.glob. You can then use the built-in grep method to filter the results with a regex.

This may not be the most efficient method though, since Dir.glob is written in C while the Find module is written in Ruby. I did a test on my home directory and it took Find a little longer to get the result than Dir.glob, but you can also use the Find module's prune method in order to not descend into particular folders, which could help make things more efficient using Find.