Grab all files in dir with specific extension regardless of extension case (case insensitive extensions) Ruby

Question

In Ruby what is the right way to get all the files in the directory with a certain extension regardless of the extension case?

For example, say I have the directory ~/myDir and it has files file1.JPG, file2.jpg, noFile.png and file3.jpg. I would like to grab only the jpg files. I was using:

results = Dir[File.join(Dir.home, 'myDir', '*.jpg')].sort

but this leaves off file1.

I don't want a hacky solution like checking the files individually while forcing each to uppercase before checking. I definitely do not want something nasty like grabbing the files with extensions JPG, JPg, Jpg, jpg, jpG, and jPG.

Please include the supported version in your answers if it isn't backward-compatible with older version. I am on 1.9.3 but others may not be.

Answer 1

We can use Dir.glob and pass it File::FNM_CASEFOLD as the second param to tell it to ignore the case. So that gives us:

Dir.glob(File.join(Dir.home, 'myDir', "*.jpg"), File::FNM_CASEFOLD).sort

I found this solution in this post where Derick Bailey talks about this post.

I am not sure if it works in all version but if anyone knows let me know and I will update it here. Trans in the last link in this post makes it seem like it wasn't always supported by saying "the docs said '(so+File::FNM_CASEFOLD+ is ignored)' ".