By the way, most of the time for practical reasons I don't bother with File::Spec at all, because why would I sacrifice myself using catfile() and no_upwards when I will not be using path separator other than "/", and parent directory other than ".." (probably for the rest of my life).

Well, if you know your scripts are only ever going to be run on *NIX, then sure. But what you're sacrificing is portability. For example, even nowadays, there are some Windows programs that can't handle / path separators and require \. Personally, although I've written code like "$path/$file" myself, I usually like my code to be as portable as possible, and if you're considering writing a re_glob(qr/\.foo/) function, you might want to release it as a module*, and then portability becomes important, IMHO.

* use Path::Tiny; my @files = path($path)->children(qr/\.foo/); But sadly, Path::Tiny "does not try to work for anything except Unix-like and Win32 platforms." Alternative: use Path::Class; my @files = grep {$_->basename=~/\.foo/} dir(".")->children;