Convert tabs to spaces in one line of Ruby

Here’s a one-liner Ruby script that converts tabs to spaces:

ruby -pe 'gsub(/([^\t]*)(\t)/) { $1 + " " * (8 - $1.length % 8) }

I’m in the early stages of rewriting a tiny editor, MicroEMACS, in Ruby, and needed a tab converter. I was sure I’d seen this somewhere before, but couldn’t find it with Google, so rewrote it from scratch.

(Update 2025: I never rewrote the editor in Ruby. Instead, I added the ability to extend the editor with commands written in Ruby.)