Question

string.sub looks like it only replaces the first instance. Is there an option for that or another method that can replace all patterns? Can you do it inside a regex like perl?

(I think something like r/blah/blah/)

… and +1 to anyone who can tell me WHY ON EARTH does string.sub replace just the FIRST match?

Answer 1

String.gsub should do the trick.

Quoting docs:

gsub(pattern, replacement) → new_str

Returns a copy of str with the all occurrences of pattern
substituted for the second argument. The pattern is typically a
Regexp; if given as a String, any regular expression metacharacters it
contains will be interpreted literally, e.g. \\d will match a
backlash followed by d, instead of a digit.