Ruby Regex Replace Characters Between Two Numbers

Question

Im trying to write a string cleaner that removes underscores, but replaces them with dots when between numbers (ie, when there is a version number in the string).

 1_1_OS_And_Network_Specific_Config

I would like this string to come out like

 1.1 OS And Network Specific Config

I can replace the underscores easy enough, but im having trouble matching the character between the numbers to replace with the dot.

\d_\d

Seems to match the two digits with the underscore .. but if there is three, like 3.4.1 it doesnt.

Can anyone help?

Answer 1

First, replace the underscores between digits:

subject = subject.gsub(/(?<=\d)_(?=\d)/, '.')

(?<=\d) and (?=\d) are lookaround assertions.

They make sure that there is a digit before ((?<=\d)) and after ((?=\d)) the current location, but they don't actually become part of the match.

Then, remove the rest of the underscores:

subject = subject.gsub(/_/, ' ')