Regex to change the number of spaces in an indent level

Question

Let\'s say you have some lines that look like this

1  int some_function() {
2    int x = 3;  // Some silly comment

And so on. The indentation i

Answer 1

In some regex flavors, you can use a lookbehind:

s/(?<=^ *)  /   /g

In all other flavors, you can reverse the string, use a lookahead (which all flavors support) and reverse again:

 s/  (?= *$)/   /g