Lets say I want to "encrypt" the ID number 123456789 - add '*' to all the digits up to the last four - *****6789.
A starting point is to replace .*(....) with *$1. But it would produce *6789, which is too short.
How can I know how many chars the first .* matched?
A starting point is to replace .*(....) with *$1. But it would produce *6789, which is too short.
How can I know how many chars the first .* matched?