Question

I would like to use a regular expression to mask all but the first three alphanumeric characters of each word in a string using a mask character (such as “x”), so “1 Buckingham Palace Road, London” would become “1 Bucxxxxxxx Palxxx Roax, Lonxxx”.

Keeping the first three characters is easily done using

s/\b(\w{0,3})(.*)\b/$1/g

but I cannot seem to figure out how to insert length($2) times the masking character instead of $2.

Thanks!

Answer 1

use warnings;
use strict;

my $string = "1 Buckingham Palace Road, London";

$string =~ s(
  \b(\w{0,3})(\w*)\b
){
  $1 . ( 'x' x length $2 )
}gex;

print $string, "\n";