Regular expressions, credit card numbs..

[VeryFrustrated]

How do you replace every digit in a credit card number with 'X'
leaving the last four digits intact using regular expressions.

example: XXXXXXXXX3567

Thanks in advance...

 

[raider2001]

Here's two different ways to do it:

$String = '1234567890123456';
$String =~ s/.(?=.{4})/X/g;
print "$String\n";

$str = '1234567890123456';
substr($str,0,(length($str)-4)) = ('X' x (length($str)-4));
print "$str\n";

 

[Thanks]

Thanks, you are king!