#!/usr/bin/env perl 
use strict;
use warnings;

my @names = (
    'BULLOCK JOE A',
    'SMITH, A DOE',
);

for my $fullname (@names) {
    my ($sname, $fname) = $fullname =~ /([A-Z]{3,})/g;
    print "Forename $fname extracted from $fullname";
}