binmode STDOUT, ':encoding(utf8)';
my $cp = "\x{3a3}";
print "$cp\n"; # Prints an upper case sigma.
print ord( $cp ), "\n"; # prints 931.
print 0x00FF & ord( $cp ), "\n"; # prints 163.
if( ord( $cp ) > 255 ) {
    print "Wide character.\n";
}
if( ord( $cp ) != ( 0x00FF & ord( $cp ) ) ) {
    print "Wide character.\n";
}