my  $magic = 'sub { ';
    foreach my $char (@chars) {
        $magic .= "\$cnts{$char} += ()= \$_[0] =~ m/$char/g;";
    }
    $magic .= '}';

    my  $magicsub = eval "$magic";
    die "eval to create anon sub failed '$@'"
        unless defined $magicsub;

    while( <DATA> ) {
        $magicsub->($_);
    }