> perl

$max_length=5;

OUTER: {
    print "Input max is $max_length!!!\n";
    while (1) {

        chomp( $input = <STDIN> );

        last OUTER
          if lc( $input )    eq "end";
        redo OUTER
          if length( $input ) > $max_length;

        print "- $input is OK\n";

    }  
}

__END__
Input max is 5!!!
1
- 1 is OK
12345
- 12345 is OK
123456
Input max is 5!!!
123
- 123 is OK
end
>