Guess a Number Game

game.pl

#!/usr/bin/env perl
# guess a number game
use strict;
use warnings;
use feature qw( say state switch );

say 'welcome';

# generate the winning number between 1 and 10
# see perlfaq4 for algorithm details
my $winning_num = 1 + int( rand( (10-1)+1 ) );

until ( $winning_num
        == ( state $guess = 0 )
        ) {
    say 'Guess a number between 1 and 10: ';
    $guess = readline(*STDIN);

    # check to see if we have a winner, or the guess is to high, or low.
    given( $guess ) {
        # sanitize input
        # this must be first otherwise it won't work right
        when ( $_ !~ /[[:digit:]]/ ) {
            say 'not a number';
            # set $guess to 0 so we don't have a numerical comparison warning
            $guess = 0;
        }
        when ( $_ > $winning_num ) {
            say 'Too high';
        }
        when ( $_ < $winning_num ) {
            say 'Too low';
        }
        when ( $winning_num ) {
            say 'You Win!';
        }
    }
}
say 'Game over!';