See Appendix A for an answer to the following exercise:
[25] Make a program that will repeatedly ask the user to guess a secret number from 1 to 100 until the user guesses the secret number. Your program should pick the number at random by using the magical formula int(1 + rand 100).[*] When the user guesses wrong, the program should respond "Too high" or "Too low." If the user enters the word quit or exit, or if the user enters a blank line, the program should quit. If the user guesses correctly, the program should quit then as well.
[*] See what the perlfunc manpage says about int and rand if you're curious about these functions.