public/subjects/devops/joker-num/README.md

joker-num

Instructions

In this exercise you are going to create a guessing game. Create the script joker-num.sh which will receive the number to guess as argument. The number should be between 1 and 100 (inclusive). The player will then have 5 tries to guess the number. To achieve this you will have to use a for loop.

When guessing a valid number the output will be:

• Number bigger than the secret one: Go down.
• Number smaller than the secret one: Go up.
• Number equal than the secret one: Congratulations, you found the number!.
• Ran out of tries: You lost, the number was <number>.

Usage

$ ./joker-num.sh 55
Enter your guess (5 tries left):
50
Go up
Enter your guess (4 tries left):
75
Go down
Enter your guess (3 tries left):
55
Congratulations, you found the number in 3 moves!
$ ./joker-num.sh 70
Enter your guess (5 tries left):
70
Congratulations, you found the number in 1 moves!
$

Error handling

• Wrong number of arguments or number not between 1 and 100: The program will print Error: wrong argument and return 1.
• The player writing something that is not a valid number as an answer: The program will ask again to enter a guess and the number of tries won't be decremented.

Here an example for the last scenario:

$ ./joker-num.sh 100
Enter your guess (5 tries left):
aaaa
Enter your guess (5 tries left):
                                    # Here the player only press enter
Enter your guess (5 tries left):
10
Go up
Enter your guess (4 tries left):
20
Go up
Enter your guess (3 tries left):
10000
Enter your guess (3 tries left):
30
Go up
Enter your guess (2 tries left):
40
Go up
Enter your guess (1 tries left):
50
Go up
You lost, the number was 100

Hints

• read: this command can be used to read input from the command line.

For example:

$ read guess

After running that line, you would type your guess, press Enter, and it would be stored in the $guess variable for later use.

• if [[ -z "$var" ]]: could be helpful to check if a string is empty.