Rock-Paper-Scissors Bash Script Game Example

Prerequisites

• Basic knowledge of Bash scripting: You should understand variables, conditional statements, and loops.
• A Bash-compatible environment: Make sure you are using a Unix-like system.
• Text editor: Any basic text editor (e.g., nano, vim, or gedit) to create the script file.
• Random number generator: This is built into Bash, so no additional installation is required.

The Script

This Bash script simulates a game of Rock-Paper-Scissors between the user and the computer. The computer randomly selects its choice, and the user inputs their choice through the command line. The winner is then determined based on the game rules.

#!/bin/bash

echo "Welcome to Rock-Paper-Scissors!"
options=("Rock" "Paper" "Scissors")
computer_choice=${options[$RANDOM % 3]}

echo "Please enter your choice (Rock, Paper, Scissors): "
read user_choice

echo "Computer chose: $computer_choice"

if [ "$user_choice" == "$computer_choice" ]; then
    echo "It's a tie!"
elif [[ ("$user_choice" == "Rock" && "$computer_choice" == "Scissors") || 
        ("$user_choice" == "Paper" && "$computer_choice" == "Rock") || 
        ("$user_choice" == "Scissors" && "$computer_choice" == "Paper") ]]; then
    echo "You win!"
else
    echo "You lose!"
fi

Step-by-Step Explanation

Let’s break down the script into manageable steps to understand its functionality:

1. Introduction and Setup: The script begins by welcoming the user and establishing the options for the game.
2. Computer Choice: The computer’s choice is selected randomly from the options using the built-in $RANDOM variable.
3. User Input: The user is prompted to enter their choice, which is then read and stored in a variable.
4. Determine Winner: The script compares the choices. It checks for ties, user wins, and computer wins, then outputs the result.

How to Run the Script

Once you have written and saved the script, you can run it by following these steps:

1. Open your terminal.
2. Navigate to the directory where your script is saved using cd.
3. Make the script executable with the command chmod +x your_script_name.sh, then execute it by typing ./your_script_name.sh.

Conclusion

The Rock-Paper-Scissors Bash script is a fun way to explore scripting while reinforcing your understanding of conditional logic and user input handling. Experiment with additional features or enhancements to make the game more interesting!

FAQ

1. What happens if I enter an invalid choice?

   The script currently does not handle invalid inputs, but you could easily add a condition to check for valid entries and prompt the user again.

2. Can I change the game’s rules?

   Yes! You can modify the conditions in the script to implement variations or new rules.

3. Is the script case-sensitive in user input?

   Yes, you should enter choices exactly as specified. You can modify the script to handle case insensitivity by converting inputs to lowercase.

4. Can I add more options to the game?

   Certainly! You can easily extend the options array and modify the logic to accommodate new rules.

5. What if I want to play multiple rounds?

   You could wrap the existing logic in a loop to continue asking the user if they want to play again.

Troubleshooting

Some common errors and their solutions include:

• Permission denied: You need to make the script executable.
• Command not found: Ensure you are using the correct path and that your shell supports the script syntax.