Hello World in Bash

Hello World in Bash

The "Hello World" program is a simple example often used to demonstrate the basics of a programming or scripting language. In Bash, creating a "Hello World" script is easy and an excellent way to start learning shell scripting.

Steps to Create and Run a Hello World Script

1. Open Your Terminal

The terminal is where you will write, save, and execute your Bash script.

2. Create a New Script File

You can create a new file using any text editor or directly from the terminal.

Command:

nano hello_world.sh

This will open the Nano editor where you can write your script.

3. Write the Script

Add the following lines to the file:

#!/bin/bash
# This is a simple Hello World script

echo "Hello, World!"

4. Save and Exit

• In Nano: Press Ctrl+O, then press Enter to save.
• Press Ctrl+X to exit the editor.

5. Make the Script Executable

Before running the script, you need to make it executable.

Command:

chmod +x hello_world.sh

6. Run the Script

Execute the script by typing:

Command:

./hello_world.sh

Output:

Hello, World!

Understanding the Script

1. #!/bin/bash:

   • This is the shebang line. It tells the system to use the Bash shell to interpret the script.

2. # This is a simple Hello World script:

   • This is a comment. It explains the purpose of the script and is ignored by the interpreter.

3. echo "Hello, World!":

   • The echo command prints text to the terminal.

Run Without chmod +x

If you don't want to make the script executable, you can run it using Bash directly:

Command:

bash hello_world.sh

Output:

Hello, World!

Using Variables in Hello World

You can customize the script by using variables.

Script:

#!/bin/bash
# Hello World with a variable

message="Hello, World!"
echo $message

Output:

Hello, World!

Adding User Interaction

Enhance the script to interact with the user:

Script:

#!/bin/bash
# Personalized Hello World script

echo "What is your name?"
read name
echo "Hello, $name! Welcome to Bash scripting!"

Output:

What is your name?
Alice
Hello, Alice! Welcome to Bash scripting!

Conclusion

Creating a "Hello World" script is a foundational step in learning Bash scripting. From here, you can explore more complex scripts involving loops, conditionals, and functions.

Let me know if you’d like a guide on more advanced Bash topics!