Basic Shell Scripting Tutorial
Basic Shell Scripting Tutorial
In this tutorial, we will learn how to write basic shell scripts using Markdown. Shell scripting allows us to automate tasks and execute commands in a sequential manner. Markdown is a lightweight markup language that provides an easy way to write formatted documentation.
Table of Contents
- Getting Started
- Creating a Shell Script
- Running a Shell Script
- Variables
- User Input
- Conditional Statements
- Loops
- Functions
- Conclusion
Getting Started
Before we begin, make sure you have a shell environment available on your machine. Common shell environments include Bash, Zsh, and PowerShell.
Creating a Shell Script
- Open a text editor and create a new file. Give it a meaningful name, such as
myscript.sh. - Add the following shebang at the top of the file to specify the shell to be used:
bash #!/bin/bash
Make sure to replace bash with the appropriate shell if you're using a different one.
3. Now you can start writing your shell script using Markdown syntax. You can include headers, lists, code blocks, and other formatting elements as needed.
4. Save the file when you're done.
Here's an example of a simple shell script written in Markdown:
markdown
# My First Shell Script This is my first shell script written in Markdown. ## Script bash #!/bin/bash echo "Hello, World!"
## Running a Shell Script To execute a shell script, you need to make it executable first. Open a terminal and navigate to the directory where your script is located. Then run the following command: bash chmod +x myscript.sh
Replace myscript.sh with the name of your script.
To run the script, use the following command:
bash
./myscript.sh
Replace myscript.sh with the name of your script.
Variables
Variables in shell scripts are used to store data and manipulate values. Here's an example of defining and using a variable in Markdown:
markdown
# Variables To define a variable, use the following syntax: bash variable_name=value
For example:
bash
name="John"
To use the variable, prefix it with a dollar sign ($):
bash
echo "Hello, $name!"
## User Input Shell scripts can interact with the user by reading input from the keyboard. Here's an example of reading user input and using it in a script: markdown # User Input To read user input, use the `read` command followed by the variable name: bash read -p "Enter your name: " name
The user's input will be stored in the name variable. You can then use it in your script:
bash
echo "Hello, $name!"
## Conditional Statements
Conditional statements allow you to execute different code blocks based on certain conditions. Here's an example of an if statement in Markdown:
markdown
# Conditional Statements
To use conditional statements, you can use the `if` statement followed by the condition and the code block:
bash
if [ condition ]; then
# code to execute if the condition is true
else
# code to execute if the condition is false
fi
For example:
bash
if [ $age -ge 18 ]; then
echo "You are an adult."
else
echo "You are a minor."
fi
## Loops
Loops allow you to repeat a block of code multiple times. Here's an example of a for loop in Markdown:
markdown
# Loops
To use loops, you can use the `for` loop followed by the variable, the list of values, and the code block:
bash
for variable in list; do
# code to execute for each value
done
For example:
bash
for fruit in apple banana cherry; do
echo "I like $fruit"
done
## Functions
Functions allow you to define reusable blocks of code. Here's an example of defining and using a function in Markdown:
markdown
# Functions
To define a function, use the following syntax:
bash
function_name() {
# code to execute
}
For example:
bash
greet() {
echo "Hello, $1!"
}
To call a function, use its name followed by any arguments:
bash
greet "John"
## Conclusion Congratulations! You've learned how to write basic shell scripts using Markdown. Shell scripting is a powerful way to automate tasks and improve your productivity. Explore more advanced features and commands to create more complex scripts. Happy scripting!