Bash Scripting: Choreographing Scripts for Seamless Automation

Introduction to Bash Scripting

Bash (Bourne Again Shell) is a popular Unix shell and command language. It allows users to automate tasks and create powerful scripts for various purposes.

Getting Started

Creating a Bash Script

To create a bash script, create a new file with a .sh extension and start with a shebang line #!/bin/bash to indicate that it's a bash script.

Example:

#!/bin/bash

Making the Script Executable

Make the script executable using the chmod command.

Example:

chmod +x script.sh

Variables

Assigning Variables

Variables in bash can be assigned using the syntax variable_name=value.

Example:

name="John"

Using Variables

Variables can be accessed using the $ prefix.

Example:

echo "Hello, $name!"

Basic Script Structure

Example Script

#!/bin/bash

# Assigning Variables
name="John"
age=30

# Printing Variables
echo "Name: $name"
echo "Age: $age"

Conditionals

If Statement

if [ condition ]; then
    # code to execute if condition is true
fi

Example:

if [ $age -gt 18 ]; then
    echo "You are an adult."
fi

Loops

For Loop

for item in list; do
    # code to execute for each item
done

Example:

for i in {1..5}; do
    echo "Number: $i"
done

While Loop

while [ condition ]; do
    # code to execute while condition is true
done

Example:

counter=0
while [ $counter -lt 5 ]; do
    echo "Count: $counter"
    ((counter++))
done

Functions

Declaring Functions

function_name() {
    # code for the function
}

Example:

greet() {
 echo "Hello, $1!"
}

Calling Functions

function_name arg1 arg2

Example:

greet "Alice"

Input/Output

Reading User Input

read variable_name

Example:

echo "Enter your name:"
read name
echo "Hello, $name!"

Conclusion

This quick reference provides an overview of bash scripting with practical examples. Experiment with these concepts to create powerful bash scripts for your needs.