Understanding the power of Shell Scripting in DevOps

Shell scripting is like a magic wand for DevOps professionals.

It allows you to execute a series of commands effortlessly, automating tasks and streamlining workflows. Imagine having a script, say "my_file.sh," that runs multiple commands in one go. Here's a simple example:

#!/bin/bash
touch devops.txt
echo "I'm learning DevOps and on day04 of my 90DaysOfDevOps journey" > devops.txt
cat devops.txt

Running this script will create a file, write a message, and display it—all in one swift motion.

The Shebang Mystery: #!/bin/bash vs. #!/bin/sh

The shebang (#!) at the start of a script tells the system which shell to use. Use #!/bin/bash for scripts that require advanced Bash features, like arrays. Opt for #!/bin/sh for basic, more portable scripts. Choose wisely based on your script's needs!

Challenge Accepted: A Simple Shell Script

Create a script named "devOps_challenge.sh" with the following content:

#!/bin/bash
echo "I will complete #90DaysOfDevOps challenge"

Save and run it to see your commitment in action!

Interactive Scripting: User Input and Arguments

Here's how to create a script that takes user input and command-line arguments:

#!/bin/bash
read -p "Enter your name: " user_name
arg1=$1
arg2=$2
echo "User input: $user_name"
echo "Argument 1: $arg1"
echo "Argument 2: $arg2"

Decision Making: If-Else in Shell Scripting

Compare two numbers using an if-else statement:

#!/bin/bash
read -p "Enter the first number: " num1
read -p "Enter the second number: " num2

if [ $num1 -gt $num2 ]; then
    echo "$num1 is greater than $num2"
elif [ $num1 -lt $num2 ]; then
    echo "$num1 is less than $num2"
else
    echo "$num1 is equal to $num2"
fi

Shell scripting is a powerful tool in the DevOps toolkit, enabling automation and efficiency. Embrace it to enhance your DevOps journey!