Shell_Script_Basics

What is Shell Scripting?

Shell scripting is writing a series of commands for the shell (command-line interpreter) to execute automatically.
It helps automate repetitive tasks, manage system operations, and simplify workflows.

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Common Shells

Bash:
The most commonly used Linux shell (Bourne Again SHell).

Zsh:
An extended version of Bash with additional features.

Sh:
The original Bourne shell.

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Basic Components of a Shell Script

Shebang (#!):
The first line in a shell script that tells the system which interpreter to use.
Example:

#!/bin/bash

Comments:
Anything following # is a comment and is ignored by the shell.
Example:

# This is a comment

Variables:
Store values in a script.
Example:

NAME="Mukund"
echo "Hello, $NAME"

Conditional Statements:
Perform different actions based on conditions.
Example:

if [ "$NAME" == "Mukund" ]; then
  echo "Welcome Mukund!"
else
  echo "Who are you?"
fi

Loops:
Repeat a block of code multiple times.
Example:

for i in 1 2 3
do
  echo "Number $i"
done

Functions:
Group commands into reusable blocks.
Example:

greet() {
  echo "Hello, Mukund!"
}
greet

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How to Run a Shell Script

1. Create a file with .sh extension.
   Example: script.sh

2. Make the script executable:

   chmod +x script.sh