A Beginner’s Guide to Linux, SSH, and Bash Scripting

January 14, 2026

🐧 Linux Basics, SSH, SCP & Bash Scripting – A Beginner-Friendly Guide

If you are starting your journey into Linux or DevOps, understanding basic Linux commands, SSH connections, file transfers, and shell scripting is a must.
This blog walks you step-by-step through essential Linux commands, connecting to a Linux server, and writing your first Bash script.

🔹 1. Basic Linux Commands

Check Current User


whoami

Displays the username of the currently logged-in user.

Create a File


touch merifile.txt

Creates an empty file named merifile.txt.

List Files and Directories

ls

For a detailed view:


ls -la

Shows file permissions, owner, size, and hidden files.

Present Working Directory

pwd

Displays the current directory path.

Create and Navigate Directories


mkdir TWG
cd TWG

Go one step back:


cd ..

Move Files


mv ../merifile.txt .

Moves merifile.txt from the parent directory to the current directory.

Clear the Terminal


clear

🔹 2. Editing Files Using Nano

Open a file:


nano merifile.txt

Add content:


Hi This is Ghouse and definitely attend my 1pm Sunday session.

Save and exit:

Ctrl + X
Press Y
Press Enter

View file content:


cat merifile.txt

🔹 3. Useful Linux Commands

Print Output


echo "hello world"

Command History


history

Shows all commands used so far.

Remove a File


rm filename

⚠️ Be careful: deleted files cannot be recovered easily.

Go to Home Directory

cd

🔹 4. SSH – Secure Shell Protocol

SSH is used to securely connect to a remote Linux server.

Requirements

A private key (.pem file)
Server username
Server public IP or DNS

Connect to a Linux Server

Assume your key is downloaded to:


Downloads/keys


cd Downloads/keys
ssh -i OurKey.pem ubuntu@ec2-65-78-69-99.eu-west-1.compute.amazonaws.com

➡ This connects to the server using:

Username: ubuntu
Authentication: private key

🔹 5. SCP – Secure Copy Protocol

Used to transfer files between local machine and server.

Copy File from Local to Server


scp -i sk-key.pem from_local.txt ubuntu@ec2-54-xx.compute.aws.com:/home/ubuntu/newfolder/

Copy File from Server to Local


scp -i sk-key.pem ubuntu@ec2-54-xx.compute.aws.com:/home/ubuntu/newfolder/merifile.txt .

📌 Note:
SCP commands are always executed from your local Linux machine, not inside EC2.

🔹 6. Bash Scripting Basics

Shebang Line


#!/bin/bash

Tells the system to use Bash shell to run the script.

Create Scripts Folder


mkdir scripts
cd scripts

Check which bash is used:


which bash

Create First Script


nano devops_first.sh

Script content:


#!/bin/bash
echo "This is Ghouse"

Run the script:


bash devops_first.sh

Make Script Executable


chmod 777 devops_first.sh
./devops_first.sh

🔹 7. Interactive Bash Script Example

Create Script


nano onescript.sh

Script Code


#!/bin/bash

echo "I will be a great DevOps engineer"

name="Ghouse"
echo "Hello ${name}, please enter your age"
read age

echo "My age is ${age}"

echo "Apka swagat hai DevopsByGhouse channel pe"
sleep 2
echo "Please subscribe"

Make it executable:


chmod +x onescript.sh
./onescript.sh

🔹 8. Script with Arguments


#!/bin/bash

echo "I will be a great DevOps engineer"
echo "Sub: Hello, I am $1"

sleep 2
echo "Welcome to DevopsByGhouse"

Run:


./onescript.sh Adnan

Output:


Sub: Hello, I am Adnan

🔹 9. Conditional Statements in Bash


#!/bin/bash

if [ "$1" = "like" ]
then
  echo "Please like the channel"
else
  echo "Please subscribe"
fi