Lab 01: Terminal Basics

Objective

Get comfortable with the Linux terminal: discover who you are, where you are, and what system you're on. These orientation commands are the foundation every Linux user starts with.

Time: 20 minutes | Level: Foundations | Docker: docker run -it --rm ubuntu:22.04 bash

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Step 1: Launch Your Environment

docker run -it --rm ubuntu:22.04 bash

You are now inside an Ubuntu 22.04 container. The prompt root@<id>:/# means you are the root user at the filesystem root.

💡 The --rm flag deletes the container when you exit. Nothing you do here persists. Experiment freely.

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Step 2: Who Are You?

whoami

📸 Verified Output:

root

id

📸 Verified Output:

uid=0(root) gid=0(root) groups=0(root)

💡 uid=0 means root — the superuser with no restrictions. In production systems, you never log in as root. Here it's safe for learning.

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Step 3: Where Are You?

pwd

📸 Verified Output:

/

echo $HOME

📸 Verified Output:

/root

💡 pwd = Print Working Directory. You're currently at / — the filesystem root, the top of the entire Linux directory tree.

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Step 4: What System Are You On?

uname -a

📸 Verified Output:

Linux 3e03e4da0e25 6.14.0-37-generic #37-Ubuntu SMP PREEMPT_DYNAMIC Fri Nov 14 22:10:32 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux

cat /etc/os-release | head -5

📸 Verified Output:

PRETTY_NAME="Ubuntu 22.04.5 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"
VERSION="22.04.5 LTS (Jammy Jellyfish)"
VERSION_CODENAME=jammy

💡 uname -a gives: kernel name, hostname, kernel version, build date, architecture. The x86_64 at the end means 64-bit Intel/AMD CPU.

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Step 5: System Status

uptime

📸 Verified Output:

 00:52:13 up 6 days,  2:22,  0 users,  load average: 1.38, 1.36, 1.37

date '+%Y-%m-%d %H:%M:%S %Z'

📸 Verified Output:

2026-03-05 00:52:13 UTC

💡 The load average (1.38, 1.36, 1.37) shows CPU demand over 1, 5, and 15 minutes. A value equal to your CPU count = 100% busy. Higher = overloaded.

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Step 6: What Shell Are You Using?

echo $SHELL

📸 Verified Output:

/bin/bash

bash --version | head -1

📸 Verified Output:

GNU bash, version 5.1.16(1)-release (x86_64-pc-linux-gnu)

💡 bash (Bourne Again SHell) is the most common Linux shell. Others include zsh (macOS default), fish, and dash. The shell interprets every command you type.

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Step 7: Hostname and Network Identity

hostname

📸 Verified Output:

3e03e4da0e25

hostname -i

📸 Verified Output:

172.17.0.2

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Step 8: Capstone — System Info Script

echo "=== System Identity Report ==="
echo "User:      $(whoami)"
echo "Host:      $(hostname)"
echo "OS:        $(grep PRETTY_NAME /etc/os-release | cut -d= -f2 | tr -d '\"')"
echo "Kernel:    $(uname -r)"
echo "Arch:      $(uname -m)"
echo "IP:        $(hostname -i)"
echo "Shell:     $SHELL"
echo "Uptime:    $(uptime -p)"
echo "Time (UTC):$(date -u '+%Y-%m-%d %H:%M:%S')"

📸 Verified Output:

=== System Identity Report ===
User:      root
Host:      3e03e4da0e25
OS:        Ubuntu 22.04.5 LTS
Kernel:    6.14.0-37-generic
Arch:      x86_64
IP:        172.17.0.2
Shell:     /bin/bash
Uptime:    up 6 days, 2 hours, 22 minutes
Time (UTC):2026-03-05 00:52:13

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Summary

Command	Purpose
whoami	Current username
id	UID, GID, and group memberships
pwd	Current directory path
uname -a	Full kernel and architecture info
hostname	System hostname
uptime	System uptime and load
date	Current date/time
echo $SHELL	Active shell