Why First Linux commands in Linux CLI? - Purpose & Use Cases

The Big Idea

What if you could control your computer faster than clicking around with a mouse?

The Scenario

Imagine you just got a new computer with Linux, and you want to find your files or check what's inside a folder. You open the file explorer and click around, but it's slow and you can't quickly see details or do many tasks at once.

The Problem

Using only the mouse and graphical tools to manage files or check system info is slow and repetitive. You might click the wrong folder, miss hidden files, or waste time opening many windows. It's easy to get lost or frustrated.

The Solution

Learning the first Linux commands lets you quickly list files, move around folders, and check system info right from the keyboard. It's like having a magic remote control that speeds up your work and gives you more power over your computer.

Before vs After

✗ Before

Open file explorer > Click folder > Scroll to find file

✓ After

ls -l
cd Documents
cat notes.txt

What It Enables

With just a few commands, you can explore, organize, and control your Linux system faster and smarter than ever before.

Real Life Example

When you want to quickly find a report saved last week, instead of clicking through many folders, you type a command to list files by date and open it instantly.

Key Takeaways

Manual file browsing is slow and error-prone.

First Linux commands give fast, precise control over files and folders.

They open the door to powerful, efficient computer use.

Practice

1. Which Linux command shows the current directory you are in?

easy

A. pwd

B. ls

C. cd

D. mkdir

Solution

1. Step 1: Understand the purpose of pwd

   The pwd command stands for "print working directory" and shows the current folder path.

2. Step 2: Compare with other commands

   ls lists files, cd changes directory, and mkdir creates a folder, so they don't show the current directory.

3. Final Answer:

   pwd -> Option A

4. Quick Check:

   Current directory command = pwd [OK]

Hint: Remember: pwd = print working directory [OK]

Common Mistakes:

• Confusing ls with pwd
• Using cd to show directory
• Thinking mkdir shows current folder

2. Which of the following is the correct syntax to create a new directory named projects?

easy

A. mkdir projects

B. mk projects

C. create projects

D. newdir projects

Solution

1. Step 1: Identify the command to create directories

   The standard Linux command to make a directory is mkdir.

2. Step 2: Check the syntax

   The correct syntax is mkdir directory_name, so mkdir projects is correct.

3. Final Answer:

   mkdir projects -> Option A

4. Quick Check:

   Create directory command = mkdir [OK]

Hint: mkdir means make directory; use it to create folders [OK]

Common Mistakes:

• Using mk instead of mkdir
• Typing create instead of mkdir
• Using newdir which is not a command

3. What will be the output of the following commands?

mkdir testdir
cd testdir
pwd

medium

A. /testdir

B. /home/testdir

C. /home/username/testdir

D. testdir

Solution

1. Step 1: Understand the commands

   mkdir testdir creates a folder named testdir. cd testdir moves into that folder. pwd prints the full path of the current directory.

2. Step 2: Determine the full path

   Assuming the user starts in their home directory (like /home/username), after changing into testdir, pwd will show /home/username/testdir.

3. Final Answer:

   /home/username/testdir -> Option C

4. Quick Check:

   pwd after cd into testdir = full path /home/username/testdir [OK]

Hint: pwd shows full path, not just folder name [OK]

Common Mistakes:

• Expecting just folder name output
• Assuming root directory path
• Confusing relative and absolute paths

4. You run the command cd myfolder but get an error: bash: cd: myfolder: No such file or directory. What is the most likely cause?

medium

A. You do not have permission to use cd

B. The folder myfolder does not exist in the current directory

C. The cd command is misspelled

D. You need to use mkdir before cd

Solution

1. Step 1: Analyze the error message

   The error says "No such file or directory", meaning the folder named myfolder is not found in the current location.

2. Step 2: Check other options

   cd is a basic command and usually not misspelled here. Permissions errors give different messages. mkdir creates folders but is not required before cd if the folder exists.

3. Final Answer:

   The folder myfolder does not exist in the current directory -> Option B

4. Quick Check:

   cd error means folder missing [OK]

Hint: Check folder exists before cd [OK]

Common Mistakes:

• Assuming permission error
• Thinking cd needs mkdir first
• Misspelling cd command

5. You want to create a new folder named backup inside your current directory and then move into it. Which sequence of commands will do this correctly?

hard

A. mkdir
cd backup

B. cd backup
mkdir backup

C. cd backup
cd backup

D. mkdir backup
cd backup

Solution

1. Step 1: Create the folder first

   The command mkdir backup creates the folder named backup in the current directory.

2. Step 2: Change directory into the new folder

   After creating it, cd backup moves you inside that folder.

3. Step 3: Check other options

   cd backup mkdir backup tries to cd into backup before it exists, causing an error. mkdir cd backup misses the folder name in mkdir. cd backup cd backup tries to cd twice without creating the folder.

4. Final Answer:

   mkdir backup cd backup -> Option D

5. Quick Check:

   Create then cd = mkdir then cd [OK]

Hint: Always mkdir before cd into new folder [OK]

Common Mistakes:

• Trying cd before mkdir
• Omitting folder name in mkdir
• Repeating cd without folder