Installing, updating, removing packages in Linux CLI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What command installs a package using apt on Debian-based systems?

Use sudo apt install <package-name> to install a package. It downloads and sets up the software for you.

beginner

How do you update the list of available packages on a Debian-based system?

Run sudo apt update. This refreshes the package list so your system knows about the latest versions.

beginner

What command removes a package but keeps its configuration files?

Use sudo apt remove <package-name>. It deletes the program but leaves settings in case you reinstall later.

intermediate

How do you completely remove a package including its configuration files?

Use sudo apt purge <package-name>. This deletes the program and all its settings.

beginner

What command upgrades all installed packages to their latest versions?

Run sudo apt upgrade. It updates all your software to the newest versions available.

Which command updates the package list on a Debian-based system?

A sudo apt update

B sudo apt upgrade

C sudo apt install

D sudo apt remove

sudo apt update refreshes the package list. upgrade installs updates, install adds new packages, and remove deletes packages.

What does sudo apt purge <package> do?

A Removes a package and its config files

B Removes a package but keeps config files

C Installs a package

D Updates all packages

purge deletes the package and all its configuration files.

Which command installs a new package?

A sudo apt update

B sudo apt remove

C sudo apt install

D sudo apt upgrade

sudo apt install downloads and installs new software.

If you want to keep configuration files after removing a package, which command do you use?

A sudo apt purge

B sudo apt upgrade

C sudo apt update

D sudo apt remove

remove deletes the package but keeps config files; purge deletes both.

What command upgrades all installed packages to their latest versions?

A sudo apt update

B sudo apt upgrade

C sudo apt install

D sudo apt remove

sudo apt upgrade updates all installed packages to the newest versions.

Explain the difference between apt remove and apt purge.

Think about what happens to the settings when you uninstall.

Describe the steps to update your system's software using apt.

Two commands are needed: one to check, one to install.

Practice

1. Which command is used to install a new package on a Debian-based Linux system?

easy

A. apt upgrade package_name

B. apt update package_name

C. apt remove package_name

D. apt install package_name

Solution

1. Step 1: Understand the purpose of apt install

   The apt install command is used to add new software packages to the system.

2. Step 2: Differentiate from other commands

   apt update refreshes package lists, apt upgrade updates installed packages, and apt remove deletes packages.

3. Final Answer:

   apt install package_name -> Option D

4. Quick Check:

   Install new software = apt install [OK]

Hint: Install packages with 'apt install' command [OK]

Common Mistakes:

• Confusing 'apt update' with installation
• Using 'apt remove' to install packages
• Trying 'apt upgrade' to add new software

2. Which of the following is the correct syntax to update the package list on a Debian-based system?

easy

A. apt update

B. apt install update

C. apt upgrade

D. apt remove update

Solution

1. Step 1: Identify the command to refresh package lists

   apt update downloads the latest package information from repositories.

2. Step 2: Understand other commands

   apt upgrade installs available updates, not refreshes lists; others are invalid.

3. Final Answer:

   apt update -> Option A

4. Quick Check:

   Refresh package list = apt update [OK]

Hint: Use 'apt update' to refresh package info before upgrades [OK]

Common Mistakes:

• Using 'apt upgrade' to update package lists
• Adding package names to 'apt update'
• Confusing 'apt remove' with update commands

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

sudo apt update
sudo apt upgrade -y

medium

A. The system installs new packages listed in the upgrade command.

B. The system refreshes package lists and upgrades all upgradable packages automatically.

C. The system removes all outdated packages without confirmation.

D. The system only updates package lists but does not upgrade any packages.

Solution

1. Step 1: Analyze sudo apt update

   This command refreshes the package lists from repositories to get the latest versions.

2. Step 2: Analyze sudo apt upgrade -y

   This command upgrades all installed packages that have updates available, and the -y flag confirms automatically.

3. Final Answer:

   The system refreshes package lists and upgrades all upgradable packages automatically. -> Option B

4. Quick Check:

   Update + upgrade -y = refresh and auto-upgrade [OK]

Hint: Update lists then upgrade with -y to auto-confirm [OK]

Common Mistakes:

• Thinking upgrade installs new packages
• Assuming remove happens automatically
• Believing update upgrades packages

4. You run apt remove package_name but get an error saying the package is not installed. What is the likely cause?

medium

A. The package is already removed but still listed in the system.

B. You need to run apt update before removing packages.

C. The package name is misspelled or does not exist on the system.

D. You must use apt upgrade before removing packages.

Solution

1. Step 1: Understand the error context

   If apt remove says the package is not installed, it means the system cannot find that package installed.

2. Step 2: Identify common causes

   Most often, this happens because the package name is wrong or the package was never installed.

3. Final Answer:

   The package name is misspelled or does not exist on the system. -> Option C

4. Quick Check:

   Remove error = wrong or missing package name [OK]

Hint: Check package name spelling before removing [OK]

Common Mistakes:

• Trying to update before removing
• Assuming upgrade is needed before remove
• Ignoring error and forcing removal

5. You want to write a script that updates the package list, upgrades all packages, and then removes a package named oldapp. Which sequence of commands is correct?

hard

A. apt update
apt upgrade -y
apt remove oldapp -y

B. apt upgrade -y
apt update
apt remove oldapp -y

C. apt remove oldapp -y
apt update
apt upgrade -y

D. apt update
apt remove oldapp -y
apt upgrade -y

Solution

1. Step 1: Understand the correct order of package management commands

   First, update the package list with apt update to get latest info, then upgrade installed packages with apt upgrade -y, and finally remove unwanted packages.

2. Step 2: Check each option's order

   apt update
   apt upgrade -y
   apt remove oldapp -y

   follows the correct order: update, upgrade, then remove. Others have wrong sequences that may cause errors or outdated upgrades.

3. Final Answer:

   apt update apt upgrade -y apt remove oldapp -y -> Option A

4. Quick Check:

   Update -> Upgrade -> Remove sequence [OK]

Hint: Always update before upgrade, remove last [OK]

Common Mistakes:

• Upgrading before updating package lists
• Removing packages before upgrading
• Skipping update before upgrade