Aliases for shortcuts in Linux CLI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an alias in the Linux command line?

An alias is a shortcut name that stands for a longer command or a series of commands. It helps you type less and work faster.

beginner

How do you create a temporary alias in Linux?

Use the command: alias name='command'. For example, alias ll='ls -l' creates an alias ll for ls -l.

intermediate

How can you make an alias permanent in Linux?

Add the alias command to your shell's configuration file like ~/.bashrc or ~/.zshrc. This way, the alias loads every time you open a terminal.

beginner

What command shows all current aliases?

Use the command alias with no arguments to list all active aliases in your current shell session.

beginner

How do you remove an alias in the current session?

Use the command unalias name. For example, unalias ll removes the alias named ll.

Which command creates a temporary alias named 'gs' for 'git status'?

A alias gs='git status'

B alias 'git status' = gs

C gs = alias git status

D create alias gs git status

The correct syntax is alias name='command'. So alias gs='git status' creates the alias.

Where should you add alias commands to make them permanent?

A /etc/aliases

B ~/.bashrc or ~/.zshrc

C /usr/bin/aliases

D ~/.aliasfile

Shell config files like ~/.bashrc or ~/.zshrc load aliases every time you open a terminal.

What does the command unalias ll do?

A Lists all aliases

B Creates a new alias named 'll'

C Renames alias 'll'

D Removes the alias named 'll' in the current session

unalias removes an alias from the current shell session.

How can you see all aliases currently active in your shell?

A alias

B show aliases

C list alias

D alias -l

Typing alias with no arguments lists all active aliases.

Why use aliases in the command line?

A To change file permissions

B To delete files faster

C To save typing and speed up commands

D To create new users

Aliases shorten long commands so you can type less and work faster.

Explain how to create, list, and remove aliases in Linux.

Think about the commands alias and unalias.

Describe how to make an alias permanent so it works every time you open a terminal.

Consider shell configuration files.

Practice

1. What does the command alias ll='ls -l' do in a Linux shell?

easy

A. Runs the ls -l command immediately

B. Deletes the ll command permanently

C. Lists all aliases currently set

D. Creates a shortcut named ll that runs ls -l

Solution

1. Step 1: Understand the alias syntax

   The command alias name='command' creates a shortcut named name for the given command.

2. Step 2: Apply to given example

   Here, ll is set as a shortcut for ls -l, so typing ll runs ls -l.

3. Final Answer:

   Creates a shortcut named ll that runs ls -l -> Option D

4. Quick Check:

   alias creates shortcut = A [OK]

Hint: Alias syntax is alias name='command' to create shortcuts [OK]

Common Mistakes:

• Thinking alias runs the command immediately
• Confusing alias with deleting commands
• Assuming alias lists all commands

2. Which of the following is the correct syntax to create an alias named gs for the command git status?

easy

A. alias gs = git status

B. alias gs='git status'

C. alias 'gs' = 'git status'

D. alias gs: git status

Solution

1. Step 1: Recall correct alias syntax

   The correct syntax is alias name='command' without spaces around the equal sign.

2. Step 2: Match options to syntax

   alias gs='git status' matches exactly: alias gs='git status'. Others have spaces or wrong punctuation.

3. Final Answer:

   alias gs='git status' -> Option B

4. Quick Check:

   Correct alias syntax = B [OK]

Hint: No spaces around = and use single quotes for commands [OK]

Common Mistakes:

• Adding spaces around equal sign
• Using colons or other punctuation instead of =
• Putting quotes around alias name

3. Given the alias alias ll='ls -l' and the command ll /tmp, what will be the output?

medium

A. Lists files in /tmp in long format

B. Shows an error: command not found

C. Lists files in current directory only

D. Prints the text 'll /tmp'

Solution

1. Step 1: Understand alias expansion

   The alias ll replaces ll with ls -l when typed.

2. Step 2: Apply alias with argument

   Typing ll /tmp runs ls -l /tmp, listing files in /tmp in long format.

3. Final Answer:

   Lists files in /tmp in long format -> Option A

4. Quick Check:

   Alias expands command with arguments = A [OK]

Hint: Alias replaces command name but keeps arguments [OK]

Common Mistakes:

• Thinking alias ignores arguments
• Expecting alias to print text
• Assuming alias causes error

4. You run alias ll='ls -l' but typing ll gives an error: command not found. What is the likely problem?

medium

A. The alias was set in a different shell session

B. You typed the alias command incorrectly

C. You forgot to export the alias

D. The ls command is missing

Solution

1. Step 1: Understand alias scope

   Aliases last only for the current shell session unless saved in config files.

2. Step 2: Identify cause of error

   If you set alias in one session but use another, the alias is not known, causing 'command not found'.

3. Final Answer:

   The alias was set in a different shell session -> Option A

4. Quick Check:

   Aliases are session-specific unless saved = C [OK]

Hint: Aliases vanish when shell closes unless saved [OK]

Common Mistakes:

• Thinking aliases need export
• Assuming alias command syntax error
• Blaming missing system commands

5. You want to create an alias update that runs sudo apt update && sudo apt upgrade -y. Which command correctly creates this alias so it works as expected?

hard

A. alias update='sudo apt update; sudo apt upgrade -y'

B. alias update = "sudo apt update && sudo apt upgrade -y"

C. alias update='sudo apt update && sudo apt upgrade -y'

D. alias update='sudo apt update & sudo apt upgrade -y'

Solution

1. Step 1: Understand command chaining in alias

   The && operator runs the second command only if the first succeeds, which is desired here.

2. Step 2: Check alias syntax and chaining

   The correct form is alias update='sudo apt update && sudo apt upgrade -y', which uses no spaces around =, single quotes, and && for conditional chaining. Forms with spaces around = cause syntax errors. Using ; runs the upgrade regardless of update's success. Using & runs upgrade in background.

3. Final Answer:

   alias update='sudo apt update && sudo apt upgrade -y' -> Option C

4. Quick Check:

   Correct alias syntax with && = D [OK]

Hint: Use && to run second command only if first succeeds [OK]

Common Mistakes:

• Using single & instead of &&
• Using ; which ignores success of first command
• Mixing quote types incorrectly