Linux overview in Intro to Computing - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to show the command that lists files in a directory.

Intro to Computing

ls [1]

Drag options to blanks, or click blank then click option'

A-l

B-z

C-x

D-q

Attempts:

3 left

💡 Hint

Common Mistakes

Using options that do not exist or do not show detailed file info.

Forgetting the dash before the option letter.

The ls -l command lists files with detailed information like permissions, owner, size, and modification date.

2fill in blank

medium

Complete the command to change the current directory to the home directory.

Intro to Computing

cd [1]

Drag options to blanks, or click blank then click option'

A/var

B/root

C/etc

D~

Attempts:

3 left

💡 Hint

Common Mistakes

Using absolute paths that are not the home directory.

Confusing system directories with user directories.

The tilde ~ symbol represents the current user's home directory in Linux.

3fill in blank

hard

Fix the error in the command to display the current working directory.

Intro to Computing

[1]

Drag options to blanks, or click blank then click option'

Als

Bcd

Cpwd

Ddir

Attempts:

3 left

💡 Hint

Common Mistakes

Using cd which changes directory instead of showing it.

Using ls which lists files but does not show the current path.

The pwd command prints the current working directory path.

4fill in blank

hard

Fill both blanks to create a command that shows the first 10 lines of a file named 'log.txt'.

Intro to Computing

[1] [2] log.txt

Drag options to blanks, or click blank then click option'

Ahead

Btail

C-10

D-f

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'tail' which shows the end of the file.

Using '-f' which follows the file continuously.

The head -10 command shows the first 10 lines of a file. By default, head shows 10 lines.

5fill in blank

hard

Fill all three blanks to create a command that finds all '.txt' files in the current directory and its subdirectories.

Intro to Computing

[1] . [2] '*.txt' [3]

Drag options to blanks, or click blank then click option'

Afind

B-name

C-type f

D-exec

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-exec' which runs commands on found files but is not needed here.

Omitting '-type f' which may include directories.

The find command searches directories. The -name '*.txt' option filters files ending with '.txt'. The -type f option ensures only files (not directories) are found.

Practice

1. What is Linux primarily known as?

easy

A. A free and open-source operating system

B. A type of hardware device

C. A programming language

D. A web browser

Solution

1. Step 1: Understand what Linux is

   Linux is an operating system, which means it manages computer hardware and software resources.

2. Step 2: Identify Linux's key feature

   Linux is free and open-source, meaning anyone can use and modify it without cost.

3. Final Answer:

   A free and open-source operating system -> Option A

4. Quick Check:

   Linux = free OS [OK]

Hint: Linux is an OS, not hardware or language [OK]

Common Mistakes:

• Confusing Linux with hardware
• Thinking Linux is a programming language
• Assuming Linux is a software application

2. Which of the following is the correct command to list files in a directory in Linux?

easy

A. list

B. dirlist

C. showfiles

D. ls

Solution

1. Step 1: Recall basic Linux commands

   The command to list files in Linux is a short, simple command.

2. Step 2: Identify the correct command

   The correct command is ls, which stands for 'list'. Other options are not valid Linux commands.

3. Final Answer:

   ls -> Option D

4. Quick Check:

   List files = ls [OK]

Hint: Remember: 'ls' lists files in Linux [OK]

Common Mistakes:

• Using Windows command 'dir' instead of 'ls'
• Typing commands that don't exist in Linux
• Confusing 'list' as a command

3. What will be the output of the command sequence shown below?

mkdir testfolder
cd testfolder
pwd

medium

A. /home/testfolder

B. /testfolder

C. /home/username/testfolder

D. testfolder

Solution

1. Step 1: Understand each command

   mkdir testfolder creates a folder named 'testfolder'. cd testfolder moves into that folder. pwd prints the current directory path.

2. Step 2: Determine the full path

   Assuming the user starts in their home directory (e.g., /home/username), after moving into 'testfolder', pwd will show the full path including the home directory and 'testfolder'.

3. Final Answer:

   /home/username/testfolder -> Option C

4. Quick Check:

   pwd after cd testfolder = full path [OK]

Hint: pwd shows full current directory path [OK]

Common Mistakes:

• Assuming pwd shows only folder name
• Ignoring starting directory path
• Confusing mkdir with cd output

4. Identify the error in the following Linux command sequence:

cd /home/user/docs
mkdir newfolder
cd newfolder
ls -l
cd ..
cd newfolder

medium

A. Second 'cd newfolder' will fail if 'newfolder' does not exist

B. No error, commands are correct

C. 'mkdir newfolder' should be 'make newfolder'

D. 'ls -l' is an invalid command

Solution

1. Step 1: Analyze the command sequence step-by-step

   cd /home/user/docs enters docs. mkdir newfolder creates newfolder inside docs. cd newfolder enters it. ls -l lists contents in long format (valid).

2. Step 2: Verify the last commands

   cd .. returns to docs where newfolder exists. cd newfolder succeeds. All commands valid, no errors.

3. Final Answer:

   No error, commands are correct -> Option B

4. Quick Check:

   Folder created persists after cd .. [OK]

Hint: Trace directory state after each cd/mkdir [OK]

Common Mistakes:

• Thinking second 'cd newfolder' fails (folder exists)
• Confusing 'mkdir' with 'make newfolder'
• Believing 'ls -l' invalid (standard command)

5. You want to create a new directory called projects inside your home directory, then create a file named notes.txt inside it with some text. Which sequence of commands will achieve this correctly?

hard

A. cd ~
mkdir projects
cd projects
echo "My notes" > notes.txt

B. mkdir projects
cd projects
cd ~
echo "My notes" > notes.txt

C. cd projects
mkdir notes.txt
echo "My notes" > notes.txt

D. echo "My notes" > notes.txt
mkdir projects
cd projects

Solution

1. Step 1: Navigate to home and create directory

   cd ~ moves to the home directory. mkdir projects creates the 'projects' folder there.

2. Step 2: Enter the new directory and create file with text

   cd projects moves inside the folder. echo "My notes" > notes.txt creates 'notes.txt' with the text 'My notes'.

3. Final Answer:

   cd ~ mkdir projects cd projects echo "My notes" > notes.txt -> Option A

4. Quick Check:

   Create dir then file inside it [OK]

Hint: Create folder first, then file inside it [OK]

Common Mistakes:

• Creating file before directory exists
• Using wrong order of commands
• Trying to create file as directory