20 Linux Commands Quiz Questions and Answers

Question 1:
What is the primary function of the ‘ls’ command in Linux?
A) To list files and directories in the current directory
B) To create a new directory
C) To copy files from one location to another
D) To remove files permanently

Answer: A
Explanation: The ‘ls’ command displays information about files and directories, such as their names and permissions, in the specified or current directory.

Question 2:
Which command is used to change the current working directory in Linux?
A) cd
B) pwd
C) ls
D) mkdir

Answer: A
Explanation: The ‘cd’ command allows users to navigate to a different directory by specifying the path.

Question 3:
What does the ‘pwd’ command do?
A) Prints the current working directory
B) Creates a new file
C) Deletes a directory
D) Displays the contents of a file

Answer: A
Explanation: The ‘pwd’ command outputs the full path of the current directory, helping users know their location in the file system.

Question 4:
How can you copy a file named ‘file1.txt’ to a new file named ‘file2.txt’ in the same directory?
A) cp file1.txt file2.txt
B) mv file1.txt file2.txt
C) rm file1.txt file2.txt
D) ls file1.txt file2.txt

Answer: A
Explanation: The ‘cp’ command is used for copying files, where the first argument is the source file and the second is the destination.

Question 5:
Which command is used to rename or move a file in Linux?
A) mv
B) cp
C) rm
D) touch

Answer: A
Explanation: The ‘mv’ command renames files within the same directory or moves them to a different location.

Question 6:
What command removes a file named ‘example.txt’?
A) rm example.txt
B) del example.txt
C) remove example.txt
D) delete example.txt

Answer: A
Explanation: The ‘rm’ command deletes files or directories; it permanently removes the specified file.

Question 7:
How do you create a new directory named ‘newdir’?
A) mkdir newdir
B) touch newdir
C) cd newdir
D) ls newdir

Answer: A
Explanation: The ‘mkdir’ command creates a new directory with the specified name in the current location.

Question 8:
Which command is used to remove an empty directory named ’emptydir’?
A) rmdir emptydir
B) rm emptydir
C) delete emptydir
D) remove emptydir

Answer: A
Explanation: The ‘rmdir’ command removes empty directories, whereas ‘rm’ can remove non-empty ones with additional options.

Question 9:
What does the ‘cat’ command do with a file?
A) Displays the contents of a file
B) Creates a new file
C) Copies the file
D) Edits the file

Answer: A
Explanation: The ‘cat’ command concatenates and displays the contents of files to the standard output.

Question 10:
Which command is used to search for a string ‘error’ in a file named ‘log.txt’?
A) grep ‘error’ log.txt
B) find ‘error’ log.txt
C) search ‘error’ log.txt
D) cat ‘error’ log.txt

Answer: A
Explanation: The ‘grep’ command searches for patterns or strings within files and outputs matching lines.

Question 11:
How do you change the permissions of a file to make it readable and writable by the owner?
A) chmod 600 filename
B) chmod 777 filename
C) chown owner filename
D) ls -l filename

Answer: A
Explanation: The ‘chmod’ command modifies file permissions; ‘600’ sets read and write for the owner and no permissions for others.

Question 12:
What command changes the owner of a file named ‘file.txt’ to ‘user1’?
A) chown user1 file.txt
B) chmod user1 file.txt
C) mv user1 file.txt
D) cp user1 file.txt

Answer: A
Explanation: The ‘chown’ command alters the ownership of files or directories to the specified user.

Question 13:
Which command lists the currently running processes in Linux?
A) ps
B) top
C) kill
D) ls

Answer: A
Explanation: The ‘ps’ command provides a snapshot of the current processes, showing details like PID and status.

Question 14:
What is the purpose of the ‘top’ command?
A) To display and update sorted information about processes
B) To create a new process
C) To delete a process
D) To list files

Answer: A
Explanation: The ‘top’ command provides a dynamic real-time view of running processes, sorted by CPU usage or other metrics.

Question 15:
How do you terminate a process with PID 1234?
A) kill 1234
B) ps 1234
C) top 1234
D) rm 1234

Answer: A
Explanation: The ‘kill’ command sends signals to processes; by default, it terminates the process with the specified PID.

Question 16:
Which command checks the disk space usage of the file system?
A) df
B) du
C) ls
D) cd

Answer: A
Explanation: The ‘df’ command reports file system disk space usage, showing how much space is used and available.

Question 17:
What does the ‘du’ command estimate?
A) Disk usage of files and directories
B) Current directory path
C) File permissions
D) Process status

Answer: A
Explanation: The ‘du’ command estimates the space used by files and directories, often recursively.

Question 18:
How can you combine the output of one command as input to another?
A) Using the pipe symbol |
B) Using the redirection >
C) Using cd
D) Using ls

Answer: A
Explanation: The pipe ‘|’ operator redirects the output of the first command to the input of the second, such as ‘ls | grep file’.

Question 19:
Which command redirects the output of ‘ls’ to a file named ‘output.txt’?
A) ls > output.txt
B) ls | output.txt
C) cat output.txt
D) echo output.txt

Answer: A
Explanation: The ‘>’ operator redirects standard output to a file, overwriting it if it exists.

Question 20:
What is the role of the ‘sudo’ command?
A) To execute a command with superuser privileges
B) To list superuser files
C) To delete superuser accounts
D) To change user directories

Answer: A
Explanation: The ‘sudo’ command allows a permitted user to run programs with the security privileges of another user, typically the superuser.