Ubuntu Interview Questions and Answers

Ques 1. What is the default package manager in Ubuntu?

The default package manager in Ubuntu is APT (Advanced Package Tool).

Example:

sudo apt-get install packageName

Ques 2. How do you update the package list with APT?

You can update the package list with the command: sudo apt-get update

Ques 3. Explain the purpose of the 'sudo' command.

The 'sudo' command is used to execute a command with administrative privileges.

Example:

sudo commandToExecute

Ques 4. How can you check the version of Ubuntu installed on your system?

You can check the Ubuntu version with the command: lsb_release -a

Ques 5. What is the purpose of the 'ls' command in Linux?

The 'ls' command is used to list files and directories in a directory.

Example:

ls

Ques 6. How do you find the IP address of your Ubuntu system?

You can find the IP address using the 'ifconfig' or 'ip addr' command.

Example:

ifconfig

Ques 7. What is the purpose of the 'grep' command?

The 'grep' command is used to search for a specific pattern or text in files.

Example:

grep pattern filename

Ques 8. How do you enable the UFW (Uncomplicated Firewall) in Ubuntu?

You can enable UFW with the command: sudo ufw enable

Ques 9. How do you check the available disk space in Ubuntu?

You can check disk space using the 'df' command. For example: df -h

Ques 10. What is the purpose of the 'tar' command?

The 'tar' command is used for compressing and archiving files and directories.

Example:

tar -cvzf archive.tar.gz /path/to/directory

Ques 11. How do you find the process ID (PID) of a running process in Ubuntu?

You can use the 'pgrep' or 'ps' command to find the PID of a running process.

Example:

pgrep processName

Ques 12. Explain the purpose of the '/etc/hostname' file.

The '/etc/hostname' file contains the hostname of the system.

Ques 13. How do you check the Ubuntu release codename?

You can check the release codename with the command: lsb_release -c

Ques 14. How do you check the CPU information in Ubuntu?

You can check CPU information using the 'lscpu' command.

Ques 15. Explain the purpose of the '/var/log' directory.

The '/var/log' directory contains log files generated by various system processes and services.

Ques 16. What is the purpose of the '/etc/apt/sources.list' file?

The '/etc/apt/sources.list' file contains a list of package repositories for APT.

Ques 17. Explain the difference between 'apt-get' and 'apt'.

'apt' is a simplified command-line interface for the APT package manager, while 'apt-get' is the traditional command-line tool.

Ques 18. How do you install a package using the 'dpkg' command?

You can install a package with the command: sudo dpkg -i package.deb

Ques 19. How do you change the ownership of a file in Ubuntu?

You can change the ownership of a file with the 'chown' command, like this: sudo chown newOwner:newGroup filename

Ques 20. What is the purpose of the '/etc/fstab' file?

The '/etc/fstab' file contains information about disk drives and partitions, and it is used by the 'mount' command.

Ques 21. Explain the purpose of the '/etc/passwd' file.

The '/etc/passwd' file contains user account information, including usernames and user IDs.

Ques 22. How do you search for a file in Ubuntu using the command line?

You can use the 'find' command to search for files. For example: find /path/to/search -name filename

Ques 23. What is the purpose of the '/etc/apt/sources.list.d/' directory?

The '/etc/apt/sources.list.d/' directory is used to store additional APT repository configuration files.

Ques 24. What is the purpose of the 'chmod' command?

The 'chmod' command is used to change the permissions of a file or directory.

Example:

chmod permissions filename

Ques 25. Explain the purpose of the 'cron' system in Ubuntu.

The 'cron' system is used for scheduling tasks to run automatically at specified intervals.

Ques 26. How do you add a user to a group in Ubuntu?

You can add a user to a group with the 'usermod' command. For example: sudo usermod -aG groupName username

Ques 27. Explain the purpose of the 'journalctl' command.

The 'journalctl' command is used to query and display messages from the journal, managed by 'systemd'.

Example:

journalctl

Ques 28. What is the purpose of the 'apt-cache' command?

The 'apt-cache' command is used to query and display information about packages in the APT cache.

Example:

apt-cache show packageName

Ques 29. What is the purpose of the 'systemctl' command?

The 'systemctl' command is used to control the 'systemd' system and service manager.

Example:

systemctl status serviceName

Ques 30. How do you install software from source code in Ubuntu?

You can install software from source code using the following commands: ./configure, make, sudo make install