Linux is an open-source operating system that is widely used in servers, desktops, mobile devices, and other embedded systems. As a Linux system administrator, you need to have a good understanding of the Linux operating system and its various tools and utilities. In this blog, we will cover 20 Linux interview questions that beginners might encounter during a job interview.
20 Linux Interview Questions
1. What is Linux?
Linux is a free and open-source operating system based on the Unix operating system. It was developed by Linus Torvalds in 1991 and is widely used today in servers, desktops, mobile devices, and other embedded systems.
2. What is the difference between Linux and Unix?
Linux is a free and open-source operating system developed by the community, while Unix is a proprietary operating system developed by AT&T Bell Labs. Linux is based on Unix, but it has its own unique features and capabilities.
3. What are some common distributions of Linux?
Some common distributions of Linux include Ubuntu, Debian, Fedora, CentOS, Red Hat Enterprise Linux, and SUSE Linux Enterprise.
4. What is the difference between a shell and a terminal?
A shell is a command-line interface that allows you to interact with the operating system. A terminal is a program that provides a shell. In other words, a terminal is a window that displays the shell prompt and allows you to enter commands.
5. How do you find a file in Linux?
You can use the find command to search for a file in Linux. For example, to search for a file named “myfile.txt” in the current directory and its subdirectories, you can use the following command:
find . -name "myfile.txt"
6. How do you check the system status in Linux?
You can use the command “top” to check the system status in Linux. This command displays a real-time view of the system’s processes and resource usage.
7. What is a process in Linux?
A process is an instance of a program that is currently running on a Linux system. Each process has its own process ID (PID) and can consume system resources such as CPU time, memory, and input/output.
8. How do you check the running processes in Linux?
You can use the command “ps” to check the running processes in Linux. This command displays a list of processes running on the system, along with their PID, CPU usage, and other information.
9. What is a daemon in Linux?
A daemon is a background process that runs continuously on a Linux system, providing some service or functionality. Daemons are typically started at boot time and run until the system is shut down.
10. How do you start and stop a daemon in Linux?
You can start and stop a daemon in Linux using the “systemctl” command. For example, to start the Apache web server daemon, you can use the following command:
sudo systemctl start apache2
To stop the daemon, you can use the following command:
sudo systemctl stop apache2
11. How do you add a user in Linux?
You can add a user in Linux using the “adduser” command. For example, to add a user named “john”, you can use the following command:
sudo adduser john
You will be prompted to set a password and other information for the user.
12. What is a process?
A process is a running program. Each process has its own unique ID and uses system resources, such as CPU and memory.
13. What is a kernel?
The kernel is the core of the operating system. It manages system resources, such as memory and CPU, and communicates with hardware devices, such as printers and disks.
14. What is a distribution?
A Linux distribution is a collection of software packages that are bundled together to create a complete operating system. Some popular Linux distributions include Ubuntu, Fedora, and Debian.
15. How do you check the disk usage in Linux?
You can check the disk usage in Linux using the df command. This command shows the amount of disk space used and available for each mounted file system.
16. What is SSH and how does it work?
SSH stands for Secure Shell. It is a network protocol that allows you to securely access and manage remote systems. SSH works by encrypting data and transmitting it over a secure channel.
17. What is a package manager and how does it work?
A package manager is a tool that is used to install, update, and remove software packages. It works by accessing a repository of software packages and downloading them to the system.
18. What is a shell?
A shell is a command-line interface that allows you to interact with the operating system. It provides a way to run commands, execute scripts, and manage files and directories.
19. What is a file system?
A file system is a way of organizing and storing files on a disk. It defines how files are named, accessed, and stored.
20. What is sudo?
Sudo is a command that allows users to perform administrative tasks on a Linux system. It stands for “superuser do”.
21. How do you change file permissions in Linux?
You can change file permissions in Linux using the chmod command. For example, the command “chmod 755 file.txt” sets the file permissions to read, write, and execute for the owner, and read and execute for everyone else.
Conclusion
Linux is a widely used operating system, and as a Linux system administrator, you need to have a good understanding of its various tools and utilities. In this blog, we covered 20 Linux interview questions that beginners might encounter during a job interview. These questions cover a range of topics, including the basics of Linux, working with files and processes, managing daemons, adding and managing users, and more. By studying and practicing these questions, you can build a strong foundation in Linux system administration and prepare yourself for a successful career in this field.