Linux is one of the most widely used operating systems in both personal and enterprise environments. Whether you’re aiming to become a system administrator, DevOps engineer, software developer, or IT professional, having a solid foundation in Linux is essential.
To support your learning and interview preparation, we’re excited to introduce a dedicated Linux Interview section on Tecmint, which will feature carefully selected Linux interview questions, along with detailed answers to help you prepare with confidence.
Every weekend, we’ll publish a new article in this section, starting from basic Linux questions and gradually moving toward more advanced topics. This initiative is one of the first of its kind among Linux-focused websites, and we’re committed to delivering high-quality, useful, and unique content.
Let’s get started with 15 basic Linux interview questions and answers to kick off the series.
Q1: What is the core of the Linux Operating System?
The core of the Linux operating system is the Kernel, which is the lowest level of the OS and acts as a bridge between the hardware and the software. It is responsible for managing system resources such as memory, CPU time, device drivers, and system calls.
The Linux Kernel is monolithic, meaning it includes the core system functions, device drivers, and file system management all within a single large block of code running in a single address space.
Q2: What Did Linus Torvalds Create?
Linus Torvalds created the Linux Kernel in 1991. It began as a hobby project while he was a student at the University of Helsinki, Finland. Initially inspired by MINIX (a Unix-like system for education), he created a free, open-source alternative.
Over time, the Linux Kernel evolved into the core of many operating systems, collectively referred to as Linux distributions (e.g., Ubuntu, Fedora, Debian).
Q3: Did Linus Torvalds Write Most of the Linux Kernel in C++?
No, this is incorrect. Linus Torvalds wrote most of the Linux Kernel in the C programming language, not C++. In fact, Linus has been publicly critical of using C++ in kernel development due to concerns about performance, complexity, and reliability.
The C language is preferred in kernel development because it provides low-level memory access, minimal runtime overhead, and maximum control over hardware resources.
Q4: Was Linux Initially Developed for Intel x86 Architecture, and Has It Been Ported to Other Platforms?
Yes, Linux was initially developed for the Intel x86 architecture (32-bit systems), but over the years, it has been successfully ported to a wide range of hardware architectures.
These include ARM, PowerPC, SPARC, MIPS, and even mainframes. Today, Linux runs on everything from smartphones and tablets to servers, supercomputers, routers, and embedded systems.
Q5: Is It Legal to Edit the Linux Kernel?
Yes, it is entirely legal to edit the Linux Kernel, as it is released under the GNU General Public License (GPL) version 2, which means it allows users to view, modify, and redistribute the source code freely, as long as any modifications are also made available under the same license.
This freedom is one of the reasons Linux has become so popular and widely adopted in various projects.
Q6: What is the Basic Difference Between UNIX and Linux?
UNIX is a proprietary operating system originally developed at AT&T’s Bell Labs in the 1970s. Linux, on the other hand, is a UNIX-like operating system that is free and open-source.
While UNIX systems are often used in commercial environments and have different variants (e.g., AIX, Solaris, HP-UX), Linux is a community-developed system that shares similar principles and design with UNIX but is not derived from UNIX code.
Key differences include:
Feature | UNIX | Linux |
---|---|---|
Licensing | Proprietary | Open-source (GNU General Public License) |
Cost | Usually requires purchasing a license | Free |
Hardware | Often used on specialized hardware | Supports a broad range of hardware devices |
Q7: Is the Linux Operating System Virus-Free?
No operating system is completely virus-free, including Linux. However, Linux is considered more secure than many others due to its permission-based structure, user role separation, and large community of developers who actively maintain and patch vulnerabilities.
Additionally, Linux is less targeted by malware due to its smaller desktop market share compared to Windows. That said, administrators should still use security best practices and tools like firewalls, SELinux, and antivirus software.
Q8: What Type of Operating System is Linux?
Linux is a multi-user, multitasking, and multi-threaded operating system.
Specifically, it is a:
- Unix-like OS
- Open-source OS
- Modular and monolithic Kernel-based OS
Linux is used as both a server OS and a desktop OS and supports features such as process scheduling, virtual memory, shared libraries, and dynamic loading.
Q9: What is the Syntax of a Linux Command?
The general syntax of a Linux command is:
command [options] [arguments]
For example:
ls -l /home/user
Here,
ls
is the command (list directory contents).-l
is an option (long listing format)./home/user
is the argument (the directory to list).
Q10: What is a Linux Distribution?
A Linux distribution (or distro) is a complete operating system based on the Linux Kernel and includes system software, package managers, and often a graphical user interface (GUI).
Examples include Ubuntu, CentOS, Fedora, Arch Linux, and Debian. Each distribution serves different purposes and caters to different users from beginners to enterprise environments.
Q11: What are Runlevels in Linux?
Runlevels are predefined states of the machine in Unix-like systems that define what services are running.
Traditional SysV init systems used numbered runlevels such as:
0
– Halt1
– Single-user mode3
– Multi-user mode (without GUI)5
– Multi-user mode with GUI6
– Reboot
Most modern Linux distributions (such as Fedora, CentOS 7+, Ubuntu 15.04+, and others) have replaced the SysV init system with systemd, which uses targets instead of runlevels for managing system states.
Here’s how systemd targets map to traditional runlevels:
Runlevel | systemd Target | Description |
---|---|---|
0 | poweroff.target | Shut down the system |
1 | rescue.target | Single-user mode |
3 | multi-user.target | Multi-user mode, CLI only |
5 | graphical.target | Multi-user mode with GUI |
6 | reboot.target | Reboot the system |
Q12: What is the Difference Between Hard Links and Soft Links?
- Hard Link: Points directly to the data on the disk (inode). If the original file is deleted, the hard link still works.
- Soft Link (Symbolic Link): Acts like a shortcut. It points to the original file by path. If the original file is removed, the symbolic link becomes broken.
Q13: What is a Shell in Linux?
A shell is a command-line interface that allows users to interact with the operating system. It interprets user commands and passes them to the Kernel for execution.
Popular Linux shells include:
- Bash (Bourne Again Shell)
- Zsh (Z Shell)
- Ksh (KornShell)
- Tcsh (TENEX C Shell)
Q14: How Do You Check Memory Usage in Linux?
You can check memory usage using the following commands:
- free -h: Displays used, free, and total memory.
- top: Real-time view of system processes and memory usage.
- vmstat: Reports memory, CPU, and I/O usage.
- htop: Interactive process viewer (needs to be installed).
Q15: How is File Permission Represented in Linux?
File permissions in Linux are represented using three sets of attributes:
- User (owner)
- Group
- Others
Each set includes permissions for:
- Read (r)
- Write (w)
- Execute (x)
Example:
-rwxr-xr-- 1 user group 1234 Jan 1 12:00 file.txt
This means:
- Owner has read, write, execute
- Group has read, execute
- Others have only read
You can change permissions using chmod
and change ownership using chown.
Conclusion
Understanding the basics of Linux is crucial for many roles in modern IT environments. These questions cover foundational knowledge you’re likely to encounter in entry-level interviews.
As you progress, consider exploring more advanced topics such as process management, scripting, file systems, and networking in Linux.
Would I in Linux have access to ancient Greek, to characters with diacritics and to phonetic characters; not be inserting them via a Menu, but install them so that I can switch keyboard from English/European to Greek, and to English with diacritics (e.g. Sanskrit)?
I think it should be pointed out, regarding #3, that the number of lines of code in Linux changes — generally upward — with each kernel release, and no-doubt the numbers shown in the answer are now outdated, but no-doubt were true at the time this article was written.
Hi,
Good article and helpful to beginner or who wants to recall their knowledge in linux.
I have observed the two things which needs to be corrected.
Thanks in advance!
@Sumit,
Thanks for finding this article useful, but do the spelling ‘Linus’ is correct – he is Linus Torvalds creator of Linux.
Great idea! Really liked! Just one thing: In Q.10, options a and c are the same.
Really…. Nice one and more to learn
Thanku for creating this article it’s very important for interview preparation..
It’s a very good.
This website is huge helpful for me, thanks for a millions.
thanks its good.
This is very good article. A lot to learn from this
Hello
Does anyone know this error?
error while loading shared libraries: libX11-xcb.so.1: can not open shared object file: No such file or directory
@Shayan,
Install the libX11 package to fix that error..
good for basic question in linux as well as in interview..
nano command …?
nano is a simple to use text editor which can be executed by nano command if and only if it is installed.
Question No.2 seems to be wrong.
Q.2: What Linus Torvalds Created?
Fedora
Slackware
Debian
Gentoo
Linux
Answer : Linus Torvalds created Linux, which is the kernel (heart) of all of the above Operating System and all other Linux Operating System.
I have installed Windows 7 on my laptop.
I have installed Virtual Box and in that installed RHEL 5 and its working fine.
When I installed RHEL 7 on that, ifconfig command is not working.
What is the reason, could you please help me out here.
@Aslam,
Just install ‘net-tools‘ package that provides ifconfig command using yum command as shown, For example, to install ifconfig command run,
U Should Activate In Bios Virtual Mode, Then Try it.
while i am creating empty file in this command
#touch file{1…..10}
#ls
#file{1…10}
Hi ravi
please help me how to installed NVIDIA grafic card drivers steps
@Narasimha,
Could you tell me on which Linux distribution, you want to have graphic drivers installed?
I believe the topic you are asking about if Brace Expansion. Various shells may perform this differently (there are many shells). Here is a reference to BASH and related patterns. See Brace Expansion near bottom. http://mywiki.wooledge.org/BashGuide/Patterns
can some one help me
while i was creating the empty files using “touch” command it is creating like this
[root@srikanth ~/nagios]# touch file{1..10}
[root@srikanth ~/nagios]#
[root@srikanth ~/nagios]# ls
file1..10
[root@srikanth ~/nagios]#
@Srikanth,
I’ve tried same command and it’s works fine, here is the output of the command.
I am kumar..I will atten the interview Linux how to prepare the interview..I have completed 2 rounds last one round technical interview ..pls give a successtion…
its very useful… bt plz give me a lots of thing on linux …….
Hello, first of all great article I’m studying for an interview and this has been helpful. It appears to me that question number 10 has the correct answer listed twice.
Best regards.
Beautiful article and complete website too.. gives basic idea i never even though of besides executing few basic commands. I am new to Linux. I will surly visit all articles one by one..
Welcome Raghu,
Keep connected! Keep Commenting!
Give good basic knowledge
Appreciation or request @ Haneesh
Good Information…..
Welcome @ Mitasmita Pradhan
it’s ok but not upto the mark
Avishek, Good info…grate to share knowledge.
Welcome @ naresh
Thanks Sir, for the useful info, ppl like you are helpful for the guys like us, u r work is appreciated and looking more forward for the knowledge .
welcome Rajesh.
Tecmint team and proficient authors team will always be guiding the needy.
Dear Sir,
I Want to start career in Linx Admin. which are the commands are essential and where should i practise it.
Well Linux Admin is proficient in commands, scripts, service/Application and a whole lot other aspects. You may start from basic commands: here is the link : https://www.tecmint.com/useful-linux-commands-for-newbies/
hello sir, this is awesome, i’m just near to complete my RHCE exam,n i know,this basic knowledge will help me strongly in interview.keep it up sir.
Welcome @ dipan Kundan.
Keep Connected!
Dear,
Can you send filter commands and uses in Linux and Solaris
Good stuff…….. keep sending like this
Dear Arvind Reddy,
we can’t send you articles in personal.
You can subscribe to us alternatively.
thanks for the notes.. It was helpful.
Welcome @ Siddhart Gupta.
Very nice information>. Thanks Avishek Kumar.
Thanks for the recognition.
nice refreshing..
It was a great pleasure knowing this.
thnxx i goted basic info… :)
Welcome @ vyaki,
It was pleasing to know that the article helped you.
Thanking you sir,
i wish to know much more questions and answers related to Linux.
Welcome @ fuhad,
keep connected to Tecmint.com for more Linux related questions and their answer.
Thank u sir …….. i want more quest on this linux
Dear Harish,
we are coming with Interview Article every Saturday (except a few exception).
Keep connected to Tecmint for that.
thanks for basic info of linux
Welcome @ jyoti.
thank you sir…. i want more qns on this linux
Dear rambabu,
welcome!
Keep connected to Tecmint.com for more such questions related to Linux.
HI.Avishek Kumar..
Hope so u doing well. Could share me the Interview questions docs for WIndows & Linux. I am beginner for linux & i have experience with windows domain. Could share me the docs.
Plz connect me on this mob no for our further conversation(8792830783).
Dear vssmanian,
As said earlier, It is not possible to send each of our readers the article in person, on their personal IDs. Moreover it is against our Policy.
You can subscribe us and keep visiting Tecmint every now and then for more such questions.
Hi Avishek,
Very nice article and interesting and knowledgeable for learners of Linux and very useful for interviews. Keep it up,
Dear Sreenivasulu,
Thanks for such a wonderful feedback. we are Honored!
Very good content easy to understand ..Way to go !!
Dear Lalu,
Thanks for your feedback.
Hello Avishek,
I am Linux Enthusiast and MCA. New in the field of Linux. It’s a great beginning for me. Excellent Basic things covered.
Thanks
Dear Harshal kulkarni,
Thanks for your feedback.
We (Tecmint Team) is happy to know, our writing is helping our readers, followers and fans.
Too Basic…..
But need to know
One man’s BASIC may be Challenge for others.
:)
Nice info
Welcome @ sarang
hello sir nice article it helped me a lot
Wonderful @ srikant,
Tecmint-Team is pleased to know we were helpful.
Good format to spread knowledge: very simple, helpful and clear 4 all.. …..plz post experience question
shukriya …
Yeah! Tanweer we are doing it only, step by step.
Keep Connected
Thanks ,Linux basic command ,,
can u add , How to install,config q mail ?
Welcome @ istafa,
we will be covering qmail, soon.
Keep connected.
Hi Avishek,
This is Eshwaran i want know basic linux system admin question ,my intrest linux admin,but i dont have experience linux. also i am looking video linux admin like CBT Nugget.I have experience 3 years but windows platform,can guide me .share linux system admin question and answer….
my email id:[email protected],7760680717
Dear Eshwaran, we keep posting, Linux stuffs, tutorials, review almost evryday. Keep connected to tecmint, for the latest posts. You can always read our Previous articles on tecmint. It surely will add to your knowledge. Hope it helps.
** Sorry dear, but we can not send our articles to anybody personally. It is against our policy. Hope you understand.
hi, i am joining to linux course need you are help
We already covering a series on Linux Foundation Certified SysAdmin course, you should follow it to learn Linux. Use the following link to visit the complete Linux course tutorials.
https://www.tecmint.com/sed-command-to-create-edit-and-manipulate-files-in-linux/
very useful informations sir.But what about Linux future ,comparing to developers which persons get more salary?
reply me sir
Dear Kumar, Thanks for the feedback.
You should choose your carrier based upon area of Interest and not Field. There is no salary Limit for a deserving person in any field of the world.
So choose your carrier on your area of expertise and interest.
this is awesome,i’m just near to complete my exam,n i know,this basic knowledge will help me strongly in interview.keep it up sir.
Thanks @ bhavik.
Nice to hear this from You.
kindly send me some questions on mail.
@ DANISH,
It would be very difficult for us to send Interview Questions/Answer in Person. Please search our website as keep connected. If you find any topic/subject we have not touched, we will be happy to help.
SUPER AM A FRESHER LEARNING LINUX PROVIDE MORE AND MORE INTERVIEW QUESTIONSSSSS…..
PROVIDE TROUBLESHOOTING INTERVIEW QUESTIONSSSS
Thanks @ PURUSHOTHAM, we will be providing Troubleshooting interview questions in our future post. Although we keep a few troubleshooting question relating to topic, in the post.
Keep connected.
its really awesome, got refreshed from my linux basic skills . Waiting for your next post.
Thanks Neal Raj Thakre. we have already published other articles of this series.
very helpful article
Good to hear that sanil kumar, Thanks.
Thanks @ Dinesh Bahadur, For your valueable Feedback.
Hi
You content is very useful.
I am having an interview next week on Linux and SQL
I am fresher and i want to know some questions based on linux and SQL for fresher level for my next interview purpose . If you could help on that i’ll be very greatful to you for this.
Waiting for positive reply asap.
my Mail id : [email protected]
Ph no. 9873734035
Thanks @ Danish.
Our sole purpose is to provide anything and everything related to Linux, in as much simple way as possible and comments of such kind, confirms we are on right Track.
This is good initiative. Looking for next set of question.
yeah !! fine article dude ;)
Thanks for your feedback @ Rahul
good brushup on basics
:)
It always helps to have fresh these concepts, Good article …
Thanks @ Juancho76 for your valueable feedback.
Thanks a lot! it was very useful. For me, at least 5 of them were completely new , and the others were good reviews.
Thanks @ saber, for your Feedback.
Happy to know it was helpful to you.
About Q.10: Syntax of any Linux command is, I don’t understand why having square brackets [] will make any difference among those answers. Could you please give me some examples to clarify?
Let me take a stab at it. In documentation, [brackets] are used to denote that something is optional. In this sense, command [options] [arguments] is the correct choice as you can often just run the command.
I would argue that the focus on the [brackets] conveys the wrong intention. The focus turns the question into more “Do you know how to read documentation for a command?” rather than “Do you know options and arguments cannot precede the command?”
Also, command [arguments] [options] is just as valid. ls -l /home/user = ls /home/user -l
Good format to spread knowledge: very simple, helpful and clear. Thanks!
Thanks @ Eduardo González for your valueable feedback.
nice one
Thanks @ niraj
i am looking for experienced interview questions on Avishek Kumar.
on Avishek Kumar?
are you kidding???
very helpful bhai waiting for next post
:) sure @ shaik, we are coming with next post of this series, soon.
Stay tuned to Tecmint.
Thank you. I look forward to the next interview question list. Your website is very helpful to me.
Thanks @ kathy,
comment of such kind makes us proud.
Great contents. Helpful. Really appreciated. Keep doing good work, Avishek Kumar. Cheers.
:) Thanks @ Mitesh Ganatra. Your feedback is appreciated on a higher note.
the option 1 and option 3 is the same with each other,what the point?
Yes, @ zlfccnu
in question number 10, option (1) and (3) are same, a mistake on our part, but still the answer is correct.
Thanks..!! .. refreshed on linux basics..
:) Thanks for your feedback @ Ganeh Maragani
helpful, looking forward to the next interview post
Thanks for the Feedback. We are coming with next article, very soon.
hi Avishek,
NIce Info..can u send me Active directoy for windows and linux Docs…
Thanks in Advance
hye avishek, im beginner to use Linux, please teach me ad guide me how to use it and master it, any guide which understand very fast..thanks
Dear yogi,
keep going through each of our articles already on Tecmint as well as new articles to come, you will learn a lot.
Hi sir, i am a beginner in linux OS, i would like to do Redhat certified system Administrator also pass the exam of corse, so can you me what type book do i need or advice me anything i can do to pass my exam. I really want to take all certificates in Redhat linux in the future., please help me. Thank you in advance.