200+ Linux technical & command interview questions and answers

Here are the best Linux technical & command interview questions and answers for freshers, devops, experienced professionals with commands to crack the interview easily.

What is Linux?
What is the difference between UNIX and LINUX?
What is the difference between Linux and Windows?
What is BASH?
What is Linux Kernel?
What is LILO?
What Is Linux Shell?
What Is Shell Script?
What Is Kernel? Explain The Task It Performs.
What Are Pipes?
Explain Trap Command; Shift Command, Getopts Command Of Linux
What Stateless Linux Server? What Feature It Offers?
What Does Nslookup Do? Explain Its Two Modes.
What Are The Process States In Linux?
What Is A Zombie?
Explain Each System Calls Used For Process Management In Linux.
How Do You List Files In A Directory?
How Do You List Files In A Directory with sorting by last modification time ?
How Do You List All Files In A Directory, Including The Hidden Files?
How Do You Find Out All Processes That Are Currently Running?
How Do You Find Out The Processes That Are Currently Running Or A Particular User?
How Do You Kill A Process?
What is a swap space?
Is Linux Open source ?
What are the best flavours of linux ?
What is the advantage of open source?
What are the basic components of Linux?
Does it help for a Linux system to have multiple desktop environments installed?
What is the basic difference between BASH and DOS?
What is the importance of the GNU project?
Explain the root account.
How to reset root password in linux ?
What are difference Between CLI and GUI ?
How do you open a command prompt when issuing a command?
How can you find out how much memory Linux is using?
What is a typical size for a swap partition under a Linux system?
What are symbolic links?
Does the Ctrl+Alt+Del key combination work on Linux?
How do you refer to the parallel port where devices such as printers are connected?
Are drives such as hard drive and floppy drives represented with drive letters?
How do you change permissions under Linux?
In Linux, what names are assigned to the different serial ports?
How do you access partitions under Linux?
What are hard links?
What is the maximum length for a filename under Linux?
What are filenames that are preceded by a dot?
Explain virtual desktop.
How do you share a program across different virtual desktops under Linux?
What does a nameless (empty) directory represent?
What is the pwd command?
What are daemons?
How do you switch from one desktop environment to another, such as switching from KDE to Gnome?
What are the kinds of permissions under Linux?
How does case sensitivity affect the way you use commands?
What are environmental variables?
What are the different modes when using vi editor?
Is it possible to use shortcuts for a long pathname?
What is redirection?
What is grep command?
What could be the problem when a command that was issued gave a different result from the last time it was used?
What are the contents of /usr/local?
How do you terminate an ongoing process?
How do you insert comments in the command line prompt?
What is command grouping and how does it work?
How do you execute more than one command or program from a single command line entry?
Write a command that will look for files with an extension “c”, and has the occurrence of the string “apple” in it.
Write a command that will display all .txt files, including its individual permission.
What is the command to calculate the size of a folder?
How can you find the status of a process?
How can you check the memory status?
How can you append one file to another in Linux?
Explain how you can find a file using Terminal?
Explain how you can create a folder using Terminal?
Explain how you can view the text file using Terminal?
Explain how to enable curl on Ubuntu LAMP stack?
Explain how to enable root logging in Ubuntu?
How can you run a Linux program in the background simultaneously when you start your Linux Server?
Explain how to uninstall the libraries in Linux?
What Would You Use To Edit Contents Of The File?
What Would You Use To View Contents Of A Large Error Log File?
How Do You Log In To A Remote Unix Box?
How Do You Get Help On A Unix Terminal?
How Do You List Contents Of A Directory Including All Of Its Subdirectories, Providing Full Details And Sorted By Modification Time?
What Is A Filesystem?
How Do You Get Its Usage (a Filesystem)?
How Do You Check For Processes Started By User ‘pat’?
How Do You Start A Job On Background?
What Utility Would You Use To Replace A String ‘2001’ For ‘2002’ In A Text File?
What Utility Would You Use To Cut Off The First Column In A Text File?
How To Copy File Into Directory?
How To Remove Directory With Files?
What Is The Difference Between Internal And External Commands?
List The Three Main Parts Of An Operating System Command:
What Is The Difference Between An Argument And An Option (or Switch)?
What Is The Purpose Of Online Help?
Name Two Forms Of Security.
What Command Do You Type To Find Help About The Command Who?
What Is The Difference Between Home Directory And Working Directory?
Which Directory Is Closer To The Top Of The File System Tree, Parent Directory Or Current Directory?
What Are Two Subtle Differences In Using The More And The Pg Commands?
When Is It Better To Use The More Command Rather Than Cat Command?
What Are Two Functions The Move Mv Command Can Carry Out?
Name Two Methods You Could Use To Rename A File?
Write a Command to List All The Files Beginning With A?
Which Of The Quoting Or Escape Characters Allows The Dollar Sign ($) To Retain Its Special Meaning?
What Is A Faster Way To Do The Same Command? Mv Fileo.txt Newdir Mv Filel.txt Newdir Mv File2.txt Newdir Mv File3.txt Newdir?
Write a commnad to create A New File:
What Is The Difference Between > And >> Operators?
How Can You See All Mounted Drives?
How Can You Find A Path To The File In The System?
What Linux Hotkeys Do You Know?
What Can You Tell About The Tar Command?
What Types Of Files You Know?
How you will zip a file or folder ?
How You Will Uncompress The File?
What Does The ‘Top’ Command Display?
How To Find Difference In Two Configuration Files On The Same Server?
What Is The Best Way To See The End Of A Logfile.log File?
Please Write A Loop For Removing All Files In The Current Directory That Contains A Word ‘log’?
How To Switch To A Previously Used Directory?
How Many Vi Editor Modes Do You Know?
How Can You Terminate Vi Session?
How Can You Copy Lines Into The Buffer In Command Mode?
We Saw The Mention On The Linux Bios Website About One Million Devices Shipped With Linux Bios. Could You Tell Us More About These Devices?
What’s Your Goal For Your Talk At Fosdem?
Can Rom Be Used As Stack?
What Is Stack?
What Is Flag?
Which Processor Structure Is Pipelined?
What Is A Compiler?
Differentiate Between Ram And Rom?
Which Transistor Is Used In Each Cell Of Eprom?
What Is Called .scratch Pad Of Computer.?
What Is Cache Memory?
What Is Interrupt?
Difference Between Static And Dynamic Ram?
What Is The Difference Between Primary & Secondary Storage Device?
What Command Would You Use To Create An Empty File Without Opening It To Edit It?
What Do You Type To Stop A Hung Process That Resists The Standard Attempts To Shut It Down?
Which Two Commands Can You Use To Delete Directories?
What Is Difference Between At And Cron?
Which Of The Following Tasks Cannot Be Accomplished With The Touch Command?
You Want To Copy The User’s Home Directories To A New Location. Which Of The Following Commands Will Accomplish This?
You Read An Article That Lists The Following Command: Dd If=/dev/fdo Bs=512 Of=/new What Does This Accomplish?
You Attempt To Delete A File Called Sales.mem Using The Rm Command But The Command Fails. What Could Be The Problem?
You Want To Search For Sale And Sales. What Regular Expression Should You Use?
You Want To Know How Many Lines In The Kickoff File Contains ‘prize’. Which Of The Following Commands Will Produce The Desired Results?
You Want To Verify Which Lines In The File Kickoff Contain ‘bob’. Which Of The Following Commands Will Accomplish This?
You Have A File Called Docs.z But Do Not Know What It Is. What Is The Easiest Way To Look At The Contents Of The File?
After Copying A File To A Floppy Disk, What Should You Do Before Removing The Disk?
You Have Set Quotas For All Your Users But Half Of Your Users Are Using More Space Than They Have Been Allotted. Which Of The Following Could Be The Problem?
What Command Should You Use To Check The Number Of Files And Disk Space Used And Each User’s Defined Quotas?
You Have A Large Spreadsheet Located In The /data Directory That Five Different People Need To Be Able To Change. How Can You Enable Each User To Edit The Spreadsheet From Their Individual Home Directories?
You Have A File Called Sales Data And Create Symbolic Links To It In Bob’s Home Directory. Bob Calls You And Says That His Link No Longer Works. How Can You Fix The Link?
What Is Meant By Sticky Bit?
Your Default Umask Is 002. What Does This Mean?
Which Of The Following Commands Will Replace All Occurrences Of The Word Rate With The Word Speed In The File Racing?
You Have A Tab Delimited File Called Phonenos And Want To Change Each Tab To Four Spaces. What Command Can You Use To Accomplish This?
You Issue The Command Head * What Would The Resulting Output Be?
What Text Filter Can You Use To Display A Binary File In Octal Numbers?
You Wish To Print The File Vacations With 60 Lines To A Page. Which Of The Following Commands Will Accomplish This?
What Would Be The Result Of Issuing The Command Cat Phonenos?
You Need To See The Last Fifteen Lines Of The Files Dog, Cat And Horse. What Command Should You Use?
What Is The Real Mean Of Dhcp?
What Is Nfs? What Is Its Job?
In Linux Os, What Is The File Server?
What Are The Techniques That You Use To Handle The Collisions In Hash Tables?
What Is The Major Advantage Of A Hash Table?
What Is Write Command?
Why You Shouldn’t Use The Root Login?
How Big Should The Swap-space Partition Be?
Which Field Is Used To Define The User’s Default Shell?
When You Create A New Partition, You Need To Designate Its Size By Defining The Starting And Ending?
What Can You Type At A Command Line To Determine Which Shell You Are Using?
In Order To Display The Last Five Commands You Have Entered Using The Fc Command, You Would Type?
What Command Should You Use To Check Your File System?
What File Defines The Levels Of Messages Written To System Log Files?
What Account Is Created When You Install Linux?
What Daemon Is Responsible For Tracking Events On Your System?
Where Standard Output Is Usually Directed?
What Utility Can You Use To Show A Dynamic Listing Of Running Processes?
Who Owns The Data Dictionary?
What Command Can You Use To Review Boot Messages?
What Is The Minimum Number Of Partitions You Need To Install Linux?
What Is The Name And Path Of The Main System Log?
What Utility Can You Use To Automate Rotation Of Logs?
What Key Combination Can You Press To Suspend A Running Job And Place It In The Background?
What Command Is Used To Remove The Password Assigned To A Group?
In Order To Improve Your System’s Security You Decide To Implement Shadow Passwords. What Command Should You Use?
What Command Should You Use To Check The Number Of Files And Disk Space Used And Each User’s Defined Quotas?
You Have A File Called Phonenos That Is Almost 4,000 Lines Long. What Text Filter Can You Use To Split It Into Four Pieces Each 1,000 Lines Long?
You Want To Create A Compressed Backup Of The Users’ Home Directories. What Utility Should You Use?
You Wish To Restore The File Memo.ben Which Was Backed Up In The Tarfile Mybackup.tar. What Command Should You Type?
Where Is Standard Output Usually Directed?
How to install lamp in linux ?
How to install Mysql in linux ?
How to install python in linux ?
What Are Mysql Transactions?
Explain Multi-version Concurrency Control In Mysql?
Explain Mysql Locks.
How to create a web server in linux ?
How to install and setup apache in linux ?
How to install and setup nginx in linux ?
How to install ssl certificate in linux ?
What is use of cat command in linux ?
How can you create a new user in linux ?
How can you give permissions for a new user in linux ?
Is refresh works in linux ?
What is TCP HandShake ?
What is an A record, an NS record, a PTR record, a CNAME record, an MX record?
What does uname command do?
What does Sar provide? Where are Sar logs stored?
What is an inode?
What is Samba? Why is it used?
What are the Linux boot files?
What is the difference between soft and hard mounting points?
What is The SSL Handshake?
What is the difference between Telnet and SSH?
What is SSH port forwarding?
What does whoami do?
What is SSH ? How can you connect to a remote server using SSH ?
How to send emails by using linux ?