Interview Questions.

Question 1. What Are The Basic Components Of Linux?

Answer :

Linux is an working system primarily based on UNIX, and turned into first brought by Linus Torvalds. It is primarily based at the Linux Kernel, and might run on exclusive hardware systems manufactured via Intel, MIPS, HP, IBM, SPARC and Motorola. Another famous detail in Linux is its mascot, a penguin figure named Tux.

Question 2. What Is The Difference Between Unix And Linux?

Answer :

Unix at the beginning commenced as a propriety operating machine from Bell Laboratories, which afterward spawned into one-of-a-kind business variations. On the opposite hand, Linux is loose, open supply and supposed as a non-propriety running device for the masses.

Python Interview Questions
Question 3. What Is Bash?

Answer :

BASH is brief for Bourne Again SHell. It become written through Steve Bourne as a replacement to the original Bourne Shell (represented by /bin/sh). It combines all of the capabilities from the unique model of Bourne Shell, plus extra functions to make it less difficult and greater handy to apply. It has since been tailored as the default shell for maximum systems walking Linux.

Question four. What Is Linux Kernel?

Answer :

The Linux Kernel is a low-degree structures software program whose predominant position is to manipulate hardware assets for the consumer. It is also used to provide an interface for person-degree interplay.

Python Tutorial
Question 5. What Is Lilo?

Answer :

LILO is a boot loader for Linux. It is used specially to load the Linux operating gadget into predominant memory so that it is able to start its operations.

Embedded Systems Interview Questions
Question 6. What Is A Swap Space?

Answer :

A change space is a positive quantity of area used by Linux to briefly preserve a few applications which are going for walks simultaneously. This happens while RAM does no longer have enough memory to hold all applications that are executing.

Question 7. What Is The Advantage Of Open Source?

Answer :

Open supply permits you to distribute your software program, along with source codes freely to everyone who is interested. People might then be capable of upload features and even debug and correct errors that are in the supply code. They can even make it run higher, and then redistribute these superior supply code freely again. This ultimately blessings every person within the community.

Linux Tutorial Linux Interview Questions
Question eight. Does It Help For A Linux System To Have Multiple Desktop Environments Installed?

Answer :

In trendy, one desktop environment, like KDE or Gnome, is ideal sufficient to operate without issues. It’s all a depend of preference for the user, even though the device lets in switching from one surroundings to another. Some applications will paintings on one environment and now not work on the opposite, so it may also be considered a element in choosing which surroundings to use.

Question 9. What Is The Basic Difference Between Bash And Dos?

Answer :

The key variations among the BASH and DOS console lies in three regions:

BASH commands are case touchy while DOS instructions aren't.
Below BASH, / man or woman is a directory separator and acts as an escape person. Under DOS, / serves as a command argument delimiter and is the directory separator.
DOS follows a convention in naming files, that's 8 individual report name observed by a dot and three person for the extension. BASH follows no such convention.
Linux Embedded systems Interview Questions
Question 10. What Is The Importance Of The Gnu Project?

Answer :

This so-called Free software movement allows several benefits, which include the liberty to run applications for any motive and freedom to study and alter a program on your wishes. It additionally permits you to redistribute copies of a software program to other human beings, in addition to freedom to improve software program and feature it launched to the general public.

Linux Embedded systems Tutorial
Question 11. Describe The Root Account?

Answer :

The root account is like a systems administrator account, and allows you complete control of the system. Here you can create and hold person debts, assigning distinct permissions for every account. It is the default account each time you install Linux.

Software Engineering Interview Questions
Question 12. What Is Cli?

Answer :

CLI is short for Command Line Interface. This interface permits user to kind declarative commands to teach the pc to perform operations. CLI offers an advantage in that there is greater flexibility. However, other users who are already accustom with the use of GUI find it tough to take into account instructions inclusive of attributes that come with it.

Python Interview Questions
Question 13. How Do You Open A Command Prompt When Issuing A Command?

Answer :

To open the default shell (which is where the command activate can be discovered), press Ctrl-Alt-F1. This will offer a command line interface (CLI) from which you may run instructions as needed.

Software Engineering Tutorial
Question 14. How Can You Find Out How Much Memory Linux Is Using?

Answer :

From a command shell, use the “concatenate” command: cat /proc/meminfo for memory usage information. You have to see a line beginning some thing like: Mem: 64655360, and so on. This is the overall reminiscence Linux thinks it has to be had to use.

Question 15. What Is Typical Size For A Swap Partition Under A Linux System?

Answer :

The favored length for a change partition is twice the amount of physical reminiscence to be had on the device. If this isn't viable, then the minimal size should be similar to the quantity of reminiscence mounted.

Git (software) Interview Questions
Question sixteen. What Are Symbolic Links?

Answer :

Symbolic links act in addition to shortcuts in Windows. Such links point to applications, files or directories. It also allows you immediately get entry to to it without having to go directly to the whole pathname.

Git (software program) Tutorial
Question 17. Does The Ctrl+alt+del Key Combination Work On Linux?

Answer :

Yes, it does. Just like Windows, you can use this key mixture to perform a machine restart. One distinction is that you received’t be getting any affirmation message and therefore, reboot is instantaneous.

Linux File Systems Interview Questions
Question 18. How Do You Refer To The Parallel Port Where Devices Such As Printers Are Connected?

Answer :

Whereas under Windows you consult with the parallel port because the LPT port, under Linux you check with it as /dev/lp . LPT1, LPT2 and LPT3 would consequently be known as /dev/lp0, /dev/lp1, or /dev/lp2 below Linux.

Embedded Systems Interview Questions
Question 19. Are Drives Such As Hard Drive And Floppy Drives Represented With Drive Letters?

Answer :

No. In Linux, each drive and tool has different designations. For example, floppy drives are called /dev/fd0 and /dev/fd1. IDE/EIDE difficult drives are known as /dev/hda, /dev/hdb, /dev/hdc, and so on.

WxPython Tutorial
Question 20. How Do You Change Permissions Under Linux?

Answer :

Assuming you're the device administrator or the owner of a record or directory, you could supply permission using the chmod command. Use + symbol to add permission or – symbol to deny permission, along with any of the subsequent letters: u (user), g (organization), o (others), a (all), r (read), w (write) and x (execute). For instance the command chmod pass+rw FILE1.TXT grants study and write get entry to to the document FILE1.TXT, which is assigned to groups and others.

Logical Volume Manager (Linux) Interview Questions
Question 21. In Linux, What Names Are Assigned To The Different Serial Ports?

Answer :

Serial ports are recognized as /dev/ttyS0 to /dev/ttyS7. These are the equivalent names of COM1 to COM8 in Windows.

Question 22. How Do You Access Partitions Under Linux?

Answer :

Linux assigns numbers on the stop of the drive identifier. For example, if the first IDE hard power had three primary walls, they would be named/numbered, /dev/hda1, /dev/hda2 and /dev/hda3.

Unix/Linux Tutorial
Question 23. What Are Hard Links?

Answer :

Hard hyperlinks factor immediately to the physical report on disk, and no longer at the route name. This manner that if you rename or flow the authentic report, the link will now not wreck, since the hyperlink is for the document itself, no longer the path wherein the file is located.

WxPython Interview Questions
Question 24. What Is The Maximum Length For A File Name Under Linux?

Answer :

Any filename can have a maximum of 255 characters. This limit does not include the direction call, so consequently the complete pathname and filename should well exceed 255 characters.

Linux Interview Questions
Question 25. What Are File Names That Are Preceded By A Dot?

Answer :

In widespread, filenames which can be preceded with the aid of a dot are hidden documents. These files can be configuration files that keep essential statistics or setup info. Setting these files as hidden makes it less probable to be by accident deleted.

Question 26. What Is Unix?

Answer :

It is a portable running machine this is designed for each efficient multi-tasking and mult-user capabilities. Its portability allows it to run on one-of-a-kind hardware structures. It become written is C and shall we user do processing and manage below a shell.

Embedded C Interview Questions
Question 27. What Is The Use Of The Tee Command?

Answer :

The tee command does two things: one is to get records from the usual enter and ship it to conventional output; the second is that it redirects a replica of that enter records into a record that changed into specific.

Linux Embedded structures Interview Questions
Question 28. What Is The Standard Convention Being Followed When Naming Files In Unix?

Answer :

One critical rule while naming files is that characters which have special which means aren't allowed, along with * / & and %. A directory, being a unique type of report, follows the equal naming convention as that of documents. Letters and numbers are used, at the side of characters like underscore and dot characters.

Question 29. Is It Possible To See Information About A Process While It Is Being Executed?

Answer :

Every process is uniquely recognized by using a manner identifier. It is possible to view details and status concerning a process by the use of the ps command.

Unix/Linux Interview Questions
Question 30. How Do You Determine And Set The Path In Unix?

Answer :

Each time you input a command, a variable named PATH or direction will define wherein listing the shell will look for that command. In cases wherein an errors message turned into back, the motive perhaps that the command became not on your course, or that the command itself does now not exist. You can also manually set the path using the “set course = [directory path]” command.

Question 31. What Is A Superuser?

Answer :

A superuser is a special kind person who has open access to all files and instructions on a system. Note that the superuser’s login is usually root, and is included by way of a so-called root password.

Question 32. What Is Piping?

Answer :

Piping, represented by means of the pipe individual”, is used to mix  or extra instructions together. The output of the primary command serves as enter the subsequent command, and so forth.

Linux Device Drivers Interview Questions
Question 33. What Is The Use Of -l When Listing A Directory?

Answer :

-l, that is typically utilized in listing command like ls, is used to reveal documents in a protracted layout, one record consistent with line. Long layout refers to extra facts this is related to the file, inclusive of possession, permissions, data and filesize.

Software Engineering Interview Questions
Question 34. Differentiate Cmp Command From Diff Command?

Answer :

The cmp command is used specifically to evaluate two files byte via byte, after which the first encountered mismatch is shown. On the alternative hand, the diff command is used to signify the modifications this is to be made so that it will make the two documents same to each other.

Question 35. Enumerate Some Of The Most Commonly Used Network Commands In Unix?

Answer :

telnet – used for far off login
ping – an echo request for testing connectivity
su – user switching command
ftp – report switch protocol used for copying files
finger – information accumulating command
Question 36. What Is Bash Shell?

Answer :

It is a loose shell designed to paintings on the UNIX machine. Being the default shell for most UNIX-based totally structures, it combines functions which are available both inside the C and Korn Shell.

Git (software program) Interview Questions
Question 37. What Are The Differences Among A System Call, A Library Function, And A Unix Command?

Answer :

A gadget call is part of the programming for the kernel. A library characteristic is a software that is not a part of the kernel but that is to be had to customers of the gadget. UNIX commands, but, are stand-by myself applications; they may comprise each gadget calls and library capabilities in their programming.

Question 38. What Are Shell Variables?

Answer :

Shell variables are a mixture of a call ( identifier), and an assigned fee, which exist in the shell. These variables may additionally have default values, or whose values may be manually set the usage of the proper undertaking command. Examples of shell variable are PATH, TERM and HOME.

Question 39. Explain The Importance Of Directories In A Unix System?

Answer :

Files in a directory can clearly be a directory itself; it might be referred to as a subdirectory of the authentic. This capability makes it possible to expand a tree-like structure of directories and documents, which is essential in keeping an organizational scheme.

Question 40. Differentiate Relative Path From Absolute Path?

Answer :

Relative course refers to the route relative to the current path. Absolute path, then again, refers to the precise course as referenced from the foundation directory.

Linux File Systems Interview Questions
Question forty one. Describe File Systems In Unix?

Answer :

Understanding file structures in UNIX has to do with knowing how files and inodes are stored on a system. What takes place is that a disk or part of a disk is set aside to store files and the inode entries. The entire purposeful unit is referred to as a record gadget.

Question forty two. Briefly Describe The Shell’s Responsibilities?

Answer :

software execution
variable and document call substitution
I/O redirection
pipeline hookup
environment manage
interpreted programming language
Logical Volume Manager (Linux) Interview Questions
Question forty three. What Is Inode?

Answer :

An inode is an access created on a phase of the disk set aside for a record machine. The inode incorporates nearly all there's to recognize about a report, which includes the region at the disk wherein the document starts, the size of the document, when the document was closing used, while the file become ultimate modified, what the numerous examine, write and execute permissions are, who owns the record, and different statistics.

Question forty four. What Is A Directory?

Answer :

Every file is assigned to a listing. A directory is a specialised shape of document that keeps a listing of all documents in it.

Question 45. Differentiate Multiuser From Multitask?

Answer :

Multiuser manner that a couple of individual can use the laptop on the equal time. Multitask manner that even a single person will have the computer work on a couple of assignment or application at the same time.

Question 46. What Is Command Substitution?

Answer :

Command substitution is one of the steps being completed whenever instructions are processed by using the shell. Commands which might be enclosed in backquotes are executed by the shell. This will then update the standard output of the command and displayed on the command line.

Question 47. What Is Kernel?

Answer :

Kernel is the UNIX operating system. It is the grasp application that controls the laptop’s sources, shelling out them to different users and to special obligations. However, the kernel doesn’t deal immediately with a consumer. Instead, it begins up a separate, interactive application, called a shell, for each person while he/she logs on.

Question 48. What Is Shell?

Answer :

A shell acts as an interface among the person and the machine. As a command interpreter, the shell takes instructions and units them up for execution.

Question 49. What Is The Chief Difference Between The –v And –x Option S To Set?

Answer :

The –v alternative echoes each command earlier than arguments and variables had been substituted for; the –x choice echoes the commands after substitution has taken place.

Question 50. Is There A Way To Erase All Files In The Current Directory, Including All Its Sub-directories, Using Only One Command?

Answer :

Yes, that is feasible. Use “rm –r *” for this purpose. The rm command is for deleting documents. The –r choice will erase directories and subdirectories, consisting of documents inside. The asterisk represents all entries.

Question 51. Brief About Init Phases?

Answer :

There are eight run stage.

Init0: Shutting down the machine and bring lower back the machine to OBP Prompt (OK)
Init1: Single consumer mode for administrative
Init2: Multi consumer mode with out resource sharing
Init3: Multi consumer mode with useful resource sharing
Init4: Not in use
Init5: Shutdown and energy off the system
Init6: Reboot the device to default run level
Inits: Single person mode but user login are disabled
Question 52. What Is The Difference Between Init 1 And Init S?

Answer :

If you turn from multiuser mode to init s and switch it returned to multiuser mode.Then remote useres automatically reconnects to the device. Wherein as within the case of init 1. They should reconnect manually method they must relogin 

Question 53. Explain The Boot Process?

Answer :

Boot manner dived into 4 levels. 

POST : Power on self take a look at (POST), It will come across hardware, gadget host ID,serial No, structure type, memory and Ethernet address and it'll load the primary application known as bootblk. 
OBPROM : Open boot programmable Diagnosing all of the device hardware and reminiscence. Initializing the boot parameter. Creating tool bushes and load the boot block from (0-15 area), it's miles called as secondary boot -- programmable ufsboot. 
KERNEL INITIALIZATION : ufsboot load the kernel (widespread unix) kernel will load all the essential gadgets modules to mount the foundation partition to maintain the booting method .
INIT PHASES : It will began via executing of /and so forth/init program and begin different system studying the /and so forth/inittab files, because the listing in the /etc/inittab documents. 
Question fifty four. Describe About Fsck?

Answer :

FSCK Utility is for checking and repairing the files system inconsistencies, It has 5 phases 

Phase 1: Check Blocks and Sizes - assessments inodes for inconsistencies
Phase 2: Check Path-Names - exams listing inode consistencies
Phase three: Check Connectivity - assessments that every one directories are linked to the document system
Phase four: Check Reference Counts - compares link count statistics from Phases 2 & 3, correcting discrepancies
Phase five: Check Cylinder Groups - assessments loose blocks and the used inode maps for consistency
Phase 6: Salvage Cylinder Groups - update the tables to mirror any adjustments made in in advance passes

Question fifty five. What Is The Difference Between Dsk And Rdsk?

Answer :

dsk: Block degree devices, FS Which are formatted and installed that tool is known as block device.
Rdsk: Raw stage device or person stage device
Question fifty six. Explain About Port Of Telnet, Ssh, Ftp, Http, Nfs, Ntp?

Answer :

ftp port : 21 
ssh port : 22 
Telnet port : 23 
ntp port : 123
smtp port : 25
printer port : 515
Question 57. How To View Vtoc (extent Table Of Contents)?And How To Copy?

Answer :

Print the VTOC
# prtvtoc /dev/rdsk/c0t0d0s2

Copy the VTOC to otherfmthard -s - /dev/rdsk/c1t0d0s2

Question fifty eight. Type Of Filesystems ?

Answer :

Disk Based FS : ufs  (Unix FS), hsfs (High Sierra FS), pcfs (PC FS for DOS FAT32), 
udfs : Universal Disk Format FS  
Network FS      : nfs (Network FS) 
Memory based FS (Pseudo FS) :  tmpfs, swapfs, procfs, mntfs
Question fifty nine. Brief Filesystem Structure?

Answer :

VTOC present inside the first sector within the uncooked disk region.
VTOC - 512 sector
Boot Block - 1-15 region
Super Block - 16-31
First Cylinder Group - 32

Question 60. How To Reduce The Reserved Space Of The Disk?

Answer :

This will reduce the reserved space to 2%
# tunefs –m 2 /dev/rdsk/c1d0s0