Interview Questions and Answers in Linux: Part-2

vivek bangare

Vivek Bangare


Interview Questions and Answers in Linux: Part-2

Hello everyone, This is the second part of the interview questions and answers in Linux. Along with that will go through some examples also. I will create a series of questions and answers for beginners to advanced levels.

Difference between Linux and Unix
  • It's an open source.
  • Free downloads and distribution/cheaper options.
  • Lightweight with no need for high-end hardware.
  • Users: Home users, developers etc.
  • Ubuntu, Debian, Red-Hat, Solaris.
  • installed on mobile phones, desktops, tablets video games consoles etc.
  • No source code for the general public.
  • Not free, different prices for different variants.
  • Need specific hardware, is comparatively costly.
  • Mainly developed for mainframe servers and workstations except for OsX.
  • AIX, HP-UX, BSD, Iris.
  • Used internet servers, mainframes and high-end computers.
Components of linux

Kernel - Core part

System Library - Special functions using which application programs access Kernel features.

System Utility - Responsible for performing individuals and specialized functions.

Why Linux is more secured than other OS?
  • Users don't have root access.
  • The virus can attack local files and folders only.
  • All Linux accesses are recorded in log files.
  • iptables to manage incoming and outgoing traffic.
grep command
  • grep (Global Regular Expression Print)
  • it is a search command; that uses pattern-based searches.
  • Uses options and parameters specified along with the command line.

Ex: cat /etc/users/user.txt | grep -i 'basictechno'

the above command will print a line which contains only 'basictechno' as a string.

root account (default account)

It's a live system admin's account.

Allows you to create and maintain user accounts and assign permissions.

root directory

The parent directory is represented by "/".

Contains all other directories and files.

Why should you avoid Telnet to administrator a system remotely?

The method of communication is insecure and The data is sent across the network without encryptions, in plain text format.

Types of files ownerships and changing them.

User - Owner/Creator of the file.

Group - All users in the group have the same permission.

Other - user with access to the file but not a part of that group.

Command: "chown"

Syntax: chown <newowner> <filename>

types of permissions for a file

  • Read (r) - open and read
  • Write (w) - modified content, renaming
  • Execute (x) - executing file
swap space and its advantage

Memory space comes into play when RAM doesn't have adequate memory to hold all executing programs.

Inactive memory pages are moved to swap space.

Soft and Hard mounting points.

Soft mount case - if the NFS client fails to receive a response from NFS servers, it reports an error without waiting.

Hard mount case - NFS client repeatedly tries to contact the server until a response is received.