Linux

Question 1

Configure IP address command on linux

Answer 1

sudo ip addr add 192.168.1.10/24 dev eth0

Question 2

Network configuration file path on Debian and Ubuntu

Answer 2

/etc/network/interfaces

Question 3

Network configuration file path on RHEL/CentOS

Answer 3

/etc/sysconfig/network-scripts/ifcfg-eth0

Question 4

Configure IP route on Linux

Answer 4

sudo ip route add 192.168.2.0/24 via 192.168.1.1 dev eth0

Question 5

DNS servers configuration file path on linux

Answer 5

/etc/resolv.conf

Question 6

Display first 20 lines of a file on Linux

Answer 6

head -n 20

Question 7

Display first 20 characters of a file on Linux

Answer 7

head -c 20

Question 8

Substitution command. Substitute ( and ) by [ and ]

Hey (my name) is (josh)

Answer 8

tr “(“ “[” | tr “)” “]”

Hey, [my name] is [josh]

Question 9

chmod 777

Answer 9

OGU
owner-group-user

7 = owner
7 = group
7 = user

Question 10

chmod permission values

r = ?
w = ?
x = ?

Answer 10

r = 4
w = 2
x = 1

Question 11

chmod with letters

Answer 11

+: adds permission
chmod o+rwx
chmod g+rwx
chmod u+rwx

-: removes permission
chmod o-x
chmod g-w
chmod u-w

=: sets permission overriding existing ones: (on below example read and write permissions won’t be granted, just execute permission)
chmod o=x
chmod g=x
chmod u=x

Question 12

basic components of Linux

Answer 12

• kernel
• system libraries
• system utilities
• programming tools

Question 13

Linux file system hierarchy

Answer 13

• /etc contains configuration files
• /dev contains device files
• /home contains user home directories
• /usr contains user utilities and applications
• /var contains variable data files

Question 14

Check Linux Memory Utilization

Answer 14

free -h

Question 15

What are Shells Used in Linux?

Answer 15

Shells in Linux are command-line interpreters that provide a user interface for access to an operating system’s services. They allow users to execute commands, run scripts, and manage files and processes.

Question 16

What is the Linux Kernel?

Answer 16

The Linux Kernel is the core of the Linux operating system. It interacts directly with the hardware and provides services for the rest of the system. It’s open-source, meaning its source code is freely available and can be modified and distributed.

Question 17

Check Linux System Information?

Answer 17

uname -a

Question 18

Run Multiple Commands in a Single Command?

Answer 18

use ; or &&

Question 19

Check Linux Disk Space Utilization

Answer 19

df -h

Question 20

Process States in Linux

Answer 20

• Running (R)
• Uninterruptible Sleep (D)
• Interruptable Sleep (S)
• Stopped (T)
• Zombie (Z)

Question 21

Soft Link (symbolic / symlink)

Answer 21

A Soft Link (also known as a symbolic link or symlink) is a file that points to another file or directory. If the original file is deleted or moved, the soft link will not work correctly.

Question 22

Hard Link

Answer 22

A Hard Link is a directory entry that associates a name with a file. Creating additional hard links for a file makes the contents of that file accessible via additional paths.

Question 23

How Long the Linux System Has Been Running

Answer 23

uptime

Question 24

Configure default route

Answer 24

sudo ip route add default via 192.168.1.1