Intro to Linux

Question 1

What argument for the -type option of the find command is used to search for directories?

Answer 1

d (as in “find -type d”)

Question 2

What command will display all files in all directories and subdirectories from the user’s home directory?

Answer 2

find ~

Question 3

Which of the following arguments for the -type option of the find command is used to search for symbolic links?

Answer 3

l (as in “find -type l”)

Question 4

What is the “wc” command?

Answer 4

Meaning “word count”, the “wc” command is used to count the number of lines, words, and bytes (or characters) in a file or input. By itself it shows the number of lines, words, and bytes (or characters) in the file(s), in that order. “wc filename.txt”

Question 5

What is the “find” command?

Answer 5

The “find” command searches for files and directories in a specific location

Question 6

Which one is NOT a valid -type option for the find command? [a, b, c, d]

Answer 6

‘a’ is not valid

Question 7

Which of the followings are logical operators of the find command? [-not, -and, -xor, -true, -or]

Answer 7

-not, -and, -or

Question 8

What is the difference between the “locate” and the “find” commands?

Answer 8

“locate” searches for the files using a pre-built database, while the “find” command searches the filesystem in real time for the desired file/directory.

Question 9

What command will remove the files you scare up with the “find” command?

Answer 9

“-remove”

Question 10

What argument for the -type option of the find command is used to search for files?

Answer 10

f (as in “-type f”

Question 11

How do you use the output of one command as the input of a second?

Answer 11

”|”, also known as “pipe”.

Question 12

What command can you use to update the locate database?

Answer 12

updatedb (“sudo updatedb”)

Question 13

What command is used to update the timestamps of files?

Answer 13

“touch”. It can also make files

Question 14

What option of the find command do you use to add another option?

Answer 14

“-and” (“find -option -and -option”)

Question 15

What option of the find command do you use to negate something, or in other words, find its’ opposite?

Answer 15

“-not” (“find -not -option”)

Question 16

What three numbers do you add up to set permissions in Linux, and what do they mean?

Answer 16

4 (read), 2 (write), 1(execute)

Question 17

What three entities do you set permissions for?

Answer 17

The owner, the group, and “other”.

Question 18

What four characters do you use to set permissions, and what do they mean?

Answer 18

r (read), w (write), x (execute), and -(null/nothing). Example: rwx, r-x, r–

Question 19

What command allows you to find files by name by looking up a database?

Answer 19

“locate”

Question 20

What command allows the user to search for files in a directory hierarchy with versatile options?

Answer 20

“find”

Question 21

Which are the symbolic notations for the chmod command?

Answer 21

u, g, o, a

Question 22

What number base do computers use?

Answer 22

Base 2.

Question 23

What are the entities in the Linux (or Unix) security model?

Answer 23

user, group, and world(others)

Question 24

What command can you use to display the user’s identity?

Answer 24

id

Question 25

What commands let you login as the super user?

Answer 25

"su - root", "su -", "su -l root"

Question 26

Tell me five valid file types in Linux as an output of ls -l command

Answer 26

"-" (regular files), "d" (directories), "c" (character devices), "b" (block devices), and "l" (symbolic link)

Question 27

What command can you use to change the group ownership of a file?

Answer 27

"chgrp"

Question 28

How do you change a file’s owner?

Answer 28

"chown"

Question 29

What does the 'w' permission attribute do?

Answer 29

Allows the file to be written and edited

Question 30

What command changes a user’s password?

Answer 30

"passwd"

Question 31

What command can you use to execute a command as another user?

Answer 31

"sudo"

Question 32

Where is user account information stored?

Answer 32

/bin/user

Question 33

How do you change a file’s mode?

Answer 33

"chmod"

Question 34

How do you set default permissions on a file?

Answer 34

"umask"

Question 35

What does the 'r' permission attribute do?

Answer 35

Allows the file to be opened and read

Question 36

What does the "ping" command do?

Answer 36

Send an ICMP ECHO_REQUEST to network hosts

Question 37

What does the "traceroute" command do?

Answer 37

Print the route packets to trace to a network host

Question 38

What does "ip" do?

Answer 38

Show/manipulate routing, devices, policy routing and tunnels

Question 39

What does "netstat" do?

Answer 39

Print network connections, routing tables, interface statistics, masquerade connections, and multicast memberships

Question 40

What does "ftp" do?

Answer 40

It is an internet file transfer program

Question 41

What does "wget" do?

Answer 41

It is a non-interactive network downloader

Question 42

What does "lcd" do within the "ftp" program?

Answer 42

It changes the directory on the local system

Question 43

What does "bye" do within the "ftp" program?

Answer 43

log off the remote server and end the session

Question 44

What is a container?

Answer 44

It's a lightweight, isolated environment where you can run applications. Each container has everything that the application needs to run: code, tools, libraries, and settings.

Question 45

How is a container different from a virtual machine?

Answer 45

A virtual machine has its own OS, while the container uses the host system's OS; It borrows its kernel. This makes containers less isolated, but more light-weight and memory efficient.

Question 46

What login name should you be given when accessing a public FTP server?

Answer 46

"anonymous". If it wants a password, its usually your email address.

Question 47

Which commands can you use to display routing information?

Answer 47

"ip route show" and "ip r"

Question 48

Which command can you use to test the connectivity to the remote host?

Answer 48

"ping "

Question 49

What does the scp command do?

Answer 49

Copies files across a network securely (Secure copy)

Question 50

Using SSH how would you connect to a remote host named remote-sys?

Answer 50

"ssh remote sys"

Question 51

What option allows you to encrypt an dssh connection?

Answer 51

The -c option in SSH specifies the encryption cipher to use for the connection

Question 52

What is a unique feature of "sftp"?

Answer 52

Only the SSH server is needed on the server side

Question 53

What is "sftp"?

Answer 53

SFTP (Secure File Transfer Protocol) is a way to transfer files between computers over the internet, using SSH to encrypt the data.

Question 54

What is "ssh"?

Answer 54

SSH (Secure Shell) is a protocol used to securely connect to a remote computer over a network. It allows you to log into another computer, execute commands, and transfer files safely, even over unsecured networks.

Question 55

Which information is displayed when ping operation succeeds?

Answer 55

Delay (or how long it took for the packets to get there), packet size, and the destination host's name (could be ip or hostname)

Question 56

What does "ssh" stand for?

Answer 56

Secure Shell

Question 57

What does "get fileName" do within the ftp program?

Answer 57

In an FTP program, "get fileName" is a command used to download a file from the remote FTP server to the local system.

Question 58

What commands can you use to display the assigned IP address information?

Answer 58

"ip address show" and "ip a"

Question 59

How do you make a script?

Answer 59

Create a file - you can use a text editor like vim or nano to do this when you open the editor - specify an interpreter, write your commands and save, and give your file execute permissions

Question 60

How do you exit insert mode in vim?

Answer 60

use ESC key

Question 61

How do you save and quit in vim?

Answer 61

:wq

Question 62

How do you run your script1.sh using the source method?

Answer 62

". " or "source "

Question 63

Run your script1.sh in a child bash shell?

Answer 63

"./"

Question 64

How do you run a script if the script isn’t executable, or you don't want to make it executable?

Answer 64

"bash "

Question 65

How do you run your script1.sh as an executable file?

Answer 65

"path/to/scriptname"

Question 66

How do you define a variable?

Answer 66

"var_name=var"

Question 67

What is a stub function?

Answer 67

Its like any other function in programming - a box you can put commands into, to tidy things up. "functionName(){ }"