Commands

Question 1

Print to Standard Output

Answer 1

echo

Question 2

Change Directory

Answer 2

cd

Question 3

Manual Page

Answer 3

man

Question 4

Print Working Directory

Answer 4

pwd

Question 5

List directory

Answer 5

ls (ls -a to list hidden files)

Question 6

Make Directory

Answer 6

mkdir (mkdir -p to create nested directories)

Question 7

Delete file

Answer 7

rm (rm -rf to force delete)

Question 8

Delete Directory

Answer 8

rmdir

Question 9

Copy

Answer 9

cp

cp -R (select a directory to copy)

Question 10

Move

Answer 10

mv

Question 11

Create a link

Answer 11

ln

Question 12

Print contents of file

Answer 12

cat

Question 13

Print contents of file with paging

Answer 13

less

Question 14

Evaluate an expression

Answer 14

expr

Question 15

Create a data disc

Answer 15

dd

Question 16

Check for a regular expression

Answer 16

grep

Question 17

Search for processed by regular expression

Answer 17

pgrep

pgrep -l to list PID and process name

Question 18

Use extended regular expressions

Answer 18

egrep

Question 19

Print the field at a particular index in a record

Answer 19

awk

Question 20

Edit each line of text

Answer 20

sed

Question 21

Determine type of file

Answer 21

file

Question 22

Find files matching a specific criteria

Answer 22

find

Question 23

Update Database of files

Answer 23

updatedb

Question 24

Search database for an entry

Answer 24

locate

Question 25

Extract the file name and remove extension

Answer 25

basename

Question 26

Extract a directory name

Answer 26

dirname

Question 27

Resolve the path for a file

Answer 27

realpath

Question 28

Extract first few lines of a file

Answer 28

head

Question 29

Extract the last few lines of a file

Answer 29

tail

Question 30

Reverse the input

Answer 30

rev

Question 31

Word count

Answer 31

wc

Question 32

Extract a charcter or word from input

Answer 32

cut

Question 33

Translate characters

Answer 33

tr

Question 34

Reads one record from input into the shell variable

Answer 34

read

Question 35

Print or set the system date

Answer 35

date

Question 36

Print the full path to the executable

Answer 36

type

Question 37

set shell variables

Answer 37

set

Question 38

Print os name

Answer 38

uname

Question 39

Print list of currently logged in users

Answer 39

w

Question 40

Compare two files to check if they are the same

Answer 40

cmp

Question 41

Compare to files to seee if they are different

Answer 41

diff

Question 42

List current running processes

Answer 42

ps

Question 43

Show system data and counters

Answer 43

top

Question 44

Kill a process

Answer 44

kill

Question 45

Pause activity in CPU

Answer 45

sleep

Question 46

Lists any unique (non-repetitive) records in input.

Answer 46

uniq

Question 47

Changes the permissions of to match .

Answer 47

chmod

Question 48

Changes the owner of to .

Answer 48

chown

Question 49

Create a file

Answer 49

touch

Question 50

Create an archive

Answer 50

tar

Question 51

Compress/Defalte an archive

Answer 51

gzip (gunzip to extract)

Question 52

Get url

Answer 52

wget

Question 53

Explain the difference between hard links and symbolic links

Answer 53

Hard links are simply another name for the original file

Symbolic links provide a pointer to the original file

Question 54

Test

Answer 54

Check if a condition is true or false

Question 55

Evaluate an expression

Answer 55

expr

Question 56

How do you examine the exit status of previous command

Answer 56

Echo the exit status of the previous command using a special shell variable:

$?

This is useful for confirming the result of the test command.

0 is true, 1 is false

Question 57

Word count

Answer 57

wc