ECM 1413 Linux commands

Question 1

ls

Answer 1

list files and directories

Question 2

ls options

Answer 2

-l: Long format listing

-a: Include hidden files

-h: Human-readable files

Question 3

cd

Answer 3

change directory

Question 4

pwd

Answer 4

Print current working directory

Question 5

mkdir

Answer 5

make new directory

Question 6

rm

Answer 6

Remove files and directories

Question 7

rm options

Answer 7

-r: Remove directories recursively
-f: Force removal without confirmation

Question 8

cp

Answer 8

copy files and directories

(-r to copy recursively)

Question 9

mv

Answer 9

move/rename files and directories

Question 10

touch

Answer 10

create an empty file or update file timestamps

Question 11

cat

Answer 11

view the contents of a file

Question 12

head

Answer 12

Display the first few lines of a file

-n to specify the number of lines to display

Question 13

tail

Answer 13

Display the last few lines of a file

-n to specify the number

Question 14

ln

Answer 14

create links between files

-s to create a soft link (hard by default)

Question 15

find

Answer 15

search for files and directories

-name to search by file name
-type to search by file type

Question 16

chmod

Answer 16

change file permissions

u: user/owner permissions

g: group permissions

o: other permissions

+: add permissions

-: remove permissions

=: set permissions explicitly

Question 17

chown

Answer 17

change file ownership

Question 18

chgrp

Answer 18

change group ownership

Question 19

unmask

Answer 19

set default file permissions

Question 20

tar

Answer 20

create or extract archive files

-c: create a new archive

-x: Extract files from an archive

-f: Specify the archive file name

-v: verbose mode

-z: compress the archive with gzip

-j: compress the archive with bzip2

Question 21

gzip

Answer 21

compress files

-d: Decompress files

Question 22

zip

Answer 22

Create compressed zip archives

-r: Recursively include directories

Question 23

ps

Answer 23

Display running processes

-aux: Show all processes

Question 24

top

Answer 24

Monitor system processes in real-time

Question 25

kill

Answer 25

Terminate a process

-9: Forcefully kill a process

Question 26

pkill

Answer 26

terminate processes based on name

Question 27

pgrep

Answer 27

List processes based on their name

Question 28

grep

Answer 28

used to search for specific patterns or regular expressions in text files or streams and display matching lines.

Question 29

*

Answer 29

wildcard equating to 0 or more characters

Question 30

?

Answer 30

wildcard equating to exactly 1 character

Question 31

[]

Answer 31

wildcard. Matches any one of the enclosed characters in the [].

Question 32

[a-z]

Answer 32

wildcard. Matches any one of the enclosed characters in the [] in a specified range.

Question 33

{}

Answer 33

wildcard equating to any of the comma-separated characters in the {}