File system

Question 1

Which command should we use to know current directory/ current location?

Answer 1

pwd

Question 2

Current directory/location can be referenced by…

Answer 2

. in commands

Question 3

Directory above the current directory can be referenced by…

Answer 3

.. in commands

Question 4

Absolute path

Answer 4

specifies the path of a file/ directory regardless of the current location

Question 5

Relative path

Answer 5

specifies the path of a file/ directory which is relative to the current location

Question 6

display the content of a directory

Answer 6

ls

Question 7

List All Files including hidden files
Hidden files start with a .
Commonly used for storing user preferences

Answer 7

ls -a

Question 8

List files in reverse order

Answer 8

ls -r

Question 9

List files in Recursive list

Answer 9

ls -R

Question 10

can be used to view a hierarchical structure of the file system

Answer 10

tree

Question 11

user’s home folder

Answer 11

~ (tilde character)

Question 12

navigate your way to other directories

Answer 12

cd

Question 13

create a directory/ multiple directories

Answer 13

mkdir

Question 14

create subdirectory and parent(s). Required if parent(s) do(es) not pre-exist

Answer 14

mkdir -p dir1/sub2/sub3

Question 15

remove empty directories

Answer 15

rmdir

Question 16

remove directories with or without content

Answer 16

rm -r

Question 17

create files

Answer 17

vi/ vim

touch: creates files, but also has another purpose which is to update time stamp if the file already exists

Question 18

Display the content of a file

Answer 18

cat

Question 19

Display a % of the file starting from the beginning

Answer 19

more

Question 20

Display a screenful of the file starting from the beginning

Answer 20

less

Question 21

Display the first 10 lines of a file

Answer 21

head

Question 22

Display the last 10 lines of a file

Answer 22

tail

Question 23

removes file

Answer 23

rm filename

Question 24

copy files

Answer 24

cp filename newfilename

Question 25

counts the number of line, words, and bytes in the files

Answer 25

wc filename

Question 26

move or rename

Answer 26

Rename: mv originalFilename newFilename

Move a file into directory:
mv filename directoryname

Move multiple files into a directory: mv file1 file2 file3 dir

Question 27

Provide information abut the content of a file

Answer 27

file filename

ASCII text, directory, empty, shell script text

Question 28

File - inode

Answer 28

ls -i
Inode holds information on files such as:
- user and group ownership
- file size
etc.

In UNIX, each file is uniquely identified by its name and by an index node number called inode.

Question 29

File - long format

Answer 29

ls -l

Question 30

Wildcards

Answer 30

• : Match zero or more characters

? : Match one character

[ ] : Match anything in the [ ] for 1 character position

[a-e] : The - is a range separator. This will match a to e.

[!0-9] : ! = negate. This will match anything except 0 to 9.

Question 31

Every file in UNIX has access permission

Answer 31

Read -r
Write -w
Execute -x

Question 32

Permissions are defined for three types of users.

Answer 32

User, Group, Other

Question 33

What does it mean?

drwxr-xr-x

Answer 33

d : file type
“d” means directory
“-“ means regular file

rwx : user permissions
r-x : group permissions

Question 34

How to change permission?

Answer 34

chmod 751 dir3

4: r - Read
2: w - Write
1: x - execute
0: No permissions