Ch.9 Permissions

Question 1

What does ssh stand for, and what does it allow?

Answer 1

Secure Shell. Remote users can log in via ssh and operate the computer if it is attached to a network or the internet.

Question 2

What does command id do

Answer 2

display user identity

Question 3

what does command chmod do

Answer 3

change a file’s mode

Question 4

what does command umask do

Answer 4

set the default file permissions

Question 5

what does command su do

Answer 5

run a shall as another user

Question 6

what does command sodu do

Answer 6

execute a command as another user

Question 7

what does command chown do

Answer 7

change a file’s owner

Question 8

what does command chgrp do

Answer 8

Change a file’s group ownership

Question 9

what does command passwd do

Answer 9

change a user’s password

Question 10

How are access rights to files and directories defined?

Answer 10

1. read access 2. write access 3. execute access

Question 11

using ls, what are the first 10 characters of the listing?

Answer 11

File attributes

Question 12

What is the attribute for a regular file

Answer 12

-

Question 13

What is the attribute for a directroy

Answer 13

d

Question 14

what is the attribute for a symbolic link

Answer 14

1

Question 15

what are the attribute for a character special file?

Answer 15

c

Question 16

what is the attribute for a block special file

Answer 16

b

Question 17

What does attribute r allow

Answer 17

Allows a file to be opened and read. Allows a directory’s contents to be listed if the execute attribute is also set.

Question 18

What does attribute w allow?

Answer 18

Allows a file to be written to or
truncated, however this attribute
does not allow files to be
renamed or deleted. The ability
to delete or rename files is
determined by directory
attributes.

Question 19

What does attribute x allow?

Answer 19

Allows a file to be treated as a
program and executed. Program
files written in scripting
languages must also be set as
readable to be executed.

Question 20

-rwx——

Answer 20

A regular file that is readable, writable, and executable by the
file’s owner. No one else has any access.

Question 21

-rw——-

Answer 21

A regular file that is readable and writable by the file’s owner.
No one else has any access.

Question 22

-rw-r–r–

Answer 22

A regular file that is readable and writable by the file’s owner.
Members of the file’s owner group may read the file. The file is
world-readable

Question 23

-rwxr-xr-x

Answer 23

A regular file that is readable, writable, and executable by the
file’s owner. The file may be read and executed by everybody
else.

Question 24

-rw-rw—-

Answer 24

A regular file that is readable and writable by the file’s owner
and members of the file’s group owner only.

Question 25

lrwxrwxrwx

Answer 25

A symbolic link. All symbolic links have “dummy” permissions. The real permissions are kept with the actual file pointed to by the symbolic link.

Question 26

drwxrwx---

Answer 26

A directory. The owner and the members of the owner group may enter the directory and create, rename and remove files within the directory.

Question 27

drwxr-x---

Answer 27

- A directory. The owner may enter the directory and create, rename, and delete files within the directory. Members of the owner group may enter the directory but cannot create, delete, or rename files.

Question 28

Who are the only entites that can change the mode of a file or directory?

Answer 28

file's owner or superuser

Question 29

What is octal number representation?

Answer 29

Base 8

Question 30

What is hexadecimal number representation?

Answer 30

base 16

Question 31

What does binary counting look like?

Answer 31

0, 1, 10, 11, 100, 101, 110, 111, 1000, 1001, 1010, 1011...

Question 32

What does octal counting look like?

Answer 32

0, 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 20, 21...

Question 33

What does hexadecimal counting look like?

Answer 33

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F, 10, 11, 12, 13...

Question 34

What is the 0 octal binary?

Answer 34

000

Question 35

what is the 1 octal binary

Answer 35

001

Question 36

What is the 2 octal binary

Answer 36

010

Question 37

what is the 3 octal binary?

Answer 37

011

Question 38

what is the 4 octal binary

Answer 38

100

Question 39

what is the 5 octal binary

Answer 39

101

Question 40

what is the 6 octal binary

Answer 40

110

Question 41

what is the 7 octal binary

Answer 41

111

Question 42

what file mode is binary 000

Answer 42

---

Question 43

what file mode is binary 001

Answer 43

--x

Question 44

what file mode is binary 010

Answer 44

-w-

Question 45

what file mode is binary 011

Answer 45

-wx

Question 46

what file mode is binary 100

Answer 46

r--

Question 47

what file mode is binary 101

Answer 47

r-x

Question 48

what file mode is binary 110

Answer 48

rw-

Question 49

what file mode is binary 111

Answer 49

rwx

Question 50

what octal is file mode ---

Answer 50

0

Question 51

what octal is file mode --x

Answer 51

1

Question 52

what octal is file mode --w-

Answer 52

2

Question 53

what octal is file mode -wx

Answer 53

3

Question 54

what octal is file mode r--

Answer 54

4

Question 55

what octal is file mode r-x

Answer 55

5

Question 56

what octal is file mode rw-

Answer 56

6

Question 57

what octal is file mode rwx

Answer 57

7

Question 58

What are the 5 most commonly used three octal digit arguments?

Answer 58

7 (rwx) 6 (rw-) 5 (r-x) 4 (r--) and 0(---)

Question 59

Chmod symbolic notation short for user

Answer 59

u

Question 60

chmod symbolic notation for group owner

Answer 60

g

Question 61

chmod symbolic notation short for world

Answer 61

o

Question 62

chmod symbolic notation short for all

Answer 62

a

Question 63

what is assumed if no character is specified for chmod?

Answer 63

All

Question 64

Add execute permission for the owner.

Answer 64

chmod u+x

Question 65

Remove execture permission from the owner

Answer 65

chmod u-x

Question 66

Add execute permission for the owner, group, and world. This is equivalent to a+x.

Answer 66

+x

Question 67

Remove the read and write permissions from anyone besides the owner and group owner.

Answer 67

o-rw

Question 68

Set the group owner and anyone besides the owner to have read and write permission. If either the group owner or the world previously had execute permission, it is removed.

Answer 68

go=rw

Question 69

Add execute permission for the owner and set the permissions for the group and others to read and execute. Multiple specifications may be separated by commas.

Answer 69

u+x,go=rx

Question 70

How do you use su to execute a singel command rather than starting a new interactive command?

Answer 70

su -c 'command'

Question 71

To see what privileges are granted by sudo

Answer 71

sudo -l

Question 72

The syntax of chown looks like | this:

Answer 72

chown [owner][:[group]] file...