105.1 Lesson 1

Question 1

Is a tty a login shell?

Answer 1

yes

Question 2

What is the command in the output of ps aux | grep bash for pts bash?

Answer 2

bash

Question 3

Which Bash specific file configures the user environment?

Answer 3

~/.bash_profile

Question 4

Which files can ~/.bash_profile source?

Answer 4

~/.bash_login and ~/.profile

Question 5

Which file will be executed if there is no ~/.bash_profile?

Answer 5

~/.bash_login

Question 6

Is ~/.profile Bash specific?

Answer 6

no

Question 7

When is ~/.profile sourced?

Answer 7

when neiter ~/.bash_profile nor ~/.bash_login exist.

Question 8

Which file does ~/.profile source?

Answer 8

~/.bashrc

Question 9

Which Bash specific file does clean-up operations when exiting the shell?

Answer 9

~/.bash_logout

Question 10

Which file is run first when starting a shell: /etc/profile or ~/.profile?

Answer 10

/etc/profile

Question 11

Where is an interactive Non-Login Bash configured globally?

Answer 11

/etc/bash.bashrc

Question 12

Where is an interactive Non-Login Bash configured locally?

Answer 12

~/.bashrc

Question 13

Which file does ~/.bashrc source?

Answer 13

~/.bash_aliases

Question 14

How can bash be invoked as an non-interactive shell?

Answer 14

bash script.sh

Question 15

Force a non-interactive bash shell to behave like a login shell!

Answer 15

bash -l script.sh

bash –login script.sh

Question 16

How do you test if /etc/profile and ~/.profile are executed when running a shell?

Answer 16

Add an echo statement

Question 17

Which files are loaded when a user logs into a machine via ssh?

Answer 17

/etc/profile

~/.profile

Question 18

Where do scripts look for a startup file?

Answer 18

in the environment variable BASH_ENV

Question 19

What does su do?

Answer 19

Execute commands with the privileges of another user account.

Question 20

What does su do when no user id is specified?

Answer 20

Uses the superuser account.

Question 21

Whats the difference between
su jane
su - jane

Answer 21

su - jane
starts a login shell. The login shell loads janes environment. The environment is not loaded when using
su jane

Question 22

List the synomys to

su -

Answer 22

su -l

su –login

Question 23

What does !$ expand to in a bash command?

Answer 23

the last argument of the previous command

Question 24

How do you source the file ~/.bashrc?

Answer 24

. ~/.bashrc

source ~/.bashrc

Question 25

What does the skel directory contain?

Answer 25

A template for the file system structure of user's home directories.

Question 26

Where is the variable SKEL defined?

Answer 26

/etc/adduser.conf

Question 27

Where are the configuration files for shells configured?

Answer 27

In the skel directory.

Question 28

What does echo$0 output in a login shell?

Answer 28

-bash or -su

Question 29

What does echo $0 output in a non-login shell?

Answer 29

bash or /bin/bash

Question 30

Use sudo to launch an interactive login shell as user2!

Answer 30

sudo su - user2 sudo su -l user2 sudo su --login user2

Question 31

Use su to launch an interactive login shell as root!

Answer 31

su - | su - root

Question 32

Run an interactive-non-login shell as root using su

Answer 32

su root | su

Question 33

When do you need to use sudo su?

Answer 33

When the root user is disabled for security reasons. E.G. Ubuntu

Question 34

Is /etc/profile read when an interactive login shell is started as root?

Answer 34

yes

Question 35

Is /etc/bash.bashrc read when an interactive login shell is started as root?

Answer 35

yes

Question 36

Is ~/.profile read when an interactive login shell is started as root?

Answer 36

no

Question 37

is ~/.bashrc read when an interactive login shell is started as root?

Answer 37

no

Question 38

is /etc/profile read when an interactive non-login shell is started as root?

Answer 38

no

Question 39

Is /etc/bash.bashrc read when an interactive non-login shell is started as root?

Answer 39

yes

Question 40

Is /etc/profile read when an interactive non-login shell is started as user2?

Answer 40

no

Question 41

Is /etc/bash.bashrc read when an interactive non-login shell is started as user2?

Answer 41

yes

Question 42

Is ~/.profile read when an interactive non-login shell is started as user2?

Answer 42

no

Question 43

Is ~/.bashrc read when an interactive non-login shell is started as user2?

Answer 43

yes

Question 44

What is a superuser?

Answer 44

A special user account used for system administration.

Question 45

What defines the superuser on Unix-like systems?

Answer 45

Her/His user identifier (UID) is zero.

Question 46

Where do you put code that should be executed every time user2 opens a terminal from an X Window session?

Answer 46

/home/user2/.bashrc

Question 47

Which type of shell is a terminal opened from an X Window session?

Answer 47

interactive non-login

Question 48

Where is the skel directory?

Answer 48

/etc/skel

Question 49

Why does a tty not source /etc/bash.bashrc or ~/.bashrc?

Answer 49

Because a login shell runs .bash_profile. bashrc can but must not be sourced from there

Question 50

Which command modifies a user account?

Answer 50

usermod

Question 51

Which command deletes a user?

Answer 51

deluser

Question 52

Which command adds a user?

Answer 52

adduser