103.1 Command Line (Shells, Sourcing, Special Characters)

Question 1

bash

default linux shell used to interpret the commands and scripts on system

Answer 1

bash

Question 2

other shells
ash
c-shell
ksh
zsh

Answer 2

other

Question 3

special shells

caution this will NOT exist if you add it and you won’t be able to login

Answer 3

/bin/false/etc/nologin

Question 4

script execution

reads contents of the file indicated and if proper permission set the commands within it are executed one by one as if typed on a command line but in a new shell

Answer 4

Bash

Question 5

script execution

this will happen to variables set within the execution space during the script once the script is complete and exits back to the command prompt

Answer 5

go out of scope

Question 6

script sourcing

Bash reads the contents of the file indicated and, if the proper permissions are set, the
commands within it are executed one by one (like they were typed on the command line)

Answer 6

CURRENT shell’s env

Question 7

script sourcing

allows anything set with that shell to remain set

Answer 7

once completed

Question 8

/etc/profile

system wide config script that will affect each user’s env provided they use the bash shell

Answer 8

/etc/profile

sourced script and executed each time a user logs in through the login shell

Question 9

/etc/bashrc

system wide config script that affects each users env as long as they use the bash shell

Answer 9

/etc/bashrc

source script and executed each time a user logs in through a login shell or executes a non-login session

Question 10

~/.bash_profile

sourced script executed when a user logs in through a login shell but ONLY affects the user logging in

Answer 10

~/.profile

~/.bash_login

Question 11

~/.bashrc

sourced script usually called by !/.bash_profile script
sources the /etc/bashrc if it exists
used to customize shell prompt, kb shortcuts command line aliases

Answer 11

~/.bashrc

Question 12

~/.bash_logout

sourced script on that is executed when the following commands executed

Answer 12

logout

exit

Question 13

session order step 1

user

Answer 13

login

Question 14

session order step 2

/etc/profile

Answer 14

sourced

Question 15

session order step 3

user ~./bash_profile

Answer 15

sourced

Question 16

session order step 4

user ~/.bashrc sourced from

Answer 16

~/.bash_profile

Question 17

session order step 5

user performs tasks

Answer 17

as needed

Question 18

session order step 6

user logs out with

Answer 18

logout
or
exit

Question 19

session order step 7

user ~/.bash_logout

Answer 19

sourced

Question 20

non login session

when root or other user uses SU command to become another user or root user then by default does not load

Answer 20

full env

Question 21

command complation

typing any command in the system path or any valid path partially and pressing this key will attempt to autocomplete the the remainder of the command or path

Answer 21

<TAB>
</TAB>

Question 22

command exit code

every command succeeds or fails and provides an exit code that you can see

echo $

Answer 22

0 == success

1 or > == failure