103.1 Work on the command line

Question 1

How do you navigate to a specific man page section?

Answer 1

#man 4 find
(4 being the section and find the command)

Question 2

What is the command that displays a list of all topics in the man pages that are related to the subject of a query?

Answer 2

apropos

Question 3

What does section 1 of the man pages contain?

Answer 3

It contains common user’s commands.

Question 4

What is the syntax to access the manual pages of a command?

Answer 4

man

Question 5

Which is the environmental variable that dictates how many lines the .bash_history will contain?

Answer 5

$HISTFILESIZE

Question 6

What is the file that contains the previously run commands in the shell?

Answer 6

.bash_history located in the user’s home directory

Question 7

How do you execute a command in the output of #history?

Answer 7

Either my pressing the up/down arrow keys or by entering an exclamation mark and the command number.

Question 8

What command helps in identifying the location of any particular command?

Answer 8

whereis

Question 9

What are weak and strong quotes?

Answer 9

weak: double quotes
strong: single quotes

Question 10

What command is used to determine if something is a function, a file, an alias, a built-in or a keyword?

Answer 10

type

Question 11

What command locates an application file that is located within the user’s PATH?

Answer 11

which

Question 12

What command starts a new shell from the current shell?

Answer 12

bash

Question 13

What is the command that displays the shell options?

Answer 13

shopt

Question 14

What command is used to remove a variable or a custom bash function?

Answer 14

unset -f

Question 15

How do you turn off bash shell debugging?

Answer 15

set +x

Question 16

How do you turn on debugging for the bash shell?

Answer 16

set -x

Question 17

What command displays environment variables?

Answer 17

env

Question 18

Give examples of different shells.

Answer 18

Bash > bourne again shell
csh > C programming style syntax
ksh > Korn shell, based on shell with csh features
zsh > includes features of bash and ksh

Question 19

What is the default shell?

Answer 19

bash (bourne again shell)

Question 20

What command displays in order all the recent commands we have run?

Answer 20

history

Question 21

What is the command that can be used to print the value of a variable to the screen?

Answer 21

echo $VARIABLENAME

Question 22

What is the Linux shell?

Answer 22

It is the CLI, the text based command line environment.

Question 23

What does the #export command do?

Answer 23

It exports a variable to the current shell and any new shells started from the current shell.

Question 24

What man page syntax do you use to search the man pages for a specified command?

Answer 24

man -k