Chapter 2

Question 1

What’s the standard Linux shell?

Answer 1

Ha! It’s both a command line interpreter and a programming language

Question 2

How do we check the exit status? (print it to the command line)

Answer 2

echo $?

Question 3

How do we search for a term within a man page?

Answer 3

/ (forward slash) term (e.g. /nana) and then ‘n’ for next entry ahead ‘N’ for next entry behind

Question 4

How to search for a specific keyword?

Answer 4

man -k wordToSearch

Question 5

What are info pages and how are they different from man pages? How do you get around there?

Answer 5

They are additional documentation with more robust capability and detail than man. You can enter into page, hit next and previous with ‘n’ and ‘p’ keys

Question 6

How to count the number of lines in a file?

Answer 6

wc -l file.txt

Question 7

How to count the total number of characters in a file?

Answer 7

wc -m file.txt

Question 8

How to count the number of characters on the longest line in a file?

Answer 8

wc -L file.txt

Question 9

How to append some stuff to an existing file?

Answer 9

use&raquo_space; file.txt (rather than ‘>’)

Question 10

How do we view all files that start with a dot?

Answer 10

ls -a

Question 11

How do we view all files?

Answer 11

ls -all

Question 12

How do we view a more detailed listing of files, including their sizw?

Answer 12

ls -lh

Question 13

How do we handle variables in shell?

Answer 13

We do not have to store them anywhere - just declare them in a window, like so:
test_var=”this is a var”
To show it, do
echo $test_var

Question 14

How do we display a home directory?

Answer 14

$HOME

Question 15

Which variable shows the user’s home directory?

Answer 15

$HOME

Question 16

Which variable is the primary prompt string?

Answer 16

$PS1

Question 17

Which variable is a colon-separated list of directories where the shell looks for commands?

Answer 17

$PATH

Question 18

How can we store the contents of a “list files” command in a variable?

Answer 18

var1=$(ls)

Question 19

How are bash single quotes different from double quotes?

Answer 19

Single quotes ‘ preserve the literal value of every character contained within the quotes, including the escape character
Double quotes ‘’ preserve the literal value of most characters contained within the quotes, exceptions include $ for variables, ‘ for single quoting, and \ for escaping a character

Question 20

What is an escape character, what does it do?

Answer 20

A non-quoted backslash \ is the bash escape character; it preserves the literal value of the next following character, with the single exception of newline

Question 21

How do we change the current directory to the user’s home directory?

Answer 21

cd ~

Question 22

How do we print the current directory?

Answer 22

pwd

Question 23

Show the list of users currently logged in to the system

Answer 23

w

Question 24

How to append something to the path variable? or any other variable, same difference

Answer 24

PATH=”$PATH:$HOME/scripts

Question 25

What does the source command do in Bash?

Answer 25

The source command reads and executes commands from the file specified as its argument in the current shell environment

Question 26

What's stored in the /boot directory?

Answer 26

Standard boot files

Question 27

What's stored in the /dev directory?

Answer 27

Device files

Question 28

What's stored in the /etc directory?

Answer 28

Configuration files

Question 29

What's stored in the /mnt directory?

Answer 29

Temporary mount points

Question 30

What's stored in the /opt directory?

Answer 30

Optional packages

Question 31

What's stored in the /proc directory?

Answer 31

Kernel and process files

Question 32

What's stored in the /root directory?

Answer 32

Root user home directory

Question 33

What's stored in the /run directory?

Answer 33

Application state files

Question 34

What's stored in the /sbin directory?

Answer 34

System administrator binaries

Question 35

What's stored in the /srv directory?

Answer 35

Service data

Question 36

What's stored in the /usr directory?

Answer 36

User ginaries

Question 37

What's stored in the /var directory?

Answer 37

Variable data files

Question 38

What's stored in the / directory?

Answer 38

Root directory

Question 39

how do we go to the previous directory location?

Answer 39

cd -

Question 40

Which ls flag sorts files by the last time the file was modified, newest first?

Answer 40

-t

Question 41

How do we view all files except . and .. ones?

Answer 41

ls -A

Question 42

how do we view more info about the files using ls?

Answer 42

-l

Question 43

How do we sort by file size in ls?

Answer 43

-s

Question 44

How do we know last time a file was accessed?q

Answer 44

-u

Question 45

How do we know last time a file was modified using ls?

Answer 45

-l

Question 46

How do we differentiate between absolute and relative paths?

Answer 46

absolute start with a "/" - slash! and relative ones start with a word.. :)

Question 47

What does a recursive specifier do in copying folders and directories? also, what does a recursive specifier look like?

Answer 47

it's an -R flag of the cp command

Question 48

What's the tag and commands for forced recursive removal?

Answer 48

rm -rf directoryname

Question 49

How do we remove any file or folder that starts with a number

Answer 49

rm -rf [1-9]*

Question 50

How do we remove any file or folder that END with .conf?

Answer 50

rm -rf *.conf

Question 51

What's the difference between ls -a and ls -A?

Answer 51

capital A shows almost everything (everything except the two dots), lower case shows everything everything!

Question 52

How to view all the environment variables?

Answer 52

env

Question 53

What is globbing?

Answer 53

Globbing is using partial matching to work with groups of files and directories. Matching patterns in fileframes or text by using a wildcard char to create a pattern

Question 54

How do we look for a filename with four characters and a "1" at the end?

Answer 54

???1

Question 55

What does a question mark do in globbing?

Answer 55

It matches any *single* character

Question 56

What does an asterisk do in globbing?

Answer 56

Finds 0 to many matching characters. I.e. file* will match file, file1, file_kseirjnsfjkevn

Question 57

What do brackets [] do?

Answer 57

They match character(s) from a range

Question 58

How do we match uppercase characters with brackets? lowercase? digits?

Answer 58

[A-Z] [a-z] [1-9]

Question 59

How do we customize which digits we want to match using brackets?

Answer 59

[2-5]

Question 60

How do we say we want a character - of either case with brackets?

Answer 60

[a-zA-Z]

Question 61

How do we say we want to match any alphanumeric character with brackets?

Answer 61

[a-zA-Z0-9]

Question 62

How do we use caret in globbing?

Answer 62

We use it to match starting characters

Question 63

How do we use dollar in globbing?

Answer 63

To match ending character

Question 64

How do we use curly brace in globbing?

Answer 64

We match more than one pattern