Linux Chapter 1

Question 1

$ vs # on bash

Answer 1

means root

Question 2

Command quiz : df

Answer 2

Current amount of free space on our disk drive

Question 3

Command quiz : free

Answer 3

Current amount of free memory

Question 4

Command quiz : pwd

Answer 4

Print Working Directory

Question 5

Do file extensions matter on Linux?

Answer 5

Nope. Contents and purpose of files are determined through other means.

Question 6

Command quiz: cd with no arguments

Answer 6

Changes the working directory to your home directory.

Question 7

Command quiz: cd ~user_name

Answer 7

Changes the working directory to the home directory of user_name. For example, typing cd ~bob will change the directory to the home directory of user “bob.

Question 8

List contents of multiple directories

Answer 8

ls ~ /etc

Question 9

Command quiz: ls -l

Answer 9

List files, but with more details (long)

Question 10

What is the general format of commands?

Answer 10

command -option arguments.
Multiple options can be strung together. There are “long options” as well, which are options preceded by two dashes instead of one. Some short options have a long option version. For example, “ls -a” is the same as ls “–all”.

Question 11

Command quiz: ls -dl

Answer 11

Ordinarily, if a directory is specified, ls will list the contents of the directory, not the directory itself. Use this option in conjunction with the -l option to see details about the directory rather than its contents.

Question 12

Command quiz: ls -F

Answer 12

This option will append an indicator character to the end of each listed name. For example, it will append a forward slash (/) if the name is a directory.

Question 13

Command quiz: ls -hl

Answer 13

In long format listings, display file sizes in human-readable format rather than in bytes.

Question 14

Command quiz: ls -S

Answer 14

Sort results by file size.

Question 15

Command quiz: ls -t

Answer 15

Sort by modification time.

Question 16

What is the meaning of each category in the long format?

-rw-r–r– 1 root root 3576296 2017-04-03 11:05 Experience ubuntu.ogg

Answer 16

-rw-r–r–
Access rights to the file. The first character indicates the type of file. Among the different types, a leading dash means a regular file, while a d indicates a directory. The next three characters are the access rights for the file’s owner, the next three are for members of the file’s group, and the final three are for everyone else. Chapter9 discusses the full meaning of this in more detail.

1
File’s number of hard links. See “Symbolic Links” on page 21 and “Hard Links” on page 22.

root
The username of the file’s owner.

root
The name of the group that owns the file.32059Size of the file in bytes.

2017-04-03 11:05
Date and time of the file’s last modification.

oo-cd-cover.odf
Name of the file.

Question 17

Command quiz: file hello.jpg

Answer 17

The file command will print a brief description of the file’s contents.