Units 01-04 Assignments (RHEL9)

(3) Describe three reasons you should learn about Linux.

Linux is a critical technology for IT professionals to understand.

Linux is in widespread use, and if you use the internet at all, you are probably already interacting with Linux systems in your daily life.

Linux manages point-of-sale systems and the world's stock markets, and also powers smart TVs and in-flight entertainment systems.

(3) List three ways Linux is used today in modern datacenters.

In application development, Linux hosts the application or its runtime.

In cloud computing, the cloud instances in the private or public cloud environment use Linux

as the operating system.

With mobile applications or the Internet of Things (IoT), the chances are high that the operating system of your device uses Linux.

(5) Explain in detail what open source software is.

Open source software is software with source code that anyone can use, study, modify, and

share.

Some software has source code that only the person, team, or organization that created it can see, or change, or distribute.

Open source software is different. - When the copyright holder provides software under an

open source license, they grant the user the right to run the program and also to view, modify, compile, and redistribute the source royalty-free to others.

Open source promotes collaboration, sharing, transparency, and rapid innovation because it encourages people beyond the original developers to make modifications and improvements to the software and to share it with others.

Just because the software is open source does not mean it is somehow not able to be used or provided commercially.

(1) In Chapter 1 you learned about the Linux CLI. Why is the CLI important in Linux?

It enables easier automation, deployment, and provisioning.

(1) According to Chapter 1, who develops open source software?

Volunteers and the academic community.

(1) In detail describe what Red Hat is.

Red Hat is the world's leading provider of opensource software solutions, using a community-powered approach to reliable and high-performance cloud, Linux, middleware, storage, and virtualization technologies.

(1) What is a Linux distribution?

A Linux distribution is an installable operating system that is constructed from a Linux kernel and that supports user programs and libraries.

(1) Explain the multistage process that Red Hat uses to integrate open source software into RHEL?

Red Hat participates in supporting individual open source projects. It contributes code, developer time, resources, and support, and often collaborates with developers from other Linux distributions, to improve the general quality of software for everyone.

(1) What is Fedora?

Fedora is a community project that produces and releases a free, comprehensive Linux-based operating system.

(1) What is CentOS?

CentOS (Community Enterprise Operating System) was a free and open-source Linux distribution built from the source code of Red Hat Enterprise Linux (RHEL).

(1) What is Red Hat Enterprise Linux?

Red Hat Enterprise Linux is the open source, enterprise-ready, commercially supported Linux distribution that Red Hat provides.

(3) List three ways to "try out" Red Hat Enterprise Linux as detailed in Chapter 1.

RHEL Evaluation Download

Red Hat Developer Subscription

Public Cloud Platforms

(3) What is bash? What is sh? What is the difference between bash and sh?

Bourne-Again Shell

Bourne Shell

Bash is an improved version of one of the most successful shells used on UNIX-like systems, the Bourne Shell (sh).

(1) Explain what is meant by command line.

A command line is a text-based interface which can be used to input instructions to a computer system.

(4) Define these terms:

a. physical console

b. shell

c. terminal

d. virtual console

a. The hardware display and keyboard to interact with a system.

b. The interpreter that executes commands that are typed as strings.

c. An interface that provides a display for output and a keyboard for input to a shell session.

d. One of multiple logical consoles that can each support an independent login session.

(3) List and define the three parts of a Linux command.

Command - The command is the name of the program to run.

Options - Options normally start with one or two dashes (-a or --all) to distinguish them from arguments.

Arguments - Commands may also be followed by one or more arguments, which often indicate a target that the command should operate on.

(1) What does the option --help do? Explain.

This causes the command to print a description of what it does, a "usage statement" that describes the command's syntax, and a list of the options it accepts and what they do.

(2) Explain what a desktop environment is; give examples.

The desktop environment is the graphical user interface on a Linux system.

The default desktop environment in Red Hat Enterprise Linux 8 is provided by GNOME 3.

(6) Define what the following features of the RHEL GNOME desktop provide:

a. Activities Overview

b. dash

c. message tray

d. top bar

e. windows list

f. Workspaces

a. This mode helps to organize windows and to start applications.

b. This configurable list of icons shows your favorite applications, running

applications, and a Show Applications button to select arbitrary applications.

c. With the message tray, you can review notifications from applications

or system components.

d. Provides the Activities button and controls for volume, networking, calendar access, and switching between keyboard input methods (if more than one method is

configured).

e. A list of open windows at the bottom of the screen that lets users quickly

switch between open windows, close them, or drag them to other workspaces.

f. Separate desktop screens that have different application windows.

(1) List the procedure to shut down a RHEL server from the GNOME desktop.

Select (User) → Power Off from the top bar or press Ctrl+Alt+Del.

(1) Who is Bruce Perens?

An American computer programmer and advocate in the free software movement.

(1) Who is Richard Stallman?

An American free software movement activist and programmer.

(1) Who is Linus Torvalds?

A Finnish software engineer who is the creator and lead developer of the Linux kernel.

(1) What is meant by a file system hierarchy?

All files on a Linux system are stored on file systems which are organized into a single inverted tree of directories, known as a file system hierarchy.

(5) What is the purpose of the following Linux directories?

a. /boot

b. /etc

c. /root

d. /usr

e. /var

a. Files needed in order to start the boot process

b. Configuration files specific to this system

c. Home directory for the administrative superuser, root

d. Installed software, shared libraries, include files, and read-only program data

e. Variable data specific to this system that should persist between boots

(2) Explain what an absolute path is. Define a relative path and compare it to an absolute path.

An absolute path is a fully qualified name, beginning at the root ( / ) directory and specifying each subdirectory traversed to reach and uniquely represent a single file.

Like an absolute path, a relative path identifies a unique file, specifying only the path necessary to reach the file from the current working directory.

(4) What do the following Linux commands do?

a. cd

b. ls

c. pwd

d. touch

a. Change directories

b. Lists directory contents for the specified directory or, if no directory is given, for the current directory

c. Displays the absolute path name of the current location, which helps determine appropriate syntax for reaching files using relative path names

d. Normally updates a file's timestamp to the current date and time without otherwise modifying it

(18) Assuming you have the necessary permissions, what behavior would you expect from the following command, option, and argument combinations?

a. cd -

b. cd .

c. cd ../..

d. cd /bin

e. cd home/ringo

f. cd ~

g. cd /bin

h. cp joe mary

i. ls -l

j. ls -l Music Pictures Videos

k. ls -la /docs/IST190

l. ls -R

m. mkdir -p docs/IST190/practice

n. mv mary /tmp/joe

o. mv mystuff ~/oldstuff

p. mv song1.mp3 song2.mp3 sing3.mp3 mymusic

q. rm -tf /tmp

r. touch awesome

a. Changes to the previous working directory

b. Stays in the current directory

c. Moves up two levels in the directory tree

d. Changes to the absolute path

e. Changes to user ringo's home directory using an absolute path

f. Changes to the current user's home directory

g. Changes into a relative path subdirectory named "bin" in the current directory

h. Copies the file "joe" to a new file named "mary" in the current directory

i. Lists directory contents in long listing format

j. Lists the contents of Music, Pictures, and Videos in long listing format, if they exist

k. Lists all files (including hidden files) in /docs/IST190 using long format

l. Recursively lists all files and directories, including their subdirectories

m. Creates the full path of directories. If "docs", "IST190", or "practice" don't exist, they're created

n. Moves (or renames) "mary" to the file path "/tmp/joe"

o. Moves "mystuff" to the "oldstuff" directory in the user's home directory

p. Moves all three songs into the "mymusic" directory

q. Recursively and forcefully removes "/tmp" and everything inside it

r. Creates an empty file named "awesome" or updates its timestamp if it already exists

(7) Define these Linux meta-characters as they apply to file globbing:

a. *

b. ?

c. [[:alpha:]]

d. [[:space:]]

e. [^aeiou]

f. [aeiou]

a. Any string of zero or more characters

b. Any single character

c. Any alphabetic character

d. Any single digit from 0 to 9

e. Any single white space character, which might include tabs, newlines, carriage, returns, form feeds, or spaces

f. Any single character that is NOT a, e, i, o, or u

g. Any single character that is a, e, i, o, or u

(5) Assuming you have the necessary permissions, what behavior would you expect from the

following command, option, and argument combinations?

a. echo "Today is $(date +%A)."

b. ls *.??

c. ls -l [xyz]*

d. ls -la z

e. touch volume {1..2}_chapter{1..6}.txt

a. This command prints the message "Today is ..." followed by the current day of the week.

b. Lists files in the current directory whose names end with a dot (.) followed by exactly two characters.

c. Lists (in long format) all files and directories in the current directory whose names start with a x, y, or z.

d. Lists (in long format, including hidden files) all files and directories in the current directory whose names contain the letter z anywhere in the name.

e. Creates (or updates the timestamp of) a series of files named volume1_chapter1.txt through volume2_chapter6.txt.

(4) Explain the difference between a hard link and a soft link, including the advantages and

disadvantages of both

Even if the original file gets deleted, the contents of the file are still available as long as at least one

hard link exists. Data is only deleted from storage when the last hard link is deleted.

Hard links can only be used with regular files.

A soft link is not a regular file, but a special type of file that points to an existing file or directory.

They can link two files on different file systems.

(1) In your own words define what metacharacters are.

A metacharacter is a character that has a special meaning to a computer program.

10. (1) How do you create a soft (symbolic) link in student's home directory that will link to

/var/www/html/ assuming that all the correct permissions apply.

Run "ln -s /var/www/html ~/html-link"

(3) Write a brief explanation of each of the following:

a. Tilde (~) expansion

b. Brace ({ }) expansion

c. Command substitution ( $(command) )

a. The tilde character, when followed by a slash delimiter, matches the current user's home directory.

Brace expansion is used to generate discretionary strings of characters. Command substitution allows the output of a command to replace the command itself.

(2) What are man pages?

The original Linux Programmer's Manual.

To distinguish identical topic names in different sections, man page references include the section

(9) List the nine different sections that can be found in man pages.

User commands

System calls

Library calls

Special files

File formats

Games and screensavers

Conventions, standards, and miscellaneous

System administration and privileged commands

Linux kernel API

(2) What is the difference between passwd(1) and passwd(5) in the passwd man pages?

passwd(1) describes the command to change passwords.

passwd(5) explains the /etc/passwd file format for storing local user accounts.

(4) When navigating man pages, what key do you press to do the following:

a. Scroll backward (up) one screen

b. Go to start of the man page

c. Scroll forward (down) one screen

d. Exit man and return to the command shell prompt

a. PageUp

b. G

c. Spacebar

d. Q

(1) Write the command to do a keyword search of the man pages for the string samba.

man -k samba

(2) What are GNU Info pages?

The GNU Project developed a different online documentation system, known as GNU info.

Info documentation is structured as hyperlinked info nodes.

(2) What is the difference between man pages and GNU Info pages?

Man pages have a much more formal format.

Info documents typically cover particular software packages as a whole.

(1) What is the RHEL8 tool used to view GNU info pages?

pinfo command

(2) After studying Unit 4, between man pages and GNU Info pages, which one are you more apt to use and why?

I am more apt to use man pages because they are quicker to access, easier to read for specific command syntax, and more universally available across Linux systems.