Consist of the following projects:

0x00. Shell, Basics

Learning objectives

At the end of this project, you are expected to be able to explain to anyone, without the help of Google:

General

• What does RTFM mean?
• What is a Shebang
• What is the Shell
• What is the shell
• What is the difference between a terminal and a shell
• What is the shell prompt
• How to use the history (the basics)

Navigation

• What do the commands or built-ins cd, pwd, ls do
• How to navigate the filesystem
• What are the . and .. directories
• What is the working directory, how to print it and how to change it
• What is the root directory
• What is the home directory, and how to go there
• What is the difference between the root directory and the home directory of the user root
• What are the characteristics of hidden files and how to list them
• What does the command cd - do

Looking Around

• What do the commands ls, less, file do
• How do you use options and arguments with commands
• Understand the ls long format and how to display it
• A Guided Tour
• What does the ln command do
• What do you find in the most common/important directories
• What is a symbolic link
• What is a hard link
• What is the difference between a hard link and a symbolic link

Manipulating Files

• What do the commands cp, mv, rm, mkdir do
• What are wildcards and how do they work
• How to use wildcards
• Working with Commands
• What do type, which, help, man commands do
• What are the different kinds of commands
• What is an alias
• When do you use the command help instead of man
• Reading Man Pages
• How to read a man page
• What are man page sections
• What are the section numbers for User commands, System calls and Library functions
• Keyboard Shortcuts for Bash
• Common shortcuts for Bash

LTS

• What does LTS mean?

---

0x01.Shell, permissions

Learning objectives

At the end of this project, you are expected to be able to explain to anyone, without the help of Google:

Permissions

• What do the commands chmod, sudo, su, chown, chgrp do
• Linux file permissions
• How to represent each of the three sets of permissions (owner, group, and other) as a single digit
• How to change permissions, owner and group of a file
• Why can’t a normal user chown a file
• How to run a command with root privileges
• How to change user ID or become superuser

Other Man Pages

• How to create a user
• How to create a group
• How to print real and effective user and group IDs
• How to print the groups a user is in
• How to print the effective userid201

---

0x02.Shell, I/O Redirections and filters

Learning objectives

At the end of this project, you are expected to be able to explain to anyone, without the help of Google:

Shell, I/O Redirection

• What do the commands head, tail, find, wc, sort, uniq, grep, tr do
• How to redirect standard output to a file
• How to get standard input from a file instead of the keyboard
• How to send the output from one program to the input of another program
• How to combine commands and filters with redirections

Special Characters

• What are special characters
• Understand what do the white spaces, single quotes, double quotes, backslash, comment, pipe, command separator, tilde and how and when to use them

Other Man Pages

• How to display a line of text
• How to concatenate files and print on the standard output
• How to reverse a string
• How to remove sections from each line of files
• What is the /etc/passwd file and what is its format
• What is the /etc/shadow file and what is its format

---

0x03.Shell, init files, variables and expansions

Learning Objectives

At the end of this project, you are expected to be able to explain to anyone, without the help of Google:

General

• What happens when you type $ ls -l *.txt
• Shell Initialization Files
• What are the /etc/profile file and the /etc/profile.d directory
• What is the ~/.bashrc file

Variables

• What is the difference between a local and a global variable
• What is a reserved variable
• How to create, update and delete shell variables
• What are the roles of the following reserved variables: HOME, PATH, PS1
• What are special parameters
• What is the special parameter $??

Expansions

• What is expansion and how to use them
• What is the difference between single and double quotes and how to use them properly
• How to do command substitution with $() and backticks

Shell Arithmetic

• How to perform arithmetic operations with the shell

The alias Command

• How to create an alias
• How to list aliases
• How to temporarily disable an alias

Other help pages

• How to execute commands from a file in the current shell

---

ModifyModify