0x00-shell_basics

shell basics

Intro

In this session, we will introduce shell scripriting and have a look at the most basic scripting commands. Hang tight.

Resources

1. What is the shell?
2. Navigation
3. Looking around
4. A guided tour
5. Manipulating files
6. Working with commands
7. Reading man pages
8. Keyboard shortcuts
9. LTS
10. Shebang

Man or help

• cd
• ls
• pwd
• less
• file
• ln
• cp
• mv
• rm
• mkdir
• type
• which
• help
• man

Learning objectives

By the end of this project, you should be able to explain to anyone Without the help of google the following concepts

General Objectives

• What does RTFM mean?
• What is 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

Keboard shortcuts for bash

• Common shortcuts for Bash

Tasks

0. Where am I? : A script that prints the absolute path of the current working directory.
1. What's in there? : A script that displays the contents of your current directory.
2. There is no place like home : A script that changes the working directory to the user's home directory.
3. The long format : A script that displays the current directory contents in a long format.
4. Hidden files : A script that displays the current directory contents including hidden files.
5. I loce numbers : A script that displays the current directory contents, using long format, while displaying group IDs in numeral and show hidden files.
6. Welcome holberton : A script that will create a directory named holberton in the /tmp/ directory.
7. Betty in Holberton : A scipt that will move a file called betty from home to the new directory created above.
8. Bye bye Betty : A script that will delete file betty from the new location.
9. Bye bye Holberton : A script that will delete the directory holberton that is in the /tmp/ directory path.
10. Back to the future Change working directory to the previous one.
11. Lists List all files (even ones with names beginning with a period character, which are normally hidden) in the current directory and the parent of the working directory and the /boot directory (in this order), in long format.
12. File type A script that prints the type of the named file iamafile. The iamafile will be in the /tmp/ directory when we will run your script.
13. We are symbols, and inhabit symbols Create a symbolic link to /bin/ls, named __ls__. The symbolic link should be created in the current working directory.
14. Copy HTML files Create a script that copies all html files from the current working directory to the parent working directory while only copying files that did not exist.
15. Let's move A script that moves all files beginning with an uppercase letter to the directory /tmp/u.
16. Clean Emacs A script that deletes all files in the current directory that end with the character ~.
17. Tree A script that creates the directory welcome/, welcome/to/ and welcome/to/holberton.
18. Life is a series of commas, not periods A script that lists all the files and directories of the current directory separated by commas ,.
19. File type: Holberton Create a magic file holberton.mgc that can be used with the command file to detect Holberton data files always contain the string HOLBERTON at offset 0.