2. Basics of Linux Command Line

Understanding the basics of the Linux command line is vital for a variety of reasons.
It allows for greater efficiency as many tasks that would take multiple steps in a GUI can be accomplished quickly with a single command in the command line.
This knowledge underpins the potential for script creation and automation, reducing repetitive tasks and enhancing productivity.
If you're responsible for remote Linux servers, these systems are often managed exclusively via the command line, making this skill an indispensable part of your toolkit. This is further compounded by the fact that all Linux distributions include a command line interface, providing a level of cross-distribution compatibility.
Many advanced and powerful tools such as grep, awk, sed, and git are utilized via the command line.
The command line provides you with a wealth of learning opportunities around the inner workings of the Linux operating system, supporting your professional development and enabling you to exploit more advanced resources and guides.
Basically, while user-friendly graphical interfaces are increasingly common in Linux distributions, command-line proficiency remains an invaluable skill at all user levels and is considered a fundamental area of knowledge in many tech roles.
Gamified Tutorial - Linux Survival

2.A Navigating the File System

The first step to using the command line is to understand how to navigate the file system.
You can always use man to get more information about a command. For example, man ls will give you more information about the ls command.
The important command here are cd, ls, and pwd. And here's a short explanation to what they do:
- cd stands for change directory. It allows you to change your current working directory.
- ls stands for list. It allows you to list the contents of a directory.
- pwd stands for print working directory. It allows you to print the current working directory.
Documentation - cd
Documentation - ls
Documentation - pwd

The important commands here are cp, mv, and rm.
cp stands for copy. It allows you to copy files and directories.
mv stands for move. It allows you to move files and directories.
rm stands for remove. It allows you to remove files and directories.
You can use the -r flag with cp and rm to copy and remove directories recursively.
Documentation - cp
Documentation - mv
Documentation - rm

The important commands here are less, cat, tail, and head.
less allows you to view the contents of a file. It is a pager, which means it allows you to view files page by page. ex: less file.txt/cat file.txt | less
cat allows you to view the contents of a file. It is a concatenation tool, which means it allows you to view multiple files at once.
tail allows you to view the last few lines of a file. ex: tail file.txt
head allows you to view the first few lines of a file. ex: head file.txt
Documentation - less
Documentation - cat
Documentation - tail
Documentation - head

There's a lot of important command line utilities that you should know about. Here are some of them:
grep allows you to search for a pattern in a file. ex: grep "pattern" file.txt
awk allows you to manipulate text files. ex: awk '{print $1}' file.txt ( prints the first column of a file)
sed allows you to manipulate text files. ex: sed 's/pattern/replacement/g' file.txt (replaces all instances of a pattern with a replacement)
find allows you to find files and directories. ex: find . -name "pattern" (finds all files and directories with a name matching the pattern)
Documentation - grep
Documentation - awk
Documentation - sed
Documentation -