CommandsStart here
Getting started with the command line. How to open a terminal on Windows, Mac and Linux, how to read the prompt, how a command is put together, and the first ten commands to try in a practice folder.
Stay safe
Dangerous commands: what never to paste. The lines that delete, overwrite, reformat, or download and run something, on all three systems. It also explains the scam that asks you to press Win + R and paste. If you ever follow instructions from the internet, read this one.
Translate
Windows and Linux commands side by side. One table per topic, with the Command Prompt, PowerShell and Linux or Mac command for the same job, and the differences that trip people up: slashes, drive letters, capital letters and variables.
PowerShell for Command Prompt users. What changes and what stays the same, the aliases that make dir and cd work, the pipeline of objects, and -WhatIf, which shows what a command would do before it does it.
Get the details right
Wildcards, quotation marks and spaces in file names. Why rm * .txt is a catastrophe and rm *.txt is not, how to handle a file name with a space in it, and what single and double quotation marks each do.
How to practise
Reading about commands teaches little. Make a folder called practice, put a few small text files in it, and try each command there as you read. Nothing in that folder matters, so nothing can go wrong. When a command surprises you, that is the lesson. Read the message it printed, and try again.
This is an independent learning site. It is not connected with Microsoft, Apple or any Linux distribution. Windows, macOS and other names belong to their owners. Try commands first in a practice folder, never on files you cannot afford to lose.