The terminal can do almost everything

SUMMARY

• Note: I use {curly brackets} to represent variables where you replace the text inside the brackets, and don’t type the brackets themselves. This is often used in documentation, but not explained, so be on the lookout.
• Note: I use code text to represent code that should be typed into the terminal command line.
• ls lists files; ls -la lists all files the long way
• cd changes directory, cd .. goes up one dir, cd {dir} takes you to the “dir” folder
• mv {dir1/old} {dir2/new} moves a file from the first dir position to the second dir position
• mv {dir1} {dir2} changes the name of the folder
• mkdir {dirname} creates a new directory
• touch {filename} creates a new empty file
• grep [options] pattern {files} searchs all the files in {files} for the “pattern” specified, e.g. grep -r "my random phrase" ~/* if you want to search all of your home directory (~/*) files recursively (-r) for the string “my random phrase”
• man {command} pulls up the MANual (documentation) for any command, it’s the best place to learn about what a command does

The terminal, command line, prompt, command prompt – what’s going on there? I’m sure most of you remember or have seen pictures of the old computers – big metal frames, tiny curved screens, probably black with green text or something. Old school, hacker looking stuff. Those computers were all text-based – there were no pictures. No graphics. No images. Well, except for the words used to give the computer commands. The whole word concept has stuck around since the very beginning, and is still the main way that computer scientists communicate with the computer. Text.

Why text? It’s pretty simple, and easy for us humans to remember key words that actually relate to what’s going on. At least, that’s the idea. The terminal is the place we give the computer commands. That’s why it’s also called the command line, or command prompt. The most minimal representation of the terminal/command line/command prompt is a special symbol that changes, I don’t know why. Typically, the symbol is $, >, %, #, or something like that. I particularly like > because it looks like an arrow.

What is a terminal? The terminal is a computer application that enables you to run commands, programs, executables, and navigate your folders and files (just like file explorer). You can do everything on your computer through the terminal. The alternative is to do everything through Graphical User Interfaces (GUIs), which are the windows that pop up when you click on an app. Oftentimes, GUIs are simpler and more intuitive since they have pictures and pretty colors, but if you learn how to use the Terminal, it unlocks many computing superpowers.

• On Mac, the default terminal app is called “Terminal”
• On Windows, the default app is called “Command Prompt”, but you can and should download “PowerShell”, a newer, better version.

What does this text mean when I open a terminal? If you’re in a terminal, the key thing to know is the terminal prompt: this is a symbol like $, %, > or something else, and it is just a random symbol that tells you to type your commands after the symbol. All of the text before the “prompt” is just for display.

• On Mac, you’ll typically see something like Blake@MyMac ~ $. The $ is the prompt, Blake is your username, MyMac is the name of your computer, and ~ represents the folder you’re currently in. In this case, the tilde ~ is shorthand for /home/Blake, your home directory. Those two addresses take you to the same spot.
• On Windows, you’ll typically just see the current folder, C:\Users\Blake> with the prompt touching the folder name. In PowerShell, you’ll see a “PS” attached to the front for no good reason, e.g. PS C:\Users\Blake>

What is a command? Typically, anything that you do in a terminal is called a “command”, rather ambiguously. These commands are mostly shell scripts, programs, and executables. You can use commands to directly open applications through the terminal, as well as manipulate files and folders.

What is the shell? The terminal comes with a “shell” interpreter that lets you use a shell scripting language, like Bash. Bash is a language that includes commands like cd, ls, mv, grep, and many more that you can run in a terminal. These do actions like change the current directory, list files in the current directory, move files and folders around, and many more.