Linux Command Line Basics

The terminal is where a developer spends a huge chunk of their time. Learning a handful of commands will unlock your entire WSL environment and make you dramatically faster.

Anatomy of a command

Every command follows the same pattern:

command [options] [arguments]

• command — the program to run (e.g. ls, cp, mkdir)
• options — flags that change the behavior, usually starting with - (e.g. -r, -a)
• arguments — what to act on (e.g. a file name or folder path)

Example:

ls -la ~/projects

Here ls is the command, -la are options (show all files in long format), and ~/projects is the argument (the folder to list).

Navigating the filesystem

Print your current location

pwd

pwd stands for print working directory. It tells you exactly where you are in the filesystem.

/home/john

List files in a folder

ls

Add -l for details (permissions, size, date) and -a to show hidden files:

ls -la

Change directory

cd projects

Useful shortcuts:

Working with files and folders

Create a folder

mkdir my-project

Create nested folders all at once with -p:

mkdir -p my-project/src/components

Create an empty file

touch index.js

Copy a file

cp index.js index-backup.js

Copy a folder with -r (recursive):

cp -r my-project my-project-backup

Move or rename a file

mv moves a file to a new location. If the destination is just a new name in the same folder, it renames it.

# Rename
mv old-name.js new-name.js

# Move to another folder
mv index.js src/index.js

Delete a file

rm index-backup.js

Delete a folder and everything inside it:

rm -r my-project-backup

Reading file contents

Print a file to the screen

cat index.js

Scroll through a long file

less package.json

Press q to quit, arrow keys to scroll, / to search.

Show just the first or last lines

head -n 10 index.js   # first 10 lines
tail -n 10 index.js   # last 10 lines

Finding things

Search inside files

grep "console.log" index.js

Search recursively through all files in a folder:

grep -r "console.log" src/

Find a file by name

find . -name "index.js"

Running programs

Run a JavaScript file

node index.js

Install a package

npm install express

Run a script from package.json

npm run dev

Stop a running program

Press Ctrl + C to interrupt and stop whatever is currently running in the terminal.

Managing output

Clear the terminal screen

clear

Or press Ctrl + L — same result, faster.

Redirect output to a file

node index.js > output.txt

Chain commands with &&

The second command only runs if the first one succeeds:

mkdir my-app && cd my-app

Getting help

Every command has a built-in manual. Add --help to see a quick summary:

ls --help
cp --help

For a full manual page:

man ls

Press q to exit the manual.

Quick reference

Next steps

You now know enough terminal to navigate confidently. Move on to How the web works to start learning what actually happens when you type a URL into a browser.