Where am I? (pwd, ls, cd)

$ the filesystem, briefly

Every file on your computer lives somewhere — inside a folder, which lives inside another folder, and so on, all the way up to the root, written as /.

When you open a terminal, you start in a particular folder called your working directory. By default that's your home folder, written as ~ (a real path like /Users/you or /home/you).

Three small commands let you navigate this whole tree. That's all we need today.

$ pwd — print working directory

"Where am I?" Run pwd. The shell prints the full path of your current folder.

› try: pwd

$ ls — list what's here

"What's around me?" Run ls. It prints the names of the files and folders in your current directory. Folders are usually shown with a trailing /.

› try: ls

You can pass flags to change how ls behaves:

• ls -a — also show hidden files (anything starting with .)
• ls -l — show a "long" listing with sizes and permissions

Flags are conventions. They start with a dash. Most commands have a few. You'll meet more as we go.

$ cd — change directory

"Take me somewhere." cd moves you into another folder. Try moving into projects:

› try: cd projects

Three magic destinations:

• cd ~ — home folder (or just cd alone)
• cd .. — up one level
• cd / — the root

You can also chain: cd projects/shio goes two levels in at once.

$ the three-step

Together, pwd, ls, and cd are a kind of compass. When you feel lost — and you will, sometimes — these three will always tell you where you are and what's near you.

Next we'll read what's inside those files.