Look around: pwd & ls

Whenever you land on a new machine, your first two questions are always the same: “Where am I?” and “What's here?” Two tiny commands answer them.

pwd: where am I?

pwd stands for print working directory. (“Directory” is the Linux word for folder.) It prints your exact location:

pwd

/home/student

That's your home folder. Every user gets one at /home/USERNAME, and it's where you land when you log in. Remember that ~ in the prompt means the same thing.

ls: what's here?

ls lists the contents of a folder. Folders are usually shown in blue.

ls            # what's in the folder I'm in?
ls /etc       # what's in /etc? (you don't have to go there first)
ls -l         # long format: more details
ls -a         # all: include hidden files
ls -la        # both at once
ls -lh        # sizes like 4.0K and 2.1M instead of bytes

Hidden files

Any file or folder whose name starts with a dot (.bashrc, .ssh) is hidden. Plain ls skips it and ls -a shows it. Linux hides settings files this way so they don't clutter your view. They aren't secret or protected, just tidied away.

With -a you'll also see two strange entries: . means “this folder” and .. means “the folder above.” You'll use .. constantly in the next lesson.

Reading ls -l

Long format looks intimidating, but it's just a table without a header row:

• The first character is the type: d = directory, - = regular file.
• The next 9 characters are permissions in groups of three: what the owner, the owner's group, and everyone else can do. r = read, w = write, x = execute (run it, or enter it if it's a folder). You'll meet them again later.

-rw-r--r--. 1 student student 332 readme.txt

-rw-r--r-- 1 student student 332 readme.txt

Try it

Quick check