Paths and Directory Navigation — Absolute vs Relative

Absolute and relative paths

A path is a string that describes the location of a file or directory.

One that starts from / is an absolute path (a complete route from the top of the file system), and one written from your current location is a relative path.

cd /tmp moves by absolute path; cd .. moves by relative path.

cd /tmp     # move by absolute path
pwd         # /tmp
cd ..       # up one level by relative path
pwd         # /
cd ~        # to home
pwd         # /root

① Move to /tmp by absolute path, and show your location with pwd to confirm.

② Then move up one directory with the relative .., and check your location with pwd.

③ Finally, return home and confirm with pwd that you're back at /root. (Run it correctly and an explanation will appear.)

Special symbols — / . .. ~

Inside a path, the following symbols have special meaning.

Combine them and you can move flexibly relative to your current location.

. refers to the directory you're in right now, and is used for things like a copy destination or an execution path.

When / appears in the middle of a path, as in /etc/hostname, it acts as a separator joining directories together.

ls .                    # the current location = same as omitting it
cp /etc/hostname .      # copy to the current directory
./script.sh             # run from the current directory

mkdir -p a/b/c   # create a hierarchy for practice
cd a/b/c         # move deep by relative path
pwd              # ends with /a/b/c
cd ../..         # go up two levels
pwd              # ends with /a

① Create a three-level hierarchy with mkdir -p a/b/c for practice.

② Move to a/b/c by relative path, and confirm with pwd that it ends with /a/b/c.

③ Join two .. to go up two levels, and confirm with pwd that it ends with /a.

Read your location — pwd and ls -l

pwd shows the absolute path of your current location.

ls -l lists the items in that directory in detail, one per line, and passing it a path like ls -l / lets you check that location's contents without moving there.

pwd          # current absolute path
ls -l        # detailed listing of the current location
ls -l /      # check directly under root without moving

① Show the absolute path of your current location with pwd.

② List the current directory's contents in detail with ls -l.

③ Use ls -l / to check what directories sit directly under root, without moving there.