Filesystem & Navigation

The filesystem hierarchy

Linux has a single tree rooted at /. Key directories: /home (user files), /etc (config), /var (logs, variable data), /bin//usr/bin (programs), /tmp (temporary files).

pwd, ls, cd

pwd prints where you are, ls lists contents, cd changes directory.

pwd
ls
cd /etc
ls -la

Output:

/home/alice
Documents  Downloads  notes.txt
/etc
drwxr-xr-x  2 root root 4096 Sep  4 09:00 .
-rw-r--r--  1 root root  120 Sep  4 09:00 hostname

Handy ls flags

ls -l long format, ls -a shows hidden files (starting with .), ls -lh human-readable sizes. Combine: ls -lah.