Linux & Docker · Lesson 1 of 7

Linux & the terminal

Why developers use Linux, the file system layout and moving around with pwd, ls and cd.

Most servers, cloud machines and containers run Linux, so developers, testers and support engineers are expected to be comfortable in its terminal (the shell, usually Bash).

The file system

Everything starts at / (root). Your home folder is /home/yourname, written ~.
/etc holds configuration, /var/log holds logs, /tmp is temporary space.
Paths are case-sensitive: Report.txt and report.txt are different files.

On Windows, install WSL (Windows Subsystem for Linux) to get a real Linux terminal.

Example in the terminal

Run these on your own computer

$ pwd
/home/anu

$ ls
Documents  projects  resume.pdf

$ ls -la projects
drwxr-xr-x  4 anu anu 4096 Nov 10 09:12 .
drwxr-xr-x 18 anu anu 4096 Nov 10 09:10 ..
drwxr-xr-x  6 anu anu 4096 Nov  8 18:40 job-portal
-rw-r--r--  1 anu anu  812 Nov  9 11:02 notes.md

$ cd projects/job-portal
$ cd ..          # up one level
$ cd ~           # back to home

Lines starting with $ are commands you type; the rest is what the terminal prints. Use Linux, macOS, WSL on Windows or a free cloud shell. Names and paths are examples.

Key points

Servers and containers mostly run Linux.
/ is root, ~ is your home folder.
pwd = where am I, ls = list, cd = change directory.
ls -la shows hidden files, sizes and permissions.

Quick check

What does ~ mean in a path?

The root folder Your home folder The previous folder A temporary folder

Practice task

Open a terminal (or WSL), print your current folder, list all files including hidden ones in your home folder, and move into and out of a sub-folder.

Interview corner

Why do developers need Linux skills?

Production servers, cloud VMs and Docker containers mostly run Linux. Deploying, reading logs, checking processes and fixing issues on servers all happen in the Linux shell.

What is the difference between an absolute and a relative path?

An absolute path starts from root (/var/log/app.log) and works from anywhere. A relative path starts from the current folder (logs/app.log).