Linux command line: start with a small win

You do not need to memorize a wall of commands. You need to know what question to ask, which tool can answer it, and how to check the result. By the end of this course, you will build a small project folder, investigate logs, produce a report, and verify a backup.

Your route: 164 command topics · 22 focused lessons · a setup chapter and a final project. Some topics pair related tools, such as top/htop. Work at your own pace; the optional playground is not a prerequisite for real work.

Set up your practice space

Use Bash on a Linux machine you control, a Linux VM, or a Linux environment such as WSL. macOS and other Unix systems have related tools but different flags. Containers are useful for file exercises, but may lack systemd, hardware access, sound, or login records.

The course never executes commands in your browser. Use each Copy button to take an example to your own terminal, read it, then run it. The guided labs create their own small datasets. Filesystem labs start in a fresh temporary folder so you do not need to modify a real project.

si_lab=$(mktemp -d)
cd "$si_lab" || exit
printf 'My first Linux lab\n' > notes.txt
pwd
cat notes.txt

What to expect: a new temporary path and the text My first Linux lab. Keep that terminal open while exploring a lesson. A new terminal does not remember its variables or working directory. Temporary files can disappear after cleanup or a restart; save your explanations in the course workbook.

Read a command before copying it

Copyable blocks do not include a shell prompt such as $. Text explaining expected output sits outside the block. If a program is missing, inspect your distribution's package documentation; you do not need to install every optional utility.

Learn in four passes

1. Predict: say what the command should do before running it.
2. Try: use the smallest useful example in your practice environment.
3. Explain: write what happened and why in your workbook.
4. Verify: answer the knowledge check, then mark the chapter complete.

Signed-in learners can save their workbook and resume this course version. A correct quiz answer plus a meaningful workbook response unlocks chapter completion. The course has no automatic terminal grader; compare your own evidence with the expected result.

Choose a learning path

Command map

Use the chapter menu to jump to a topic or return after practice.

• 1. Find your feet in the terminal: pwd, ls, cd, dir, clear, help, man, whatis, apropos
• 2. Build a workspace you can trust: mkdir, touch, cp, mv, rm, rmdir, ln, basename, stat, tree
• 3. Read files without information overload: cat, tac, head, tail, less, nl, wc, fold
• 4. Find the right file and the actual change: find, locate, grep, which, whereis, diff / sdiff, cmp
• 5. Turn text into answers with pipelines: sort, uniq, cut, paste, tr, sed, awk, column, xargs
• 6. Make the shell predictable: echo, printf, alias, history, !!, env, printenv, export, exit, tty
• 7. Edit a file and make a repeatable task: nano, vim, make
• 8. Package files and prove you can restore them: gzip, gunzip, zcat, bzip2, tar, zip, unzip, split, cpio
• 9. Understand identities and sessions: whoami, who, w, groups, finger, last, login, passwd, su, sudo
• 10. Grant access with intent: chmod, chown, useradd, usermod, userdel
• 11. Trace a process before stopping it: ps, top / htop, pstree, pidof, kill, killall, nice / renice, ionice
• 12. Manage work that takes time: jobs, bg, fg, wait, nohup, screen, sleep, watch, time, crontab
• 13. Know the machine before changing it: uname, hostname, hostnamectl, lscpu, lsb_release, lspci, dmidecode
• 14. Measure before you tune: free, df, du, ncdu, vmstat, mpstat, iostat, quota
• 15. Read service evidence before restarting: systemctl, service, journalctl, dmesg, shutdown, reboot
• 16. Trace connectivity from your own host: ip, ifconfig, nmcli, nmtui, ifplugstatus, ping, traceroute
• 17. Separate DNS, HTTP, and listening ports: dig, nslookup, whois, curl, wget, nc, netstat, lsof
• 18. Move work remotely and respect access boundaries: ssh, scp, rsync, iptables, ufw
• 19. Use the package manager your system has: apt, yum, rpm
• 20. Understand storage before writing to it: lsblk, mount, fdisk, parted, cfdisk, badblocks, fsck, mkfs
• 21. Use small tools for calculations and reports: cal, bc, factor, date, expr, shuf, yes, wall
• 22. Optional playground: explore the terminal: sl, cmatrix, aplay, spd-say, xeyes, banner

Built on open knowledge

This SI course adapts the topic collection in 101 Linux Commands by Bobby Iliev and contributors. The supplied HTML contains more topics than its title suggests. SI reorganized and rewrote the teaching material, examples, labs, and assessments. Affiliate promotions and referral links are omitted. The original MIT copyright and permission notice are retained in the final chapter.