Video Summary - 60 Linux Commands you NEED to know (in 10 minutes)

Summary of the 60 Linux Commands (Grouped by What They Do)

ssh user@server Connect to a remote Linux machine (using IP/domain, accepts host fingerprints, then prompts for password).
ls [-l] [-a] List directory contents; -l gives a detailed listing, -a includes hidden files.
pwd Print the current working directory.
cd <path> Change directories; examples include:
- cd .. (one level up)
- cd (back to home)
- going to filesystem root (e.g., /)
- touch <file> (including multiple filenames) Create empty files quickly; supports setting times in the future via touch -d <date> <file>.

echo ... > file / >> file Write quickly to a file using output redirection (> overwrites, >> appends).
nano <file> Terminal text editor. Save/exit with:
- Ctrl+X → Y → Enter

It also mentions vi-style flow with vi/vim:

- insert with `i`
- save + quit with `:wq`

clear Clear the terminal screen.
whoami Show current user.
adduser <username> Create a new user (and typically requires sudo/su for permission).
su <username> Switch user identity.
exit Exit back from the current shell/context.
passwd <user> Set or change passwords.

apt update + apt install finger Install finger after updating repositories. (Also notes different package managers like yum on Red Hat-based systems.)
finger <user> Inspect user info.
man <command> Read manual pages (example given: man finger).
what is <thing>, which <command> Quick lookup and locating binaries. (whatis is mentioned as a man alternative.)

wget <url> Download from the internet (example: downloading a large text like the “entire Bible”).
curl <url> > file Download and redirect output to a file.
zip <zipfile> <files...> Compress files.
unzip <zipfile> Extract archives.
less <file> Paginated viewing (better than dumping everything with cat).
head <file> / tail <file> View beginning/end of a file.
cmp <file1> <file2> Compare files (reports if different and where).
diff <file1> <file2> Show exactly what differs.
sort <file> Sort text alphabetically (often used with pipes).

find <path> -name/-regex ... Search for files (mentions patterns/regex, hidden files, empty dirs, executables).
chmod +x <file> Make a file executable.
chown <user> <file> Change file ownership.

ip address / ip a Show IP addresses.
ifconfig (if installed) Alternative command to view network info.
grep + pipes (e.g., ip a | grep ...) Filter output to specific interfaces/lines (using regex-style matching).
DNS checks:
- cat /etc/resolv.conf (simple view)
- resolvectl status (more informative on newer Ubuntu/systemd-resolved setups)
ping <host> Check if a host is reachable; stop with Ctrl+C; limit with -c <count>.
traceroute <host> Show route hops and latency.
Open ports / sockets:
- netstat (mentions netstat -tulpen as a better multi-switch example)
- ss -tulpen Modern replacement for checking listening ports.
Firewall (ufw):
- ufw allow 80 (open port 80)
- ufw status (check rules)
- ufw enable (enable the firewall)

uname [-a] Kernel/system info (more detail with -a).
neofetch Pretty system summary (installed via apt install neofetch).
cal (and install ncal) Display calendar.
echo <expr> | bc Do math in the terminal.
free Memory usage (RAM + swap overview).
df -h Disk space usage in human-readable form.
ps aux List processes with details.
top / htop Live process monitoring; htop is a prettier interactive alternative.
kill -9 <pid> Force-kill a process (after finding PID with ps/filtering).
pkill -f <pattern> Kill by process name/pattern (avoids manually looking up PID).
Service control (Systemd):
- systemctl <service> start|stop|status|restart (example: systemctl apache2 ...)
- If systemd isn’t available, fallback to service.
history Show command history.
sudo reboot / sudo shutdown (and shutdown -h now) Reboot or power off/shutdown quickly.