Most used Linux/OSx/Unix/BSD commands

The TOP most used *nix commands with tldr cheat sheets. Every user should know.

File system, directories

vim (vi) — text editor.
nano — text editor.
cat — creates, prints and concatenates files.
touch — creates and changes a file access and modification times.
emacs (emacsclient) — the extensible, customizable, self-documenting, real-time display editor.
less — open a file for interactive reading, allowing scrolling and search.
tail (head) — display the last (first) part of a file.
hexdump — an ASCII, decimal, hexadecimal, octal dump.
xxd — create a hexadecimal representation (hexdump) from a binary file, or vice-versa.
cp — copy files and directories.
mv — move or rename files and directories.
find — find files or directories under the given directory tree, recursively.
locate (linux), locate (osx) — find filenames quickly.
grep — find patterns in files using regular expressions.
tar — archiving utility.
gzip — compress/uncompress files with gzip compression (LZ77).
zip (unzip) — package and compress/uncompress files with zip format.
chmod — change the access permissions of a file or directory.
chown — change user and group ownership of files and directories.
wc — count lines, words, and bytes.

whoami — print the username associated with the current effective user ID.
tty — returns terminal name.
uname — print details about the current machine and the operating system running on it.
sudo (su) — executes a single command as the superuser or another user (switch shell to another user).
useradd (userdel) — create (remove) a user.
chmod — change the access permissions of a file or directory.
chown — change user and group ownership of files and directories.
passwd — change a user's password.
exit — exit the shell.
shutdown (linux), shutdown(osx) — shutdown and reboot the system.
top (linux), top (osx) — display dynamic real-time information about running processes.
ps — information about running processes.
kill (killall) — sends a signal to a process, usually related to stopping the process.
passwd — change a user's password.
free — display amount of free and used memory in the system.

apt (apt-get, dpkg) — package management utility for Debian based distributions (f.e. Ubuntu).
dnf — package management utility for RHEL, Fedora, and CentOS (replaces yum).
brew — package manager for macOS and Linux.
pacman — Arch Linux package manager utility.
pip — Python package manager.
npm — JavaScript and Node.js package manager.
env — show the environment or run a program in a modified environment.

ping — ping host (send ICMP ECHO_REQUEST packets to network hosts).
traceroute — print the route packets trace to network host.
wget — download files from the Web. Supports HTTP, HTTPS, and FTP.
curl — transfers data from or to a server.
host — lookup Domain Name Server.
nslookup — query name server(s) for various domain records.
whois — command-line client for the WHOIS (RFC 3912) protocol.
dig — DNS lookup utility.
ssh — Secure Shell is a protocol used to securely log onto remote systems.
scp — secure copy files between hosts using Secure Copy Protocol over SSH.
telnet — connect to a specified port of a host using the telnet protocol.
ftp (sftp) — tools to interact with a server via File Transfer Protocol.
firefox — a free and open source web browser.
chromium — open-source web browser principally developed and maintained by Google.
lynx — command-line web browser.
netstat — displays network-related information such as open connections, open socket ports, etc.
ifconfig — network interface configurator.
ip — show / manipulate routing, devices, policy routing and tunnels.
nc — Netcat is a versatile utility for working with TCP or UDP data.

git (git *) — distributed version control system.
gcc (g++) — the GNU preprocessor, compiler (assembler), and linker for C, C++, and other languages.
gdb — the GNU Debugger.
clang (clang++) — compiler for C, C++, Objective-C, and other source files.
python — Python language interpreter.
java (javac) — Java Application Launcher (Java Application Compiler).
go — tool for managing go source code.
julia — Julia language tools.
perl — the Perl 5 language interpreter.
awk — a versatile programming language for working on files.
make — task runner for targets described in Makefile.
crontab — schedule cron jobs to run on a time interval for the current user.
env — show the environment or run a program in a modified environment.

man — format and display manual pages.
whatis (linux), whatis (osx) — display one-line descriptions from manual pages.
tldr — displays simple help pages for command-line tools, from the tldr-pages project.
which — locate a program in the user's path.

echo — print given arguments.
history — command-line history.
clear — clears the screen of the terminal.
youtube-dl (yt-dlp) — download videos from YouTube and other websites.
ffmpeg — video tools.
cal — prints calendar information, with the current day highlighted.
bc (dc) — an arbitrary precision calculator language.
alias (unalias) — creates (removes) aliases - words that are replaced by a command string.
uptime — tell how long the system has been running and other information.