Command

Description

 man <tool>

Opens man pages for the specified tool.

<tool> -h

Prints the help page of the tool.

apropos <keyword>

Searches through man pages’ descriptions for instances of a given keyword.

cat

Concatenate and print files.

whoami

Displays current username.

id

Returns users identity.

hostname

Sets or prints the name of the current host system.

uname

Prints operating system name.

pwd

Returns working directory name.

ifconfig

The ifconfig utility is used to assign or view an address to a network interface and/or configure network interface parameters.

ip

Ip is a utility to show or manipulate routing, network devices, interfaces, and tunnels.

netstat

Shows network status.

ss

Another utility to investigate sockets.

ps

Shows process status.

who

Displays who is logged in.

env

Prints environment or sets and executes a command.

lsblk

Lists block devices.

lsusb

Lists USB devices.

lsof

Lists opened files.

lspci

Lists PCI devices.

sudo

Execute command as a different user.

su

The su utility requests appropriate user credentials via PAM and switches to that user ID (the default user is the superuser). A shell is then executed.

useradd

Creates a new user or update default new user information.

userdel

Deletes a user account and related files.

usermod

Modifies a user account.

addgroup

Adds a group to the system.

delgroup

Removes a group from the system.

passwd

Changes user password.

dpkg

Install, remove and configure Debian-based packages.

apt

High-level package management command-line utility.

aptitude

Alternative to apt.

snap

Install, remove and configure snap packages.

gem

Standard package manager for Ruby.

pip

Standard package manager for Python.

git

Revision control system command-line utility.

systemctl

Command-line based service and systemd control manager.

ps

Prints a snapshot of the current processes.

journalctl

Query the systemd journal.

kill

Sends a signal to a process.

bg

Puts a process into background.

jobs

Lists all processes that are running in the background.

fg

Puts a process into the foreground.

curl

Command-line utility to transfer data from or to a server.

wget

An alternative to curl that downloads files from FTP or HTTP(s) server.

python3 -m http.server

Starts a Python3 web server on TCP port 8000.

ls

Lists directory contents.

cd

Changes the directory.

clear

Clears the terminal.

touch

Creates an empty file.

mkdir

Creates a directory.

tree

Lists the contents of a directory recursively.

mv

Move or rename files or directories.

cp

Copy files or directories.

nano

Terminal based text editor.

which

Returns the path to a file or link.

find

Searches for files in a directory hierarchy.

updatedb

Updates the locale database for existing contents on the system.

locate

Uses the locale database to find contents on the system.

more

Pager that is used to read STDOUT or files.

less

An alternative to more with more features.

head

Prints the first ten lines of STDOUT or a file.

tail

Prints the last ten lines of STDOUT or a file.

sort

Sorts the contents of STDOUT or a file.

grep

Searches for specific results that contain given patterns.

cut

Removes sections from each line of files.

tr

Replaces certain characters.

column

Command-line based utility that formats its input into multiple columns.

awk

Pattern scanning and processing language.

sed

A stream editor for filtering and transforming text.

wc

Prints newline, word, and byte counts for a given input.

chmod

Changes permission of a file or directory.

chown

Changes the owner and group of a file or directory.