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.