Online user manuals

acl — Access Control Lists

adduser, addgroup - add or manipulate users or groups

AppArmor - kernel enhancement to confine programs to a limited set of resources.

apt - command-line interface

apt-get - APT package handling utility -- command-line interface

AS - the portable GNU assembler.

gawk - pattern scanning and processing language

basename - strip directory and suffix from filenames

BusyBox - The Swiss Army Knife of Embedded Linux

bzip2, bunzip2 - a block-sorting file compressor, v1.0.8

cat - concatenate files and print on the standard output

chmod - change file mode bits

chown - change file owner and group

chsh - change login shell

comm - compare two sorted files line by line

cp - copy files and directories

cpio - copy files to and from archives

cron - daemon to execute scheduled commands (Vixie Cron)

crontab - maintain crontab files for individual users (Vixie Cron)

cryptsetup - utility for configuring and managing encrypted storage devices

csplit - split a file into sections determined by context lines

cut - remove sections from each line of files

date - print or set the system date and time

deluser, delgroup - remove a user or group from the system

df - report file system space usage

diff - compare files line by line

dig - DNS lookup utility

discover — hardware detection utility

dmesg - print or control the kernel ring buffer

dpkg - package manager for Debian

du - estimate file space usage

efivar - Tool to manipulate UEFI variables

emacs - GNU project Emacs editor

env - run a program in a modified environment

expand - convert tabs to spaces

expr - evaluate expressions

file — determine file type

find - search for files in a directory hierarchy

flatpak - Build, install and run applications and runtimes

fmt - simple optimal text formatter

fold - wrap each input line to fit in specified width

free - Display amount of free and used memory in the system

tnftp — Internet file transfer program

fuse - Filesystem in Userspace (FUSE) device

gettext - translate message

git - the stupid content tracker

go - tool for managing Go source code

gpg - OpenPGP encryption and signing tool

gpm - a cut and paste utility and mouse server for virtual consoles

grep, egrep, fgrep, rgrep - print lines that match patterns

groff - front end to the GNU roff document formatting system

groupadd - create a new group

groupdel - delete a group

groupmod - modify a group definition on the system

gzip, gunzip, zcat - compress or expand files

head - output the first part of files

host - DNS lookup utility

hostname - show or set the system's host name

htop, pcp-htop - interactive process viewer

id - print real and effective user and group IDs

ifconfig - configure a network interface

ifup - bring a network interface up

install - copy files and set attributes

iotop - simple top-like I/O monitor

ip - show / manipulate routing, network devices, interfaces and tunnels

iptables/ip6tables — administration tool for IPv4/IPv6 packet filtering and NAT

join - join lines of two files on a common field

journalctl - Print log entries from the systemd journal

kill - send a signal to a process

killall - kill processes by name

ld - The GNU linker

less - display the contents of a file in a terminal

ln - make links between files

plocate - find files by name, quickly

logrotate ‐ rotates, compresses, and mails system logs

ls - list directory contents

lsblk - list block devices

lscpu - display information about the CPU architecture

lsof - list open files

lua - Lua interpreter

lz - gunzips and shows a listing of a gzip'd tar'd archive

mail, mailx, Mail — send and receive mail

make - GNU Make utility to maintain groups of programs

man - an interface to the system reference manuals

mandb - create or update the manual page index caches

mkdir - make directories

mount - mount a filesystem

MultiTail - browse through several files at once

mutt - The Mutt Mail User Agent

mv - move (rename) files

nano - Nano's ANOther text editor, inspired by Pico

nc — arbitrary TCP and UDP connections and listens

netstat - Print network connections, routing tables, interface statistics, masquerade connections, and multicast memberships

nice - run a program with modified scheduling priority

nl - number lines of files

nload - displays the current network usage

nohup - run a command immune to hangups, with output to a non-tty

nslookup - query Internet name servers interactively

numfmt - Convert numbers from/to human-readable strings

od - dump files in octal and other formats

openssl - OpenSSL command line program

pam - Netpbm common 2-dimensional bitmap format

passwd - change user password

paste - merge lines of files

patch - apply a diff file to an original

ping - send ICMP ECHO_REQUEST to network hosts

pinky - lightweight finger

pip3 - package manager for Python packages

pgrep, pkill, pidwait - look up, signal, or wait for processes based on name and other attributes

postfix - Postfix control program

pr - convert text files for printing

printf - format and print data

ps - report a snapshot of the current processes.

pstree - display a tree of processes

ptx - produce a permuted index of file contents

python - an interpreted, interactive, object-oriented programming language

readlink - print resolved symbolic links or canonical file names

realpath - print the resolved path

poweroff, reboot, halt - Power off, reboot, or halt the machine

rev - reverse lines characterwise

rm - remove files or directories

rmdir - remove empty directories

route - show / manipulate the IP routing table

ruby — Interpreted object-oriented scripting language

scp — OpenSSH secure file copy

screen - screen manager with VT100/ANSI terminal emulation

sed - stream editor for filtering and transforming text

seq - print a sequence of numbers

service - run a System V init script

sftp — OpenSSH secure file transfer

dash — command interpreter (shell)

shred - overwrite a file to hide its contents, and optionally delete it

shuf - generate random permutations

shutdown - Halt, power off or reboot the machine

snap - Tool to interact with snaps

sort - sort lines of text files

split - split a file into pieces

sqlite3 - A command line interface for SQLite version 3

ss - another utility to investigate sockets

ssh — OpenSSH remote login client

sshd — OpenSSH daemon

startx - initialize an X session

stat - display file or file system status

su - run a command with substitute user and group ID

sudo, sudoedit — execute a command as another user

sysctl - configure kernel parameters at runtime

systemctl - Control the systemd system and service manager

systemd, init - systemd system and service manager

tac - concatenate and print files in reverse

tail - output the last part of files

tar - an archiving utility

tasksel - a user interface for installing tasks

tee - read from standard input and write to standard output and files

telnet — user interface to the TELNET protocol

test - check file types and compare values

timeout - run a command with a time limit

tmux — terminal multiplexer

top - display Linux processes

touch - change file timestamps

tr - translate or delete characters

traceroute - print the route packets trace to network host

truncate - shrink or extend the size of a file to the specified size

ucf - Update Configuration File: preserve user changes in configuration files

umount - unmount filesystems

uname - print system information

unexpand - convert spaces to tabs

uniq - report or omit repeated lines

unlink - call the unlink function to remove the specified file

unzip - list, test and extract compressed files in a ZIP archive

uptime - Tell how long the system has been running.

useradd - create a new user or update default new user information

userdel - delete a user account and related files

usermod - modify a user account

vim - Vi IMproved, a programmer's text editor

vmstat - Report virtual memory statistics

w - Show who is logged on and what they are doing.

wc - print newline, word, and byte counts for each file

who - show who is logged on

whoami - print effective user name

xauth - X authority file utility

xhost - server access control program for X

xinit - X Window System initializer

Xorg - X11R7 X server

xrandr - primitive command line interface to RandR extension

xset - user preference utility for X

xz, unxz, xzcat, lzma, unlzma, lzcat - Compress or decompress .xz and .lzma files

zip - package and compress (archive) files

zlib - compression/decompression library