Cheatsheet for Linux commands

There are hundreds commands available in Linux.
Only a very small subset of those commands are used on a day-to-day basis.
This Linux Commands Cheat Sheet offers a quick reference for both experienced and basic users.

Command Description Alternative Example
BASICS --- --- ---
man Display the manual page for a specific command tldr (*) man ls
history Print a history list of all commands history
clear Clear the terminal clear
echo Print anything to the terminal output echo "Hello world!"
export Set environment variable export var1="Hello world!"
alias Set another name for a command that you’ve defined alias lsl="ls -l"
SYS INFO --- --- ---
date Display the current system date and time date
hostnamectl Get system information including, operating system, kernel, and release version uname, lsb_release, hostname hostnamectl && hostname && uname -a
free Display free and used memory in the system free -m
USER MGT --- --- ---
sudo Escalate privileges (equivalent to logging in as root) sudo command1 && sudo -i
w Display all currently logged in users w
whoami Display current user’s username whoami
passwd Set the password for your own account, or for other accounts if you have the permissions passwd && passwd -f username1
id Display UID and GID of the current user id
last Display information of the last login user last
useradd Add a new user account useradd user1
userdel Delete a user account userdel -r user1
usermod Change the user account information including, group, home directory, shell, expiration date usermod [option] user1 && usermod -aG group1 user1
groupadd Create a new group groupadd group1
groupdel Remove a group groupdel group1
groups Print the names of the primary and any supplementary groups for each given username, or the current process if no names are given groups username1
FILE MGT --- --- ---
ls List all files and directories in the current working directory ls -al
pwd Print working directory pwd
cd Change the current directory cd && cd ..
mkdir Create a directory mkdir dir1
touch Creates an empty file or updates the timestamp of an existing file touch file1
cp Copy files cp oldfile newfile
mv Move/Rename a file mv oldfile newfile
rm Delete a file / directory rm file1 && rm -rfi dir1
ln Create a link to another file ln -s file1 link1 && ln -l
chmod Assign (read, write, and execute) permission to files and directories chmod 777 file1 && chmod -R 777 dir1 && chmod 766 file1 && chmod -x file1
chown Change the owner and group ownership of a file or directory chown user1 file1 && chown user1:group1 file1 && chown -R user1:group1 dir1
rsync Transfer and synchronize files between local and remote devices using a delta-transfer algorithm (using ssh) rsync -a /opt/filename.zip /tmp/
nc Transfer data between machines using netcat ip a && nc -lv 1337 > dest.bin && nc -w 1 192.168.0.91 1337 < src.bin
tar List/Compress/Uncompress files in/from the Tar archive tar -tvf file1.tar && tar -cvf file1.tar file2 && tar -xvf file1.tar && tar -xvf file1.tar file2.txt && tar -rvf file1.tar file2.txt
zip Compress files to a zip zip file1.zip file2.txt file3.txt file4.txt && zip -u file1.zip file2.txt && zip -d file1.zip file2.txt
unzip List/Uncompress files in/from a zip archive file unzip file1.zip && unzip file1.zip -d /dir1
extra: ~ Home folder of current user cd ~
extra: .bashrc File with commands to execute each time a new interactive, non-login shell is started echo 'alias ll="ls -lah"' >> .bashrc
extra: .bash_profile File with commands to execute when you start a login shell echo "neofetch" >> .bash_profile && echo ". ~/.bashrc" >> .bash_profile
FILE VIEWING --- --- ---
cat Display the content of the file cat file1
head / tail Display the first/last 10 lines of a file head file1 && tail file2
less, more Break down the output and scroll through it using enter or space keys cat file1 | less -sN
diff, cmp, comm Compare files: find text/binary/sorted differences, diff file1 file2 && cmp file1 file2 && comm file1 file2
sort Sort lines in a text file or standard input cat file1 | sort -n
grep Search for specific patterns or strings in string; "global regular expression print" cat file1 | grep "Hello"
awk Powerful search through text files by columns awk '/manager/ {print}' employee.txt
sed Powerful stream editor gsed sed 's/unix/linux/' geekfile.txt
cut Cut sections from each line of a file, and write the result to the standard output cut -b 1-3,5-7 state.txt
nano, msedit Start this text editor using a command line interface vim, gedit nano file1 && sudo snap install msedit && msedit file1
DISK MGT --- --- ---
fdisk List all disk partitions / Create partition fdisk -l && fdisk /dev/sda
mkfs Format a partition mkfs.ext4 /dev/sda1
fsck Check and repair a filesystem for any error fsck.ext4 /dev/sda1
mount Mount any partition to any directory mount /dev/sda1 /mnt
df Display free space of mounted file system df -h
du Display the size of your current directory du -hs
lsblk Display information about block devices lsblk
lsusb Display all USB devices lsusb -tv
hdparam Perform a read speed test on disk hdparm -tT /dev/sda
badblocks Test for unreadable blocks on disk badblocks -s /dev/sda
PROCESS MGT --- --- ---
which Locate the executable file associated with a given command including binaries, scripts, and aliases whereis, whatis which ls
pidof Get the PID of any process pidof processname1
ps Display all active processes ps && ps -ef | grep processname1 && ps -p pid1
pstree Display processes in the tree-like diagram pstree
bg Display stopped or background jobs bg
top Manage and display all processes in realtime htop (*) top
kill Kill a specific process using process ID kill pid1
killall Kill all processes by name killall processname1
shutdown Shut down the system shutdown -h now
reboot Restart the system reboot
systemctl Manage system services and units with commands to start, stop, restart, check status via systemd and service manager (prefer over "service") systemctl status serviceName1
journalctl Allows to filter logs by boot sessions, time ranges, systemd units, process IDs, user IDs, group IDs, and more journalctl -r
service Manage system services (long-running processes that are started at boot time and run in background) serice ssh status && service ssh stop && service ssh start
lsof List all files opened by running processes lsof
extra: $PATH Environmental variable that tells the shell which directories to search for executable files echo $PATH
NETWORK MGT --- --- ---
ip Display the IP and Mac Address of the system ifconfig (*) ip a && ifconfig && ip addr show
netstat Display all listening port netstat -pnltu
ping Check connectivity between two hosts ping ip_host1
traceroute Trace the route of network packet traceroute host1
ssh Establish a secure shell connection to a remote server ssh user1@host1
wget Download a file wget linkToFile1
PACKAGE MGT --- --- ---
apt List/Install/Remove the package on Debian based distributions apt-get, dpkg, apt apt-get install packagename1 && apt-get remove packagename1 && apt-get update && dpkg -l | grep -i installed && dpkg -i packagename1.deb && apt-get upgrade packagename1 && apt-get autoremove
dnf List/Install/Remove a package on RPM-based distributions rpm, yum, dnf yum install packagename1 && yum remove packagename1 && yum update && yum list --installed && yum list --available
nix (*) Declative and tranactional package manager for all distros nix profile install nixpkgs#tmux

Package managers are used to install apps (and libraries):

Linux File System

Category Directory Description
BINARIES --- ---
System Binaries /bin essential executable binaries for all users
/sbin essential executable binaries for root user
/lib, /lib* libraries with shared code between binaries
User Binaries /usr "unix system resources", non-essential and installed binaries or applications
Optional Software /opt optional or add-on or large third-party software - rarely used, eg /opt/google/chrome
CONFIGURATION --- ---
Configuration files /etc system-wide/global configuration files "Et cetera / Editable Text Config"
DATA --- ---
User-related directories /home permission based personal space for regular users
/root personal space for root user
Service Files /var "variable" secured files which change frequently during system operations, eg logging, caching
/run temporary runtime data for system and applications right after boot
/srv temporary runtime data for services
Temporary Files /tmp modifyable files for short time use, created by apps or users
/lost+found chunks of broken files after system crash
MOUNT --- ---
Mount Points & Media /media automatically mounted removable media, and used by regular users
/mnt storage mounted by root/sysadmin and used by scripts
BOOT & KERNEL --- ---
Boot & Kernel related /dev device or hardware files - dynamically created, eg /dev/sda represents first hard drive
/boot all files to boot the system, eg grub.cfg
System Info /proc virtual fs containing dynamic data about running processes
/sys virtual fs containing dynamic data about linux kernel