Linux Cheat Sheet

Hardware Information

lscpu See CPU information
lsblk See block devices
lspci -tv Show PCI devices
lsusb -tv Show USB devices
lshw Show hardware information
cat /proc/cpuinfo View CPU details
cat /proc/meminfo View memory details
cat /proc/mounts View mounted file systems
free -h Check free and used memory
sudo dmidecode Show hardware info from BIOS
hdparm -i /dev/[device] Show info about disk device
hdparm -tT /dev/[device] Conduct a read speed test on device
badblocks -s /dev/[device] Test for unreadable blocks on device
fsck /dev/[device] Run a disk check on unmounted partition

Searching

find [path] -name [pattern] Find files and directories
find [path] -size [+100M] Find files larger than 100MB
grep [pattern] [file] Search for a specific pattern in file
grep -r [pattern] [dir] Search recursively for pattern in directory
locate [name] Locate all files and directories by name
which [command] Show the full path of a command
whereis [command] Locate the binary, source, and manual page files
awk '[pattern] {print $0}' [file] Print all lines matching a pattern
sed 's/[old]/[new]/' [file] Find and replace text in a file

File Commands

mkdir [dir] Create a new directory
rm [file] Remove a file
rm -r [dir] Remove a directory recursively
rm -rf [dir] Force remove a directory recursively
cp [src] [dest] Copy a file
cp -r [src_dir] [dest_dir] Copy a directory recursively
mv [src] [dest] Move or rename files/directories
ln -s [path]/[file] [link] Create a symbolic link
touch [file] Create a new empty file
cat [file] Show the contents of a file
head [file] Show the first 10 lines of a file
tail [file] Show the last 10 lines of a file
more [file] Display file content page by page
less [file] Similar to more but allows backward movement
nano [file] Open file in Nano text editor
vim [file] Open file in Vim text editor
gpg -c [file] Encrypt a file
gpg [file].gpg Decrypt a file
wc -w [file] Count words in a file
cut -d [delim] [file] Cut a section of a file
shred -u [file] Overwrite and delete a file securely
diff [file1] [file2] Compare two files
source [file] Read and execute file content in current shell
[cmd] | tee [file] Output command result to screen and file

Directory Navigation

ls List files and directories
ls -a List all files (including hidden)
ls -l List files with detailed info
pwd Show current working directory
cd Change to home directory
cd .. Move up one directory level
cd - Move to previous directory
cd [path] Change to specified directory

File Compression

tar cf [archive.tar] [dir] Create a tar archive
tar xf [archive.tar] Extract a tar archive
tar czf [archive.tar.gz] Create a compressed tar archive
gzip [file] Compress a file (.gz)
gunzip [file.gz] Decompress a .gz file
bzip2 [file] Compress a file (.bz2)
bunzip2 [file.bz2] Decompress a .bz2 file

File Transfer

scp [file] [user]@[host]:[path] Securely copy file to remote host
rsync -a [src] [user]@[host]:[dest] Synchronize files with remote host
wget [link] Download file from URL
curl -O [link] Download file from URL
sftp [user]@[host] Connect via SFTP

User and Group

id Show user and group IDs
last Show last logged in users
who Show who is logged in
w Show who is logged in and what they are doing
sudo useradd [user] Create a new user
sudo userdel [user] Delete a user
sudo usermod -aG [group] [user] Add user to a group
passwd [user] Change user password
sudo groupadd [group] Create a new group
sudo groupdel [group] Delete a group
su - [user] Switch to another user account

Package Installation

sudo apt install [pkg] Install package (Debian/Ubuntu)
apt search [keyword] Search for package
apt show [pkg] Show package info
sudo dpkg -i [pkg.deb] Install .deb file
sudo yum install [pkg] Install package (RHEL/CentOS)
sudo dnf install [pkg] Install package (Fedora)
sudo rpm -i [pkg.rpm] Install .rpm file
sudo snap install [pkg] Install Snap package
flatpak install [pkg] Install Flatpak package

Process Related

ps List active processes
top View all running processes
htop Interactive process viewer
kill [pid] Kill process by ID
pkill [name] Kill process by name
killall [name] Kill all processes by name
bg Resume suspended job in background
fg Bring background job to foreground
lsof List open files

System Management

uname -a Show kernel and system info
uptime Show system uptime
hostname -i Show IP address
date Show current date and time
timedatectl Query and change system clock
shutdown now Shutdown system immediately
reboot Reboot system
dmesg Show bootup messages

Disk Usage

df -h Show free disk space
du -sh [dir] Show size of directory
fdisk -l List partition tables
mount [dev] [point] Mount a device
findmnt List all mounted filesystems

SSH Login

ssh [user]@[host] Connect to remote host
ssh -p [port] [user]@[host] Connect on specific port
ssh-keygen Generate SSH key pairs

File Permission

chmod 777 [file] Read, write, execute for all
chmod 755 [file] Read/execute for group/others
chown [user]:[group] [file] Change owner and group

Variable Commands

let "[var]=[val]" Assign integer value
export [var] Export Bash variable
declare [var]="[val]" Declare Bash variable
set List variables/functions
unset [var] Remove variable
echo $[var] Display variable value

Shell Command Management

alias [name]='[cmd]' Create alias
watch -n [sec] [cmd] Run periodically
sleep [sec] && [cmd] Run after delay
at [hh:mm] Schedule command
man [command] Show manual
history Show history

Linux Shell Shortcuts

Ctrl + C Kill process
Ctrl + Z Suspend process
Ctrl + D Log out
Ctrl + W Erase word
Ctrl + U Erase line
Ctrl + R Search history
fg Resume foreground
bg Resume background
clear Clear screen
!! Repeat last command
exit Log out

Hardware Information

Searching

File Commands

Directory Navigation

File Compression

File Transfer

User and Group

Package Installation

Process Related

System Management

Disk Usage

SSH Login

File Permission

Network

Variable Commands

Shell Command Management

Linux Shell Shortcuts