75+ Essential Linux Commands Every User Should Know [with pdf]

Jun 22, 2025

The command line is where you get real control in Linux. It lets you dig into the system, automate tasks, and solve problems directly.

This guide includes a hand-picked list of fundamental Linux commands, grouped by category. You’ll find commands for managing files, users, hardware, networking, and more.

System-Based Commands

uname - Displays system information: kernel version, machine type, and more.
uname -r - Displays the running Linux kernel's release version.
uptime - Shows current time, system uptime, users, and load averages.
hostname - Shows the system hostname.
hostname -i - Displays the IP address of the current host.
last reboot - Shows last reboot times and durations in logs.
date - Displays the current date and time information.
timedatectl - Displays detailed system clock and time zone information.
cal - Displays a simple calendar of the current month.
w - Shows who is logged on and their activity.
whoami - Displays the username of the current user.
finger username - Displays information about a user named username.

Hardware-Based Commands

dmesg - Displays messages from the kernel's ring buffer.
cat /proc/cpuinfo - Displays detailed information about the CPU.
cat /proc/meminfo - Displays detailed system memory usage information.
lscpu - Lists information about the CPU.
lshw - Lists detailed hardware configuration of the system.
lsblk - Lists information about all available block devices.
free -m - Shows system memory usage in megabytes.
lspci -tv - Displays PCI devices in tree format, verbosely.
lsusb -tv - Shows USB devices as a tree, verbosely.
dmidecode - Displays hardware information from system BIOS.
hdparm -i /dev/sda - Displays information of disk /dev/sda.
badblocks -s /dev/sda - Checks /dev/sda for bad blocks, showing progress.

User Management Commands

id - Displays the user's UID, GID, and groups.
last - Shows list of last logged-in users.
who - Displays who is currently logged in.
groupadd admin - Creates a new user group named admin.
adduser Sam - Creates a new user account named Sam.
userdel Sam - Deletes the user account named Sam.
usermod - Modifies properties of an existing user account.

File Commands

ls -al - Lists all files, with detailed information, in long format.
pwd - Displays the present working directory's path.
mkdir dir1 - Creates a new directory named dir1.
rm file1 - Deletes the file named file1.
rm -f file2 - Forcefully deletes the file named file2.
rm -r dir1 - Recursively removes directory dir1 and its contents.
rm -rf dir1 - Forcefully deletes directory dir1 and its contents.
cp file1 file2 - Copies file1, creating or overwriting file2.
cp -r dir1 dir2 - Copies dir1 to dir2, including subdirectories.
mv file1 file2 - Renames or moves file1 to file2.
ln -s /path/to/file_name link_name - Creates symbolic link named link_name to file_name.
touch file1 - Creates an empty file named file1.
cat > file1 - Creates or overwrites file1, awaiting standard input.
more file1 - Displays file1 content, paginating through output.
head file1 - Displays the first ten lines of file1.
tail file1 - Displays the last ten lines of file1.
gpg -c file1 - Encrypts file1 with a symmetric cipher using a passphrase.
gpg file2.gpg - Decrypts file2.gpg, prompting for the passphrase.
wc - Counts words, lines, and characters in files.
xargs - Executes commands with piped or file-provided arguments.

Network Commands

ip addr show - Displays all network interfaces and their information.
ip address add 192.168.0.1/24 dev eth0 - Assigns IP address 192.168.0.1 to interface eth0.
ifconfig - Shows network interfaces and their configuration.
ping host - Sends ICMP packets, measures round-trip time to host.
whois domain - Retrieves and displays a domain's registration information.
dig domain - Queries DNS, provides domain's DNS information.
dig -x host - Resolves IP address to hostname, shows reverse DNS info.
host google.com - Performs an IP lookup for the domain name.
wget file_path - Downloads file from the specified path.
netstat - Displays various network-related information and statistics.
ss - Displays information about network sockets.

Compression / Archive Commands

tar -cf backup.tar /home/ubuntu - Creates a tar archive of the /home/ubuntu directory.
tar -xf backup.tar - Extracts files from the backup.tar archive.
tar -zcvf backup.tar.gz /home/ubuntu - Creates compressed backup.tar.gz archive of /home/ubuntu.
gzip file1 - Compresses file1 into file1.gz; original file is removed.

Install Packages Commands

rpm -i pkg_name.rpm - Installs the package pkg_name.rpm using RPM.
rpm -e pkg_name - Uninstalls the specified RPM package.
dnf install pkg_name - Installs the specified package using DNF.
pacman -S pkg_name - Installs the specified package using Pacman.

Install from Source (Compilation)

./configure - Checks system compatibility and generates Makefile.
make - Compiles code using the Makefile.
make install - Installs compiled code into appropriate system locations.

Search Commands

grep pattern file - Searches for a given pattern within the specified file.
grep -r pattern dir1 - Recursively searches for pattern in directory dir1.
locate file - Finds files named file using a prebuilt index database.
find /home -name index - Searches /home for files named index.
find /home -size +10000k - Finds files over 10,000 KB in /home.

Login Commands

ssh user@hostname - Initiates SSH connection to specified host.
ssh -p port_number user@hostname - Connects over SSH using a specific port.
ssh hostname - Connects to hostname using SSH on port 22.
telnet host - Connects to host via Telnet on port 23.

File Transfer Commands

scp file.txt remoteuser@remote_host:/remote/directory - Copies file.txt to a remote directory.
rsync -a /home/ubuntu /backup/ - Synchronizes /home/ubuntu to /backup/, preserving attributes.
rsync -a /var/www/web/ user@remote_host:/backup/web_backup/ - Syncs local directory to remote backup.