Linux Command Line Cheat Sheet : 75 Essential Linux Commands

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

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• 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

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• 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

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• 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

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• 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

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• 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

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• 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

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• 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)

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

Search Commands

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• 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

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• 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

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• 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.

Disk Usage Commands

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• df -h - Shows human-readable disk space usage.
• df -i - Shows inode usage for all mounted filesystems.
• fdisk -l - Lists all partitions and information for all drives.
• du -sh /dir1 - Displays total disk usage of /dir1 in human-readable form.
• findmnt - Lists all mounted filesystems and their properties.
• mount device-path mount-point - Mounts a device to the specified mount point.

Directory Traversal Commands

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• cd .. - Navigates to the parent directory.
• cd - Changes the current directory to the user’s home.
• cd /mnt - Changes the current directory to /mnt.