A. File and Directory Management Linux Commands:
- ssh - Secure Shell, used for secure remote access to a system
- ls - List directory contents.
- pwd - Print the current working directory.
- cd - Change directory to a different folder.
- touch - Create an empty file or update the modified timestamp of an existing file.
- echo - Print a message or the value of a variable.
- nano - A simple text editor.
- vim - A more advanced text editor with many features.
- cat - Print the contents of a file to the console.
- shred - Securely delete a file by overwriting its contents.
- mkdir - Create a new directory.
- cp - Copy a file from one location to another.
- mv - Move a file from one location to another, or rename a file.
- rm - Remove a file.
- rmdir - Remove a directory if it is empty.
- ln - Create a link to a file or directory.
B. System Management Commands:
- clear - Clear the console.
- useradd - Add a new user to the system.
- sudo - Run a command with administrative privileges.
- adduser - Add a new user to the system with more options than useradd.
- su - Switch to another user account.
- exit - Close the current terminal or log out of the current user account.
- sudo passwd - Change the password for the current user.
- sudo passwd [username] - Change the password for another user.
- sudo apt - A package manager used to install, update and remove software packages on Debian-based systems.
- 2sudo apt update & install - Update package lists and install packages.
- finger - Display information about a user.
- man - Display the manual page of a command.
- whatis - Display a brief description of a command.
- which - Locate a command and display its path.
- whereis - Locate the binary, source, and manual page files for a command.
- wget - Download files from the web.
- curl - Transfer data to or from a server.
- zip - Compress files into a zip archive.
- unzip - Extract files from a zip archive.
- less - View a file one page at a time.
B. System Management Commands:
- head - Display the first lines of a file.
- tail - Display the last lines of a file.
- cmp - Compare two files byte by byte.
- diff - Display the differences between two files.
- sort - Sort the lines of a file.
- find - Search for files in a directory hierarchy.
- chmod - Change the permissions of a file or directory.
- chown - Change the owner of a file or directory.
D. Networking Management & Monitoring Commands Overview:
- ifconfig - Configure network interfaces.
- ip address - Display IP address information.
- ip address | grep eth0 - Display the IP address of the eth0 interface.
- **ip address | grep eth0 | grep inet | awk **- Display the IP address of the eth0 interface using awk.
- resolvectl status - Display the current DNS resolver configuration.
- ping - Test network connectivity by sending packets to a host.
- netstat - Display network connections, routing tables, and interface statistics.
- -tulpn - Display active listening ports and associated programs.
- ss - Display socket statistics.
- iptables - Configure and administer the netfilter firewall.
- ufw - A user-friendly interface to manage iptables firewall rules.
E. System Information & Process Management Commands:
- uname - Print system information, including kernel name, network node hostname, kernel release, and kernel version.
- neofetch - Display system information in a colorful and visually appealing way.
- cal - Display a calendar of the current month or year.
- free - Display the amount of free and used system memory.
- df and df-H - Display disk usage statistics for a file system.
- ps - Report a snapshot of current processes.
- top - Display dynamic real-time information about running processes.
- kill - Send a signal to terminate a process.
- pkill - Send a signal to terminate one or more processes based on their name.
- systemctl - Control the systemd system and service manager.
- history - Display previously executed commands.
- sudo reboot - Reboot the system with administrative privileges.
- shutdown - Shutdown or reboot the system.