1. File Commands

• ls: List files and directories in the current directory.

• pwd: Print the current working directory.

• cd: Change the current working directory.

• mkdir: Create a new directory.

• rmdir: Remove an empty directory.

• rm: Remove files and directories.

• cp: Copy files and directories.

• mv: Move or rename files and directories.

• ln: Create links to files and directories.

• touch: Create or update a file's timestamp.

• cat: Concatenate or display files.

• less: View files in a pager with scrolling and searching features.

• more: View files in a pager with limited features.

• head: Display the first few lines of a file.

• tail: Display the last few lines of a file.

• wc: Count words, lines, and characters in a file.

• diff: Compare two files and show the differences.

• grep: Search for a pattern in a file or input stream.

• find: Find files that match certain criteria.

• locate: Find files by name using a database.

1. Text Processing

   • grep: Search for a pattern in a file or input stream.

   • cat: Concatenate or display files.

   • awk: Processes and manipulates text files.

   • sed: Stream editor for modifying files.

2. File Compression and Archiving:

   • tar: Archives files into a tarball.

   • gzip: Compresses files.

   • zip/unzip: Compresses and extracts files in ZIP format.

   • rsync: Synchronizes files and directories.

3. Package Management:

• apt-get: Package management for Debian-based systems.

• yum: Package management for RPM-based systems.

• dnf: Next-generation package manager (RPM-based).

• pacman: Package management for Arch Linux.

1. System Information Commands

• uname: Print system information such as kernel name, version, and architecture.

• hostname: Print or set the system hostname.

• date: Print or set the system date and time.

• uptime: Show how long the system has been running and the load average.

• who: Show who is logged in to the system.

• w: Show who is logged in and what they are doing.

• last: Show the last logins to the system.

• free: Show the amount of free and used memory in the system.

• df: Show the disk space usage of the file systems.

• du: Show the disk space usage of files and directories.

1. Process Management

   • ps: Show information about the running processes.

   • top: Show the processes that are using the most CPU and memory resources.

   • htop: Show the processes that are using the most CPU and memory resources in an interactive interface.

   • Nice: Sets Process Priority

2. User Management Commands

• useradd: Create a new user account.

• userdel: Delete a user account and its home directory.

• usermod: Modify a user account's attributes.

• passwd: Change a user's password.

• chage: Change a user's password expiration settings.

• su: Switch to another user's account.

• groups: Print the groups that a user belongs to.

• id: Print the user ID and group ID of a user.

• umask: Set the default permissions for newly created files and directories.

1. Permissions and ownership:

   • chown: Change the owner and group of files and directories.

   • chmod: Change the permissions of files and directories.

   • sudo: Execute a command as another user, usually the superuser.

   • sudo: Executes commands with elevated privileges.

1. Network Commands

• ping: Test the connectivity to another host by sending packets and measuring the response time.

• traceroute: Trace the route that packets take to reach another host.

• ip: Show or manipulate IP addresses and routing tables.

• ifconfig: Show or configure network interfaces.

• iwconfig: Show or configure wireless network interfaces.

• netstat: Show network connections, routing tables, and statistics.

• ss: Show network connections, sockets, and statistics.

• tcpdump: Capture and analyze network traffic.

• nmap: Scan ports and services on a network host.

• curl: Transfer data from or to a server using various protocols.

• wget: Download files from the web.

• ssh: Connect to a remote host using secure shell protocol.

• scp: Copy files securely between hosts using secure copy protocol.

• sftp: Transfer files securely between hosts using secure file transfer protocol.

• rsync: Synchronize files between hosts using remote sync protocol.

1. System Administration:

• systemctl: Controls system services (systemd).

• cron: Schedules periodic tasks.

• journalctl: Views system logs.

• fdisk: Disk partitioning utility.

Package Management Commands Depending on your Linux distribution, you may use different commands to install, update, remove, and search for software packages. Here are some examples:

Debian/Ubuntu based distributions Use apt or apt-get commands.

apt update apt upgrade apt install [package] apt remove [package] apt search [package]

Red Hat/CentOS/Fedora based distributions Use yum or dnf commands.

yum update yum install [package] yum remove [package] yum search [package]

dnf update dnf install [package] dnf remove [package] dnf search [package]

Arch Linux based distributions Use pacman command.

pacman -Syu pacman -S [package] pacman -R [package] pacman -Ss [package]