LINUX COMMANDS DAY 2

LINUX COMMANDS
Here are the 50 essential Linux commands with explanations:

Basic File and Directory Commands

1. ls – Lists files and directories.
2. pwd – Prints the current working directory.
3. cd – Changes directories.
4. mkdir – Creates a new directory.
5. mv – Moves or renames files and directories.
6. cp – Copies files and directories.
7. rm – Removes (deletes) files or directories.
8. touch – Creates a new empty file.
9. ln – Creates symbolic (soft) or hard links.
10. clear – Clears the terminal screen.

File Viewing and Editing

1. cat – Displays the contents of a file.
2. echo – Prints text or variables to the terminal.
3. less – Views a file page-by-page.
4. man – Shows the manual for a command.
5. uname – Displays system information.
6. whoami – Shows the current logged-in user.
7. tar – Archives files (tarballs).
8. grep – Searches for patterns in files.
9. head – Displays the first few lines of a file.
10. tail – Displays the last few lines of a file.

File Comparison and Sorting

1. diff – Compares two files line by line.
2. cmp – Compares two files byte by byte.
3. comm – Finds common and unique lines in two files.
4. sort – Sorts the lines of a text file.
5. export – Sets environment variables.

File Compression and Networking

1. zip – Compresses files into a .zip archive.
2. unzip – Extracts files from a .zip archive.
3. ssh – Securely connects to a remote server.
4. service – Manages system services.
5. ps – Lists running processes.

Process and Disk Management

1. kill / killall – Terminates processes.
2. df – Displays disk space usage.
3. mount – Mounts a filesystem.
4. chmod – Changes file permissions.
5. chown – Changes file ownership.

Networking and Security

1. ifconfig – Displays or configures network interfaces.
2. traceroute – Shows the path packets take to a destination.
3. wget – Downloads files from the web.
4. ufw – Manages the firewall (Ubuntu).
5. iptables – Configures packet filtering rules.

Package Management and System Administration

1. apt, pacman, yum, rpm – Package managers for different Linux distros.
2. sudo – Runs a command as the superuser (root).
3. cal – Displays a calendar.
4. alias – Creates shortcuts for commands.
5. dd – Copies and converts files (often used for disk cloning).
6. wheris – Shows the location of a command.
7. whatis – Provides a brief description of a command.
8. top – Displays real-time system resource usage.
9. useradd – Creates a new user.
10. passwd – Changes a user’s password.