#REDHAT Certified System Admin in Telugu | Day 02 | RHCSA | Basic Commands | VI

Introduction

This tutorial provides a comprehensive guide to mastering basic Linux commands and tools, as taught in the #REDHAT Certified System Admin course. By following these steps, you will develop a solid foundation in Linux, which is crucial for system administration and other IT roles. This guide covers essential commands, working with the Bash shell, file system hierarchy, and using the Vim editor.

Step 1: Learn Basic Linux Commands

Understanding basic Linux commands is essential for navigating and managing the Linux operating system. Here are some key commands to start with:

• ls: Lists files and directories in the current directory.
• cd: Changes the current directory.
• pwd: Prints the current working directory.
• cp: Copies files or directories.
• mv: Moves or renames files or directories.
• rm: Removes files or directories.
• mkdir: Creates a new directory.
• rmdir: Removes an empty directory.

Practical Tips

• Use man <command> to access the manual for any command, which provides detailed information about its usage.

Step 2: Working with Bash Shell

The Bash shell is a command-line interface that allows you to interact with the system. Familiarize yourself with the following concepts:

• Command Syntax: Understand how to structure commands and use options/flags (e.g., ls -l for a detailed list).
• File Paths: Learn the difference between absolute and relative paths.
• Tab Completion: Use the Tab key to auto-complete commands and file names, which saves time and reduces errors.

Practical Tips

• To view command history, use the history command. You can re-run commands using the ! followed by the command number.

Step 3: I/O Redirecting and Piping

Input/Output (I/O) redirection allows you to control where input comes from and where output goes. Piping is a way to send the output of one command as input to another.

• Output Redirection: Use > to redirect output to a file (e.g., ls > filelist.txt).
• Input Redirection: Use < to take input from a file (e.g., sort < filelist.txt).
• Piping: Use | to connect commands (e.g., ls -l | grep "txt" to filter output).

Practical Tips

• Be cautious with the > operator, as it overwrites the file. Use >> to append instead.

Step 4: Understanding the Linux File System Hierarchy

Familiarize yourself with the structure of the Linux file system, which is hierarchical. Key directories include:

• /: Root directory
• /home: User home directories
• /etc: Configuration files
• /var: Variable files like logs
• /usr: User programs and applications

Practical Tips

• Use tree (if installed) to visualize the directory structure.

Step 5: Accessing Man Pages

Manual pages (man pages) provide documentation for commands. To access them:

• Use man <command> to read about the command’s options and usage.
• Navigate using the arrow keys, and press q to exit.

Practical Tips

• Explore different sections of man pages by specifying the section number, e.g., man 5 passwd.

Step 6: Complete Vim Commands

Vim is a powerful text editor in Linux. Here are essential commands to get started:

• Open a file: vim filename
• Insert mode: Press i to start editing.
• Save and exit: Type :wq, or just :q! to exit without saving.
• Delete a line: Press dd.
• Undo changes: Press u.

Practical Tips

• Vim has a steep learning curve; practice frequently to become proficient.

Conclusion

By mastering these basic commands and concepts, you will establish a strong foundation in Linux system administration. Next steps include practicing these commands in a Linux environment, exploring additional resources, and considering advanced topics like scripting and system management. Keep experimenting and learning to enhance your skills further!