What are the functions of the vi command in Linux?

The Vi command is a commonly used text editor in the Linux system, with a variety of features, including but not limited to the following:

1. Edit text files: The vi command can be used to open, create, and edit text files.
2. Insert text: In edit mode, you can insert, modify, or delete text content.
3. Search and replace: You can use the vi command to search for specific content in the text and replace it.
4. Move cursor: You can use vi commands to move the cursor position in the text.
5. Undo and restore: You can use the vi command to undo previous actions and restore the previous state.
6. Copy and paste: You can use the vi command to duplicate text content and paste it elsewhere.
7. Save a file: Use the vi command to save changes to a text file.
8. To exit the vi editor, you can use the vi command.
9. Configure vi editor: You can customize the behavior of the editor by modifying vi’s configuration file.

Though the vi command is powerful, there might be a learning curve for beginners. Therefore, there are alternative text editor tools like nano, emacs, etc., that can be used.