Objective: Enhance the cat utility to add line numbers to the output and a flag to display non-printing characters.

Approach: Update the cat utility to support two new flags: -n for adding line numbers and -v for displaying non-printing characters in a visible format. The utility will read from files or standard input and process the content based on the provided flags.

Files to be Modified/Added:

1. user/cat.c: Modify the existing cat utility to handle new flags and implement the required features.

Detailed Steps:

1. Update cat Function:

• Modify the cat function to accept additional parameters for line numbering and non-printing character display.
• Implement logic to add line numbers at the beginning of each line if the -n flag is set.
• Implement logic to convert non-printing characters to a visible format if the -v flag is set.

2. Parse Command-Line Arguments:

• Update the main function to parse the -n and -v flags.
• Pass the parsed flags to the cat function.

3. Implement Line Numbering:

• In the cat function, maintain a line counter.
• Print the line number at the beginning of each line if the -n flag is set.

4. Display Non-Printing Characters:

• In the cat function, check each character.
• If the character is non-printing (ASCII value < 32 or 127), convert it to a visible format (e.g., ^A for ASCII 1).

Future Development:

1. Add Support for Additional Flags:

• Implement a -b flag to number non-blank lines only.
• Implement a -E flag to display $ at the end of each line.

2. Improve Performance:

• Optimize the reading and writing process to handle larger files more efficiently.

3. Add Unit Tests:

• Create unit tests to verify the functionality of the new features and ensure they work correctly under various conditions.