Help Help with C input handling

Code

int main() {

    Playlist **playlists = NULL;

    int playlistCount = 0;

    int choice = 0;

    do{

        printMainMenu();

        scanf("%d", &choice);

            switch (choice) {

                case 4:

                {

                    break;

                }

                case 1:

                {

                    showPlaylists(playlists, playlistCount);

                    break;

                }

                case 2:

                {

                    addPlaylist(&playlists, &playlistCount);

                    break;

                }

                case 3:

                {

                    deletePlaylist(&playlists, &playlistCount);

                    break;

                }

            }

    }while(choice != 4);

    for (int i = 0; i < playlistCount; i++) {

        freePlaylist(playlists[i]);

    }

    free(playlists);

    printf("Goodbye!\n");

    return 0;

}

AI Quote:
The issue you're facing is due to how scanf interacts with the input buffer. When you paste multiple lines into the terminal, scanf can leave a newline (\n) or other characters in the input buffer. This often results in the last input being unprocessed if not followed by a whitespace or newline, especially when using scanf("%d", &choice).

Here's how you can fix or mitigate the issue:
Key Points:

Flushing the Input Buffer: After every scanf, you should clear the remaining characters in the buffer to ensure the program doesn't hang or behave unexpectedly.

Using fgets Instead of scanf: fgets is safer for handling input as it reads the entire line, making it less likely to leave stray characters in the input buffer.

Updated Main Loop with Buffer Management:

Replace your scanf("%d", &choice) with a safer approach:

Code 
#include <stdio.h>

#include <stdlib.h>

int main() {

    Playlist **playlists = NULL;

    int playlistCount = 0;

    int choice = 0;

    char buffer[100]; // Buffer to read input as a string

    do {

        printMainMenu();

        if (fgets(buffer, sizeof(buffer), stdin) != NULL) {

            // Convert input string to integer

            if (sscanf(buffer, "%d", &choice) != 1) {

                printf("Invalid input. Please enter a number.\n");

                continue;

            }

        } else {

            printf("Error reading input.\n");

            break;

        }

        switch (choice) {

            case 4:

                break;

            case 1:

                showPlaylists(playlists, playlistCount);

                break;

            case 2:

                addPlaylist(&playlists, &playlistCount);

                break;

            case 3:

                deletePlaylist(&playlists, &playlistCount);

                break;

            default:

                printf("Invalid choice. Please try again.\n");

        }

    } while (choice != 4);

    for (int i = 0; i < playlistCount; i++) {

        freePlaylist(playlists[i]);

    }

    free(playlists);

    printf("Goodbye!\n");

    return 0;

}

Why This Works:

fgets Reads Entire Line: Ensures that any leftover newline characters are included in the input, preventing issues when pasting multiple lines of input.
sscanf for Parsing: Safely converts the input string into an integer while avoiding issues caused by stray characters in the buffer.
Buffer Size: Use a sufficiently large buffer (char buffer[100]) to handle user input, but ensure it aligns with your maximum expected input size.

Notes:

Menu Loop Safety: Adding clear prompts and handling invalid inputs ensures your program doesn’t break when unexpected input is given.
Test Edge Cases: Paste inputs with trailing newlines, without trailing spaces, or even with invalid characters to verify robustness.