macOS Question about reading into a character array (C)

General ideas.

1. Find a way to remove newlines or other control characters directly from the input stream. You mentioned fflush(). So either investigate that function more deeply as to why it's not working on a file, or find another function that does what you want.

"Investigate more deeply" means at least reading its man page, since I don't see anything there that suggests fflush() does what you said. If you have an example, you should post the code that shows this behavior. I realize you said you weren't posting code, so make it the smallest possible example that illustrates what you said, since what you said it does isn't working for what you want. It would hardly count against you to post code that doesn't work in fulfilling an assignment.

2. Read the data including the control chars you don't want, and then remove anything you don't want after it's been read into memory.

3. Read characters one by one, ignoring anything you don't want, so all the chars you don't want are never placed into memory.

4. Any or all of these can be done by writing your own function that performs a filtered read, then your main code calls your filtered-read function instead of fread() or fgets() or whatever.