Using fseek to backtrack

Question

Is using fseek to backtrack character fscanf operations reliable?

Like for example if I have just fscanf-ed 10 characters but

Answer 1

Fseek has no understanding of the file's contents and just moves the filepointer 10 characters back.

fscanf depending on the OS, may interpret newlines differently; it may even be so that fscanf will insert the ^M if you're on DOS and the ^M does not appear in the file. Check your manual that came with your C compiler