5.28 fsetpos—restore position of a stream or file

Synopsis

#include <stdio.h>
int fsetpos(FILE *fp, const fpos_t *pos);
int _fsetpos_r(struct _reent *ptr, FILE *fp,
    const fpos_t *pos);

Description
Objects of type FILE can have a “position” that records how much of the file your program has already read. Many of the stdio functions depend on this position, and many change it as a side effect.

You can use