fxlibc/src/libc/stdio/fsetpos.c

#include <stdio.h>
#include <unistd.h>

int fsetpos(FILE *fp, fpos_t const *pos)
{
	if(fflush(fp) == EOF)
		return -1;

	off_t rc = lseek(fp->fd, *pos, SEEK_SET);
	if(rc < 0)
		return -1;

	fp->fdpos = *pos;
	fp->eof = 0;
	return 0;
}