1#include "stdio_impl.h"
2#include <limits.h>
3#include <errno.h>
4
5off_t __ftello_unlocked(FILE *f)
6{
7	off_t pos = lseek(f->fd, (off_t)0,
8		(f->flags & F_APP) && f->wpos != f->wbase
9		? SEEK_END : SEEK_CUR);
10	if (pos < 0) return pos;
11
12	/* Adjust for data in buffer. */
13	if (f->rend)
14		pos += f->rpos - f->rend;
15	else if (f->wbase)
16		pos += f->wpos - f->wbase;
17	return pos;
18}
19
20off_t __ftello(FILE *f)
21{
22	off_t pos;
23	FLOCK(f);
24	pos = __ftello_unlocked(f);
25	FUNLOCK(f);
26	return pos;
27}
28
29long ftell(FILE *f)
30{
31	off_t pos = __ftello(f);
32	if (pos > LONG_MAX) {
33		errno = EOVERFLOW;
34		return -1;
35	}
36	return pos;
37}
38
39weak_alias(__ftello, ftello);
40