summaryrefslogtreecommitdiff
path: root/src/stdio/ftell.c
blob: 3904a1d871dd9229b59ba0c97d13923dfc8d5c14 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
#include "stdio_impl.h"

off_t __ftello_unlocked(FILE *f)
{
	off_t pos = f->seek(f, 0, SEEK_CUR);
	if (pos < 0) return pos;

	/* Adjust for data in buffer. */
	return pos - (f->rend - f->rpos) + (f->wpos - f->wbase);
}

off_t __ftello(FILE *f)
{
	off_t pos;
	FLOCK(f);
	pos = __ftello_unlocked(f);
	FUNLOCK(f);
	return pos;
}

long ftell(FILE *f)
{
	off_t pos = __ftello(f);
	if (pos > LONG_MAX) {
		errno = EOVERFLOW;
		return -1;
	}
	return pos;
}

weak_alias(__ftello, ftello);

LFS64(ftello);