1/*
2 * This code was written by Rich Felker in 2010; no copyright is claimed.
3 * This code is in the public domain. Attribution is appreciated but
4 * unnecessary.
5 */
6
7#include <wchar.h>
8
9size_t wcsnrtombs(char *restrict dst, const wchar_t **restrict wcs, size_t wn, size_t n, mbstate_t *restrict st)
10{
11	size_t l, cnt=0, n2;
12	char *s, buf[256];
13	const wchar_t *ws = *wcs;
14
15	if (!dst) s = buf, n = sizeof buf;
16	else s = dst;
17
18	while ( ws && n && ( (n2=wn)>=n || n2>32 ) ) {
19		if (n2>=n) n2=n;
20		wn -= n2;
21		l = wcsrtombs(s, &ws, n2, 0);
22		if (!(l+1)) {
23			cnt = l;
24			n = 0;
25			break;
26		}
27		if (s != buf) {
28			s += l;
29			n -= l;
30		}
31		cnt += l;
32	}
33	if (ws) while (n && wn) {
34		l = wcrtomb(s, *ws, 0);
35		if ((l+1)<=1) {
36			if (!l) ws = 0;
37			else cnt = l;
38			break;
39		}
40		ws++; wn--;
41		/* safe - this loop runs fewer than sizeof(buf) times */
42		s+=l; n-=l;
43		cnt++;
44	}
45	if (dst) *wcs = ws;
46	return cnt;
47}
48