1 #include <wchar.h>
2
wcsnrtombs(char * restrict dst,const wchar_t ** restrict wcs,size_t wn,size_t n,mbstate_t * restrict st)3 size_t wcsnrtombs(char *restrict dst, const wchar_t **restrict wcs, size_t wn, size_t n, mbstate_t *restrict st)
4 {
5 size_t l, cnt=0, n2;
6 char *s, buf[256];
7 const wchar_t *ws = *wcs;
8 const wchar_t *tmp_ws;
9
10 if (!dst) s = buf, n = sizeof buf;
11 else s = dst;
12
13 while ( ws && n && ( (n2=wn)>=n || n2>32 ) ) {
14 if (n2>=n) n2=n;
15 tmp_ws = ws;
16 l = wcsrtombs(s, &ws, n2, 0);
17 if (!(l+1)) {
18 cnt = l;
19 n = 0;
20 break;
21 }
22 if (s != buf) {
23 s += l;
24 n -= l;
25 }
26 wn = ws ? wn - (ws - tmp_ws) : 0;
27 cnt += l;
28 }
29 if (ws) while (n && wn) {
30 l = wcrtomb(s, *ws, 0);
31 if ((l+1)<=1) {
32 if (!l) ws = 0;
33 else cnt = l;
34 break;
35 }
36 ws++; wn--;
37 /* safe - this loop runs fewer than sizeof(buf) times */
38 s+=l; n-=l;
39 cnt += l;
40 }
41 if (dst) *wcs = ws;
42 return cnt;
43 }
44