src/multibyte/wcsnrtombs.c

   1 #include <wchar.h>
   2
   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 }