src/multibyte/wcsrtombs.c

   1 #include <wchar.h>
   2
   3 size_t wcsrtombs(char *restrict s, const wchar_t **restrict ws, size_t n, mbstate_t *restrict st)
   4 {
   5         const wchar_t *ws2;
   6         char buf[4];
   7         size_t N = n, l;
   8         if (!s) {
   9                 for (n=0, ws2=*ws; *ws2; ws2++) {
  10                         if (*ws2 >= 0x80u) {
  11                                 l = wcrtomb(buf, *ws2, 0);
  12                                 if (!(l+1)) return -1;
  13                                 n += l;
  14                         } else n++;
  15                 }
  16                 return n;
  17         }
  18         while (n>=4) {
  19                 if (**ws-1u >= 0x7fu) {
  20                         if (!**ws) {
  21                                 *s = 0;
  22                                 *ws = 0;
  23                                 return N-n;
  24                         }
  25                         l = wcrtomb(s, **ws, 0);
  26                         if (!(l+1)) return -1;
  27                         s += l;
  28                         n -= l;
  29                 } else {
  30                         *s++ = **ws;
  31                         n--;
  32                 }
  33                 (*ws)++;
  34         }
  35         while (n) {
  36                 if (**ws-1u >= 0x7fu) {
  37                         if (!**ws) {
  38                                 *s = 0;
  39                                 *ws = 0;
  40                                 return N-n;
  41                         }
  42                         l = wcrtomb(buf, **ws, 0);
  43                         if (!(l+1)) return -1;
  44                         if (l>n) return N-n;
  45                         wcrtomb(s, **ws, 0);
  46                         s += l;
  47                         n -= l;
  48                 } else {
  49                         *s++ = **ws;
  50                         n--;
  51                 }
  52                 (*ws)++;
  53         }
  54         return N;
  55 }