nsz Git - musl/blob - src/multibyte/wcsrtombs.c

   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
   9 size_t wcsrtombs(char *restrict s, const wchar_t **restrict ws, size_t n, mbstate_t *restrict st)
  10 {
  11         const wchar_t *ws2;
  12         char buf[4];
  13         size_t N = n, l;
  14         if (!s) {
  15                 for (n=0, ws2=*ws; *ws2; ws2++) {
  16                         if (*ws2 >= 0x80u) {
  17                                 l = wcrtomb(buf, *ws2, 0);
  18                                 if (!(l+1)) return -1;
  19                                 n += l;
  20                         } else n++;
  21                 }
  22                 return n;
  23         }
  24         while (n>=4) {
  25                 if (**ws-1u >= 0x7fu) {
  26                         if (!**ws) {
  27                                 *s = 0;
  28                                 *ws = 0;
  29                                 return N-n;
  30                         }
  31                         l = wcrtomb(s, **ws, 0);
  32                         if (!(l+1)) return -1;
  33                         s += l;
  34                         n -= l;
  35                 } else {
  36                         *s++ = **ws;
  37                         n--;
  38                 }
  39                 (*ws)++;
  40         }
  41         while (n) {
  42                 if (**ws-1u >= 0x7fu) {
  43                         if (!**ws) {
  44                                 *s = 0;
  45                                 *ws = 0;
  46                                 return N-n;
  47                         }
  48                         l = wcrtomb(buf, **ws, 0);
  49                         if (!(l+1)) return -1;
  50                         if (l>n) return N-n;
  51                         wcrtomb(s, **ws, 0);
  52                         s += l;
  53                         n -= l;
  54                 } else {
  55                         *s++ = **ws;
  56                         n--;
  57                 }
  58                 (*ws)++;
  59         }
  60         return N;
  61 }