src/stdio/fgetwc.c

   1 #include "stdio_impl.h"
   2 #include "locale_impl.h"
   3 #include <wchar.h>
   4 #include <errno.h>
   5
   6 static wint_t __fgetwc_unlocked_internal(FILE *f)
   7 {
   8         mbstate_t st = { 0 };
   9         wchar_t wc;
  10         int c;
  11         unsigned char b;
  12         size_t l;
  13
  14         /* Convert character from buffer if possible */
  15         if (f->rpos < f->rend) {
  16                 l = mbrtowc(&wc, (void *)f->rpos, f->rend - f->rpos, &st);
  17                 if (l+2 >= 2) {
  18                         f->rpos += l + !l; /* l==0 means 1 byte, null */
  19                         return wc;
  20                 }
  21                 if (l == -1) {
  22                         f->rpos++;
  23                         return WEOF;
  24                 }
  25         } else l = -2;
  26
  27         /* Convert character byte-by-byte */
  28         while (l == -2) {
  29                 b = c = getc_unlocked(f);
  30                 if (c < 0) {
  31                         if (!mbsinit(&st)) errno = EILSEQ;
  32                         return WEOF;
  33                 }
  34                 l = mbrtowc(&wc, (void *)&b, 1, &st);
  35                 if (l == -1) return WEOF;
  36         }
  37
  38         return wc;
  39 }
  40
  41 wint_t __fgetwc_unlocked(FILE *f)
  42 {
  43         locale_t *ploc = &CURRENT_LOCALE, loc = *ploc;
  44         if (f->mode <= 0) fwide(f, 1);
  45         *ploc = f->locale;
  46         wchar_t wc = __fgetwc_unlocked_internal(f);
  47         *ploc = loc;
  48         return wc;
  49 }
  50
  51 wint_t fgetwc(FILE *f)
  52 {
  53         wint_t c;
  54         FLOCK(f);
  55         c = __fgetwc_unlocked(f);
  56         FUNLOCK(f);
  57         return c;
  58 }
  59
  60 weak_alias(__fgetwc_unlocked, fgetwc_unlocked);
  61 weak_alias(__fgetwc_unlocked, getwc_unlocked);