sys/src/cmd/unix/u9fs/utfrune.c

   1 #include <plan9.h>
   2
   3 char*
   4 utfrune(char *s, long c)
   5 {
   6         long c1;
   7         Rune r;
   8         int n;
   9
  10         if(c < Runesync)                /* not part of utf sequence */
  11                 return strchr(s, c);
  12
  13         for(;;) {
  14                 c1 = *(uchar*)s;
  15                 if(c1 < Runeself) {     /* one byte rune */
  16                         if(c1 == 0)
  17                                 return 0;
  18                         if(c1 == c)
  19                                 return s;
  20                         s++;
  21                         continue;
  22                 }
  23                 n = chartorune(&r, s);
  24                 if(r == c)
  25                         return s;
  26                 s += n;
  27         }
  28         return 0;
  29 }