ref: 638a4aaaa3a837efe603efcf48ce6e33a4fd4161
dir: /libc/utfrune.c/
#include <u.h> #include <libc.h> char* utfrune(char *s, long c) { long c1; Rune r; int n; if(c < Runesync) /* not part of utf sequence */ return strchr(s, c); for(;;) { c1 = *(uchar*)s; if(c1 < Runeself) { /* one byte rune */ if(c1 == 0) return 0; if(c1 == c) return s; s++; continue; } n = chartorune(&r, s); if(r == c) return s; s += n; } return 0; }