ref: c11957a7915d355d80ff7e6a21721ba05441ca29
dir: /libkern/utflen.c/
#include "lib9.h" int utflen(char *s) { int c; long n; Rune rune; n = 0; for(;;) { c = *(uchar*)s; if(c < Runeself) { if(c == 0) return n; s++; } else s += chartorune(&rune, s); n++; } }