ref: 6042bb8adffe111049edfcb8b2eb1ad84814ed69
dir: /lib9/utfrrune.c/
#include "lib9.h" char* utfrrune(char *s, long c) { long c1; Rune r; char *s1; if(c < Runesync) /* not part of utf sequence */ return strrchr(s, c); s1 = 0; for(;;) { c1 = *(uchar*)s; if(c1 < Runeself) { /* one byte rune */ if(c1 == 0) return s1; if(c1 == c) s1 = s; s++; continue; } c1 = chartorune(&r, s); if(r == c) s1 = s; s += c1; } }