ref: a19d90dc8c4d48ec613ac3e2e1462b9099c0a857
dir: /sys/src/libc/port/utfrrune.c/
#include <u.h> #include <libc.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; } }