ref: 67ce0bdcd2da7045d3d758561b2d4ac55ee35b69
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; } }