#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;	}	return 0;}