ref: cce5422e79699bc71e6525d77dfc3d8a9f5b1b9d
dir: /sys/src/libc/port/strrchr.c/
#include <u.h>
#include <libc.h>
char*
strrchr(char *s, int c)
{
char *r;
if(c == 0)
return strchr(s, 0);
r = 0;
while(s = strchr(s, c))
r = s++;
return r;
}