strrchr : strrchr « string.h « C Tutorial

Item	Value
Header file	string.h
Declaration	char strrchr(const char str, int ch);
Return	returns a pointer to the last occurrence of ch in *str.

If no match is found, a null pointer is returned.

#include <string.h>
  #include <stdio.h>

  int main(void){
    char *p;

    p = strrchr("this is a test", 'i');
    printf(p);

    return 0;
  }

is a test