A pointer is

Declaration: char *strstr(const char *s1, const char *s2);

Return Value:
On success, strstr returns a pointer to the element in s1 where s2 begins (points to s2 in s1).
On error (if s2 does not occur in s1), strstr returns null.

Example:

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

int main(void)
{
   char *str1 = "CuriousTab", *str2 = "ia", *ptr;

   ptr = strstr(str1, str2);
   printf("The substring is: %s\n", ptr);
   return 0;
}

Output: The substring is: iaCURIOUSTAB

It scans a string s in the reverse direction, looking for a specific character c.

Example:

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

int main(void)
{
   char text[] = "I learn through CuriousTab.com";
   char *ptr, c = 'i';

   ptr = strrchr(text, c);
   if (ptr)
      printf("The position of '%c' is: %d\n", c, ptr-text);
   else
      printf("The character was not found\n");
   return 0;
}

Output:

The position of 'i' is: 19