Imagine you had this:

  struct file_handle {
     char name[16];
     /* other stuff */
  } file_table[N];

Suppose you know that three consecutive entries have "CON" for the name. If you can find them in memory, then the distance between the "CON" strings is the same as the value of sizeof (struct file_handle). Unless somehow there are some false positive "CON" bytes in there somewhere.