Description

   The type size_t is defined in the header file <stdio.h> as
   follows:

   typedef unsigned int size_t

   The reading begins at the current location in the file. The items
   read are placed in storage beginning at the location given by
   the first argument. You must also specify the size of an item, in
   bytes.

   If the file pointed to by file_ptr was opened in record mode,
   fread will read size_of_item multiplied by number_items bytes
   from the file. That is, it does not necessarily read number_items
   records.