/* Include files needed */
 # include <stdio.h>

 /* The function */

 unsigned long filesizeof(FILE *stream){

   long curpos, length;

   /* Save the current position of the file pointer */
   curpos = ftell(stream);

   /* Go to the end of file */
   fseek(stream, 0L, SEEK_END);

   /* The length is the position of the pointer */
   length = ftell(stream);

   /* Set the pointer to the old position */
   fseek(stream, curpos, SEEK_SET);

   /* Return the length */
   return length;

 }