Listing 3

EXTERN.H

/*  References to all extern variables
extern char date[9];

FILE #1

#include "extern.h"
char date[9];
main()
     {
     strcpy ( date, "01-01-90" );
     foo();
     puts ( date );
    }

FILE #2
 
 #include "extern.h"
  
  foo()
    {
    puts ( date );
    strcpy ( date, "02-02-90");
    puts (date );
    }