Sample code to demonstrate make dependencies using the "touch" command.

all.cpp

//------------------------------------------------------------
// dog.cpp
//
#include <iostream>
#include "dogSays.h"
using namespace std;

int main() {
  cout << "  dog says:  " << dogSays() << endl;
}

//------------------------------------------------------------
// dogSays.cpp
//
#include "dogSound.h"
#include "dogSays.h"
using namespace std;

StrType dogSays( void ) {
  StrType result = dogSound; 
  return result;
}

//------------------------------------------------------------
// dogSays.h 
//
#include <string>
#include "strType.h"
using namespace std;

StrType dogSays( void );

//------------------------------------------------------------
// dogSound.h 
//
#define  dogSound  (char*)"bark"

//------------------------------------------------------------
// strType.h 
//
#define StrType char*