//-----------------------------------------------------------------
//	execdemo.cpp
//
//	This is the program we wrote quickly during class, to show
//	how an application can fork a child-process which then may
//	execute another program.  Now we have added some comments.
//
//	     to compile:  $ g++ execdemo.cpp -o execdemo		
//	     to execute:  $ ./execdemo <program> [<args>...]
//
//	programmer: ALLAN CRUSE
//	written on: 04 MAR 2009
//-----------------------------------------------------------------

#include <stdio.h>	// for printf()
#include <unistd.h>	// for fork() 
#include <stdlib.h>	// for exit()
#include <wait.h>	// for wait()

int main( int argc, char *argv[] )
{
	// parent forks a child-process
	int	retval = fork();	

	if (retval == 0)
		{
		// child-process executes this block
		execve( argv[1], &argv[1], 0 );
		printf( "unknown program -- child is quitting\n" );
		exit( 1 );
		}
	
	// parent-process waits for child-process to exit
	wait( NULL );
	printf( "parent is quitting\n" );
}