/* This is a simple program written in c that will print a 
   Greeting message to the monitor. This program is parallelized
   so all/some of the cores (more than one) at a time can print the   
   greeting message. Therefore, there are two lines that you will 
   not see in a pure c greetings message program.
	- #include <omp.h> // The omp.h files is library that defines OpenMP
	specifications such as functions, environment variables and runtime 
	functionalities. We use OpenMP when we are writing programs for 
	computers with multiple cores in them.
	  
	- #pragma omp parallel //when compiler is reading the source code file
	it stops the compiler and tell it that imidiately after the #pragama * line
	something special will be happening, and in our case its OpenMP parallelization
	the the printf(*) function will be run in parallel by the number of threads 	
	that were setup by the user useing $ export OMP_NUM_THREADS=N. (N=integer value)

	How to Compile this Program:
		$ cc omp_hello_world.c -o omp_hello_world
	How to setup runtime environment for this program:
		$ export OMP_NUM_THREADS=8
	How to Run this Program:
		$ aprun -n 1 -d 8 ./omp_hello_world
*/	
#include <stdio.h>  // Tells the compiler I am using standard c
#include <omp.h>   // Tells the compiler I am using OpenMP 

// Every has to start somewhere. In C/C++ programs they all start at main. 
int main(){       
	#pragma omp parallel   
	printf("Hello from thread %d, of nthreads %d: \n", omp_get_thread_num(), omp_get_num_threads()); 

}// End of main