/*
 * ISA 563, Spring 2011
 * Copyleft by Muhammad Abdulla
 */

#include <stdio.h>

/*
 *  macros.c -- demonstrates the use of macros
 */

#define PI 3.14159265
#define AREA(r) (PI * r * r)
#define SQUARE1(a) a*a
#define SQUARE2(a) (a)*(a)
#define SQUARE3(a) ((a)*(a))

int main ( int argc, char *argv[] )
{
   char *fname = "/etc/shadow";
   FILE *fp;

   double r = 2.0;

   printf("Area of a circle with a radius %g is %g\n", r, AREA(r));
   printf("r = %g, square (v1) of r is: %g\n", r, SQUARE1(r));
   printf("r = %g, square (v1) of r+1 is: %g\n", r, SQUARE1(r+1));
   printf("r = %g, square (v2) of r+1 is: %g\n", r, SQUARE2(r+1));
   printf("r = %g, 1 over square (v1) of r+1 is: %g\n", r, 1.0/SQUARE1(r+1));
   printf("r = %g, 1 over square (v2) of r+1 is: %g\n", r, 1.0/SQUARE2(r+1));
   printf("r = %g, 1 over square (v3) of r+1 is: %g\n", r, 1.0/SQUARE3(r+1));

   printf("r = %g, ", r);
   SQUARE3(r++); 
   printf("but after calling SQUARE3(r++), r = %g\n", r);
   

   fp = fopen(fname, "r");

   if ( fp == NULL ) {
       fprintf(stderr, "Could not open file %s, exiting. (file: %s, line: %d)\n", fname, __FILE__, __LINE__);
   }

   return 0;
}