Stuff

/*
 *  read_nums.c
 *
 *  Functions to read numbers with input error detection.
 *
 *    Started by:  S. A. Norman
 *
 *  Completed by:
 *   Lab section:
 *          Date:
 */

#include <stdio.h>
#include <stdlib.h>

int read_int(void);
/*
 *  REQUIRES
 *      User has been prompted to type in an int.
 *  PROMISES
 *      If an int can be read from the standard input stream, that
 *      int is the return value.  If not, an error message is printed
 *      and exit is called with an argument of 1.
 */

double read_double(void);
/*
 *  REQUIRES
 *      User has been prompted to type in a double.
 *  PROMISES
 *      If a double can be read from the standard input stream, that
 *      double is the return value.  If not, an error message is printed
 *      and exit is called with an argument of 1.
 */

int main(void)
{
  int the_int;
  double the_double;

  printf("Doing tests of read_int and read_double functions ...\n\n");  
  
  printf("Please try to enter an int: ");
  the_int = read_int();
  printf("read_int succeeded.  It read a value of %d.\n", the_int);

  printf("Please try to enter an double: ");
  the_double = read_double();
  printf("read_double succeeded.  It read a value of %g.\n", the_double);

  return 0;
}

read_int(void)
{
  int nscan;
  int a;
  nscan=scanf("%d",&a);
  if (nscan != 1)
    {
      printf("Your input is not an integer. Program will terminate.\n");
      exit(1);
    }
  else
    return a;
}

read_double(void)
{
  double b;
  int nscan;
  nscan = scanf("%lf",&b);
  if (nscan !=1)
    {
      printf("Your input is not a double. Program will terminate.");
      exit(1);
    }
  else
    return b;
}