CTC++ example source files

 1 /* File calc.h ----------------------------------------------- */
 2 
 3 /* Tell if the argument is a prime (ret 0) or not (ret 1) */
 4 int is_prime(unsigned val);
 
 1 /* File calc.c ----------------------------------------------- */
 2 #include "calc.h"
 3 /* Tell if the argument is a prime (ret 1) or not (ret 0) */
 4 int is_prime(unsigned val)
 5 {
 6     unsigned divisor;
 7 
 8     if (val == 1 || val == 2 || val == 3)
 9         return 1;
10     if (val % 2 == 0)
11         return 0;
12     for (divisor = 3; divisor < val / 2; divisor += 2)
13     {
14         if (val % divisor == 0)
15             return 0;
16     }
17     return 1;
18 }

 1 /* File io.h ------------------------------------------------- */
 2 
 3 /* Prompt for an unsigend int value and return it */
 4 unsigned io_ask();
 5 
 6 /* Display an unsigned int value and associated string */
 7 void io_report(unsigned val, char* str); 

 1 /* File io.c ------------------------------------------------- */
 2 #include <stdio.h>
 3 #include "io.h"
 4 /* Prompt for an unsigend int value and return it */
 5 unsigned io_ask()
 6 {
 7     unsigned    val;
 8     int         amount;
 9 
10    printf("Enter a number (0 for stop program): ");
11     if ((amount = scanf("%u", &val)) <= 0) {
12         val = 0;    /* on 'non sense' input force 0 */
13     }
14     return val;
15 }
16 
17 /* Display an unsigned int value and associated string */
18 void io_report(unsigned val, char* str)
19 {
20     printf("%u %s\n\n", val, str);
21 }

 1 /* File prime.c ---------------------------------------------- */
 2 /* This example demonstrates some elementary CTC++ properties. */
 3 /* Not meant to be any good solution to the 'prime' problem.   */
 4 
 5 #include "io.h"
 6 #include "calc.h"
 7 
 8 int main(void)
 9 {
10     unsigned prime_candidate;
11 
12     while((prime_candidate = io_ask()) > 0)
13     {
14         if (is_prime(prime_candidate))
15             io_report(prime_candidate, "IS a prime.");
16         else
17             io_report(prime_candidate, "IS NOT a prime.");
18     }
19     return 0;
20 }