A Sample C Program

This program, cookie.c, asks for a cookie. The response must be entered in uppercase, or it is incorrect. You can also find the prime factor of a number. In the process of doing these two things, you can see how the trace function works.

To compile this program and get an executable called cookie(), use

$ cc -o cookie cookie.c 

Five probe points are defined (and highlighted) in this program. They are named start (line 17), inloop (line 33), factor_start (line 60), found_a_factor (line 65), and factor_end (line 72). More information about these probe points is gathered and explained in "A Sample prex Session".

Example 1-2 Code for cookie.c()

#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <tnf/probe.h>

#define MAX_RESPONSE_SIZE	256

static void find_factor(int n);

int
main(int argc, char **argv)
{
    boolean_t	shouldexit = B_FALSE;
    int 	sum = 0, max_loop = 5;
    int		i;

    TNF_PROBE_0(start, "cookie main", 
         "sunw%debug starting main");

    while (!shouldexit) {
	      char	response[MAX_RESPONSE_SIZE];
	      int	factor_input;

      	(void) printf("give me a COOKIE! ");
	      (void) scanf("%s", response);

      	if (!strcmp(response, "COOKIE")) {
	           (void) printf("thanks!\n");
	           shouldexit = B_TRUE;
      	}

      	else if (!strcmp(response, "loop")) {
       	    for (i = 0; i < max_loop; i++) {
	             	TNF_PROBE_2(inloop, "cookie main
                           loop","sunw%debug in the loop",
			                       	tnf_long, loop_count, 	i,
		                       		tnf_long, total_iterations, 	sum);
             		sum++;
           	}
	         		max_loop += 2 ;
     		}

	    	else if (!strcmp(response, "factor")) {
         			(void) printf("number you want factored? ");
	         		(void) scanf("%d", &factor_input);
	         		find_factor(factor_input);
    		}

	    	else {
	         		(void) printf("not a %s, ", response);
		    }
    }
    return 0;

}   /* end main */
static void
find_factor(int n)
{
    int i;

    (void) printf("\tfactors of %d = ", n);
    TNF_PROBE_1(factor_start, "factor", "",
      		tnf_long, input_number, n);

    for (i=2; i <= n; i++) {
      		while (n % i == 0) {
		        	TNF_PROBE_2(found_a_factor, "cookie find_factor",
               "", tnf_long, searching_for, n,
	           			tnf_long, factor, i);
	        		(void) printf("%d ", i);
	        		n /= i;
      		}
    }
    TNF_PROBE_0(factor_end, "factor", "");
    (void) printf("\n");
}