#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/wait.h>
#include <unistd.h>

void dowait ()
{
	int status;
	pid_t pid;
	while (1) {
		pid = wait (&status);
		if (pid < 0) {
			if (errno == ECHILD) {
				printf ("No children to wait for?\n");
				break;
			} else {
				perror ("wait");
				continue;
			}
		}
		if (WIFEXITED (status)) {
			printf ("Child exited normally, exit code: %d\n",
				WEXITSTATUS (status));
		} else if (WIFSIGNALED (status)) {
			printf ("Child died due to signal %d, ",
				WTERMSIG (status));
			if (WCOREDUMP (status)) {
				printf ("core dumped\n");
			} else {
				printf ("no core\n");
			}
		} else {
			printf ("Something else\n");
		}
		break;
	}
}

int doexec (char * arg1)
{
	pid_t pid = fork ();
	if (pid < 0) {			/* Error */
		perror ("fork");
		return 0;
	}
	if (pid == 0) {			/* Child */
		if (arg1 == NULL)
			execl ("./toexec", "toexec", NULL);
		else
			execl ("./toexec", "toexec", arg1, NULL);
		perror ("exec");
		exit (1);
	}
	/* Parent: Nothing else to do. */
	return 1;
}


int main ()
{
	char arg[2];
	if (doexec (NULL))
		dowait ();
	arg[1] = 0;
	for (arg[0] = 'a'; arg[0] <= 'z'; arg[0]++) {
		if (doexec (arg))
			dowait ();
	}
	return 0;
}