#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
#include <unistd.h>

int main (int argc, char * argv[], char * env[])
{
	int pid;
	int i, code, count;

	pid = fork ();
	if (pid) {  /* Parent */
		sleep (10);
		printf ("Killing Children (SIGTERM)\n");
		if (kill (-pid, SIGTERM) < 0)
			perror ("kill (SIGTERM)");
		printf ("Done\n");
		sleep (10);
		printf ("Killing Children (SIGKILL)\n");
		if (kill (-pid, SIGKILL) < 0)
			perror ("kill (SIGKILL)");
		printf ("Done\n");
		while (pid != wait (&code));
		if (WIFEXITED (code)) {
			printf ("Normal exit with exitcode %d\n", WEXITSTATUS (code));
		} else if (WIFSIGNALED (code)) {
			printf ("Signal %d received", WTERMSIG (code));
			if (WCOREDUMP (code)) {
				printf (" (core dumped).\n");
			} else {
				printf (" (no core).\n");
			}
		} else {
			printf ("Neither normal exit nor signal\n");
		}
		return 0;
	} else {  /* Child */
		char ** envp;
		if (setpgrp () < 0) {
			perror ("setpgrp");
			kill (getppid (), SIGTERM);
			exit (1);
		}
		printf ("Process Group created\n");
		count = 1;
		while (argv[count] && strchr (argv[count], '='))
			count++;
		if (argv[count] == NULL) {
			fprintf (stderr, "No command specified\n");
			return 1;
		}
		envp = malloc ((count+1)*sizeof (char*));
		for (i=1; i < count; ++i)
			envp[i-1] = argv[i];
		envp[i] = NULL;
		argv += count;
		execve (argv[0], argv, envp);
		/* Exec failed */
		perror ("execve");
		return 1;
	}
	return 0;
}