#include	<sys/types.h>
#include	<sys/wait.h>
#include <stdio.h>
#include <stdlib.h> /* for exit */
#include <unistd.h>


void  err_sys(char * msg) {
  printf("%s \n", msg);
  exit(-1); 
}

int main(void)
{
	pid_t	pid;

	if ( (pid = fork()) < 0)
		err_sys("fork error");
	else if (pid == 0) {	/* specify filename, inherit environment */
		if (execlp("ping",
				   "ping", "www.usm.cl", (char *) 0) < 0)
			err_sys("execlp error");
	}
	if (waitpid(pid, NULL, 0) < 0)
		err_sys("wait error");
	exit(0);
}