#include "apue.h"#include <fcntl.h>intmain(void){	if (open("tempfile", O_RDWR) < 0)		err_sys("open error");	if (unlink("tempfile") < 0)		err_sys("unlink error");	printf("file unlinked\n");	sleep(15);	printf("done\n");	exit(0);}