#include <u.h>#include <libc.h> int uflg, nflg; voidmain(int argc, char *argv[]){	ulong now; 	ARGBEGIN{	case 'n':	nflg = 1; break;	case 'u':	uflg = 1; break;	default:	fprint(2, "usage: date [-un] [seconds]\n"); exits("usage");	}ARGEND 	if(argc == 1)		now = strtoul(*argv, 0, 0);	else		now = time(0); 	if(nflg)		print("%ld\n", now);	else if(uflg)		print("%s", asctime(gmtime(now)));	else		print("%s", ctime(now));		exits(0);}