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c_sh.c revision 1.1.1.3
      1 /*
      2  * built-in Bourne commands
      3  */
      4 
      5 #include "sh.h"
      6 #include "ksh_stat.h" 	/* umask() */
      7 #include "ksh_time.h"
      8 #include "ksh_times.h"
      9 
     10 static	char *clocktos ARGS((clock_t t));
     11 
     12 
     13 /* :, false and true */
     14 int
     15 c_label(wp)
     16 	char **wp;
     17 {
     18 	return wp[0][0] == 'f' ? 1 : 0;
     19 }
     20 
     21 int
     22 c_shift(wp)
     23 	char **wp;
     24 {
     25 	register struct block *l = e->loc;
     26 	register int n;
     27 	long val;
     28 	char *arg;
     29 
     30 	if (ksh_getopt(wp, &builtin_opt, null) == '?')
     31 		return 1;
     32 	arg = wp[builtin_opt.optind];
     33 
     34 	if (arg) {
     35 		evaluate(arg, &val, KSH_UNWIND_ERROR);
     36 		n = val;
     37 	} else
     38 		n = 1;
     39 	if (n < 0) {
     40 		bi_errorf("%s: bad number", arg);
     41 		return (1);
     42 	}
     43 	if (l->argc < n) {
     44 		bi_errorf("nothing to shift");
     45 		return (1);
     46 	}
     47 	l->argv[n] = l->argv[0];
     48 	l->argv += n;
     49 	l->argc -= n;
     50 	return 0;
     51 }
     52 
     53 int
     54 c_umask(wp)
     55 	char **wp;
     56 {
     57 	register int i;
     58 	register char *cp;
     59 	int symbolic = 0;
     60 	int old_umask;
     61 	int optc;
     62 
     63 	while ((optc = ksh_getopt(wp, &builtin_opt, "S")) != EOF)
     64 		switch (optc) {
     65 		  case 'S':
     66 			symbolic = 1;
     67 			break;
     68 		  case '?':
     69 			return 1;
     70 		}
     71 	cp = wp[builtin_opt.optind];
     72 	if (cp == NULL) {
     73 		old_umask = umask(0);
     74 		umask(old_umask);
     75 		if (symbolic) {
     76 			char buf[18];
     77 			int j;
     78 
     79 			old_umask = ~old_umask;
     80 			cp = buf;
     81 			for (i = 0; i < 3; i++) {
     82 				*cp++ = "ugo"[i];
     83 				*cp++ = '=';
     84 				for (j = 0; j < 3; j++)
     85 					if (old_umask & (1 << (8 - (3*i + j))))
     86 						*cp++ = "rwx"[j];
     87 				*cp++ = ',';
     88 			}
     89 			cp[-1] = '\0';
     90 			shprintf("%s\n", buf);
     91 		} else
     92 			shprintf("%#3.3o\n", old_umask);
     93 	} else {
     94 		int new_umask;
     95 
     96 		if (digit(*cp)) {
     97 			for (new_umask = 0; *cp >= '0' && *cp <= '7'; cp++)
     98 				new_umask = new_umask * 8 + (*cp - '0');
     99 			if (*cp) {
    100 				bi_errorf("bad number");
    101 				return 1;
    102 			}
    103 		} else {
    104 			/* symbolic format */
    105 			int positions, new_val;
    106 			char op;
    107 
    108 			old_umask = umask(0);
    109 			umask(old_umask); /* in case of error */
    110 			old_umask = ~old_umask;
    111 			new_umask = old_umask;
    112 			positions = 0;
    113 			while (*cp) {
    114 				while (*cp && strchr("augo", *cp))
    115 					switch (*cp++) {
    116 					case 'a': positions |= 0111; break;
    117 					case 'u': positions |= 0100; break;
    118 					case 'g': positions |= 0010; break;
    119 					case 'o': positions |= 0001; break;
    120 					}
    121 				if (!positions)
    122 					positions = 0111; /* default is a */
    123 				if (!strchr("=+-", op = *cp))
    124 					break;
    125 				cp++;
    126 				new_val = 0;
    127 				while (*cp && strchr("rwxugoXs", *cp))
    128 					switch (*cp++) {
    129 					case 'r': new_val |= 04; break;
    130 					case 'w': new_val |= 02; break;
    131 					case 'x': new_val |= 01; break;
    132 					case 'u': new_val |= old_umask >> 6;
    133 						  break;
    134 					case 'g': new_val |= old_umask >> 3;
    135 						  break;
    136 					case 'o': new_val |= old_umask >> 0;
    137 						  break;
    138 					case 'X': if (old_umask & 0111)
    139 							new_val |= 01;
    140 						  break;
    141 					case 's': /* ignored */
    142 						  break;
    143 					}
    144 				new_val = (new_val & 07) * positions;
    145 				switch (op) {
    146 				case '-':
    147 					new_umask &= ~new_val;
    148 					break;
    149 				case '=':
    150 					new_umask = new_val
    151 					    | (new_umask & ~(positions * 07));
    152 					break;
    153 				case '+':
    154 					new_umask |= new_val;
    155 				}
    156 				if (*cp == ',') {
    157 					positions = 0;
    158 					cp++;
    159 				} else if (!strchr("=+-", *cp))
    160 					break;
    161 			}
    162 			if (*cp) {
    163 				bi_errorf("bad mask");
    164 				return 1;
    165 			}
    166 			new_umask = ~new_umask;
    167 		}
    168 		umask(new_umask);
    169 	}
    170 	return 0;
    171 }
    172 
    173 int
    174 c_dot(wp)
    175 	char **wp;
    176 {
    177 	char *file, *cp;
    178 	char **argv;
    179 	int argc;
    180 	int i;
    181 	int err;
    182 
    183 	if (ksh_getopt(wp, &builtin_opt, null) == '?')
    184 		return 1;
    185 
    186 	if ((cp = wp[builtin_opt.optind]) == NULL)
    187 		return 0;
    188 	file = search(cp, path, R_OK, &err);
    189 	if (file == NULL) {
    190 		bi_errorf("%s: %s", cp, err ? strerror(err) : "not found");
    191 		return 1;
    192 	}
    193 
    194 	/* Set positional parameters? */
    195 	if (wp[builtin_opt.optind + 1]) {
    196 		argv = wp + builtin_opt.optind;
    197 		argv[0] = e->loc->argv[0]; /* preserve $0 */
    198 		for (argc = 0; argv[argc + 1]; argc++)
    199 			;
    200 	} else {
    201 		argc = 0;
    202 		argv = (char **) 0;
    203 	}
    204 	i = include(file, argc, argv, 0);
    205 	if (i < 0) { /* should not happen */
    206 		bi_errorf("%s: %s", cp, strerror(errno));
    207 		return 1;
    208 	}
    209 	return i;
    210 }
    211 
    212 int
    213 c_wait(wp)
    214 	char **wp;
    215 {
    216 	int UNINITIALIZED(rv);
    217 	int sig;
    218 
    219 	if (ksh_getopt(wp, &builtin_opt, null) == '?')
    220 		return 1;
    221 	wp += builtin_opt.optind;
    222 	if (*wp == (char *) 0) {
    223 		while (waitfor((char *) 0, &sig) >= 0)
    224 			;
    225 		rv = sig;
    226 	} else {
    227 		for (; *wp; wp++)
    228 			rv = waitfor(*wp, &sig);
    229 		if (rv < 0)
    230 			rv = sig ? sig : 127; /* magic exit code: bad job-id */
    231 	}
    232 	return rv;
    233 }
    234 
    235 int
    236 c_read(wp)
    237 	char **wp;
    238 {
    239 	register int c = 0;
    240 	int expand = 1, history = 0;
    241 	int expanding;
    242 	int ecode = 0;
    243 	register char *cp;
    244 	int fd = 0;
    245 	struct shf *shf;
    246 	int optc;
    247 	const char *emsg;
    248 	XString cs, xs;
    249 	struct tbl *vp;
    250 	char UNINITIALIZED(*xp);
    251 
    252 	while ((optc = ksh_getopt(wp, &builtin_opt, "prsu,")) != EOF)
    253 		switch (optc) {
    254 #ifdef KSH
    255 		  case 'p':
    256 			if ((fd = coproc_getfd(R_OK, &emsg)) < 0) {
    257 				bi_errorf("-p: %s", emsg);
    258 				return 1;
    259 			}
    260 			break;
    261 #endif /* KSH */
    262 		  case 'r':
    263 			expand = 0;
    264 			break;
    265 		  case 's':
    266 			history = 1;
    267 			break;
    268 		  case 'u':
    269 			if (!*(cp = builtin_opt.optarg))
    270 				fd = 0;
    271 			else if ((fd = check_fd(cp, R_OK, &emsg)) < 0) {
    272 				bi_errorf("-u: %s: %s", cp, emsg);
    273 				return 1;
    274 			}
    275 			break;
    276 		  case '?':
    277 			return 1;
    278 		}
    279 	wp += builtin_opt.optind;
    280 
    281 	if (*wp == NULL)
    282 		*--wp = "REPLY";
    283 
    284 	/* Since we can't necessarily seek backwards on non-regular files,
    285 	 * don't buffer them so we can't read too much.
    286 	 */
    287 	shf = shf_reopen(fd, SHF_RD | SHF_INTERRUPT | can_seek(fd), shl_spare);
    288 
    289 	if ((cp = strchr(*wp, '?')) != NULL) {
    290 		*cp = 0;
    291 		if (isatty(fd)) {
    292 			/* at&t ksh says it prints prompt on fd if it's open
    293 			 * for writing and is a tty, but it doesn't do it
    294 			 * (it also doesn't check the interactive flag,
    295 			 * as is indicated in the Kornshell book).
    296 			 */
    297 			shellf("%s", cp+1);
    298 		}
    299 	}
    300 
    301 #ifdef KSH
    302 	/* If we are reading from the co-process for the first time,
    303 	 * make sure the other side of the pipe is closed first.  This allows
    304 	 * the detection of eof.
    305 	 *
    306 	 * This is not compatiable with at&t ksh... the fd is kept so another
    307 	 * coproc can be started with same ouput, however, this means eof
    308 	 * can't be detected...  This is why it is closed here.
    309 	 * If this call is removed, remove the eof check below, too.
    310 	* coproc_readw_close(fd);
    311 	 */
    312 #endif /* KSH */
    313 
    314 	if (history)
    315 		Xinit(xs, xp, 128, ATEMP);
    316 	expanding = 0;
    317 	Xinit(cs, cp, 128, ATEMP);
    318 	for (; *wp != NULL; wp++) {
    319 		for (cp = Xstring(cs, cp); ; ) {
    320 			if (c == '\n' || c == EOF)
    321 				break;
    322 			while (1) {
    323 				c = shf_getc(shf);
    324 				if (c == '\0'
    325 #ifdef OS2
    326 				    || c == '\r'
    327 #endif /* OS2 */
    328 				    )
    329 					continue;
    330 				if (c == EOF && shf_error(shf)
    331 				    && shf_errno(shf) == EINTR)
    332 				{
    333 					/* Was the offending signal one that
    334 					 * would normally kill a process?
    335 					 * If so, pretend the read was killed.
    336 					 */
    337 					ecode = fatal_trap_check();
    338 
    339 					/* non fatal (eg, CHLD), carry on */
    340 					if (!ecode) {
    341 						shf_clearerr(shf);
    342 						continue;
    343 					}
    344 				}
    345 				break;
    346 			}
    347 			if (history) {
    348 				Xcheck(xs, xp);
    349 				Xput(xs, xp, c);
    350 			}
    351 			Xcheck(cs, cp);
    352 			if (expanding) {
    353 				expanding = 0;
    354 				if (c == '\n') {
    355 					c = 0;
    356 					if (Flag(FTALKING_I) && isatty(fd)) {
    357 						/* set prompt in case this is
    358 						 * called from .profile or $ENV
    359 						 */
    360 						set_prompt(PS2, (Source *) 0);
    361 						pprompt(prompt, 0);
    362 					}
    363 				} else if (c != EOF)
    364 					Xput(cs, cp, c);
    365 				continue;
    366 			}
    367 			if (expand && c == '\\') {
    368 				expanding = 1;
    369 				continue;
    370 			}
    371 			if (c == '\n' || c == EOF)
    372 				break;
    373 			if (ctype(c, C_IFS)) {
    374 				if (Xlength(cs, cp) == 0 && ctype(c, C_IFSWS))
    375 					continue;
    376 				if (wp[1])
    377 					break;
    378 			}
    379 			Xput(cs, cp, c);
    380 		}
    381 		/* strip trailing IFS white space from last variable */
    382 		if (!wp[1])
    383 			while (Xlength(cs, cp) && ctype(cp[-1], C_IFS)
    384 			       && ctype(cp[-1], C_IFSWS))
    385 				cp--;
    386 		Xput(cs, cp, '\0');
    387 		vp = global(*wp);
    388 		/* Must be done before setting export. */
    389 		if (vp->flag & RDONLY) {
    390 			shf_flush(shf);
    391 			bi_errorf("%s is read only", *wp);
    392 			return 1;
    393 		}
    394 		if (Flag(FEXPORT))
    395 			typeset(*wp, EXPORT, 0, 0, 0);
    396 		if (!setstr(vp, Xstring(cs, cp), KSH_RETURN_ERROR)) {
    397 		    shf_flush(shf);
    398 		    return 1;
    399 		}
    400 	}
    401 
    402 	shf_flush(shf);
    403 	if (history) {
    404 		Xput(xs, xp, '\0');
    405 		source->line++;
    406 		histsave(source->line, Xstring(xs, xp), 1);
    407 		Xfree(xs, xp);
    408 	}
    409 #ifdef KSH
    410 	/* if this is the co-process fd, close the file descriptor
    411 	 * (can get eof if and only if all processes are have died, ie,
    412 	 * coproc.njobs is 0 and the pipe is closed).
    413 	 */
    414 	if (c == EOF && !ecode)
    415 		coproc_read_close(fd);
    416 #endif /* KSH */
    417 
    418 	return ecode ? ecode : c == EOF;
    419 }
    420 
    421 int
    422 c_eval(wp)
    423 	char **wp;
    424 {
    425 	register struct source *s;
    426 
    427 	if (ksh_getopt(wp, &builtin_opt, null) == '?')
    428 		return 1;
    429 	s = pushs(SWORDS, ATEMP);
    430 	s->u.strv = wp + builtin_opt.optind;
    431 	if (!Flag(FPOSIX)) {
    432 		/*
    433 		 * Handle case where the command is empty due to failed
    434 		 * command substitution, eg, eval "$(false)".
    435 		 * In this case, shell() will not set/change exstat (because
    436 		 * compiled tree is empty), so will use this value.
    437 		 * subst_exstat is cleared in execute(), so should be 0 if
    438 		 * there were no substitutions.
    439 		 *
    440 		 * A strict reading of POSIX says we don't do this (though
    441 		 * it is traditionally done). [from 1003.2-1992]
    442 		 *    3.9.1: Simple Commands
    443 		 *	... If there is a command name, execution shall
    444 		 *	continue as described in 3.9.1.1.  If there
    445 		 *	is no command name, but the command contained a command
    446 		 *	substitution, the command shall complete with the exit
    447 		 *	status of the last command substitution
    448 		 *    3.9.1.1: Command Search and Execution
    449 		 *	...(1)...(a) If the command name matches the name of
    450 		 *	a special built-in utility, that special built-in
    451 		 *	utility shall be invoked.
    452 		 * 3.14.5: Eval
    453 		 *	... If there are no arguments, or only null arguments,
    454 		 *	eval shall return an exit status of zero.
    455 		 */
    456 		exstat = subst_exstat;
    457 	}
    458 
    459 	return shell(s, FALSE);
    460 }
    461 
    462 int
    463 c_trap(wp)
    464 	char **wp;
    465 {
    466 	int i;
    467 	char *s;
    468 	register Trap *p;
    469 
    470 	if (ksh_getopt(wp, &builtin_opt, null) == '?')
    471 		return 1;
    472 	wp += builtin_opt.optind;
    473 
    474 	if (*wp == NULL) {
    475 		int anydfl = 0;
    476 
    477 		for (p = sigtraps, i = SIGNALS+1; --i >= 0; p++) {
    478 			if (p->trap == NULL)
    479 				anydfl = 1;
    480 			else {
    481 				shprintf("trap -- ");
    482 				print_value_quoted(p->trap);
    483 				shprintf(" %s\n", p->name);
    484 			}
    485 		}
    486 #if 0 /* this is ugly and not clear POSIX needs it */
    487 		/* POSIX may need this so output of trap can be saved and
    488 		 * used to restore trap conditions
    489 		 */
    490 		if (anydfl) {
    491 			shprintf("trap -- -");
    492 			for (p = sigtraps, i = SIGNALS+1; --i >= 0; p++)
    493 				if (p->trap == NULL && p->name)
    494 					shprintf(" %s", p->name);
    495 			shprintf(newline);
    496 		}
    497 #endif
    498 		return 0;
    499 	}
    500 
    501 	/*
    502 	 * Use case sensitive lookup for first arg so the
    503 	 * command 'exit' isn't confused with the pseudo-signal
    504 	 * 'EXIT'.
    505 	 */
    506 	s = (gettrap(*wp, FALSE) == NULL) ? *wp++ : NULL; /* get command */
    507 	if (s != NULL && s[0] == '-' && s[1] == '\0')
    508 		s = NULL;
    509 
    510 	/* set/clear traps */
    511 	while (*wp != NULL) {
    512 		p = gettrap(*wp++, TRUE);
    513 		if (p == NULL) {
    514 			bi_errorf("bad signal %s", wp[-1]);
    515 			return 1;
    516 		}
    517 		settrap(p, s);
    518 	}
    519 	return 0;
    520 }
    521 
    522 int
    523 c_exitreturn(wp)
    524 	char **wp;
    525 {
    526 	int how = LEXIT;
    527 	int n;
    528 	char *arg;
    529 
    530 	if (ksh_getopt(wp, &builtin_opt, null) == '?')
    531 		return 1;
    532 	arg = wp[builtin_opt.optind];
    533 
    534 	if (arg) {
    535 	    if (!getn(arg, &n)) {
    536 		    exstat = 1;
    537 		    warningf(TRUE, "%s: bad number", arg);
    538 	    } else
    539 		    exstat = n;
    540 	}
    541 	if (wp[0][0] == 'r') { /* return */
    542 		struct env *ep;
    543 
    544 		/* need to tell if this is exit or return so trap exit will
    545 		 * work right (POSIX)
    546 		 */
    547 		for (ep = e; ep; ep = ep->oenv)
    548 			if (STOP_RETURN(ep->type)) {
    549 				how = LRETURN;
    550 				break;
    551 			}
    552 	}
    553 
    554 	if (how == LEXIT && !really_exit && j_stopped_running()) {
    555 		really_exit = 1;
    556 		how = LSHELL;
    557 	}
    558 
    559 	quitenv();	/* get rid of any i/o redirections */
    560 	unwind(how);
    561 	/*NOTREACHED*/
    562 	return 0;
    563 }
    564 
    565 int
    566 c_brkcont(wp)
    567 	char **wp;
    568 {
    569 	int n, quit;
    570 	struct env *ep, *last_ep = (struct env *) 0;
    571 	char *arg;
    572 
    573 	if (ksh_getopt(wp, &builtin_opt, null) == '?')
    574 		return 1;
    575 	arg = wp[builtin_opt.optind];
    576 
    577 	if (!arg)
    578 		n = 1;
    579 	else if (!bi_getn(arg, &n))
    580 		return 1;
    581 	quit = n;
    582 	if (quit <= 0) {
    583 		/* at&t ksh does this for non-interactive shells only - weird */
    584 		bi_errorf("%s: bad value", arg);
    585 		return 1;
    586 	}
    587 
    588 	/* Stop at E_NONE, E_PARSE, E_FUNC, or E_INCL */
    589 	for (ep = e; ep && !STOP_BRKCONT(ep->type); ep = ep->oenv)
    590 		if (ep->type == E_LOOP) {
    591 			if (--quit == 0)
    592 				break;
    593 			ep->flags |= EF_BRKCONT_PASS;
    594 			last_ep = ep;
    595 		}
    596 
    597 	if (quit) {
    598 		/* at&t ksh doesn't print a message - just does what it
    599 		 * can.  We print a message 'cause it helps in debugging
    600 		 * scripts, but don't generate an error (ie, keep going).
    601 		 */
    602 		if (n == quit) {
    603 			warningf(TRUE, "%s: cannot %s", wp[0], wp[0]);
    604 			return 0;
    605 		}
    606 		/* POSIX says if n is too big, the last enclosing loop
    607 		 * shall be used.  Doesn't say to print an error but we
    608 		 * do anyway 'cause the user messed up.
    609 		 */
    610 		last_ep->flags &= ~EF_BRKCONT_PASS;
    611 		warningf(TRUE, "%s: can only %s %d level(s)",
    612 			wp[0], wp[0], n - quit);
    613 	}
    614 
    615 	unwind(*wp[0] == 'b' ? LBREAK : LCONTIN);
    616 	/*NOTREACHED*/
    617 }
    618 
    619 int
    620 c_set(wp)
    621 	char **wp;
    622 {
    623 	int argi, setargs;
    624 	struct block *l = e->loc;
    625 	register char **owp = wp;
    626 
    627 	if (wp[1] == NULL) {
    628 		static const char *const args [] = { "set", "-", NULL };
    629 		return c_typeset((char **) args);
    630 	}
    631 
    632 	argi = parse_args(wp, OF_SET, &setargs);
    633 	if (argi < 0)
    634 		return 1;
    635 	/* set $# and $* */
    636 	if (setargs) {
    637 		owp = wp += argi - 1;
    638 		wp[0] = l->argv[0]; /* save $0 */
    639 		while (*++wp != NULL)
    640 			*wp = str_save(*wp, &l->area);
    641 		l->argc = wp - owp - 1;
    642 		l->argv = (char **) alloc(sizeofN(char *, l->argc+2), &l->area);
    643 		for (wp = l->argv; (*wp++ = *owp++) != NULL; )
    644 			;
    645 	}
    646 	/* POSIX says set exit status is 0, but old scripts that use
    647 	 * getopt(1), use the construct: set -- `getopt ab:c "$@"`
    648 	 * which assumes the exit value set will be that of the ``
    649 	 * (subst_exstat is cleared in execute() so that it will be 0
    650 	 * if there are no command substitutions).
    651 	 */
    652 	return Flag(FPOSIX) ? 0 : subst_exstat;
    653 }
    654 
    655 int
    656 c_unset(wp)
    657 	char **wp;
    658 {
    659 	register char *id;
    660 	int optc, unset_var = 1;
    661 	int ret = 0;
    662 
    663 	while ((optc = ksh_getopt(wp, &builtin_opt, "fv")) != EOF)
    664 		switch (optc) {
    665 		  case 'f':
    666 			unset_var = 0;
    667 			break;
    668 		  case 'v':
    669 			unset_var = 1;
    670 			break;
    671 		  case '?':
    672 			return 1;
    673 		}
    674 	wp += builtin_opt.optind;
    675 	for (; (id = *wp) != NULL; wp++)
    676 		if (unset_var) {	/* unset variable */
    677 			struct tbl *vp = global(id);
    678 
    679 			if (!(vp->flag & ISSET))
    680 			    ret = 1;
    681 			if ((vp->flag&RDONLY)) {
    682 				bi_errorf("%s is read only", vp->name);
    683 				return 1;
    684 			}
    685 			unset(vp, strchr(id, '[') ? 1 : 0);
    686 		} else {		/* unset function */
    687 			if (define(id, (struct op *) NULL))
    688 				ret = 1;
    689 		}
    690 	return ret;
    691 }
    692 
    693 int
    694 c_times(wp)
    695 	char **wp;
    696 {
    697 	struct tms all;
    698 
    699 	(void) ksh_times(&all);
    700 	shprintf("Shell: %8ss user ", clocktos(all.tms_utime));
    701 	shprintf("%8ss system\n", clocktos(all.tms_stime));
    702 	shprintf("Kids:  %8ss user ", clocktos(all.tms_cutime));
    703 	shprintf("%8ss system\n", clocktos(all.tms_cstime));
    704 
    705 	return 0;
    706 }
    707 
    708 /*
    709  * time pipeline (really a statement, not a built-in command)
    710  */
    711 int
    712 timex(t, f)
    713 	struct op *t;
    714 	int f;
    715 {
    716 #define TF_NOARGS	BIT(0)
    717 #define TF_NOREAL	BIT(1)		/* don't report real time */
    718 #define TF_POSIX	BIT(2)		/* report in posix format */
    719 	int rv = 0;
    720 	struct tms t0, t1, tms;
    721 	clock_t t0t, t1t = 0;
    722 	int tf = 0;
    723 	extern clock_t j_usrtime, j_systime; /* computed by j_wait */
    724 	char opts[1];
    725 
    726 	t0t = ksh_times(&t0);
    727 	if (t->left) {
    728 		/*
    729 		 * Two ways of getting cpu usage of a command: just use t0
    730 		 * and t1 (which will get cpu usage from other jobs that
    731 		 * finish while we are executing t->left), or get the
    732 		 * cpu usage of t->left. at&t ksh does the former, while
    733 		 * pdksh tries to do the later (the j_usrtime hack doesn't
    734 		 * really work as it only counts the last job).
    735 		 */
    736 		j_usrtime = j_systime = 0;
    737 		if (t->left->type == TCOM)
    738 			t->left->str = opts;
    739 		opts[0] = 0;
    740 		rv = execute(t->left, f | XTIME);
    741 		tf |= opts[0];
    742 		t1t = ksh_times(&t1);
    743 	} else
    744 		tf = TF_NOARGS;
    745 
    746 	if (tf & TF_NOARGS) { /* ksh93 - report shell times (shell+kids) */
    747 		tf |= TF_NOREAL;
    748 		tms.tms_utime = t0.tms_utime + t0.tms_cutime;
    749 		tms.tms_stime = t0.tms_stime + t0.tms_cstime;
    750 	} else {
    751 		tms.tms_utime = t1.tms_utime - t0.tms_utime + j_usrtime;
    752 		tms.tms_stime = t1.tms_stime - t0.tms_stime + j_systime;
    753 	}
    754 
    755 	if (!(tf & TF_NOREAL))
    756 		shf_fprintf(shl_out,
    757 			tf & TF_POSIX ? "real %8s\n" : "%8ss real ",
    758 			clocktos(t1t - t0t));
    759 	shf_fprintf(shl_out, tf & TF_POSIX ? "user %8s\n" : "%8ss user ",
    760 		clocktos(tms.tms_utime));
    761 	shf_fprintf(shl_out, tf & TF_POSIX ? "sys  %8s\n" : "%8ss system\n",
    762 		clocktos(tms.tms_stime));
    763 	shf_flush(shl_out);
    764 
    765 	return rv;
    766 }
    767 
    768 void
    769 timex_hook(t, app)
    770 	struct op *t;
    771 	char ** volatile *app;
    772 {
    773 	char **wp = *app;
    774 	int optc;
    775 	int i, j;
    776 	Getopt opt;
    777 
    778 	ksh_getopt_reset(&opt, 0);
    779 	opt.optind = 0;	/* start at the start */
    780 	while ((optc = ksh_getopt(wp, &opt, ":p")) != EOF)
    781 		switch (optc) {
    782 		  case 'p':
    783 			t->str[0] |= TF_POSIX;
    784 			break;
    785 		  case '?':
    786 			errorf("time: -%s unknown option", opt.optarg);
    787 		  case ':':
    788 			errorf("time: -%s requires an argument",
    789 				opt.optarg);
    790 		}
    791 	/* Copy command words down over options. */
    792 	if (opt.optind != 0) {
    793 		for (i = 0; i < opt.optind; i++)
    794 			afree(wp[i], ATEMP);
    795 		for (i = 0, j = opt.optind; (wp[i] = wp[j]); i++, j++)
    796 			;
    797 	}
    798 	if (!wp[0])
    799 		t->str[0] |= TF_NOARGS;
    800 	*app = wp;
    801 }
    802 
    803 static char *
    804 clocktos(t)
    805 	clock_t t;
    806 {
    807 	static char temp[22]; /* enough for 64 bit clock_t */
    808 	register int i;
    809 	register char *cp = temp + sizeof(temp);
    810 
    811 	/* note: posix says must use max precision, ie, if clk_tck is
    812 	 * 1000, must print 3 places after decimal (if non-zero, else 1).
    813 	 */
    814 	if (CLK_TCK != 100)	/* convert to 1/100'ths */
    815 	    t = (t < 1000000000/CLK_TCK) ?
    816 		    (t * 100) / CLK_TCK : (t / CLK_TCK) * 100;
    817 
    818 	*--cp = '\0';
    819 	for (i = -2; i <= 0 || t > 0; i++) {
    820 		if (i == 0)
    821 			*--cp = '.';
    822 		*--cp = '0' + (char)(t%10);
    823 		t /= 10;
    824 	}
    825 	return cp;
    826 }
    827 
    828 /* exec with no args - args case is taken care of in comexec() */
    829 int
    830 c_exec(wp)
    831 	char ** wp;
    832 {
    833 	int i;
    834 
    835 	/* make sure redirects stay in place */
    836 	if (e->savefd != NULL) {
    837 		for (i = 0; i < NUFILE; i++) {
    838 			if (e->savefd[i] > 0)
    839 				close(e->savefd[i]);
    840 			/*
    841 			 * For ksh keep anything > 2 private,
    842 			 * for sh, let them be (POSIX says what
    843 			 * happens is unspecified and the bourne shell
    844 			 * keeps them open).
    845 			 */
    846 #ifdef KSH
    847 			if (i > 2 && e->savefd[i])
    848 				fd_clexec(i);
    849 #endif /* KSH */
    850 		}
    851 		e->savefd = NULL;
    852 	}
    853 	return 0;
    854 }
    855 
    856 /* dummy function, special case in comexec() */
    857 int
    858 c_builtin(wp)
    859 	char ** wp;
    860 {
    861 	return 0;
    862 }
    863 
    864 extern	int c_test ARGS((char **wp));		/* in c_test.c */
    865 extern	int c_ulimit ARGS((char **wp));		/* in c_ulimit.c */
    866 
    867 /* A leading = means assignments before command are kept;
    868  * a leading * means a POSIX special builtin;
    869  * a leading + means a POSIX regular builtin
    870  * (* and + should not be combined).
    871  */
    872 const struct builtin shbuiltins [] = {
    873 	{"*=.", c_dot},
    874 	{"*=:", c_label},
    875 	{"[", c_test},
    876 	{"*=break", c_brkcont},
    877 	{"=builtin", c_builtin},
    878 	{"*=continue", c_brkcont},
    879 	{"*=eval", c_eval},
    880 	{"*=exec", c_exec},
    881 	{"*=exit", c_exitreturn},
    882 	{"+false", c_label},
    883 	{"*=return", c_exitreturn},
    884 	{"*=set", c_set},
    885 	{"*=shift", c_shift},
    886 	{"=times", c_times},
    887 	{"*=trap", c_trap},
    888 	{"+=wait", c_wait},
    889 	{"+read", c_read},
    890 	{"test", c_test},
    891 	{"+true", c_label},
    892 	{"ulimit", c_ulimit},
    893 	{"+umask", c_umask},
    894 	{"*=unset", c_unset},
    895 #ifdef OS2
    896 	/* In OS2, the first line of a file can be "extproc name", which
    897 	 * tells the command interpreter (cmd.exe) to use name to execute
    898 	 * the file.  For this to be useful, ksh must ignore commands
    899 	 * starting with extproc and this does the trick...
    900 	 */
    901 	{"extproc", c_label},
    902 #endif /* OS2 */
    903 	{NULL, NULL}
    904 };
    905