xref: /netbsd-src/bin/ksh/c_sh.c (revision d710132b4b8ce7f7cccaaf660cb16aa16b4077a0)
1 /*	$NetBSD: c_sh.c,v 1.7 2003/06/23 11:38:53 agc Exp $	*/
2 
3 /*
4  * built-in Bourne commands
5  */
6 #include <sys/cdefs.h>
7 
8 #ifndef lint
9 __RCSID("$NetBSD: c_sh.c,v 1.7 2003/06/23 11:38:53 agc Exp $");
10 #endif
11 
12 
13 #include "sh.h"
14 #include "ksh_stat.h" 	/* umask() */
15 #include "ksh_time.h"
16 #include "ksh_times.h"
17 
18 static	char *clocktos ARGS((clock_t t));
19 extern clock_t j_usrtime, j_systime; /* computed by j_wait */
20 
21 
22 /* :, false and true */
23 int
24 c_label(wp)
25 	char **wp;
26 {
27 	return wp[0][0] == 'f' ? 1 : 0;
28 }
29 
30 int
31 c_shift(wp)
32 	char **wp;
33 {
34 	register struct block *l = e->loc;
35 	register int n;
36 	long val;
37 	char *arg;
38 
39 	if (ksh_getopt(wp, &builtin_opt, null) == '?')
40 		return 1;
41 	arg = wp[builtin_opt.optind];
42 
43 	if (arg) {
44 		evaluate(arg, &val, KSH_UNWIND_ERROR);
45 		n = val;
46 	} else
47 		n = 1;
48 	if (n < 0) {
49 		bi_errorf("%s: bad number", arg);
50 		return (1);
51 	}
52 	if (l->argc < n) {
53 		bi_errorf("nothing to shift");
54 		return (1);
55 	}
56 	l->argv[n] = l->argv[0];
57 	l->argv += n;
58 	l->argc -= n;
59 	return 0;
60 }
61 
62 int
63 c_umask(wp)
64 	char **wp;
65 {
66 	register int i;
67 	register char *cp;
68 	int symbolic = 0;
69 	int old_umask;
70 	int optc;
71 
72 	while ((optc = ksh_getopt(wp, &builtin_opt, "S")) != EOF)
73 		switch (optc) {
74 		  case 'S':
75 			symbolic = 1;
76 			break;
77 		  case '?':
78 			return 1;
79 		}
80 	cp = wp[builtin_opt.optind];
81 	if (cp == NULL) {
82 		old_umask = umask(0);
83 		umask(old_umask);
84 		if (symbolic) {
85 			char buf[18];
86 			int j;
87 
88 			old_umask = ~old_umask;
89 			cp = buf;
90 			for (i = 0; i < 3; i++) {
91 				*cp++ = "ugo"[i];
92 				*cp++ = '=';
93 				for (j = 0; j < 3; j++)
94 					if (old_umask & (1 << (8 - (3*i + j))))
95 						*cp++ = "rwx"[j];
96 				*cp++ = ',';
97 			}
98 			cp[-1] = '\0';
99 			shprintf("%s\n", buf);
100 		} else
101 			shprintf("%#3.3o\n", old_umask);
102 	} else {
103 		int new_umask;
104 
105 		if (digit(*cp)) {
106 			for (new_umask = 0; *cp >= '0' && *cp <= '7'; cp++)
107 				new_umask = new_umask * 8 + (*cp - '0');
108 			if (*cp) {
109 				bi_errorf("bad number");
110 				return 1;
111 			}
112 		} else {
113 			/* symbolic format */
114 			int positions, new_val;
115 			char op;
116 
117 			old_umask = umask(0);
118 			umask(old_umask); /* in case of error */
119 			old_umask = ~old_umask;
120 			new_umask = old_umask;
121 			positions = 0;
122 			while (*cp) {
123 				while (*cp && strchr("augo", *cp))
124 					switch (*cp++) {
125 					case 'a': positions |= 0111; break;
126 					case 'u': positions |= 0100; break;
127 					case 'g': positions |= 0010; break;
128 					case 'o': positions |= 0001; break;
129 					}
130 				if (!positions)
131 					positions = 0111; /* default is a */
132 				if (!strchr("=+-", op = *cp))
133 					break;
134 				cp++;
135 				new_val = 0;
136 				while (*cp && strchr("rwxugoXs", *cp))
137 					switch (*cp++) {
138 					case 'r': new_val |= 04; break;
139 					case 'w': new_val |= 02; break;
140 					case 'x': new_val |= 01; break;
141 					case 'u': new_val |= old_umask >> 6;
142 						  break;
143 					case 'g': new_val |= old_umask >> 3;
144 						  break;
145 					case 'o': new_val |= old_umask >> 0;
146 						  break;
147 					case 'X': if (old_umask & 0111)
148 							new_val |= 01;
149 						  break;
150 					case 's': /* ignored */
151 						  break;
152 					}
153 				new_val = (new_val & 07) * positions;
154 				switch (op) {
155 				case '-':
156 					new_umask &= ~new_val;
157 					break;
158 				case '=':
159 					new_umask = new_val
160 					    | (new_umask & ~(positions * 07));
161 					break;
162 				case '+':
163 					new_umask |= new_val;
164 				}
165 				if (*cp == ',') {
166 					positions = 0;
167 					cp++;
168 				} else if (!strchr("=+-", *cp))
169 					break;
170 			}
171 			if (*cp) {
172 				bi_errorf("bad mask");
173 				return 1;
174 			}
175 			new_umask = ~new_umask;
176 		}
177 		umask(new_umask);
178 	}
179 	return 0;
180 }
181 
182 int
183 c_dot(wp)
184 	char **wp;
185 {
186 	char *file, *cp;
187 	char **argv;
188 	int argc;
189 	int i;
190 	int err;
191 
192 	if (ksh_getopt(wp, &builtin_opt, null) == '?')
193 		return 1;
194 
195 	if ((cp = wp[builtin_opt.optind]) == NULL)
196 		return 0;
197 	file = search(cp, path, R_OK, &err);
198 	if (file == NULL) {
199 		bi_errorf("%s: %s", cp, err ? strerror(err) : "not found");
200 		return 1;
201 	}
202 
203 	/* Set positional parameters? */
204 	if (wp[builtin_opt.optind + 1]) {
205 		argv = wp + builtin_opt.optind;
206 		argv[0] = e->loc->argv[0]; /* preserve $0 */
207 		for (argc = 0; argv[argc + 1]; argc++)
208 			;
209 	} else {
210 		argc = 0;
211 		argv = (char **) 0;
212 	}
213 	i = include(file, argc, argv, 0);
214 	if (i < 0) { /* should not happen */
215 		bi_errorf("%s: %s", cp, strerror(errno));
216 		return 1;
217 	}
218 	return i;
219 }
220 
221 int
222 c_wait(wp)
223 	char **wp;
224 {
225 	int UNINITIALIZED(rv);
226 	int sig;
227 
228 	if (ksh_getopt(wp, &builtin_opt, null) == '?')
229 		return 1;
230 	wp += builtin_opt.optind;
231 	if (*wp == (char *) 0) {
232 		while (waitfor((char *) 0, &sig) >= 0)
233 			;
234 		rv = sig;
235 	} else {
236 		for (; *wp; wp++)
237 			rv = waitfor(*wp, &sig);
238 		if (rv < 0)
239 			rv = sig ? sig : 127; /* magic exit code: bad job-id */
240 	}
241 	return rv;
242 }
243 
244 int
245 c_read(wp)
246 	char **wp;
247 {
248 	register int c = 0;
249 	int expand = 1, history = 0;
250 	int expanding;
251 	int ecode = 0;
252 	register char *cp;
253 	int fd = 0;
254 	struct shf *shf;
255 	int optc;
256 	const char *emsg;
257 	XString cs, xs;
258 	struct tbl *vp;
259 	char UNINITIALIZED(*xp);
260 
261 	while ((optc = ksh_getopt(wp, &builtin_opt, "prsu,")) != EOF)
262 		switch (optc) {
263 #ifdef KSH
264 		  case 'p':
265 			if ((fd = coproc_getfd(R_OK, &emsg)) < 0) {
266 				bi_errorf("-p: %s", emsg);
267 				return 1;
268 			}
269 			break;
270 #endif /* KSH */
271 		  case 'r':
272 			expand = 0;
273 			break;
274 		  case 's':
275 			history = 1;
276 			break;
277 		  case 'u':
278 			if (!*(cp = builtin_opt.optarg))
279 				fd = 0;
280 			else if ((fd = check_fd(cp, R_OK, &emsg)) < 0) {
281 				bi_errorf("-u: %s: %s", cp, emsg);
282 				return 1;
283 			}
284 			break;
285 		  case '?':
286 			return 1;
287 		}
288 	wp += builtin_opt.optind;
289 
290 	if (*wp == NULL)
291 		*--wp = "REPLY";
292 
293 	/* Since we can't necessarily seek backwards on non-regular files,
294 	 * don't buffer them so we can't read too much.
295 	 */
296 	shf = shf_reopen(fd, SHF_RD | SHF_INTERRUPT | can_seek(fd), shl_spare);
297 
298 	if ((cp = strchr(*wp, '?')) != NULL) {
299 		*cp = 0;
300 		if (isatty(fd)) {
301 			/* at&t ksh says it prints prompt on fd if it's open
302 			 * for writing and is a tty, but it doesn't do it
303 			 * (it also doesn't check the interactive flag,
304 			 * as is indicated in the Kornshell book).
305 			 */
306 			shellf("%s", cp+1);
307 		}
308 	}
309 
310 #ifdef KSH
311 	/* If we are reading from the co-process for the first time,
312 	 * make sure the other side of the pipe is closed first.  This allows
313 	 * the detection of eof.
314 	 *
315 	 * This is not compatiable with at&t ksh... the fd is kept so another
316 	 * coproc can be started with same output, however, this means eof
317 	 * can't be detected...  This is why it is closed here.
318 	 * If this call is removed, remove the eof check below, too.
319 	* coproc_readw_close(fd);
320 	 */
321 #endif /* KSH */
322 
323 	if (history)
324 		Xinit(xs, xp, 128, ATEMP);
325 	expanding = 0;
326 	Xinit(cs, cp, 128, ATEMP);
327 	for (; *wp != NULL; wp++) {
328 		for (cp = Xstring(cs, cp); ; ) {
329 			if (c == '\n' || c == EOF)
330 				break;
331 			while (1) {
332 				c = shf_getc(shf);
333 				if (c == '\0'
334 #ifdef OS2
335 				    || c == '\r'
336 #endif /* OS2 */
337 				    )
338 					continue;
339 				if (c == EOF && shf_error(shf)
340 				    && shf_errno(shf) == EINTR)
341 				{
342 					/* Was the offending signal one that
343 					 * would normally kill a process?
344 					 * If so, pretend the read was killed.
345 					 */
346 					ecode = fatal_trap_check();
347 
348 					/* non fatal (eg, CHLD), carry on */
349 					if (!ecode) {
350 						shf_clearerr(shf);
351 						continue;
352 					}
353 				}
354 				break;
355 			}
356 			if (history) {
357 				Xcheck(xs, xp);
358 				Xput(xs, xp, c);
359 			}
360 			Xcheck(cs, cp);
361 			if (expanding) {
362 				expanding = 0;
363 				if (c == '\n') {
364 					c = 0;
365 					if (Flag(FTALKING_I) && isatty(fd)) {
366 						/* set prompt in case this is
367 						 * called from .profile or $ENV
368 						 */
369 						set_prompt(PS2, (Source *) 0);
370 						pprompt(prompt, 0);
371 					}
372 				} else if (c != EOF)
373 					Xput(cs, cp, c);
374 				continue;
375 			}
376 			if (expand && c == '\\') {
377 				expanding = 1;
378 				continue;
379 			}
380 			if (c == '\n' || c == EOF)
381 				break;
382 			if (ctype(c, C_IFS)) {
383 				if (Xlength(cs, cp) == 0 && ctype(c, C_IFSWS))
384 					continue;
385 				if (wp[1])
386 					break;
387 			}
388 			Xput(cs, cp, c);
389 		}
390 		/* strip trailing IFS white space from last variable */
391 		if (!wp[1])
392 			while (Xlength(cs, cp) && ctype(cp[-1], C_IFS)
393 			       && ctype(cp[-1], C_IFSWS))
394 				cp--;
395 		Xput(cs, cp, '\0');
396 		vp = global(*wp);
397 		/* Must be done before setting export. */
398 		if (vp->flag & RDONLY) {
399 			shf_flush(shf);
400 			bi_errorf("%s is read only", *wp);
401 			return 1;
402 		}
403 		if (Flag(FEXPORT))
404 			typeset(*wp, EXPORT, 0, 0, 0);
405 		if (!setstr(vp, Xstring(cs, cp), KSH_RETURN_ERROR)) {
406 		    shf_flush(shf);
407 		    return 1;
408 		}
409 	}
410 
411 	shf_flush(shf);
412 	if (history) {
413 		Xput(xs, xp, '\0');
414 		source->line++;
415 		histsave(source->line, Xstring(xs, xp), 1);
416 		Xfree(xs, xp);
417 	}
418 #ifdef KSH
419 	/* if this is the co-process fd, close the file descriptor
420 	 * (can get eof if and only if all processes are have died, ie,
421 	 * coproc.njobs is 0 and the pipe is closed).
422 	 */
423 	if (c == EOF && !ecode)
424 		coproc_read_close(fd);
425 #endif /* KSH */
426 
427 	return ecode ? ecode : c == EOF;
428 }
429 
430 int
431 c_eval(wp)
432 	char **wp;
433 {
434 	register struct source *s;
435 
436 	if (ksh_getopt(wp, &builtin_opt, null) == '?')
437 		return 1;
438 	s = pushs(SWORDS, ATEMP);
439 	s->u.strv = wp + builtin_opt.optind;
440 	if (!Flag(FPOSIX)) {
441 		/*
442 		 * Handle case where the command is empty due to failed
443 		 * command substitution, eg, eval "$(false)".
444 		 * In this case, shell() will not set/change exstat (because
445 		 * compiled tree is empty), so will use this value.
446 		 * subst_exstat is cleared in execute(), so should be 0 if
447 		 * there were no substitutions.
448 		 *
449 		 * A strict reading of POSIX says we don't do this (though
450 		 * it is traditionally done). [from 1003.2-1992]
451 		 *    3.9.1: Simple Commands
452 		 *	... If there is a command name, execution shall
453 		 *	continue as described in 3.9.1.1.  If there
454 		 *	is no command name, but the command contained a command
455 		 *	substitution, the command shall complete with the exit
456 		 *	status of the last command substitution
457 		 *    3.9.1.1: Command Search and Execution
458 		 *	...(1)...(a) If the command name matches the name of
459 		 *	a special built-in utility, that special built-in
460 		 *	utility shall be invoked.
461 		 * 3.14.5: Eval
462 		 *	... If there are no arguments, or only null arguments,
463 		 *	eval shall return an exit status of zero.
464 		 */
465 		exstat = subst_exstat;
466 	}
467 
468 	return shell(s, FALSE);
469 }
470 
471 int
472 c_trap(wp)
473 	char **wp;
474 {
475 	int i;
476 	char *s;
477 	register Trap *p;
478 
479 	if (ksh_getopt(wp, &builtin_opt, null) == '?')
480 		return 1;
481 	wp += builtin_opt.optind;
482 
483 	if (*wp == NULL) {
484 		int anydfl = 0;
485 
486 		for (p = sigtraps, i = SIGNALS+1; --i >= 0; p++) {
487 			if (p->trap == NULL)
488 				anydfl = 1;
489 			else {
490 				shprintf("trap -- ");
491 				print_value_quoted(p->trap);
492 				shprintf(" %s\n", p->name);
493 			}
494 		}
495 #if 0 /* this is ugly and not clear POSIX needs it */
496 		/* POSIX may need this so output of trap can be saved and
497 		 * used to restore trap conditions
498 		 */
499 		if (anydfl) {
500 			shprintf("trap -- -");
501 			for (p = sigtraps, i = SIGNALS+1; --i >= 0; p++)
502 				if (p->trap == NULL && p->name)
503 					shprintf(" %s", p->name);
504 			shprintf(newline);
505 		}
506 #endif
507 		return 0;
508 	}
509 
510 	/*
511 	 * Use case sensitive lookup for first arg so the
512 	 * command 'exit' isn't confused with the pseudo-signal
513 	 * 'EXIT'.
514 	 */
515 	s = (gettrap(*wp, FALSE) == NULL) ? *wp++ : NULL; /* get command */
516 	if (s != NULL && s[0] == '-' && s[1] == '\0')
517 		s = NULL;
518 
519 	/* set/clear traps */
520 	while (*wp != NULL) {
521 		p = gettrap(*wp++, TRUE);
522 		if (p == NULL) {
523 			bi_errorf("bad signal %s", wp[-1]);
524 			return 1;
525 		}
526 		settrap(p, s);
527 	}
528 	return 0;
529 }
530 
531 int
532 c_exitreturn(wp)
533 	char **wp;
534 {
535 	int how = LEXIT;
536 	int n;
537 	char *arg;
538 
539 	if (ksh_getopt(wp, &builtin_opt, null) == '?')
540 		return 1;
541 	arg = wp[builtin_opt.optind];
542 
543 	if (arg) {
544 	    if (!getn(arg, &n)) {
545 		    exstat = 1;
546 		    warningf(TRUE, "%s: bad number", arg);
547 	    } else
548 		    exstat = n;
549 	}
550 	if (wp[0][0] == 'r') { /* return */
551 		struct env *ep;
552 
553 		/* need to tell if this is exit or return so trap exit will
554 		 * work right (POSIX)
555 		 */
556 		for (ep = e; ep; ep = ep->oenv)
557 			if (STOP_RETURN(ep->type)) {
558 				how = LRETURN;
559 				break;
560 			}
561 	}
562 
563 	if (how == LEXIT && !really_exit && j_stopped_running()) {
564 		really_exit = 1;
565 		how = LSHELL;
566 	}
567 
568 	quitenv();	/* get rid of any i/o redirections */
569 	unwind(how);
570 	/*NOTREACHED*/
571 	return 0;
572 }
573 
574 int
575 c_brkcont(wp)
576 	char **wp;
577 {
578 	int n, quit;
579 	struct env *ep, *last_ep = (struct env *) 0;
580 	char *arg;
581 
582 	if (ksh_getopt(wp, &builtin_opt, null) == '?')
583 		return 1;
584 	arg = wp[builtin_opt.optind];
585 
586 	if (!arg)
587 		n = 1;
588 	else if (!bi_getn(arg, &n))
589 		return 1;
590 	quit = n;
591 	if (quit <= 0) {
592 		/* at&t ksh does this for non-interactive shells only - weird */
593 		bi_errorf("%s: bad value", arg);
594 		return 1;
595 	}
596 
597 	/* Stop at E_NONE, E_PARSE, E_FUNC, or E_INCL */
598 	for (ep = e; ep && !STOP_BRKCONT(ep->type); ep = ep->oenv)
599 		if (ep->type == E_LOOP) {
600 			if (--quit == 0)
601 				break;
602 			ep->flags |= EF_BRKCONT_PASS;
603 			last_ep = ep;
604 		}
605 
606 	if (quit) {
607 		/* at&t ksh doesn't print a message - just does what it
608 		 * can.  We print a message 'cause it helps in debugging
609 		 * scripts, but don't generate an error (ie, keep going).
610 		 */
611 		if (n == quit) {
612 			warningf(TRUE, "%s: cannot %s", wp[0], wp[0]);
613 			return 0;
614 		}
615 		/* POSIX says if n is too big, the last enclosing loop
616 		 * shall be used.  Doesn't say to print an error but we
617 		 * do anyway 'cause the user messed up.
618 		 */
619 		last_ep->flags &= ~EF_BRKCONT_PASS;
620 		warningf(TRUE, "%s: can only %s %d level(s)",
621 			wp[0], wp[0], n - quit);
622 	}
623 
624 	unwind(*wp[0] == 'b' ? LBREAK : LCONTIN);
625 	/*NOTREACHED*/
626 }
627 
628 int
629 c_set(wp)
630 	char **wp;
631 {
632 	int argi, setargs;
633 	struct block *l = e->loc;
634 	register char **owp = wp;
635 
636 	if (wp[1] == NULL) {
637 		static const char *const args [] = { "set", "-", NULL };
638 		return c_typeset((char **) args);
639 	}
640 
641 	argi = parse_args(wp, OF_SET, &setargs);
642 	if (argi < 0)
643 		return 1;
644 	/* set $# and $* */
645 	if (setargs) {
646 		owp = wp += argi - 1;
647 		wp[0] = l->argv[0]; /* save $0 */
648 		while (*++wp != NULL)
649 			*wp = str_save(*wp, &l->area);
650 		l->argc = wp - owp - 1;
651 		l->argv = (char **) alloc(sizeofN(char *, l->argc+2), &l->area);
652 		for (wp = l->argv; (*wp++ = *owp++) != NULL; )
653 			;
654 	}
655 	/* POSIX says set exit status is 0, but old scripts that use
656 	 * getopt(1), use the construct: set -- `getopt ab:c "$@"`
657 	 * which assumes the exit value set will be that of the ``
658 	 * (subst_exstat is cleared in execute() so that it will be 0
659 	 * if there are no command substitutions).
660 	 */
661 	return Flag(FPOSIX) ? 0 : subst_exstat;
662 }
663 
664 int
665 c_unset(wp)
666 	char **wp;
667 {
668 	register char *id;
669 	int optc, unset_var = 1;
670 	int ret = 0;
671 
672 	while ((optc = ksh_getopt(wp, &builtin_opt, "fv")) != EOF)
673 		switch (optc) {
674 		  case 'f':
675 			unset_var = 0;
676 			break;
677 		  case 'v':
678 			unset_var = 1;
679 			break;
680 		  case '?':
681 			return 1;
682 		}
683 	wp += builtin_opt.optind;
684 	for (; (id = *wp) != NULL; wp++)
685 		if (unset_var) {	/* unset variable */
686 			struct tbl *vp = global(id);
687 
688 			if (!(vp->flag & ISSET))
689 			    ret = 1;
690 			if ((vp->flag&RDONLY)) {
691 				bi_errorf("%s is read only", vp->name);
692 				return 1;
693 			}
694 			unset(vp, strchr(id, '[') ? 1 : 0);
695 		} else {		/* unset function */
696 			if (define(id, (struct op *) NULL))
697 				ret = 1;
698 		}
699 	return ret;
700 }
701 
702 int
703 c_times(wp)
704 	char **wp;
705 {
706 	struct tms all;
707 
708 	(void) ksh_times(&all);
709 	shprintf("Shell: %8ss user ", clocktos(all.tms_utime));
710 	shprintf("%8ss system\n", clocktos(all.tms_stime));
711 	shprintf("Kids:  %8ss user ", clocktos(all.tms_cutime));
712 	shprintf("%8ss system\n", clocktos(all.tms_cstime));
713 
714 	return 0;
715 }
716 
717 /*
718  * time pipeline (really a statement, not a built-in command)
719  */
720 int
721 timex(t, f)
722 	struct op *t;
723 	int f;
724 {
725 #define TF_NOARGS	BIT(0)
726 #define TF_NOREAL	BIT(1)		/* don't report real time */
727 #define TF_POSIX	BIT(2)		/* report in posix format */
728 	int rv = 0;
729 	struct tms t0, t1, tms;
730 	clock_t t0t, t1t = 0;
731 	int tf = 0;
732 	char opts[1];
733 
734 	t0t = ksh_times(&t0);
735 	if (t->left) {
736 		/*
737 		 * Two ways of getting cpu usage of a command: just use t0
738 		 * and t1 (which will get cpu usage from other jobs that
739 		 * finish while we are executing t->left), or get the
740 		 * cpu usage of t->left. at&t ksh does the former, while
741 		 * pdksh tries to do the later (the j_usrtime hack doesn't
742 		 * really work as it only counts the last job).
743 		 */
744 		j_usrtime = j_systime = 0;
745 		if (t->left->type == TCOM)
746 			t->left->str = opts;
747 		opts[0] = 0;
748 		rv = execute(t->left, f | XTIME);
749 		tf |= opts[0];
750 		t1t = ksh_times(&t1);
751 	} else
752 		tf = TF_NOARGS;
753 
754 	if (tf & TF_NOARGS) { /* ksh93 - report shell times (shell+kids) */
755 		tf |= TF_NOREAL;
756 		tms.tms_utime = t0.tms_utime + t0.tms_cutime;
757 		tms.tms_stime = t0.tms_stime + t0.tms_cstime;
758 	} else {
759 		tms.tms_utime = t1.tms_utime - t0.tms_utime + j_usrtime;
760 		tms.tms_stime = t1.tms_stime - t0.tms_stime + j_systime;
761 	}
762 
763 	if (!(tf & TF_NOREAL))
764 		shf_fprintf(shl_out,
765 			tf & TF_POSIX ? "real %8s\n" : "%8ss real ",
766 			clocktos(t1t - t0t));
767 	shf_fprintf(shl_out, tf & TF_POSIX ? "user %8s\n" : "%8ss user ",
768 		clocktos(tms.tms_utime));
769 	shf_fprintf(shl_out, tf & TF_POSIX ? "sys  %8s\n" : "%8ss system\n",
770 		clocktos(tms.tms_stime));
771 	shf_flush(shl_out);
772 
773 	return rv;
774 }
775 
776 void
777 timex_hook(t, app)
778 	struct op *t;
779 	char ** volatile *app;
780 {
781 	char **wp = *app;
782 	int optc;
783 	int i, j;
784 	Getopt opt;
785 
786 	ksh_getopt_reset(&opt, 0);
787 	opt.optind = 0;	/* start at the start */
788 	while ((optc = ksh_getopt(wp, &opt, ":p")) != EOF)
789 		switch (optc) {
790 		  case 'p':
791 			t->str[0] |= TF_POSIX;
792 			break;
793 		  case '?':
794 			errorf("time: -%s unknown option", opt.optarg);
795 		  case ':':
796 			errorf("time: -%s requires an argument",
797 				opt.optarg);
798 		}
799 	/* Copy command words down over options. */
800 	if (opt.optind != 0) {
801 		for (i = 0; i < opt.optind; i++)
802 			afree(wp[i], ATEMP);
803 		for (i = 0, j = opt.optind; (wp[i] = wp[j]); i++, j++)
804 			;
805 	}
806 	if (!wp[0])
807 		t->str[0] |= TF_NOARGS;
808 	*app = wp;
809 }
810 
811 static char *
812 clocktos(t)
813 	clock_t t;
814 {
815 	static char temp[22]; /* enough for 64 bit clock_t */
816 	register int i;
817 	register char *cp = temp + sizeof(temp);
818 
819 	/* note: posix says must use max precision, ie, if clk_tck is
820 	 * 1000, must print 3 places after decimal (if non-zero, else 1).
821 	 */
822 	if (CLK_TCK != 100)	/* convert to 1/100'ths */
823 	    t = (t < 1000000000/CLK_TCK) ?
824 		    (t * 100) / CLK_TCK : (t / CLK_TCK) * 100;
825 
826 	*--cp = '\0';
827 	for (i = -2; i <= 0 || t > 0; i++) {
828 		if (i == 0)
829 			*--cp = '.';
830 		*--cp = '0' + (char)(t%10);
831 		t /= 10;
832 	}
833 	return cp;
834 }
835 
836 /* exec with no args - args case is taken care of in comexec() */
837 int
838 c_exec(wp)
839 	char ** wp;
840 {
841 	int i;
842 
843 	/* make sure redirects stay in place */
844 	if (e->savefd != NULL) {
845 		for (i = 0; i < NUFILE; i++) {
846 			if (e->savefd[i] > 0)
847 				close(e->savefd[i]);
848 			/*
849 			 * For ksh keep anything > 2 private,
850 			 * for sh, let them be (POSIX says what
851 			 * happens is unspecified and the bourne shell
852 			 * keeps them open).
853 			 */
854 #ifdef KSH
855 			if (i > 2 && e->savefd[i])
856 				fd_clexec(i);
857 #endif /* KSH */
858 		}
859 		e->savefd = NULL;
860 	}
861 	return 0;
862 }
863 
864 /* dummy function, special case in comexec() */
865 int
866 c_builtin(wp)
867 	char ** wp;
868 {
869 	return 0;
870 }
871 
872 /* A leading = means assignments before command are kept;
873  * a leading * means a POSIX special builtin;
874  * a leading + means a POSIX regular builtin
875  * (* and + should not be combined).
876  */
877 const struct builtin shbuiltins [] = {
878 	{"*=.", c_dot},
879 	{"*=:", c_label},
880 	{"[", c_test},
881 	{"*=break", c_brkcont},
882 	{"=builtin", c_builtin},
883 	{"*=continue", c_brkcont},
884 	{"*=eval", c_eval},
885 	{"*=exec", c_exec},
886 	{"*=exit", c_exitreturn},
887 	{"+false", c_label},
888 	{"*=return", c_exitreturn},
889 	{"*=set", c_set},
890 	{"*=shift", c_shift},
891 	{"*=times", c_times},
892 	{"*=trap", c_trap},
893 	{"+=wait", c_wait},
894 	{"+read", c_read},
895 	{"test", c_test},
896 	{"+true", c_label},
897 	{"ulimit", c_ulimit},
898 	{"+umask", c_umask},
899 	{"*=unset", c_unset},
900 #ifdef OS2
901 	/* In OS2, the first line of a file can be "extproc name", which
902 	 * tells the command interpreter (cmd.exe) to use name to execute
903 	 * the file.  For this to be useful, ksh must ignore commands
904 	 * starting with extproc and this does the trick...
905 	 */
906 	{"extproc", c_label},
907 #endif /* OS2 */
908 	{NULL, NULL}
909 };
910