xref: /netbsd/bin/ksh/exec.c (revision bf9ec67e)
1 /*	$NetBSD: exec.c,v 1.6 2001/09/29 15:05:47 wiz Exp $	*/
2 
3 /*
4  * execute command tree
5  */
6 
7 #include "sh.h"
8 #include "c_test.h"
9 #include <ctype.h>
10 #include "ksh_stat.h"
11 
12 /* Does ps4 get parameter substitutions done? */
13 #ifdef KSH
14 # define PS4_SUBSTITUTE(s)	substitute((s), 0)
15 #else
16 # define PS4_SUBSTITUTE(s)	(s)
17 #endif /* KSH */
18 
19 static int	comexec	 ARGS((struct op *t, struct tbl *volatile tp, char **ap,
20 			      int volatile flags));
21 static void	scriptexec ARGS((struct op *tp, char **ap));
22 static int	call_builtin ARGS((struct tbl *tp, char **wp));
23 static int	iosetup ARGS((struct ioword *iop, struct tbl *tp));
24 static int	herein ARGS((const char *content, int sub));
25 #ifdef KSH
26 static char 	*do_selectargs ARGS((char **ap, bool_t print_menu));
27 #endif /* KSH */
28 #ifdef KSH
29 static int	dbteste_isa ARGS((Test_env *te, Test_meta meta));
30 static const char *dbteste_getopnd ARGS((Test_env *te, Test_op op,
31 					 int do_eval));
32 static int	dbteste_eval ARGS((Test_env *te, Test_op op, const char *opnd1,
33 				const char *opnd2, int do_eval));
34 static void	dbteste_error ARGS((Test_env *te, int offset, const char *msg));
35 #endif /* KSH */
36 #ifdef OS2
37 static int	search_access1 ARGS((const char *path, int mode, int *errnop));
38 #endif /* OS2 */
39 
40 
41 /*
42  * handle systems that don't have F_SETFD
43  */
44 #ifndef F_SETFD
45 # ifndef MAXFD
46 #   define  MAXFD 64
47 # endif
48 /* a bit field would be smaller, but this will work */
49 static char clexec_tab[MAXFD+1];
50 #endif
51 
52 /*
53  * we now use this function always.
54  */
55 int
56 fd_clexec(fd)
57     int fd;
58 {
59 #ifndef F_SETFD
60 	if (fd >= 0 && fd < sizeof(clexec_tab)) {
61 		clexec_tab[fd] = 1;
62 		return 0;
63 	}
64 	return -1;
65 #else
66 	return fcntl(fd, F_SETFD, 1);
67 #endif
68 }
69 
70 
71 /*
72  * execute command tree
73  */
74 int
75 execute(t, flags)
76 	struct op * volatile t;
77 	volatile int flags;	/* if XEXEC don't fork */
78 {
79 	int i;
80 	volatile int rv = 0;
81 	volatile int rv_prop = 0; /* rv being propogated or newly generated? */
82 	int pv[2];
83 	char ** volatile ap;
84 	char *s, *cp;
85 	struct ioword **iowp;
86 	struct tbl *tp = NULL;
87 
88 	if (t == NULL)
89 		return 0;
90 
91 	/* Is this the end of a pipeline?  If so, we want to evaluate the
92 	 * command arguments
93 	bool_t eval_done = FALSE;
94 	if ((flags&XFORK) && !(flags&XEXEC) && (flags&XPCLOSE)) {
95 		eval_done = TRUE;
96 		tp = eval_execute_args(t, &ap);
97 	}
98 	 */
99 	if ((flags&XFORK) && !(flags&XEXEC) && t->type != TPIPE)
100 		return exchild(t, flags & ~XTIME, -1); /* run in sub-process */
101 
102 	newenv(E_EXEC);
103 	if (trap)
104 		runtraps(0);
105 
106 	if (t->type == TCOM) {
107 		/* Clear subst_exstat before argument expansion.  Used by
108 		 * null commands (see comexec() and c_eval()) and by c_set().
109 		 */
110 		subst_exstat = 0;
111 
112 		current_lineno = t->lineno;	/* for $LINENO */
113 
114 		/* POSIX says expand command words first, then redirections,
115 		 * and assignments last..
116 		 */
117 		ap = eval(t->args, t->u.evalflags | DOBLANK | DOGLOB | DOTILDE);
118 		if (flags & XTIME)
119 			/* Allow option parsing (bizarre, but POSIX) */
120 			timex_hook(t, &ap);
121 		if (Flag(FXTRACE) && ap[0]) {
122 			shf_fprintf(shl_out, "%s",
123 				PS4_SUBSTITUTE(str_val(global("PS4"))));
124 			for (i = 0; ap[i]; i++)
125 				shf_fprintf(shl_out, "%s%s", ap[i],
126 					ap[i + 1] ? space : newline);
127 			shf_flush(shl_out);
128 		}
129 		if (ap[0])
130 			tp = findcom(ap[0], FC_BI|FC_FUNC);
131 	}
132 	flags &= ~XTIME;
133 
134 	if (t->ioact != NULL || t->type == TPIPE || t->type == TCOPROC) {
135 		e->savefd = (short *) alloc(sizeofN(short, NUFILE), ATEMP);
136 		/* initialize to not redirected */
137 		memset(e->savefd, 0, sizeofN(short, NUFILE));
138 	}
139 
140 	/* do redirection, to be restored in quitenv() */
141 	if (t->ioact != NULL)
142 		for (iowp = t->ioact; *iowp != NULL; iowp++) {
143 			if (iosetup(*iowp, tp) < 0) {
144 				exstat = rv = 1;
145 				/* Redirection failures for special commands
146 				 * cause (non-interactive) shell to exit.
147 				 */
148 				if (tp && tp->type == CSHELL
149 				    && (tp->flag & SPEC_BI))
150 					errorf(null);
151 				/* Deal with FERREXIT, quitenv(), etc. */
152 				goto Break;
153 			}
154 		}
155 
156 	switch(t->type) {
157 	  case TCOM:
158 		rv = comexec(t, tp, ap, flags);
159 		break;
160 
161 	  case TPAREN:
162 		rv = execute(t->left, flags|XFORK);
163 		rv_prop = 1;
164 		break;
165 
166 	  case TPIPE:
167 		flags |= XFORK;
168 		flags &= ~XEXEC;
169 		e->savefd[0] = savefd(0, 0);
170 		(void) ksh_dup2(e->savefd[0], 0, FALSE); /* stdin of first */
171 		e->savefd[1] = savefd(1, 0);
172 		while (t->type == TPIPE) {
173 			openpipe(pv);
174 			(void) ksh_dup2(pv[1], 1, FALSE); /* stdout of curr */
175 			/* Let exchild() close pv[0] in child
176 			 * (if this isn't done, commands like
177 			 *    (: ; cat /etc/termcap) | sleep 1
178 			 *  will hang forever).
179 			 */
180 			exchild(t->left, flags|XPIPEO|XCCLOSE, pv[0]);
181 			(void) ksh_dup2(pv[0], 0, FALSE); /* stdin of next */
182 			closepipe(pv);
183 			flags |= XPIPEI;
184 			t = t->right;
185 		}
186 		restfd(1, e->savefd[1]); /* stdout of last */
187 		e->savefd[1] = 0; /* no need to re-restore this */
188 		/* Let exchild() close 0 in parent, after fork, before wait */
189 		i = exchild(t, flags|XPCLOSE, 0);
190 		if (!(flags&XBGND) && !(flags&XXCOM))
191 			rv = i;
192 		break;
193 
194 	  case TLIST:
195 		while (t->type == TLIST) {
196 			execute(t->left, flags & XERROK);
197 			t = t->right;
198 		}
199 		rv = execute(t, flags & XERROK);
200 		break;
201 
202 #ifdef KSH
203 	  case TCOPROC:
204 	  {
205 # ifdef JOB_SIGS
206 		sigset_t	omask;
207 # endif /* JOB_SIGS */
208 
209 # ifdef JOB_SIGS
210 		/* Block sigchild as we are using things changed in the
211 		 * signal handler
212 		 */
213 		sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
214 		e->type = E_ERRH;
215 		i = ksh_sigsetjmp(e->jbuf, 0);
216 		if (i) {
217 			sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
218 			quitenv();
219 			unwind(i);
220 			/*NOTREACHED*/
221 		}
222 # endif /* JOB_SIGS */
223 		/* Already have a (live) co-process? */
224 		if (coproc.job && coproc.write >= 0)
225 			errorf("coprocess already exists");
226 
227 		/* Can we re-use the existing co-process pipe? */
228 		coproc_cleanup(TRUE);
229 
230 		/* do this before opening pipes, in case these fail */
231 		e->savefd[0] = savefd(0, 0);
232 		e->savefd[1] = savefd(1, 0);
233 
234 		openpipe(pv);
235 		ksh_dup2(pv[0], 0, FALSE);
236 		close(pv[0]);
237 		coproc.write = pv[1];
238 		coproc.job = (void *) 0;
239 
240 		if (coproc.readw >= 0)
241 			ksh_dup2(coproc.readw, 1, FALSE);
242 		else {
243 			openpipe(pv);
244 			coproc.read = pv[0];
245 			ksh_dup2(pv[1], 1, FALSE);
246 			coproc.readw = pv[1];	 /* closed before first read */
247 			coproc.njobs = 0;
248 			/* create new coprocess id */
249 			++coproc.id;
250 		}
251 # ifdef JOB_SIGS
252 		sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
253 		e->type = E_EXEC; /* no more need for error handler */
254 # endif /* JOB_SIGS */
255 
256 		/* exchild() closes coproc.* in child after fork,
257 		 * will also increment coproc.njobs when the
258 		 * job is actually created.
259 		 */
260 		flags &= ~XEXEC;
261 		exchild(t->left, flags|XBGND|XFORK|XCOPROC|XCCLOSE,
262 			coproc.readw);
263 		break;
264 	  }
265 #endif /* KSH */
266 
267 	  case TASYNC:
268 		/* XXX non-optimal, I think - "(foo &)", forks for (),
269 		 * forks again for async...  parent should optimize
270 		 * this to "foo &"...
271 		 */
272 		rv = execute(t->left, (flags&~XEXEC)|XBGND|XFORK);
273 		break;
274 
275 	  case TOR:
276 	  case TAND:
277 		rv = execute(t->left, XERROK);
278 		if (t->right != NULL && (rv == 0) == (t->type == TAND))
279 			rv = execute(t->right, flags & XERROK);
280 		else
281 			flags |= XERROK;
282 		rv_prop = 1;
283 		break;
284 
285 	  case TBANG:
286 		rv = !execute(t->right, XERROK);
287 		break;
288 
289 #ifdef KSH
290 	  case TDBRACKET:
291 	    {
292 		Test_env te;
293 
294 		te.flags = TEF_DBRACKET;
295 		te.pos.wp = t->args;
296 		te.isa = dbteste_isa;
297 		te.getopnd = dbteste_getopnd;
298 		te.eval = dbteste_eval;
299 		te.error = dbteste_error;
300 
301 		rv = test_parse(&te);
302 		break;
303 	    }
304 #endif /* KSH */
305 
306 	  case TFOR:
307 #ifdef KSH
308 	  case TSELECT:
309 	    {
310 		volatile bool_t is_first = TRUE;
311 #endif /* KSH */
312 		ap = (t->vars != NULL) ?
313 			  eval(t->vars, DOBLANK|DOGLOB|DOTILDE)
314 			: e->loc->argv + 1;
315 		e->type = E_LOOP;
316 		while (1) {
317 			i = ksh_sigsetjmp(e->jbuf, 0);
318 			if (!i)
319 				break;
320 			if ((e->flags&EF_BRKCONT_PASS)
321 			    || (i != LBREAK && i != LCONTIN))
322 			{
323 				quitenv();
324 				unwind(i);
325 			} else if (i == LBREAK) {
326 				rv = 0;
327 				goto Break;
328 			}
329 		}
330 		rv = 0; /* in case of a continue */
331 		rv_prop = 1;
332 		if (t->type == TFOR) {
333 			while (*ap != NULL) {
334 				setstr(global(t->str), *ap++, KSH_UNWIND_ERROR);
335 				rv = execute(t->left, flags & XERROK);
336 			}
337 		}
338 #ifdef KSH
339 		else { /* TSELECT */
340 			for (;;) {
341 				if (!(cp = do_selectargs(ap, is_first))) {
342 					rv = 1;
343 					rv_prop = 0;
344 					break;
345 				}
346 				is_first = FALSE;
347 				setstr(global(t->str), cp, KSH_UNWIND_ERROR);
348 				rv = execute(t->left, flags & XERROK);
349 			}
350 		}
351 	    }
352 #endif /* KSH */
353 		break;
354 
355 	  case TWHILE:
356 	  case TUNTIL:
357 		e->type = E_LOOP;
358 		while (1) {
359 			i = ksh_sigsetjmp(e->jbuf, 0);
360 			if (!i)
361 				break;
362 			if ((e->flags&EF_BRKCONT_PASS)
363 			    || (i != LBREAK && i != LCONTIN))
364 			{
365 				quitenv();
366 				unwind(i);
367 			} else if (i == LBREAK) {
368 				rv = 0;
369 				goto Break;
370 			}
371 		}
372 		rv = 0; /* in case of a continue */
373 		while ((execute(t->left, XERROK) == 0) == (t->type == TWHILE))
374 			rv = execute(t->right, flags & XERROK);
375 		rv_prop = 1;
376 		break;
377 
378 	  case TIF:
379 	  case TELIF:
380 		if (t->right == NULL)
381 			break;	/* should be error */
382 		rv = execute(t->left, XERROK) == 0 ?
383 			execute(t->right->left, flags & XERROK) :
384 			execute(t->right->right, flags & XERROK);
385 		rv_prop = 1;
386 		break;
387 
388 	  case TCASE:
389 		cp = evalstr(t->str, DOTILDE);
390 		for (t = t->left; t != NULL && t->type == TPAT; t = t->right)
391 		    for (ap = t->vars; *ap; ap++)
392 			if ((s = evalstr(*ap, DOTILDE|DOPAT))
393 			    && gmatch(cp, s, FALSE))
394 				goto Found;
395 		break;
396 	  Found:
397 		rv = execute(t->left, flags & XERROK);
398 		rv_prop = 1;
399 		break;
400 
401 	  case TBRACE:
402 		rv = execute(t->left, flags & XERROK);
403 		rv_prop = 1;
404 		break;
405 
406 	  case TFUNCT:
407 		rv = define(t->str, t);
408 		break;
409 
410 	  case TTIME:
411 		/* Clear XEXEC so nested execute() call doesn't exit
412 		 * (allows "ls -l | time grep foo").
413 		 */
414 		rv = timex(t, flags & ~XEXEC);
415 		rv_prop = 1;
416 		break;
417 
418 	  case TEXEC:		/* an eval'd TCOM */
419 		s = t->args[0];
420 		ap = makenv();
421 #ifndef F_SETFD
422 		for (i = 0; i < sizeof(clexec_tab); i++)
423 			if (clexec_tab[i]) {
424 				close(i);
425 				clexec_tab[i] = 0;
426 			}
427 #endif
428 		restoresigs();
429 		cleanup_proc_env();
430 		/* XINTACT bit is for OS2 */
431 		ksh_execve(t->str, t->args, ap, (flags & XINTACT) ? 1 : 0);
432 		if (errno == ENOEXEC)
433 			scriptexec(t, ap);
434 		else
435 			errorf("%s: %s", s, strerror(errno));
436 	}
437     Break:
438 	exstat = rv;
439 
440 	quitenv();		/* restores IO */
441 	if ((flags&XEXEC)) {
442 		unwind(LEXIT);	/* exit child */
443 		/* NOTREACHED */
444 	}
445 	if (rv != 0 && !rv_prop && !(flags & XERROK)) {
446 		if (Flag(FERREXIT))
447 			unwind(LERROR);
448 		trapsig(SIGERR_);
449 	}
450 	return rv;
451 }
452 
453 /*
454  * execute simple command
455  */
456 
457 static int
458 comexec(t, tp, ap, flags)
459 	struct op *t;
460 	struct tbl *volatile tp;
461 	register char **ap;
462 	int volatile flags;
463 {
464 	int i;
465 	int rv = 0;
466 	register char *cp;
467 	register char **lastp;
468 	static struct op texec; /* Must be static (XXX but why?) */
469 	int type_flags;
470 	int keepasn_ok;
471 	int fcflags = FC_BI|FC_FUNC|FC_PATH;
472 #ifdef __GNUC__
473 	(void) &rv;
474 #endif
475 
476 #ifdef KSH
477 	/* snag the last argument for $_ XXX not the same as at&t ksh,
478 	 * which only seems to set $_ after a newline (but not in
479 	 * functions/dot scripts, but in interactive and scipt) -
480 	 * perhaps save last arg here and set it in shell()?.
481 	 */
482 	if (Flag(FTALKING) && *(lastp = ap)) {
483 		while (*++lastp)
484 			;
485 		/* setstr() can't fail here */
486 		setstr(typeset("_", LOCAL, 0, INTEGER, 0), *--lastp,
487 		       KSH_RETURN_ERROR);
488 	}
489 #endif /* KSH */
490 
491 	/* Deal with the shell builtins builtin, exec and command since
492 	 * they can be followed by other commands.  This must be done before
493 	 * we know if we should create a local block, which must be done
494 	 * before we can do a path search (in case the assignments change
495 	 * PATH).
496 	 * Odd cases:
497 	 *   FOO=bar exec > /dev/null		FOO is kept but not exported
498 	 *   FOO=bar exec foobar		FOO is exported
499 	 *   FOO=bar command exec > /dev/null	FOO is neither kept nor exported
500 	 *   FOO=bar command			FOO is neither kept nor exported
501 	 *   PATH=... foobar			use new PATH in foobar search
502 	 */
503 	keepasn_ok = 1;
504 	while (tp && tp->type == CSHELL) {
505 		fcflags = FC_BI|FC_FUNC|FC_PATH;/* undo effects of command */
506 		if (tp->val.f == c_builtin) {
507 			if ((cp = *++ap) == NULL) {
508 				tp = NULL;
509 				break;
510 			}
511 			tp = findcom(cp, FC_BI);
512 			if (tp == NULL)
513 				errorf("builtin: %s: not a builtin", cp);
514 			continue;
515 		} else if (tp->val.f == c_exec) {
516 			if (ap[1] == NULL)
517 				break;
518 			ap++;
519 			flags |= XEXEC;
520 		} else if (tp->val.f == c_command) {
521 			int optc, saw_p = 0;
522 
523 			/* Ugly dealing with options in two places (here and
524 			 * in c_command(), but such is life)
525 			 */
526 			ksh_getopt_reset(&builtin_opt, 0);
527 			while ((optc = ksh_getopt(ap, &builtin_opt, ":p"))
528 									== 'p')
529 				saw_p = 1;
530 			if (optc != EOF)
531 				break;	/* command -vV or something */
532 			/* don't look for functions */
533 			fcflags = FC_BI|FC_PATH;
534 			if (saw_p) {
535 				if (Flag(FRESTRICTED)) {
536 					warningf(TRUE,
537 						"command -p: restricted");
538 					rv = 1;
539 					goto Leave;
540 				}
541 				fcflags |= FC_DEFPATH;
542 			}
543 			ap += builtin_opt.optind;
544 			/* POSIX says special builtins lose their status
545 			 * if accessed using command.
546 			 */
547 			keepasn_ok = 0;
548 			if (!ap[0]) {
549 				/* ensure command with no args exits with 0 */
550 				subst_exstat = 0;
551 				break;
552 			}
553 		} else
554 			break;
555 		tp = findcom(ap[0], fcflags & (FC_BI|FC_FUNC));
556 	}
557 	if (keepasn_ok && (!ap[0] || (tp && (tp->flag & KEEPASN))))
558 		type_flags = 0;
559 	else {
560 		/* create new variable/function block */
561 		newblock();
562 		/* ksh functions don't keep assignments, POSIX functions do. */
563 		if (keepasn_ok && tp && tp->type == CFUNC
564 		    && !(tp->flag & FKSH))
565 			type_flags = 0;
566 		else
567 			type_flags = LOCAL|LOCAL_COPY|EXPORT;
568 	}
569 	if (Flag(FEXPORT))
570 		type_flags |= EXPORT;
571 	for (i = 0; t->vars[i]; i++) {
572 		cp = evalstr(t->vars[i], DOASNTILDE);
573 		if (Flag(FXTRACE)) {
574 			if (i == 0)
575 				shf_fprintf(shl_out, "%s",
576 					PS4_SUBSTITUTE(str_val(global("PS4"))));
577 			shf_fprintf(shl_out, "%s%s", cp,
578 				t->vars[i + 1] ? space : newline);
579 			if (!t->vars[i + 1])
580 				shf_flush(shl_out);
581 		}
582 		typeset(cp, type_flags, 0, 0, 0);
583 	}
584 
585 	if ((cp = *ap) == NULL) {
586 		rv = subst_exstat;
587 		goto Leave;
588 	} else if (!tp) {
589 		if (Flag(FRESTRICTED) && ksh_strchr_dirsep(cp)) {
590 			warningf(TRUE, "%s: restricted", cp);
591 			rv = 1;
592 			goto Leave;
593 		}
594 		tp = findcom(cp, fcflags);
595 	}
596 
597 	switch (tp->type) {
598 	  case CSHELL:			/* shell built-in */
599 		rv = call_builtin(tp, ap);
600 		break;
601 
602 	  case CFUNC:			/* function call */
603 	  {
604 		volatile int old_xflag;
605 		volatile Tflag old_inuse;
606 		const char *volatile old_kshname;
607 
608 		if (!(tp->flag & ISSET)) {
609 			struct tbl *ftp;
610 
611 			if (!tp->u.fpath) {
612 				if (tp->u2.errno_) {
613 					warningf(TRUE,
614 				"%s: can't find function definition file - %s",
615 						cp, strerror(tp->u2.errno_));
616 					rv = 126;
617 				} else {
618 					warningf(TRUE,
619 				"%s: can't find function definition file", cp);
620 					rv = 127;
621 				}
622 				break;
623 			}
624 			if (include(tp->u.fpath, 0, (char **) 0, 0) < 0) {
625 				warningf(TRUE,
626 			    "%s: can't open function definition file %s - %s",
627 					cp, tp->u.fpath, strerror(errno));
628 				rv = 127;
629 				break;
630 			}
631 			if (!(ftp = findfunc(cp, hash(cp), FALSE))
632 			    || !(ftp->flag & ISSET))
633 			{
634 				warningf(TRUE,
635 					"%s: function not defined by %s",
636 					cp, tp->u.fpath);
637 				rv = 127;
638 				break;
639 			}
640 			tp = ftp;
641 		}
642 
643 		/* ksh functions set $0 to function name, POSIX functions leave
644 		 * $0 unchanged.
645 		 */
646 		old_kshname = kshname;
647 		if (tp->flag & FKSH)
648 			kshname = ap[0];
649 		else
650 			ap[0] = (char *) kshname;
651 		e->loc->argv = ap;
652 		for (i = 0; *ap++ != NULL; i++)
653 			;
654 		e->loc->argc = i - 1;
655 		/* ksh-style functions handle getopts sanely,
656 		 * bourne/posix functions are insane...
657 		 */
658 		if (tp->flag & FKSH) {
659 			e->loc->flags |= BF_DOGETOPTS;
660 			e->loc->getopts_state = user_opt;
661 			getopts_reset(1);
662 		}
663 
664 		old_xflag = Flag(FXTRACE);
665 		Flag(FXTRACE) = tp->flag & TRACE ? TRUE : FALSE;
666 
667 		old_inuse = tp->flag & FINUSE;
668 		tp->flag |= FINUSE;
669 
670 		e->type = E_FUNC;
671 		i = ksh_sigsetjmp(e->jbuf, 0);
672 		if (i == 0) {
673 			/* seems odd to pass XERROK here, but at&t ksh does */
674 			exstat = execute(tp->val.t, flags & XERROK);
675 			i = LRETURN;
676 		}
677 		kshname = old_kshname;
678 		Flag(FXTRACE) = old_xflag;
679 		tp->flag = (tp->flag & ~FINUSE) | old_inuse;
680 		/* Were we deleted while executing?  If so, free the execution
681 		 * tree.  todo: Unfortunately, the table entry is never re-used
682 		 * until the lookup table is expanded.
683 		 */
684 		if ((tp->flag & (FDELETE|FINUSE)) == FDELETE) {
685 			if (tp->flag & ALLOC) {
686 				tp->flag &= ~ALLOC;
687 				tfree(tp->val.t, tp->areap);
688 			}
689 			tp->flag = 0;
690 		}
691 		switch (i) {
692 		  case LRETURN:
693 		  case LERROR:
694 			rv = exstat;
695 			break;
696 		  case LINTR:
697 		  case LEXIT:
698 		  case LLEAVE:
699 		  case LSHELL:
700 			quitenv();
701 			unwind(i);
702 			/*NOTREACHED*/
703 		  default:
704 			quitenv();
705 			internal_errorf(1, "CFUNC %d", i);
706 		}
707 		break;
708 	  }
709 
710 	  case CEXEC:		/* executable command */
711 	  case CTALIAS:		/* tracked alias */
712 		if (!(tp->flag&ISSET)) {
713 			/* errno_ will be set if the named command was found
714 			 * but could not be executed (permissions, no execute
715 			 * bit, directory, etc).  Print out a (hopefully)
716 			 * useful error message and set the exit status to 126.
717 			 */
718 			if (tp->u2.errno_) {
719 				warningf(TRUE, "%s: cannot execute - %s", cp,
720 					strerror(tp->u2.errno_));
721 				rv = 126;	/* POSIX */
722 			} else {
723 				warningf(TRUE, "%s: not found", cp);
724 				rv = 127;
725 			}
726 			break;
727 		}
728 
729 #ifdef KSH
730 		/* set $_ to program's full path */
731 		/* setstr() can't fail here */
732 		setstr(typeset("_", LOCAL|EXPORT, 0, INTEGER, 0), tp->val.s,
733 		       KSH_RETURN_ERROR);
734 #endif /* KSH */
735 
736 		if (flags&XEXEC) {
737 			j_exit();
738 			if (!(flags&XBGND) || Flag(FMONITOR)) {
739 				setexecsig(&sigtraps[SIGINT], SS_RESTORE_ORIG);
740 				setexecsig(&sigtraps[SIGQUIT], SS_RESTORE_ORIG);
741 			}
742 		}
743 
744 		/* to fork we set up a TEXEC node and call execute */
745 		texec.type = TEXEC;
746 		texec.left = t;	/* for tprint */
747 		texec.str = tp->val.s;
748 		texec.args = ap;
749 		rv = exchild(&texec, flags, -1);
750 		break;
751 	}
752   Leave:
753 	if (flags & XEXEC) {
754 		exstat = rv;
755 		unwind(LLEAVE);
756 	}
757 	return rv;
758 }
759 
760 static void
761 scriptexec(tp, ap)
762 	register struct op *tp;
763 	register char **ap;
764 {
765 	char *shell;
766 
767 	shell = str_val(global(EXECSHELL_STR));
768 	if (shell && *shell)
769 		shell = search(shell, path, X_OK, (int *) 0);
770 	if (!shell || !*shell)
771 		shell = EXECSHELL;
772 
773 	*tp->args-- = tp->str;
774 #ifdef	SHARPBANG
775 	{
776 		char buf[LINE];
777 		register char *cp;
778 		register int fd, n;
779 
780 		buf[0] = '\0';
781 		if ((fd = open(tp->str, O_RDONLY)) >= 0) {
782 			if ((n = read(fd, buf, LINE - 1)) > 0)
783 				buf[n] = '\0';
784 			(void) close(fd);
785 		}
786 		if ((buf[0] == '#' && buf[1] == '!' && (cp = &buf[2]))
787 # ifdef OS2
788 		    || (strncmp(buf, "extproc", 7) == 0 && isspace(buf[7])
789 			&& (cp = &buf[7]))
790 # endif /* OS2 */
791 		    )
792 		{
793 			while (*cp && (*cp == ' ' || *cp == '\t'))
794 				cp++;
795 			if (*cp && *cp != '\n') {
796 				char *a0 = cp, *a1 = (char *) 0;
797 # ifdef OS2
798 				char *a2 = cp;
799 # endif /* OS2 */
800 
801 				while (*cp && *cp != '\n' && *cp != ' '
802 				       && *cp != '\t')
803 				{
804 # ifdef OS2
805 			/* Allow shell search without prepended path
806 			 * if shell with / in pathname cannot be found.
807 			 * Use / explicitly so \ can be used if explicit
808 			 * needs to be forced.
809 			 */
810 					if (*cp == '/')
811 						a2 = cp + 1;
812 # endif /* OS2 */
813 					cp++;
814 				}
815 				if (*cp && *cp != '\n') {
816 					*cp++ = '\0';
817 					while (*cp
818 					       && (*cp == ' ' || *cp == '\t'))
819 						cp++;
820 					if (*cp && *cp != '\n') {
821 						a1 = cp;
822 						/* all one argument */
823 						while (*cp && *cp != '\n')
824 							cp++;
825 					}
826 				}
827 				if (*cp == '\n') {
828 					*cp = '\0';
829 					if (a1)
830 						*tp->args-- = a1;
831 # ifdef OS2
832 					if (a0 != a2) {
833 						char *tmp_a0 = str_nsave(a0,
834 							strlen(a0) + 5, ATEMP);
835 						if (search_access(tmp_a0, X_OK,
836 								(int *) 0))
837 							a0 = a2;
838 						afree(tmp_a0, ATEMP);
839 					}
840 # endif /* OS2 */
841 					shell = a0;
842 				}
843 			}
844 # ifdef OS2
845 		} else {
846 		        /* Use ksh documented shell default if present
847 			 * else use OS2_SHELL which is assumed to need
848 			 * the /c option and '\' as dir separater.
849 			 */
850 		         char *p = shell;
851 
852 			 shell = str_val(global("EXECSHELL"));
853 			 if (shell && *shell)
854 				 shell = search(shell, path, X_OK, (int *) 0);
855 			 if (!shell || !*shell) {
856 				 shell = p;
857 				 *tp->args-- = "/c";
858 				 for (p = tp->str; *p; p++)
859 					 if (*p == '/')
860 						 *p = '\\';
861 			 }
862 # endif /* OS2 */
863 		}
864 	}
865 #endif	/* SHARPBANG */
866 	*tp->args = shell;
867 
868 	ksh_execve(tp->args[0], tp->args, ap, 0);
869 
870 	/* report both the program that was run and the bogus shell */
871 	errorf("%s: %s: %s", tp->str, shell, strerror(errno));
872 }
873 
874 int
875 shcomexec(wp)
876 	register char **wp;
877 {
878 	register struct tbl *tp;
879 
880 	tp = tsearch(&builtins, *wp, hash(*wp));
881 	if (tp == NULL)
882 		internal_errorf(1, "shcomexec: %s", *wp);
883 	return call_builtin(tp, wp);
884 }
885 
886 /*
887  * Search function tables for a function.  If create set, a table entry
888  * is created if none is found.
889  */
890 struct tbl *
891 findfunc(name, h, create)
892 	const char *name;
893 	unsigned int h;
894 	int create;
895 {
896 	struct block *l;
897 	struct tbl *tp = (struct tbl *) 0;
898 
899 	for (l = e->loc; l; l = l->next) {
900 		tp = tsearch(&l->funs, name, h);
901 		if (tp)
902 			break;
903 		if (!l->next && create) {
904 			tp = tenter(&l->funs, name, h);
905 			tp->flag = DEFINED;
906 			tp->type = CFUNC;
907 			tp->val.t = (struct op *) 0;
908 			break;
909 		}
910 	}
911 	return tp;
912 }
913 
914 /*
915  * define function.  Returns 1 if function is being undefined (t == 0) and
916  * function did not exist, returns 0 otherwise.
917  */
918 int
919 define(name, t)
920 	const char *name;
921 	struct op *t;
922 {
923 	struct tbl *tp;
924 	int was_set = 0;
925 
926 	while (1) {
927 		tp = findfunc(name, hash(name), TRUE);
928 
929 		if (tp->flag & ISSET)
930 			was_set = 1;
931 		/* If this function is currently being executed, we zap this
932 		 * table entry so findfunc() won't see it
933 		 */
934 		if (tp->flag & FINUSE) {
935 			tp->name[0] = '\0';
936 			tp->flag &= ~DEFINED; /* ensure it won't be found */
937 			tp->flag |= FDELETE;
938 		} else
939 			break;
940 	}
941 
942 	if (tp->flag & ALLOC) {
943 		tp->flag &= ~(ISSET|ALLOC);
944 		tfree(tp->val.t, tp->areap);
945 	}
946 
947 	if (t == NULL) {		/* undefine */
948 		tdelete(tp);
949 		return was_set ? 0 : 1;
950 	}
951 
952 	tp->val.t = tcopy(t->left, tp->areap);
953 	tp->flag |= (ISSET|ALLOC);
954 	if (t->u.ksh_func)
955 		tp->flag |= FKSH;
956 
957 	return 0;
958 }
959 
960 /*
961  * add builtin
962  */
963 void
964 builtin(name, func)
965 	const char *name;
966 	int (*func) ARGS((char **));
967 {
968 	register struct tbl *tp;
969 	Tflag flag;
970 
971 	/* see if any flags should be set for this builtin */
972 	for (flag = 0; ; name++) {
973 		if (*name == '=')	/* command does variable assignment */
974 			flag |= KEEPASN;
975 		else if (*name == '*')	/* POSIX special builtin */
976 			flag |= SPEC_BI;
977 		else if (*name == '+')	/* POSIX regular builtin */
978 			flag |= REG_BI;
979 		else
980 			break;
981 	}
982 
983 	tp = tenter(&builtins, name, hash(name));
984 	tp->flag = DEFINED | flag;
985 	tp->type = CSHELL;
986 	tp->val.f = func;
987 }
988 
989 /*
990  * find command
991  * either function, hashed command, or built-in (in that order)
992  */
993 struct tbl *
994 findcom(name, flags)
995 	const char *name;
996 	int	flags;		/* FC_* */
997 {
998 	static struct tbl temp;
999 	unsigned int h = hash(name);
1000 	struct tbl *tp = NULL, *tbi;
1001 	int insert = Flag(FTRACKALL);	/* insert if not found */
1002 	char *fpath;			/* for function autoloading */
1003 	char *npath;
1004 
1005 	if (ksh_strchr_dirsep(name) != NULL) {
1006 		insert = 0;
1007 		/* prevent FPATH search below */
1008 		flags &= ~FC_FUNC;
1009 		goto Search;
1010 	}
1011 	tbi = (flags & FC_BI) ? tsearch(&builtins, name, h) : NULL;
1012 	/* POSIX says special builtins first, then functions, then
1013 	 * POSIX regular builtins, then search path...
1014 	 */
1015 	if ((flags & FC_SPECBI) && tbi && (tbi->flag & SPEC_BI))
1016 		tp = tbi;
1017 	if (!tp && (flags & FC_FUNC)) {
1018 		tp = findfunc(name, h, FALSE);
1019 		if (tp && !(tp->flag & ISSET)) {
1020 			if ((fpath = str_val(global("FPATH"))) == null) {
1021 				tp->u.fpath = (char *) 0;
1022 				tp->u2.errno_ = 0;
1023 			} else
1024 				tp->u.fpath = search(name, fpath, R_OK,
1025 					&tp->u2.errno_);
1026 		}
1027 	}
1028 	if (!tp && (flags & FC_REGBI) && tbi && (tbi->flag & REG_BI))
1029 		tp = tbi;
1030 	/* todo: posix says non-special/non-regular builtins must
1031 	 * be triggered by some user-controllable means like a
1032 	 * special directory in PATH.  Requires modifications to
1033 	 * the search() function.  Tracked aliases should be
1034 	 * modified to allow tracking of builtin commands.
1035 	 * This should be under control of the FPOSIX flag.
1036 	 * If this is changed, also change c_whence...
1037 	 */
1038 	if (!tp && (flags & FC_UNREGBI) && tbi)
1039 		tp = tbi;
1040 	if (!tp && (flags & FC_PATH) && !(flags & FC_DEFPATH)) {
1041 		tp = tsearch(&taliases, name, h);
1042 		if (tp && (tp->flag & ISSET) && eaccess(tp->val.s, X_OK) != 0) {
1043 			if (tp->flag & ALLOC) {
1044 				tp->flag &= ~ALLOC;
1045 				afree(tp->val.s, APERM);
1046 			}
1047 			tp->flag &= ~ISSET;
1048 		}
1049 	}
1050 
1051   Search:
1052 	if ((!tp || (tp->type == CTALIAS && !(tp->flag&ISSET)))
1053 	    && (flags & FC_PATH))
1054 	{
1055 		if (!tp) {
1056 			if (insert && !(flags & FC_DEFPATH)) {
1057 				tp = tenter(&taliases, name, h);
1058 				tp->type = CTALIAS;
1059 			} else {
1060 				tp = &temp;
1061 				tp->type = CEXEC;
1062 			}
1063 			tp->flag = DEFINED;	/* make ~ISSET */
1064 		}
1065 		npath = search(name, flags & FC_DEFPATH ? def_path : path,
1066 				X_OK, &tp->u2.errno_);
1067 		if (npath) {
1068 			tp->val.s = tp == &temp ? npath : str_save(npath, APERM);
1069 			tp->flag |= ISSET|ALLOC;
1070 		} else if ((flags & FC_FUNC)
1071 			   && (fpath = str_val(global("FPATH"))) != null
1072 			   && (npath = search(name, fpath, R_OK,
1073 					      &tp->u2.errno_)) != (char *) 0)
1074 		{
1075 			/* An undocumented feature of at&t ksh is that it
1076 			 * searches FPATH if a command is not found, even
1077 			 * if the command hasn't been set up as an autoloaded
1078 			 * function (ie, no typeset -uf).
1079 			 */
1080 			tp = &temp;
1081 			tp->type = CFUNC;
1082 			tp->flag = DEFINED; /* make ~ISSET */
1083 			tp->u.fpath = npath;
1084 		}
1085 	}
1086 	return tp;
1087 }
1088 
1089 /*
1090  * flush executable commands with relative paths
1091  */
1092 void
1093 flushcom(all)
1094 	int all;		/* just relative or all */
1095 {
1096 	struct tbl *tp;
1097 	struct tstate ts;
1098 
1099 	for (twalk(&ts, &taliases); (tp = tnext(&ts)) != NULL; )
1100 		if ((tp->flag&ISSET) && (all || !ISDIRSEP(tp->val.s[0]))) {
1101 			if (tp->flag&ALLOC) {
1102 				tp->flag &= ~(ALLOC|ISSET);
1103 				afree(tp->val.s, APERM);
1104 			}
1105 			tp->flag &= ~ISSET;
1106 		}
1107 }
1108 
1109 /* Check if path is something we want to find.  Returns -1 for failure. */
1110 int
1111 search_access(path, mode, errnop)
1112 	const char *path;
1113 	int mode;
1114 	int *errnop;		/* set if candidate found, but not suitable */
1115 {
1116 #ifndef OS2
1117 	int ret, err = 0;
1118 	struct stat statb;
1119 
1120 	if (stat(path, &statb) < 0)
1121 		return -1;
1122 	ret = eaccess(path, mode);
1123 	if (ret < 0)
1124 		err = errno; /* File exists, but we can't access it */
1125 	else if (mode == X_OK
1126 		 && (!S_ISREG(statb.st_mode)
1127 		     /* This 'cause access() says root can execute everything */
1128 		     || !(statb.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH))))
1129 	{
1130 		ret = -1;
1131 		err = S_ISDIR(statb.st_mode) ? EISDIR : EACCES;
1132 	}
1133 	if (err && errnop && !*errnop)
1134 		*errnop = err;
1135 	return ret;
1136 #else /* !OS2 */
1137 	/*
1138 	 * NOTE: ASSUMES path can be modified and has enough room at the
1139 	 *       end of the string for a suffix (ie, 4 extra characters).
1140 	 *	 Certain code knows this (eg, eval.c(globit()),
1141 	 *	 exec.c(search())).
1142 	 */
1143 	static char *xsuffixes[] = { ".ksh", ".exe", ".", ".sh", ".cmd",
1144 				     ".com", ".bat", (char *) 0
1145 				   };
1146 	static char *rsuffixes[] = { ".ksh", ".", ".sh", ".cmd", ".bat",
1147 				      (char *) 0
1148 				   };
1149 	int i;
1150 	char *mpath = (char *) path;
1151 	char *tp = mpath + strlen(mpath);
1152 	char *p;
1153 	char **sfx;
1154 
1155 	/* If a suffix has been specified, check if it is one of the
1156 	 * suffixes that indicate the file is executable - if so, change
1157 	 * the access test to R_OK...
1158 	 * This code assumes OS/2 files can have only one suffix...
1159 	 */
1160 	if ((p = strrchr((p = ksh_strrchr_dirsep(mpath)) ? p : mpath, '.'))) {
1161 		if (mode == X_OK)
1162 			mode = R_OK;
1163 		return search_access1(mpath, mode, errnop);
1164 	}
1165 	/* Try appending the various suffixes.  Different suffixes for
1166 	 * read and execute 'cause we don't want to read an executable...
1167 	 */
1168 	sfx = mode == R_OK ? rsuffixes : xsuffixes;
1169 	for (i = 0; sfx[i]; i++) {
1170 		strcpy(tp, p = sfx[i]);
1171 		if (search_access1(mpath, R_OK, errnop) == 0)
1172 			return 0;
1173 		*tp = '\0';
1174 	}
1175 	return -1;
1176 #endif /* !OS2 */
1177 }
1178 
1179 #ifdef OS2
1180 static int
1181 search_access1(path, mode, errnop)
1182 	const char *path;
1183 	int mode;
1184 	int *errnop;		/* set if candidate found, but not suitable */
1185 {
1186 	int ret, err = 0;
1187 	struct stat statb;
1188 
1189 	if (stat(path, &statb) < 0)
1190 		return -1;
1191 	ret = eaccess(path, mode);
1192 	if (ret < 0)
1193 		err = errno; /* File exists, but we can't access it */
1194 	else if (!S_ISREG(statb.st_mode)) {
1195 		ret = -1;
1196 		err = S_ISDIR(statb.st_mode) ? EISDIR : EACCES;
1197 	}
1198 	if (err && errnop && !*errnop)
1199 		*errnop = err;
1200 	return ret;
1201 }
1202 #endif /* OS2 */
1203 
1204 /*
1205  * search for command with PATH
1206  */
1207 char *
1208 search(name, path, mode, errnop)
1209 	const char *name;
1210 	const char *path;
1211 	int mode;		/* R_OK or X_OK */
1212 	int *errnop;		/* set if candidate found, but not suitable */
1213 {
1214 	const char *sp, *p;
1215 	char *xp;
1216 	XString xs;
1217 	int namelen;
1218 
1219 	if (errnop)
1220 		*errnop = 0;
1221 #ifdef OS2
1222 	/* Xinit() allocates 8 additional bytes, so appended suffixes won't
1223 	 * overflow the memory.
1224 	 */
1225 	namelen = strlen(name) + 1;
1226 	Xinit(xs, xp, namelen, ATEMP);
1227 	memcpy(Xstring(xs, xp), name, namelen);
1228 
1229  	if (ksh_strchr_dirsep(name)) {
1230 		if (search_access(Xstring(xs, xp), mode, errnop) >= 0)
1231 			return Xstring(xs, xp); /* not Xclose() - see above */
1232 		Xfree(xs, xp);
1233 		return NULL;
1234 	}
1235 
1236 	/* Look in current context always. (os2 style) */
1237 	if (search_access(Xstring(xs, xp), mode, errnop) == 0)
1238 		return Xstring(xs, xp); /* not Xclose() - xp may be wrong */
1239 #else /* OS2 */
1240 	if (ksh_strchr_dirsep(name)) {
1241 		if (search_access(name, mode, errnop) == 0)
1242 			return (char *) name;
1243 		return NULL;
1244 	}
1245 
1246 	namelen = strlen(name) + 1;
1247 	Xinit(xs, xp, 128, ATEMP);
1248 #endif /* OS2 */
1249 
1250 	sp = path;
1251 	while (sp != NULL) {
1252 		xp = Xstring(xs, xp);
1253 		if (!(p = strchr(sp, PATHSEP)))
1254 			p = sp + strlen(sp);
1255 		if (p != sp) {
1256 			XcheckN(xs, xp, p - sp);
1257 			memcpy(xp, sp, p - sp);
1258 			xp += p - sp;
1259 			*xp++ = DIRSEP;
1260 		}
1261 		sp = p;
1262 		XcheckN(xs, xp, namelen);
1263 		memcpy(xp, name, namelen);
1264  		if (search_access(Xstring(xs, xp), mode, errnop) == 0)
1265 #ifdef OS2
1266  			return Xstring(xs, xp); /* Not Xclose() - see above */
1267 #else /* OS2 */
1268 			return Xclose(xs, xp + namelen);
1269 #endif /* OS2 */
1270 		if (*sp++ == '\0')
1271 			sp = NULL;
1272 	}
1273 	Xfree(xs, xp);
1274 	return NULL;
1275 }
1276 
1277 static int
1278 call_builtin(tp, wp)
1279 	struct tbl *tp;
1280 	char **wp;
1281 {
1282 	int rv;
1283 
1284 	builtin_argv0 = wp[0];
1285 	builtin_flag = tp->flag;
1286 	shf_reopen(1, SHF_WR, shl_stdout);
1287 	shl_stdout_ok = 1;
1288 	ksh_getopt_reset(&builtin_opt, GF_ERROR);
1289 	rv = (*tp->val.f)(wp);
1290 	shf_flush(shl_stdout);
1291 	shl_stdout_ok = 0;
1292 	builtin_flag = 0;
1293 	builtin_argv0 = (char *) 0;
1294 	return rv;
1295 }
1296 
1297 /*
1298  * set up redirection, saving old fd's in e->savefd
1299  */
1300 static int
1301 iosetup(iop, tp)
1302 	register struct ioword *iop;
1303 	struct tbl *tp;
1304 {
1305 	register int u = -1;
1306 	char *cp = iop->name;
1307 	int iotype = iop->flag & IOTYPE;
1308 	int do_open = 1, do_close = 0, UNINITIALIZED(flags);
1309 	struct ioword iotmp;
1310 	struct stat statb;
1311 
1312 	if (iotype != IOHERE)
1313 		cp = evalonestr(cp, DOTILDE|(Flag(FTALKING_I) ? DOGLOB : 0));
1314 
1315 	/* Used for tracing and error messages to print expanded cp */
1316 	iotmp = *iop;
1317 	iotmp.name = (iotype == IOHERE) ? (char *) 0 : cp;
1318 	iotmp.flag |= IONAMEXP;
1319 
1320 	if (Flag(FXTRACE))
1321 		shellf("%s%s\n",
1322 			PS4_SUBSTITUTE(str_val(global("PS4"))),
1323 			snptreef((char *) 0, 32, "%R", &iotmp));
1324 
1325 	switch (iotype) {
1326 	  case IOREAD:
1327 		flags = O_RDONLY;
1328 		break;
1329 
1330 	  case IOCAT:
1331 		flags = O_WRONLY | O_APPEND | O_CREAT;
1332 		break;
1333 
1334 	  case IOWRITE:
1335 		flags = O_WRONLY | O_CREAT | O_TRUNC;
1336 		/* The stat() is here to allow redirections to
1337 		 * things like /dev/null without error.
1338 		 */
1339 		if (Flag(FNOCLOBBER) && !(iop->flag & IOCLOB)
1340 		    && (stat(cp, &statb) < 0 || S_ISREG(statb.st_mode)))
1341 			flags |= O_EXCL;
1342 		break;
1343 
1344 	  case IORDWR:
1345 		flags = O_RDWR | O_CREAT;
1346 		break;
1347 
1348 	  case IOHERE:
1349 		do_open = 0;
1350 		/* herein() returns -2 if error has been printed */
1351 		u = herein(iop->heredoc, iop->flag & IOEVAL);
1352 		/* cp may have wrong name */
1353 		break;
1354 
1355 	  case IODUP:
1356 	  {
1357 		const char *emsg;
1358 
1359 		do_open = 0;
1360 		if (*cp == '-' && !cp[1]) {
1361 			u = 1009;	 /* prevent error return below */
1362 			do_close = 1;
1363 		} else if ((u = check_fd(cp,
1364 				X_OK | ((iop->flag & IORDUP) ? R_OK : W_OK),
1365 				&emsg)) < 0)
1366 		{
1367 			warningf(TRUE, "%s: %s",
1368 				snptreef((char *) 0, 32, "%R", &iotmp), emsg);
1369 			return -1;
1370 		}
1371 		break;
1372 	  }
1373 	}
1374 	if (do_open) {
1375 		if (Flag(FRESTRICTED) && (flags & O_CREAT)) {
1376 			warningf(TRUE, "%s: restricted", cp);
1377 			return -1;
1378 		}
1379 		u = open(cp, flags, 0666);
1380 #ifdef OS2
1381 		if (u < 0 && strcmp(cp, "/dev/null") == 0)
1382 			u = open("nul", flags, 0666);
1383 #endif /* OS2 */
1384 	}
1385 	if (u < 0) {
1386 		/* herein() may already have printed message */
1387 		if (u == -1)
1388 			warningf(TRUE, "cannot %s %s: %s",
1389 			       iotype == IODUP ? "dup"
1390 				: (iotype == IOREAD || iotype == IOHERE) ?
1391 				    "open" : "create", cp, strerror(errno));
1392 		return -1;
1393 	}
1394 	/* Do not save if it has already been redirected (i.e. "cat >x >y"). */
1395 	if (e->savefd[iop->unit] == 0)
1396 		/* c_exec() assumes e->savefd[fd] set for any redirections.
1397 		 * Ask savefd() not to close iop->unit - allows error messages
1398 		 * to be seen if iop->unit is 2; also means we can't lose
1399 		 * the fd (eg, both dup2 below and dup2 in restfd() failing).
1400 		 */
1401 		e->savefd[iop->unit] = savefd(iop->unit, 1);
1402 
1403 	if (do_close)
1404 		close(iop->unit);
1405 	else if (u != iop->unit) {
1406 		if (ksh_dup2(u, iop->unit, TRUE) < 0) {
1407 			warningf(TRUE,
1408 				"could not finish (dup) redirection %s: %s",
1409 				snptreef((char *) 0, 32, "%R", &iotmp),
1410 				strerror(errno));
1411 			if (iotype != IODUP)
1412 				close(u);
1413 			return -1;
1414 		}
1415 		if (iotype != IODUP)
1416 			close(u);
1417 #ifdef KSH
1418 		/* Touching any co-process fd in an empty exec
1419 		 * causes the shell to close its copies
1420 		 */
1421 		else if (tp && tp->type == CSHELL && tp->val.f == c_exec) {
1422 			if (iop->flag & IORDUP)	/* possible exec <&p */
1423 				coproc_read_close(u);
1424 			else			/* possible exec >&p */
1425 				coproc_write_close(u);
1426 		}
1427 #endif /* KSH */
1428 	}
1429 	if (u == 2) /* Clear any write errors */
1430 		shf_reopen(2, SHF_WR, shl_out);
1431 	return 0;
1432 }
1433 
1434 /*
1435  * open here document temp file.
1436  * if unquoted here, expand here temp file into second temp file.
1437  */
1438 static int
1439 herein(content, sub)
1440 	const char *content;
1441 	int sub;
1442 {
1443 	volatile int fd = -1;
1444 	struct source *s, *volatile osource;
1445 	struct shf *volatile shf;
1446 	struct temp *h;
1447 	int i;
1448 
1449 	/* ksh -c 'cat << EOF' can cause this... */
1450 	if (content == (char *) 0) {
1451 		warningf(TRUE, "here document missing");
1452 		return -2; /* special to iosetup(): don't print error */
1453 	}
1454 
1455 	/* Create temp file to hold content (done before newenv so temp
1456 	 * doesn't get removed too soon).
1457 	 */
1458 	h = maketemp(ATEMP, TT_HEREDOC_EXP, &e->temps);
1459 	if (!(shf = h->shf) || (fd = open(h->name, O_RDONLY, 0)) < 0) {
1460 		warningf(TRUE, "can't %s temporary file %s: %s",
1461 			!shf ? "create" : "open",
1462 			h->name, strerror(errno));
1463 		if (shf)
1464 			shf_close(shf);
1465 		return -2 /* special to iosetup(): don't print error */;
1466 	}
1467 
1468 	osource = source;
1469 	newenv(E_ERRH);
1470 	i = ksh_sigsetjmp(e->jbuf, 0);
1471 	if (i) {
1472 		source = osource;
1473 		quitenv();
1474 		shf_close(shf);	/* after quitenv */
1475 		close(fd);
1476 		return -2; /* special to iosetup(): don't print error */
1477 	}
1478 	if (sub) {
1479 		/* Do substitutions on the content of heredoc */
1480 		s = pushs(SSTRING, ATEMP);
1481 		s->start = s->str = content;
1482 		source = s;
1483 		if (yylex(ONEWORD) != LWORD)
1484 			internal_errorf(1, "herein: yylex");
1485 		source = osource;
1486 		shf_puts(evalstr(yylval.cp, 0), shf);
1487 	} else
1488 		shf_puts(content, shf);
1489 
1490 	quitenv();
1491 
1492 	if (shf_close(shf) == EOF) {
1493 		close(fd);
1494 		warningf(TRUE, "error writing %s: %s", h->name,
1495 			strerror(errno));
1496 		return -2; /* special to iosetup(): don't print error */
1497 	}
1498 
1499 	return fd;
1500 }
1501 
1502 #ifdef KSH
1503 /*
1504  *	ksh special - the select command processing section
1505  *	print the args in column form - assuming that we can
1506  */
1507 static char *
1508 do_selectargs(ap, print_menu)
1509 	register char **ap;
1510 	bool_t print_menu;
1511 {
1512 	static const char *const read_args[] = {
1513 					"read", "-r", "REPLY", (char *) 0
1514 				    };
1515 	char *s;
1516 	int i, argct;
1517 
1518 	for (argct = 0; ap[argct]; argct++)
1519 		;
1520 	while (1) {
1521 		/* Menu is printed if
1522 		 *	- this is the first time around the select loop
1523 		 *	- the user enters a blank line
1524 		 *	- the REPLY parameter is empty
1525 		 */
1526 		if (print_menu || !*str_val(global("REPLY")))
1527 			pr_menu(ap);
1528 		shellf("%s", str_val(global("PS3")));
1529 		if (call_builtin(findcom("read", FC_BI), (char **) read_args))
1530 			return (char *) 0;
1531 		s = str_val(global("REPLY"));
1532 		if (*s) {
1533 			i = atoi(s);
1534 			return (i >= 1 && i <= argct) ? ap[i - 1] : null;
1535 		}
1536 		print_menu = 1;
1537 	}
1538 }
1539 
1540 struct select_menu_info {
1541 	char	*const *args;
1542 	int	arg_width;
1543 	int	num_width;
1544 } info;
1545 
1546 static char *select_fmt_entry ARGS((void *arg, int i, char *buf, int buflen));
1547 
1548 /* format a single select menu item */
1549 static char *
1550 select_fmt_entry(arg, i, buf, buflen)
1551 	void *arg;
1552 	int i;
1553 	char *buf;
1554 	int buflen;
1555 {
1556 	struct select_menu_info *smi = (struct select_menu_info *) arg;
1557 
1558 	shf_snprintf(buf, buflen, "%*d) %s",
1559 		smi->num_width, i + 1, smi->args[i]);
1560 	return buf;
1561 }
1562 
1563 /*
1564  *	print a select style menu
1565  */
1566 int
1567 pr_menu(ap)
1568 	char *const *ap;
1569 {
1570 	struct select_menu_info smi;
1571 	char *const *pp;
1572 	int nwidth, dwidth;
1573 	int i, n;
1574 
1575 	/* Width/column calculations were done once and saved, but this
1576 	 * means select can't be used recursively so we re-calculate each
1577 	 * time (could save in a structure that is returned, but its probably
1578 	 * not worth the bother).
1579 	 */
1580 
1581 	/*
1582 	 * get dimensions of the list
1583 	 */
1584 	for (n = 0, nwidth = 0, pp = ap; *pp; n++, pp++) {
1585 		i = strlen(*pp);
1586 		nwidth = (i > nwidth) ? i : nwidth;
1587 	}
1588 	/*
1589 	 * we will print an index of the form
1590 	 *	%d)
1591 	 * in front of each entry
1592 	 * get the max width of this
1593 	 */
1594 	for (i = n, dwidth = 1; i >= 10; i /= 10)
1595 		dwidth++;
1596 
1597 	smi.args = ap;
1598 	smi.arg_width = nwidth;
1599 	smi.num_width = dwidth;
1600 	print_columns(shl_out, n, select_fmt_entry, (void *) &smi,
1601 		dwidth + nwidth + 2);
1602 
1603 	return n;
1604 }
1605 #endif /* KSH */
1606 #ifdef KSH
1607 
1608 /*
1609  *	[[ ... ]] evaluation routines
1610  */
1611 
1612 extern const char *const dbtest_tokens[];
1613 extern const char db_close[];
1614 
1615 /* Test if the current token is a whatever.  Accepts the current token if
1616  * it is.  Returns 0 if it is not, non-zero if it is (in the case of
1617  * TM_UNOP and TM_BINOP, the returned value is a Test_op).
1618  */
1619 static int
1620 dbteste_isa(te, meta)
1621 	Test_env *te;
1622 	Test_meta meta;
1623 {
1624 	int ret = 0;
1625 	int uqword;
1626 	char *p;
1627 
1628 	if (!*te->pos.wp)
1629 		return meta == TM_END;
1630 
1631 	/* unquoted word? */
1632 	for (p = *te->pos.wp; *p == CHAR; p += 2)
1633 		;
1634 	uqword = *p == EOS;
1635 
1636 	if (meta == TM_UNOP || meta == TM_BINOP) {
1637 		if (uqword) {
1638 			char buf[8];	/* longer than the longest operator */
1639 			char *q = buf;
1640 			for (p = *te->pos.wp; *p == CHAR
1641 					      && q < &buf[sizeof(buf) - 1];
1642 					      p += 2)
1643 				*q++ = p[1];
1644 			*q = '\0';
1645 			ret = (int) test_isop(te, meta, buf);
1646 		}
1647 	} else if (meta == TM_END)
1648 		ret = 0;
1649 	else
1650 		ret = uqword
1651 			&& strcmp(*te->pos.wp, dbtest_tokens[(int) meta]) == 0;
1652 
1653 	/* Accept the token? */
1654 	if (ret)
1655 		te->pos.wp++;
1656 
1657 	return ret;
1658 }
1659 
1660 static const char *
1661 dbteste_getopnd(te, op, do_eval)
1662 	Test_env *te;
1663 	Test_op op;
1664 	int do_eval;
1665 {
1666 	char *s = *te->pos.wp;
1667 
1668 	if (!s)
1669 		return (char *) 0;
1670 
1671 	te->pos.wp++;
1672 
1673 	if (!do_eval)
1674 		return null;
1675 
1676 	if (op == TO_STEQL || op == TO_STNEQ)
1677 		s = evalstr(s, DOTILDE | DOPAT);
1678 	else
1679 		s = evalstr(s, DOTILDE);
1680 
1681 	return s;
1682 }
1683 
1684 static int
1685 dbteste_eval(te, op, opnd1, opnd2, do_eval)
1686 	Test_env *te;
1687 	Test_op op;
1688 	const char *opnd1;
1689 	const char *opnd2;
1690 	int do_eval;
1691 {
1692 	return test_eval(te, op, opnd1, opnd2, do_eval);
1693 }
1694 
1695 static void
1696 dbteste_error(te, offset, msg)
1697 	Test_env *te;
1698 	int offset;
1699 	const char *msg;
1700 {
1701 	te->flags |= TEF_ERROR;
1702 	internal_errorf(0, "dbteste_error: %s (offset %d)", msg, offset);
1703 }
1704 #endif /* KSH */
1705