xref: /openbsd-src/bin/ksh/exec.c (revision 62a742911104f98b9185b2c6b6007d9b1c36396c)
1 /*	$OpenBSD: exec.c,v 1.16 1999/01/19 20:41:52 millert 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((char *hname, 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 	int pv[2];
82 	char ** volatile ap;
83 	char *s, *cp;
84 	struct ioword **iowp;
85 	struct tbl *tp = NULL;
86 
87 	if (t == NULL)
88 		return 0;
89 
90 	/* Is this the end of a pipeline?  If so, we want to evaluate the
91 	 * command arguments
92 	bool_t eval_done = FALSE;
93 	if ((flags&XFORK) && !(flags&XEXEC) && (flags&XPCLOSE)) {
94 		eval_done = TRUE;
95 		tp = eval_execute_args(t, &ap);
96 	}
97 	 */
98 	if ((flags&XFORK) && !(flags&XEXEC) && t->type != TPIPE)
99 		return exchild(t, flags, -1); /* run in sub-process */
100 
101 	newenv(E_EXEC);
102 	if (trap)
103 		runtraps(0);
104 
105 	if (t->type == TCOM) {
106 		/* Clear subst_exstat before argument expansion.  Used by
107 		 * null commands (see comexec() and c_eval()) and by c_set().
108 		 */
109 		subst_exstat = 0;
110 
111 		/* POSIX says expand command words first, then redirections,
112 		 * and assignments last..
113 		 */
114 		ap = eval(t->args, t->u.evalflags | DOBLANK | DOGLOB | DOTILDE);
115 		if (Flag(FXTRACE) && ap[0]) {
116 			shf_fprintf(shl_out, "%s",
117 				PS4_SUBSTITUTE(str_val(global("PS4"))));
118 			for (i = 0; ap[i]; i++)
119 				shf_fprintf(shl_out, "%s%s", ap[i],
120 					ap[i + 1] ? space : newline);
121 			shf_flush(shl_out);
122 		}
123 		if (ap[0])
124 			tp = findcom(ap[0], FC_BI|FC_FUNC);
125 	}
126 
127 	if (t->ioact != NULL || t->type == TPIPE || t->type == TCOPROC) {
128 		e->savefd = (short *) alloc(sizeofN(short, NUFILE), ATEMP);
129 		/* initialize to not redirected */
130 		memset(e->savefd, 0, sizeofN(short, NUFILE));
131 	}
132 
133 	/* do redirection, to be restored in quitenv() */
134 	if (t->ioact != NULL)
135 		for (iowp = t->ioact; *iowp != NULL; iowp++) {
136 			if (iosetup(*iowp, tp) < 0) {
137 				exstat = rv = 1;
138 				/* Redirection failures for special commands
139 				 * cause (non-interactive) shell to exit.
140 				 */
141 				if (tp && tp->type == CSHELL
142 				    && (tp->flag & SPEC_BI))
143 					errorf(null);
144 				/* Deal with FERREXIT, quitenv(), etc. */
145 				goto Break;
146 			}
147 		}
148 
149 	switch(t->type) {
150 	  case TCOM:
151 		rv = comexec(t, tp, ap, flags);
152 		break;
153 
154 	  case TPAREN:
155 		rv = execute(t->left, flags|XFORK);
156 		break;
157 
158 	  case TPIPE:
159 		flags |= XFORK;
160 		flags &= ~XEXEC;
161 		e->savefd[0] = savefd(0, 0);
162 		(void) ksh_dup2(e->savefd[0], 0, FALSE); /* stdin of first */
163 		e->savefd[1] = savefd(1, 0);
164 		while (t->type == TPIPE) {
165 			openpipe(pv);
166 			(void) ksh_dup2(pv[1], 1, FALSE); /* stdout of curr */
167 			/* Let exchild() close pv[0] in child
168 			 * (if this isn't done, commands like
169 			 *    (: ; cat /etc/termcap) | sleep 1
170 			 *  will hang forever).
171 			 */
172 			exchild(t->left, flags|XPIPEO|XCCLOSE, pv[0]);
173 			(void) ksh_dup2(pv[0], 0, FALSE); /* stdin of next */
174 			closepipe(pv);
175 			flags |= XPIPEI;
176 			t = t->right;
177 		}
178 		restfd(1, e->savefd[1]); /* stdout of last */
179 		e->savefd[1] = 0; /* no need to re-restore this */
180 		/* Let exchild() close 0 in parent, after fork, before wait */
181 		i = exchild(t, flags|XPCLOSE, 0);
182 		if (!(flags&XBGND) && !(flags&XXCOM))
183 			rv = i;
184 		break;
185 
186 	  case TLIST:
187 		while (t->type == TLIST) {
188 			execute(t->left, flags & XERROK);
189 			t = t->right;
190 		}
191 		rv = execute(t, flags & XERROK);
192 		break;
193 
194 #ifdef KSH
195 	  case TCOPROC:
196 	  {
197 # ifdef JOB_SIGS
198 		sigset_t	omask;
199 # endif /* JOB_SIGS */
200 
201 # ifdef JOB_SIGS
202 		/* Block sigchild as we are using things changed in the
203 		 * signal handler
204 		 */
205 		sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
206 		e->type = E_ERRH;
207 		i = ksh_sigsetjmp(e->jbuf, 0);
208 		if (i) {
209 			sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
210 			quitenv();
211 			unwind(i);
212 			/*NOTREACHED*/
213 		}
214 # endif /* JOB_SIGS */
215 		/* Already have a (live) co-process? */
216 		if (coproc.job && coproc.write >= 0)
217 			errorf("coprocess already exists");
218 
219 		/* Can we re-use the existing co-process pipe? */
220 		coproc_cleanup(TRUE);
221 
222 		/* do this before opening pipes, in case these fail */
223 		e->savefd[0] = savefd(0, 0);
224 		e->savefd[1] = savefd(1, 0);
225 
226 		openpipe(pv);
227 		ksh_dup2(pv[0], 0, FALSE);
228 		close(pv[0]);
229 		coproc.write = pv[1];
230 		coproc.job = (void *) 0;
231 
232 		if (coproc.readw >= 0)
233 			ksh_dup2(coproc.readw, 1, FALSE);
234 		else {
235 			openpipe(pv);
236 			coproc.read = pv[0];
237 			ksh_dup2(pv[1], 1, FALSE);
238 			coproc.readw = pv[1];	 /* closed before first read */
239 			coproc.njobs = 0;
240 			/* create new coprocess id */
241 			++coproc.id;
242 		}
243 # ifdef JOB_SIGS
244 		sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
245 		e->type = E_EXEC; /* no more need for error handler */
246 # endif /* JOB_SIGS */
247 
248 		/* exchild() closes coproc.* in child after fork,
249 		 * will also increment coproc.njobs when the
250 		 * job is actually created.
251 		 */
252 		flags &= ~XEXEC;
253 		exchild(t->left, flags|XBGND|XFORK|XCOPROC|XCCLOSE,
254 			coproc.readw);
255 		break;
256 	  }
257 #endif /* KSH */
258 
259 	  case TASYNC:
260 		/* XXX non-optimal, I think - "(foo &)", forks for (),
261 		 * forks again for async...  parent should optimize
262 		 * this to "foo &"...
263 		 */
264 		rv = execute(t->left, (flags&~XEXEC)|XBGND|XFORK);
265 		break;
266 
267 	  case TOR:
268 	  case TAND:
269 		rv = execute(t->left, XERROK);
270 		if (t->right != NULL && (rv == 0) == (t->type == TAND))
271 			rv = execute(t->right, flags & XERROK);
272 		else
273 			flags |= XERROK;
274 		break;
275 
276 	  case TBANG:
277 		rv = !execute(t->right, XERROK);
278 		break;
279 
280 #ifdef KSH
281 	  case TDBRACKET:
282 	    {
283 		Test_env te;
284 
285 		te.flags = TEF_DBRACKET;
286 		te.pos.wp = t->args;
287 		te.isa = dbteste_isa;
288 		te.getopnd = dbteste_getopnd;
289 		te.eval = dbteste_eval;
290 		te.error = dbteste_error;
291 
292 		rv = test_parse(&te);
293 		break;
294 	    }
295 #endif /* KSH */
296 
297 	  case TFOR:
298 #ifdef KSH
299 	  case TSELECT:
300 	    {
301 		volatile bool_t is_first = TRUE;
302 #endif /* KSH */
303 		ap = (t->vars != NULL) ?
304 			  eval(t->vars, DOBLANK|DOGLOB|DOTILDE)
305 			: e->loc->argv + 1;
306 		e->type = E_LOOP;
307 		while (1) {
308 			i = ksh_sigsetjmp(e->jbuf, 0);
309 			if (!i)
310 				break;
311 			if ((e->flags&EF_BRKCONT_PASS)
312 			    || (i != LBREAK && i != LCONTIN))
313 			{
314 				quitenv();
315 				unwind(i);
316 			} else if (i == LBREAK) {
317 				rv = 0;
318 				goto Break;
319 			}
320 		}
321 		rv = 0; /* in case of a continue */
322 		if (t->type == TFOR) {
323 			struct tbl *vq;
324 
325 			while (*ap != NULL) {
326 				vq = global(t->str);
327 				if (vq->flag & RDONLY)
328 					errorf("%s is read only", t->str);
329 				/* SETSTR: fail (put readonly check in setstr,
330 				 * controlled by a flag?)
331 				 */
332 				setstr(vq, *ap++);
333 				rv = execute(t->left, flags & XERROK);
334 			}
335 		}
336 #ifdef KSH
337 		else { /* TSELECT */
338 			struct tbl *vq;
339 
340 			for (;;) {
341 				if (!(cp = do_selectargs(ap, is_first))) {
342 					rv = 1;
343 					break;
344 				}
345 				is_first = FALSE;
346 				vq = global(t->str);
347 				if (vq->flag & RDONLY)
348 					errorf("%s is read only", t->str);
349 				/* SETSTR: fail (put readonly check in setstr,
350 				 * controlled by a flag?)
351 				 */
352 				setstr(vq, cp);
353 				rv = execute(t->left, flags & XERROK);
354 			}
355 		}
356 	    }
357 #endif /* KSH */
358 		break;
359 
360 	  case TWHILE:
361 	  case TUNTIL:
362 		e->type = E_LOOP;
363 		while (1) {
364 			i = ksh_sigsetjmp(e->jbuf, 0);
365 			if (!i)
366 				break;
367 			if ((e->flags&EF_BRKCONT_PASS)
368 			    || (i != LBREAK && i != LCONTIN))
369 			{
370 				quitenv();
371 				unwind(i);
372 			} else if (i == LBREAK) {
373 				rv = 0;
374 				goto Break;
375 			}
376 		}
377 		rv = 0; /* in case of a continue */
378 		while ((execute(t->left, XERROK) == 0) == (t->type == TWHILE))
379 			rv = execute(t->right, flags & XERROK);
380 		break;
381 
382 	  case TIF:
383 	  case TELIF:
384 		if (t->right == NULL)
385 			break;	/* should be error */
386 		rv = execute(t->left, XERROK) == 0 ?
387 			execute(t->right->left, flags & XERROK) :
388 			execute(t->right->right, flags & XERROK);
389 		break;
390 
391 	  case TCASE:
392 		cp = evalstr(t->str, DOTILDE);
393 		for (t = t->left; t != NULL && t->type == TPAT; t = t->right)
394 		    for (ap = t->vars; *ap; ap++)
395 			if ((s = evalstr(*ap, DOTILDE|DOPAT))
396 			    && gmatch(cp, s, FALSE))
397 				goto Found;
398 		break;
399 	  Found:
400 		rv = execute(t->left, flags & XERROK);
401 		break;
402 
403 	  case TBRACE:
404 		rv = execute(t->left, flags & XERROK);
405 		break;
406 
407 	  case TFUNCT:
408 		rv = define(t->str, t);
409 		break;
410 
411 	  case TTIME:
412 		rv = timex(t, flags);
413 		break;
414 
415 	  case TEXEC:		/* an eval'd TCOM */
416 		s = t->args[0];
417 		ap = makenv();
418 #ifndef F_SETFD
419 		for (i = 0; i < sizeof(clexec_tab); i++)
420 			if (clexec_tab[i]) {
421 				close(i);
422 				clexec_tab[i] = 0;
423 			}
424 #endif
425 		restoresigs();
426 		cleanup_proc_env();
427 		/* XINTACT bit is for OS2 */
428 		ksh_execve(t->str, t->args, ap, (flags & XINTACT) ? 1 : 0);
429 		if (errno == ENOEXEC)
430 			scriptexec(t, ap);
431 		else
432 			errorf("%s: %s", s, strerror(errno));
433 	}
434     Break:
435 	exstat = rv;
436 
437 	quitenv();		/* restores IO */
438 	if ((flags&XEXEC))
439 		unwind(LEXIT);	/* exit child */
440 	if (rv != 0 && !(flags & XERROK)) {
441 		if (Flag(FERREXIT))
442 			unwind(LERROR);
443 		trapsig(SIGERR_);
444 	}
445 	return rv;
446 }
447 
448 /*
449  * execute simple command
450  */
451 
452 static int
453 comexec(t, tp, ap, flags)
454 	struct op *t;
455 	struct tbl *volatile tp;
456 	register char **ap;
457 	int volatile flags;
458 {
459 	int i;
460 	int rv = 0;
461 	register char *cp;
462 	register char **lastp;
463 	static struct op texec; /* Must be static (XXX but why?) */
464 	int type_flags;
465 	int keepasn_ok;
466 	int fcflags = FC_BI|FC_FUNC|FC_PATH;
467 
468 #ifdef __GNUC__
469 	(void)&rv;
470 #endif
471 
472 #ifdef KSH
473 	/* snag the last argument for $_ XXX not the same as at&t ksh,
474 	 * which only seems to set $_ after a newline (but not in
475 	 * functions/dot scripts, but in interactive and scipt) -
476 	 * perhaps save last arg here and set it in shell()?.
477 	 */
478 	if (!Flag(FSH) && Flag(FTALKING) && *(lastp = ap)) {
479 		while (*++lastp)
480 			;
481 		/* SETSTR: can't fail */
482 		setstr(typeset("_", LOCAL, 0, INTEGER, 0), *--lastp);
483 	}
484 #endif /* KSH */
485 
486 	/* Deal with the shell builtins builtin, exec and command since
487 	 * they can be followed by other commands.  This must be done before
488 	 * we know if we should create a local block, which must be done
489 	 * before we can do a path search (in case the assignments change
490 	 * PATH).
491 	 * Odd cases:
492 	 *   FOO=bar exec > /dev/null		FOO is kept but not exported
493 	 *   FOO=bar exec foobar		FOO is exported
494 	 *   FOO=bar command exec > /dev/null	FOO is neither kept nor exported
495 	 *   FOO=bar command			FOO is neither kept nor exported
496 	 *   PATH=... foobar			use new PATH in foobar search
497 	 */
498 	keepasn_ok = 1;
499 	while (tp && tp->type == CSHELL) {
500 		fcflags = FC_BI|FC_FUNC|FC_PATH;/* undo effects of command */
501 		if (tp->val.f == c_builtin) {
502 			if ((cp = *++ap) == NULL) {
503 				tp = NULL;
504 				break;
505 			}
506 			tp = findcom(cp, FC_BI);
507 			if (tp == NULL)
508 				errorf("builtin: %s: not a builtin", cp);
509 			continue;
510 		} else if (tp->val.f == c_exec) {
511 			if (ap[1] == NULL)
512 				break;
513 			ap++;
514 			flags |= XEXEC;
515 		} else if (tp->val.f == c_command) {
516 			int optc, saw_p = 0;
517 
518 			/* Ugly dealing with options in two places (here and
519 			 * in c_command(), but such is life)
520 			 */
521 			ksh_getopt_reset(&builtin_opt, 0);
522 			while ((optc = ksh_getopt(ap, &builtin_opt, ":p"))
523 									== 'p')
524 				saw_p = 1;
525 			if (optc != EOF)
526 				break;	/* command -vV or something */
527 			/* don't look for functions */
528 			fcflags = FC_BI|FC_PATH;
529 			if (saw_p) {
530 				if (Flag(FRESTRICTED)) {
531 					warningf(TRUE,
532 						"command -p: restricted");
533 					rv = 1;
534 					goto Leave;
535 				}
536 				fcflags |= FC_DEFPATH;
537 			}
538 			ap += builtin_opt.optind;
539 			/* POSIX says special builtins lose their status
540 			 * if accessed using command.
541 			 */
542 			keepasn_ok = 0;
543 			if (!ap[0]) {
544 				/* ensure command with no args exits with 0 */
545 				subst_exstat = 0;
546 				break;
547 			}
548 		} else
549 			break;
550 		tp = findcom(ap[0], fcflags & (FC_BI|FC_FUNC));
551 	}
552 	if (keepasn_ok && (!ap[0] || (tp && (tp->flag & KEEPASN))))
553 		type_flags = 0;
554 	else {
555 		/* create new variable/function block */
556 		newblock();
557 		/* ksh functions don't keep assignments, POSIX functions do. */
558 		if (keepasn_ok && tp && tp->type == CFUNC
559 		    && !(tp->flag & FKSH))
560 			type_flags = 0;
561 		else
562 			type_flags = LOCAL|LOCAL_COPY|EXPORT;
563 	}
564 	if (Flag(FEXPORT))
565 		type_flags |= EXPORT;
566 	for (i = 0; t->vars[i]; i++) {
567 		cp = evalstr(t->vars[i], DOASNTILDE);
568 		if (Flag(FXTRACE)) {
569 			if (i == 0)
570 				shf_fprintf(shl_out, "%s",
571 					PS4_SUBSTITUTE(str_val(global("PS4"))));
572 			shf_fprintf(shl_out, "%s%s", cp,
573 				t->vars[i + 1] ? space : newline);
574 			if (!t->vars[i + 1])
575 				shf_flush(shl_out);
576 		}
577 		typeset(cp, type_flags, 0, 0, 0);
578 	}
579 
580 	if ((cp = *ap) == NULL) {
581 		rv = subst_exstat;
582 		goto Leave;
583 	} else if (!tp) {
584 		if (Flag(FRESTRICTED) && ksh_strchr_dirsep(cp)) {
585 			warningf(TRUE, "%s: restricted", cp);
586 			rv = 1;
587 			goto Leave;
588 		}
589 		tp = findcom(cp, fcflags);
590 	}
591 
592 	switch (tp->type) {
593 	  case CSHELL:			/* shell built-in */
594 		rv = call_builtin(tp, ap);
595 		break;
596 
597 	  case CFUNC:			/* function call */
598 	  {
599 		volatile int old_xflag;
600 		volatile Tflag old_inuse;
601 		const char *volatile old_kshname;
602 
603 		if (!(tp->flag & ISSET)) {
604 			struct tbl *ftp;
605 
606 			if (!tp->u.fpath) {
607 				if (tp->u2.errno_) {
608 					warningf(TRUE,
609 				"%s: can't find function definition file - %s",
610 						cp, strerror(tp->u2.errno_));
611 					rv = 126;
612 				} else {
613 					warningf(TRUE,
614 				"%s: can't find function definition file", cp);
615 					rv = 127;
616 				}
617 				break;
618 			}
619 			if (include(tp->u.fpath, 0, (char **) 0, 0) < 0) {
620 				warningf(TRUE,
621 			    "%s: can't open function definition file %s - %s",
622 					cp, tp->u.fpath, strerror(errno));
623 				rv = 127;
624 				break;
625 			}
626 			if (!(ftp = findfunc(cp, hash(cp), FALSE))
627 			    || !(ftp->flag & ISSET))
628 			{
629 				warningf(TRUE,
630 					"%s: function not defined by %s",
631 					cp, tp->u.fpath);
632 				rv = 127;
633 				break;
634 			}
635 			tp = ftp;
636 		}
637 
638 		/* ksh functions set $0 to function name, POSIX functions leave
639 		 * $0 unchanged.
640 		 */
641 		old_kshname = kshname;
642 		if (tp->flag & FKSH)
643 			kshname = ap[0];
644 		else
645 			ap[0] = (char *) kshname;
646 		e->loc->argv = ap;
647 		for (i = 0; *ap++ != NULL; i++)
648 			;
649 		e->loc->argc = i - 1;
650 		/* ksh-style functions handle getopts sanely,
651 		 * bourne/posix functions are insane...
652 		 */
653 		if (tp->flag & FKSH) {
654 			e->loc->flags |= BF_DOGETOPTS;
655 			e->loc->getopts_state = user_opt;
656 			getopts_reset(1);
657 		}
658 
659 		old_xflag = Flag(FXTRACE);
660 		Flag(FXTRACE) = tp->flag & TRACE ? TRUE : FALSE;
661 
662 		old_inuse = tp->flag & FINUSE;
663 		tp->flag |= FINUSE;
664 
665 		e->type = E_FUNC;
666 		i = ksh_sigsetjmp(e->jbuf, 0);
667 		if (i == 0) {
668 			/* seems odd to pass XERROK here, but at&t ksh does */
669 			exstat = execute(tp->val.t, flags & XERROK);
670 			i = LRETURN;
671 		}
672 		kshname = old_kshname;
673 		Flag(FXTRACE) = old_xflag;
674 		tp->flag = (tp->flag & ~FINUSE) | old_inuse;
675 		/* Were we deleted while executing?  If so, free the execution
676 		 * tree.  todo: Unfortunately, the table entry is never re-used
677 		 * until the lookup table is expanded.
678 		 */
679 		if ((tp->flag & (FDELETE|FINUSE)) == FDELETE) {
680 			if (tp->flag & ALLOC) {
681 				tp->flag &= ~ALLOC;
682 				tfree(tp->val.t, tp->areap);
683 			}
684 			tp->flag = 0;
685 		}
686 		switch (i) {
687 		  case LRETURN:
688 		  case LERROR:
689 			rv = exstat;
690 			break;
691 		  case LINTR:
692 		  case LEXIT:
693 		  case LLEAVE:
694 		  case LSHELL:
695 			quitenv();
696 			unwind(i);
697 			/*NOTREACHED*/
698 		  default:
699 			quitenv();
700 			internal_errorf(1, "CFUNC %d", i);
701 		}
702 		break;
703 	  }
704 
705 	  case CEXEC:		/* executable command */
706 	  case CTALIAS:		/* tracked alias */
707 		if (!(tp->flag&ISSET)) {
708 			/* errno_ will be set if the named command was found
709 			 * but could not be executed (permissions, no execute
710 			 * bit, directory, etc).  Print out a (hopefully)
711 			 * useful error message and set the exit status to 126.
712 			 */
713 			if (tp->u2.errno_) {
714 				warningf(TRUE, "%s: cannot execute - %s", cp,
715 					strerror(tp->u2.errno_));
716 				rv = 126;	/* POSIX */
717 			} else {
718 				warningf(TRUE, "%s: not found", cp);
719 				rv = 127;
720 			}
721 			break;
722 		}
723 
724 #ifdef KSH
725 		if (!Flag(FSH)) {
726 			/* set $_ to program's full path */
727 			/* SETSTR: can't fail */
728 			setstr(typeset("_", LOCAL|EXPORT, 0, 0, 0), tp->val.s);
729 		}
730 #endif /* KSH */
731 
732 		if (flags&XEXEC) {
733 			j_exit();
734 			if (!(flags&XBGND) || Flag(FMONITOR)) {
735 				setexecsig(&sigtraps[SIGINT], SS_RESTORE_ORIG);
736 				setexecsig(&sigtraps[SIGQUIT], SS_RESTORE_ORIG);
737 			}
738 		}
739 
740 		/* to fork we set up a TEXEC node and call execute */
741 		texec.type = TEXEC;
742 		texec.left = t;	/* for tprint */
743 		texec.str = tp->val.s;
744 		texec.args = ap;
745 		rv = exchild(&texec, flags, -1);
746 		break;
747 	}
748   Leave:
749 	if (flags & XEXEC) {
750 		exstat = rv;
751 		unwind(LLEAVE);
752 	}
753 	return rv;
754 }
755 
756 static void
757 scriptexec(tp, ap)
758 	register struct op *tp;
759 	register char **ap;
760 {
761 	char *shell;
762 
763 	shell = str_val(global(EXECSHELL_STR));
764 	if (shell && *shell)
765 		shell = search(shell, path, X_OK, (int *) 0);
766 	if (!shell || !*shell)
767 		shell = EXECSHELL;
768 
769 	*tp->args-- = tp->str;
770 #ifdef	SHARPBANG
771 	{
772 		char buf[LINE];
773 		register char *cp;
774 		register int fd, n;
775 
776 		buf[0] = '\0';
777 		if ((fd = open(tp->str, O_RDONLY)) >= 0) {
778 			if ((n = read(fd, buf, LINE - 1)) > 0)
779 				buf[n] = '\0';
780 			(void) close(fd);
781 		}
782 		if ((buf[0] == '#' && buf[1] == '!' && (cp = &buf[2]))
783 # ifdef OS2
784 		    || (strncmp(buf, "extproc", 7) == 0 && isspace(buf[7])
785 			&& (cp = &buf[7]))
786 # endif /* OS2 */
787 		    )
788 		{
789 			while (*cp && (*cp == ' ' || *cp == '\t'))
790 				cp++;
791 			if (*cp && *cp != '\n') {
792 				char *a0 = cp, *a1 = (char *) 0;
793 # ifdef OS2
794 				char *a2 = cp;
795 # endif /* OS2 */
796 
797 				while (*cp && *cp != '\n' && *cp != ' '
798 				       && *cp != '\t')
799 				{
800 # ifdef OS2
801 			/* Allow shell search without prepended path
802 			 * if shell with / in pathname cannot be found.
803 			 * Use / explicitly so \ can be used if explicit
804 			 * needs to be forced.
805 			 */
806 					if (*cp == '/')
807 						a2 = cp + 1;
808 # endif /* OS2 */
809 					cp++;
810 				}
811 				if (*cp && *cp != '\n') {
812 					*cp++ = '\0';
813 					while (*cp
814 					       && (*cp == ' ' || *cp == '\t'))
815 						cp++;
816 					if (*cp && *cp != '\n') {
817 						a1 = cp;
818 						/* all one argument */
819 						while (*cp && *cp != '\n')
820 							cp++;
821 					}
822 				}
823 				if (*cp == '\n') {
824 					*cp = '\0';
825 					if (a1)
826 						*tp->args-- = a1;
827 # ifdef OS2
828 					if (a0 != a2) {
829 						char *tmp_a0 = str_nsave(a0,
830 							strlen(a0) + 5, ATEMP);
831 						if (search_access(tmp_a0, X_OK,
832 								(int *) 0))
833 							a0 = a2;
834 						afree(tmp_a0, ATEMP);
835 					}
836 # endif /* OS2 */
837 					shell = a0;
838 				}
839 			}
840 # ifdef OS2
841 		} else {
842 		        /* Use ksh documented shell default if present
843 			 * else use OS2_SHELL which is assumed to need
844 			 * the /c option and '\' as dir separater.
845 			 */
846 		         char *p = shell;
847 
848 			 shell = str_val(global("EXECSHELL"));
849 			 if (shell && *shell)
850 				 shell = search(shell, path, X_OK, (int *) 0);
851 			 if (!shell || !*shell) {
852 				 shell = p;
853 				 *tp->args-- = "/c";
854 				 for (p = tp->str; *p; p++)
855 					 if (*p == '/')
856 						 *p = '\\';
857 			 }
858 # endif /* OS2 */
859 		}
860 	}
861 #endif	/* SHARPBANG */
862 	*tp->args = shell;
863 
864 	ksh_execve(tp->args[0], tp->args, ap, 0);
865 
866 	/* report both the program that was run and the bogus shell */
867 	errorf("%s: %s: %s", tp->str, shell, strerror(errno));
868 }
869 
870 int
871 shcomexec(wp)
872 	register char **wp;
873 {
874 	register struct tbl *tp;
875 
876 	tp = tsearch(&builtins, *wp, hash(*wp));
877 	if (tp == NULL)
878 		internal_errorf(1, "shcomexec: %s", *wp);
879 	return call_builtin(tp, wp);
880 }
881 
882 /*
883  * Search function tables for a function.  If create set, a table entry
884  * is created if none is found.
885  */
886 struct tbl *
887 findfunc(name, h, create)
888 	const char *name;
889 	unsigned int	h;
890 	int	create;
891 {
892 	struct block *l;
893 	struct tbl *tp = (struct tbl *) 0;
894 
895 	for (l = e->loc; l; l = l->next) {
896 		tp = tsearch(&l->funs, name, h);
897 		if (tp)
898 			break;
899 		if (!l->next && create) {
900 			tp = tenter(&l->funs, name, h);
901 			tp->flag = DEFINED;
902 			tp->type = CFUNC;
903 			tp->val.t = (struct op *) 0;
904 			break;
905 		}
906 	}
907 	return tp;
908 }
909 
910 /*
911  * define function.  Returns 1 if function is being undefined (t == 0) and
912  * function did not exist, returns 0 otherwise.
913  */
914 int
915 define(name, t)
916 	const char *name;
917 	struct op *t;
918 {
919 	struct tbl *tp;
920 	int was_set = 0;
921 
922 	while (1) {
923 		tp = findfunc(name, hash(name), TRUE);
924 
925 		if (tp->flag & ISSET)
926 			was_set = 1;
927 		/* If this function is currently being executed, we zap this
928 		 * table entry so findfunc() won't see it
929 		 */
930 		if (tp->flag & FINUSE) {
931 			tp->name[0] = '\0';
932 			tp->flag &= ~DEFINED; /* ensure it won't be found */
933 			tp->flag |= FDELETE;
934 		} else
935 			break;
936 	}
937 
938 	if (tp->flag & ALLOC) {
939 		tp->flag &= ~(ISSET|ALLOC);
940 		tfree(tp->val.t, tp->areap);
941 	}
942 
943 	if (t == NULL) {		/* undefine */
944 		tdelete(tp);
945 		return was_set ? 0 : 1;
946 	}
947 
948 	tp->val.t = tcopy(t->left, tp->areap);
949 	tp->flag |= (ISSET|ALLOC);
950 	if (t->u.ksh_func)
951 	    tp->flag |= FKSH;
952 
953 	return 0;
954 }
955 
956 /*
957  * add builtin
958  */
959 void
960 builtin(name, func)
961 	const char *name;
962 	int (*func) ARGS((char **));
963 {
964 	register struct tbl *tp;
965 	Tflag flag;
966 
967 	/* see if any flags should be set for this builtin */
968 	for (flag = 0; ; name++) {
969 		if (*name == '=')	/* command does variable assignment */
970 			flag |= KEEPASN;
971 		else if (*name == '*')	/* POSIX special builtin */
972 			flag |= SPEC_BI;
973 		else if (*name == '+')	/* POSIX regular builtin */
974 			flag |= REG_BI;
975 		else
976 			break;
977 	}
978 
979 	tp = tenter(&builtins, name, hash(name));
980 	tp->flag = DEFINED | flag;
981 	tp->type = CSHELL;
982 	tp->val.f = func;
983 }
984 
985 /*
986  * find command
987  * either function, hashed command, or built-in (in that order)
988  */
989 struct tbl *
990 findcom(name, flags)
991 	const char *name;
992 	int	flags;		/* FC_* */
993 {
994 	static struct tbl temp;
995 	unsigned int h = hash(name);
996 	struct tbl *tp = NULL, *tbi;
997 	int insert = Flag(FTRACKALL);	/* insert if not found */
998 	char *fpath;			/* for function autoloading */
999 	char *npath;
1000 
1001 	if (ksh_strchr_dirsep(name) != NULL) {
1002 		insert = 0;
1003 		/* prevent FPATH search below */
1004 		flags &= ~FC_FUNC;
1005 		goto Search;
1006 	}
1007 	tbi = (flags & FC_BI) ? tsearch(&builtins, name, h) : NULL;
1008 	/* POSIX says special builtins first, then functions, then
1009 	 * POSIX regular builtins, then search path...
1010 	 */
1011 	if ((flags & FC_SPECBI) && tbi && (tbi->flag & SPEC_BI))
1012 		tp = tbi;
1013 	if (!tp && (flags & FC_FUNC)) {
1014 		tp = findfunc(name, h, FALSE);
1015 		if (tp && !(tp->flag & ISSET)) {
1016 			if ((fpath = str_val(global("FPATH"))) == null) {
1017 				tp->u.fpath = (char *) 0;
1018 				tp->u2.errno_ = 0;
1019 			} else
1020 				tp->u.fpath = search(name, fpath, R_OK,
1021 					&tp->u2.errno_);
1022 		}
1023 	}
1024 	if (!tp && (flags & FC_REGBI) && tbi && (tbi->flag & REG_BI))
1025 		tp = tbi;
1026 	/* todo: posix says non-special/non-regular builtins must
1027 	 * be triggered by some user-controllable means like a
1028 	 * special directory in PATH.  Requires modifications to
1029 	 * the search() function.  Tracked aliases should be
1030 	 * modified to allow tracking of builtin commands.
1031 	 * This should be under control of the FPOSIX flag.
1032 	 * If this is changed, also change c_whence...
1033 	 */
1034 	if (!tp && (flags & FC_UNREGBI) && tbi)
1035 		tp = tbi;
1036 	if (!tp && (flags & FC_PATH) && !(flags & FC_DEFPATH)) {
1037 		tp = tsearch(&taliases, name, h);
1038 		if (tp && (tp->flag & ISSET) && eaccess(tp->val.s, X_OK) != 0) {
1039 			if (tp->flag & ALLOC) {
1040 				tp->flag &= ~ALLOC;
1041 				afree(tp->val.s, APERM);
1042 			}
1043 			tp->flag &= ~ISSET;
1044 		}
1045 	}
1046 
1047   Search:
1048 	if ((!tp || (tp->type == CTALIAS && !(tp->flag&ISSET)))
1049 	    && (flags & FC_PATH))
1050 	{
1051 		if (!tp) {
1052 			if (insert && !(flags & FC_DEFPATH)) {
1053 				tp = tenter(&taliases, name, h);
1054 				tp->type = CTALIAS;
1055 			} else {
1056 				tp = &temp;
1057 				tp->type = CEXEC;
1058 			}
1059 			tp->flag = DEFINED;	/* make ~ISSET */
1060 		}
1061 		npath = search(name, flags & FC_DEFPATH ? def_path : path,
1062 				X_OK, &tp->u2.errno_);
1063 		if (npath) {
1064 			tp->val.s = tp == &temp ? npath : str_save(npath, APERM);
1065 			tp->flag |= ISSET|ALLOC;
1066 		} else if ((flags & FC_FUNC)
1067 			   && (fpath = str_val(global("FPATH"))) != null
1068 			   && (npath = search(name, fpath, R_OK,
1069 					      &tp->u2.errno_)) != (char *) 0)
1070 		{
1071 			/* An undocumented feature of at&t ksh is that it
1072 			 * searches FPATH if a command is not found, even
1073 			 * if the command hasn't been set up as an autoloaded
1074 			 * function (ie, no typeset -uf).
1075 			 */
1076 			tp = &temp;
1077 			tp->type = CFUNC;
1078 			tp->flag = DEFINED; /* make ~ISSET */
1079 			tp->u.fpath = npath;
1080 		}
1081 	}
1082 	return tp;
1083 }
1084 
1085 /*
1086  * flush executable commands with relative paths
1087  */
1088 void
1089 flushcom(all)
1090 	int all;		/* just relative or all */
1091 {
1092 	struct tbl *tp;
1093 	struct tstate ts;
1094 
1095 	for (twalk(&ts, &taliases); (tp = tnext(&ts)) != NULL; )
1096 		if ((tp->flag&ISSET) && (all || !ISDIRSEP(tp->val.s[0]))) {
1097 			if (tp->flag&ALLOC) {
1098 				tp->flag &= ~(ALLOC|ISSET);
1099 				afree(tp->val.s, APERM);
1100 			}
1101 			tp->flag &= ~ISSET;
1102 		}
1103 }
1104 
1105 /* Check if path is something we want to find.  Returns -1 for failure. */
1106 int
1107 search_access(path, mode, errnop)
1108 	const char *path;
1109 	int mode;
1110 	int *errnop;		/* set if candidate found, but not suitable */
1111 {
1112 #ifndef OS2
1113 	int ret, err = 0;
1114 	struct stat statb;
1115 
1116 	if (stat(path, &statb) < 0)
1117 		return -1;
1118 	ret = eaccess(path, mode);
1119 	if (ret < 0)
1120 		err = errno; /* File exists, but we can't access it */
1121 	else if (mode == X_OK
1122 		 && (!S_ISREG(statb.st_mode)
1123 		     /* This 'cause access() says root can execute everything */
1124 		     || !(statb.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH))))
1125 	{
1126 		ret = -1;
1127 		err = S_ISDIR(statb.st_mode) ? EISDIR : EACCES;
1128 	}
1129 	if (err && errnop && !*errnop)
1130 		*errnop = err;
1131 	return ret;
1132 #else /* !OS2 */
1133 	/*
1134 	 * NOTE: ASSUMES path can be modified and has enough room at the
1135 	 *       end of the string for a suffix (ie, 4 extra characters).
1136 	 *	 Certain code knows this (eg, eval.c(globit()),
1137 	 *	 exec.c(search())).
1138 	 */
1139 	static char *xsuffixes[] = { ".ksh", ".exe", ".", ".sh", ".cmd",
1140 				     ".com", ".bat", (char *) 0
1141 				   };
1142 	static char *rsuffixes[] = { ".ksh", ".", ".sh", ".cmd", ".bat",
1143 				      (char *) 0
1144 				   };
1145 	int i;
1146 	char *mpath = (char *) path;
1147 	char *tp = mpath + strlen(mpath);
1148 	char *p;
1149 	char **sfx;
1150 
1151 	/* If a suffix has been specified, check if it is one of the
1152 	 * suffixes that indicate the file is executable - if so, change
1153 	 * the access test to R_OK...
1154 	 * This code assumes OS/2 files can have only one suffix...
1155 	 */
1156 	if ((p = strrchr((p = ksh_strrchr_dirsep(mpath)) ? p : mpath, '.'))) {
1157 		if (mode == X_OK)
1158 			mode = R_OK;
1159 		return search_access1(mpath, mode, errnop);
1160 	}
1161 	/* Try appending the various suffixes.  Different suffixes for
1162 	 * read and execute 'cause we don't want to read an executable...
1163 	 */
1164 	sfx = mode == R_OK ? rsuffixes : xsuffixes;
1165 	for (i = 0; sfx[i]; i++) {
1166 		strcpy(tp, p = sfx[i]);
1167 		if (search_access1(mpath, R_OK, errnop) == 0)
1168 			return 0;
1169 		*tp = '\0';
1170 	}
1171 	return -1;
1172 #endif /* !OS2 */
1173 }
1174 
1175 #ifdef OS2
1176 static int
1177 search_access1(path, mode, errnop)
1178 	const char *path;
1179 	int mode;
1180 	int *errnop;		/* set if candidate found, but not suitable */
1181 {
1182 	int ret, err = 0;
1183 	struct stat statb;
1184 
1185 	if (stat(path, &statb) < 0)
1186 		return -1;
1187 	ret = eaccess(path, mode);
1188 	if (ret < 0)
1189 		err = errno; /* File exists, but we can't access it */
1190 	else if (!S_ISREG(statb.st_mode)) {
1191 		ret = -1;
1192 		err = S_ISDIR(statb.st_mode) ? EISDIR : EACCES;
1193 	}
1194 	if (err && errnop && !*errnop)
1195 		*errnop = err;
1196 	return ret;
1197 }
1198 #endif /* OS2 */
1199 
1200 /*
1201  * search for command with PATH
1202  */
1203 char *
1204 search(name, path, mode, errnop)
1205 	const char *name;
1206 	const char *path;
1207 	int mode;		/* R_OK or X_OK */
1208 	int *errnop;		/* set if candidate found, but not suitable */
1209 {
1210 	const char *sp, *p;
1211 	char *xp;
1212 	XString xs;
1213 	int namelen;
1214 
1215 	if (errnop)
1216 		*errnop = 0;
1217 #ifdef OS2
1218 	/* Xinit() allocates 8 additional bytes, so appended suffixes won't
1219 	 * overflow the memory.
1220 	 */
1221 	namelen = strlen(name) + 1;
1222 	Xinit(xs, xp, namelen, ATEMP);
1223 	memcpy(Xstring(xs, xp), name, namelen);
1224 
1225  	if (ksh_strchr_dirsep(name)) {
1226 		if (search_access(Xstring(xs, xp), mode, errnop) >= 0)
1227 			return Xstring(xs, xp); /* not Xclose() - see above */
1228 		Xfree(xs, xp);
1229 		return NULL;
1230 	}
1231 
1232 	/* Look in current context always. (os2 style) */
1233 	if (search_access(Xstring(xs, xp), mode, errnop) == 0)
1234 		return Xstring(xs, xp); /* not Xclose() - xp may be wrong */
1235 #else /* OS2 */
1236 	if (ksh_strchr_dirsep(name)) {
1237 		if (search_access(name, mode, errnop) == 0)
1238 			return (char *) name;
1239 		return NULL;
1240 	}
1241 
1242 	namelen = strlen(name) + 1;
1243 	Xinit(xs, xp, 128, ATEMP);
1244 #endif /* OS2 */
1245 
1246 	sp = path;
1247 	while (sp != NULL) {
1248 		xp = Xstring(xs, xp);
1249 		if (!(p = strchr(sp, PATHSEP)))
1250 			p = sp + strlen(sp);
1251 		if (p != sp) {
1252 			XcheckN(xs, xp, p - sp);
1253 			memcpy(xp, sp, p - sp);
1254 			xp += p - sp;
1255 			*xp++ = DIRSEP;
1256 		}
1257 		sp = p;
1258 		XcheckN(xs, xp, namelen);
1259 		memcpy(xp, name, namelen);
1260  		if (search_access(Xstring(xs, xp), mode, errnop) == 0)
1261 #ifdef OS2
1262  			return Xstring(xs, xp); /* Not Xclose() - see above */
1263 #else /* OS2 */
1264 			return Xclose(xs, xp + namelen);
1265 #endif /* OS2 */
1266 		if (*sp++ == '\0')
1267 			sp = NULL;
1268 	}
1269 	Xfree(xs, xp);
1270 	return NULL;
1271 }
1272 
1273 static int
1274 call_builtin(tp, wp)
1275 	struct tbl *tp;
1276 	char **wp;
1277 {
1278 	int rv;
1279 
1280 	builtin_argv0 = wp[0];
1281 	builtin_flag = tp->flag;
1282 	shf_reopen(1, SHF_WR, shl_stdout);
1283 	shl_stdout_ok = 1;
1284 	ksh_getopt_reset(&builtin_opt, GF_ERROR);
1285 	rv = (*tp->val.f)(wp);
1286 	shf_flush(shl_stdout);
1287 	shl_stdout_ok = 0;
1288 	builtin_flag = 0;
1289 	builtin_argv0 = (char *) 0;
1290 	return rv;
1291 }
1292 
1293 /*
1294  * set up redirection, saving old fd's in e->savefd
1295  */
1296 static int
1297 iosetup(iop, tp)
1298 	register struct ioword *iop;
1299 	struct tbl *tp;
1300 {
1301 	register int u = -1;
1302 	char *cp = iop->name;
1303 	int iotype = iop->flag & IOTYPE;
1304 	int do_open = 1, do_close = 0, UNINITIALIZED(flags);
1305 	struct ioword iotmp;
1306 	struct stat statb;
1307 
1308 	if (iotype != IOHERE)
1309 		cp = evalonestr(cp, DOTILDE|(Flag(FTALKING_I) ? DOGLOB : 0));
1310 
1311 	/* Used for tracing and error messages to print expanded cp */
1312 	iotmp = *iop;
1313 	iotmp.name = (iotype == IOHERE) ? (char *) 0 : cp;
1314 	iotmp.flag |= IONAMEXP;
1315 
1316 	if (Flag(FXTRACE))
1317 		shellf("%s%s\n",
1318 			PS4_SUBSTITUTE(str_val(global("PS4"))),
1319 			snptreef((char *) 0, 32, "%R", &iotmp));
1320 
1321 	switch (iotype) {
1322 	  case IOREAD:
1323 		flags = O_RDONLY;
1324 		break;
1325 
1326 	  case IOCAT:
1327 		flags = O_WRONLY | O_APPEND | O_CREAT;
1328 		break;
1329 
1330 	  case IOWRITE:
1331 		flags = O_WRONLY | O_CREAT | O_TRUNC;
1332 		if (Flag(FNOCLOBBER) && !(iop->flag & IOCLOB)
1333 		    && (stat(cp, &statb) < 0 || S_ISREG(statb.st_mode)))
1334 			flags |= O_EXCL;
1335 		break;
1336 
1337 	  case IORDWR:
1338 		flags = O_RDWR | O_CREAT;
1339 		break;
1340 
1341 	  case IOHERE:
1342 		do_open = 0;
1343 		/* herein() returns -2 if error has been printed */
1344 		u = herein(cp, iop->flag & IOEVAL);
1345 		/* cp may have wrong name */
1346 		break;
1347 
1348 	  case IODUP:
1349 	  {
1350 		const char *emsg;
1351 
1352 		do_open = 0;
1353 		if (*cp == '-' && !cp[1]) {
1354 			u = 1009;	 /* prevent error return below */
1355 			do_close = 1;
1356 		} else if ((u = check_fd(cp,
1357 				X_OK | ((iop->flag & IORDUP) ? R_OK : W_OK),
1358 				&emsg)) < 0)
1359 		{
1360 			warningf(TRUE, "%s: %s",
1361 				snptreef((char *) 0, 32, "%R", &iotmp), emsg);
1362 			return -1;
1363 		}
1364 		break;
1365 	  }
1366 	}
1367 	if (do_open) {
1368 		if (Flag(FRESTRICTED) && (flags & O_CREAT)) {
1369 			warningf(TRUE, "%s: restricted", cp);
1370 			return -1;
1371 		}
1372 		u = open(cp, flags, 0666);
1373 #ifdef OS2
1374 		if (u < 0 && strcmp(cp, "/dev/null") == 0)
1375 			u = open("nul", flags, 0666);
1376 #endif /* OS2 */
1377 	}
1378 	if (u < 0) {
1379 		/* herein() may already have printed message */
1380 		if (u == -1)
1381 			warningf(TRUE, "cannot %s %s: %s",
1382 			       iotype == IODUP ? "dup"
1383 				: (iotype == IOREAD || iotype == IOHERE) ?
1384 				    "open" : "create", cp, strerror(errno));
1385 		return -1;
1386 	}
1387 	/* Do not save if it has already been redirected (i.e. "cat >x >y"). */
1388 	if (e->savefd[iop->unit] == 0)
1389 		/* c_exec() assumes e->savefd[fd] set for any redirections.
1390 		 * Ask savefd() not to close iop->unit - allows error messages
1391 		 * to be seen if iop->unit is 2; also means we can't lose
1392 		 * the fd (eg, both dup2 below and dup2 in restfd() failing).
1393 		 */
1394 		e->savefd[iop->unit] = savefd(iop->unit, 1);
1395 
1396 	if (do_close)
1397 		close(iop->unit);
1398 	else if (u != iop->unit) {
1399 		if (ksh_dup2(u, iop->unit, TRUE) < 0) {
1400 			warningf(TRUE,
1401 				"could not finish (dup) redirection %s: %s",
1402 				snptreef((char *) 0, 32, "%R", &iotmp),
1403 				strerror(errno));
1404 			if (iotype != IODUP)
1405 				close(u);
1406 			return -1;
1407 		}
1408 		if (iotype != IODUP)
1409 			close(u);
1410 #ifdef KSH
1411 		/* Touching any co-process fd in an empty exec
1412 		 * causes the shell to close its copies
1413 		 */
1414 		else if (tp && tp->type == CSHELL && tp->val.f == c_exec) {
1415 			if (iop->flag & IORDUP)	/* possible exec <&p */
1416 				coproc_read_close(u);
1417 			else			/* possible exec >&p */
1418 				coproc_write_close(u);
1419 		}
1420 #endif /* KSH */
1421 	}
1422 	if (u == 2) /* Clear any write errors */
1423 		shf_reopen(2, SHF_WR, shl_out);
1424 	return 0;
1425 }
1426 
1427 /*
1428  * open here document temp file.
1429  * if unquoted here, expand here temp file into second temp file.
1430  */
1431 static int
1432 herein(hname, sub)
1433 	char *hname;
1434 	int sub;
1435 {
1436 	int fd;
1437 
1438 	/* ksh -c 'cat << EOF' can cause this... */
1439 	if (hname == (char *) 0) {
1440 		warningf(TRUE, "here document missing");
1441 		return -2; /* special to iosetup(): don't print error */
1442 	}
1443 	if (sub) {
1444 		char *cp;
1445 		struct source *s, *volatile osource = source;
1446 		struct temp *h;
1447 		struct shf *volatile shf;
1448 		int i;
1449 
1450 		/* must be before newenv() 'cause shf uses ATEMP */
1451 		shf = shf_open(hname, O_RDONLY, 0, SHF_MAPHI|SHF_CLEXEC);
1452 		if (shf == NULL)
1453 			return -1;
1454 		newenv(E_ERRH);
1455 		i = ksh_sigsetjmp(e->jbuf, 0);
1456 		if (i) {
1457 			if (shf)
1458 				shf_close(shf);
1459 			source = osource;
1460 			quitenv(); /* after shf_close() due to alloc */
1461 			return -2; /* special to iosetup(): don't print error */
1462 		}
1463 		/* set up yylex input from here file */
1464 		s = pushs(SFILE, ATEMP);
1465 		s->u.shf = shf;
1466 		source = s;
1467 		if (yylex(ONEWORD) != LWORD)
1468 			internal_errorf(1, "herein: yylex");
1469 		shf_close(shf);
1470 		shf = (struct shf *) 0;
1471 		cp = evalstr(yylval.cp, 0);
1472 
1473 		/* write expanded input to another temp file */
1474 		h = maketemp(ATEMP);
1475 		h->next = e->temps; e->temps = h;
1476 		if (!(shf = h->shf) || (fd = open(h->name, O_RDONLY, 0)) < 0)
1477 			/* shf closeed by error handler */
1478 			errorf("%s: %s", h->name, strerror(errno));
1479 		shf_puts(cp, shf);
1480 		if (shf_close(shf) == EOF) {
1481 			close(fd);
1482 			shf = (struct shf *) 0;
1483 			errorf("error writing %s: %s", h->name,
1484 				strerror(errno));
1485 		}
1486 		shf = (struct shf *) 0;
1487 
1488 		quitenv();
1489 	} else {
1490 		fd = open(hname, O_RDONLY, 0);
1491 		if (fd < 0)
1492 			return -1;
1493 	}
1494 
1495 	return fd;
1496 }
1497 
1498 #if defined(KSH) || defined(EDIT)
1499 /*
1500  *	ksh special - the select command processing section
1501  *	print the args in column form - assuming that we can
1502  */
1503 static char *
1504 do_selectargs(ap, print_menu)
1505 	register char **ap;
1506 	bool_t print_menu;
1507 {
1508 	static const char *const read_args[] = {
1509 					"read", "-r", "REPLY", (char *) 0
1510 				    };
1511 	char *s;
1512 	int i, argct;
1513 
1514 	for (argct = 0; ap[argct]; argct++)
1515 		;
1516 	while (1) {
1517 		/* Menu is printed if
1518 		 *	- this is the first time around the select loop
1519 		 *	- the user enters a blank line
1520 		 *	- the REPLY parameter is empty
1521 		 */
1522 		if (print_menu || !*str_val(global("REPLY")))
1523 			pr_menu(ap);
1524 		shellf("%s", str_val(global("PS3")));
1525 		if (call_builtin(findcom("read", FC_BI), (char **) read_args))
1526 			return (char *) 0;
1527 		s = str_val(global("REPLY"));
1528 		if (*s) {
1529 			i = atoi(s);
1530 			return (i >= 1 && i <= argct) ? ap[i - 1] : null;
1531 		}
1532 		print_menu = 1;
1533 	}
1534 }
1535 
1536 struct select_menu_info {
1537 	char	*const *args;
1538 	int	arg_width;
1539 	int	num_width;
1540 } info;
1541 
1542 static char *select_fmt_entry ARGS((void *arg, int i, char *buf, int buflen));
1543 
1544 /* format a single select menu item */
1545 static char *
1546 select_fmt_entry(arg, i, buf, buflen)
1547 	void *arg;
1548 	int i;
1549 	char *buf;
1550 	int buflen;
1551 {
1552 	struct select_menu_info *smi = (struct select_menu_info *) arg;
1553 
1554 	shf_snprintf(buf, buflen, "%*d) %s",
1555 		smi->num_width, i + 1, smi->args[i]);
1556 	return buf;
1557 }
1558 
1559 /*
1560  *	print a select style menu
1561  */
1562 int
1563 pr_menu(ap)
1564 	char *const *ap;
1565 {
1566 	struct select_menu_info smi;
1567 	char *const *pp;
1568 	int nwidth, dwidth;
1569 	int i, n;
1570 
1571 	/* Width/column calculations were done once and saved, but this
1572 	 * means select can't be used recursively so we re-calculate each
1573 	 * time (could save in a structure that is returned, but its probably
1574 	 * not worth the bother).
1575 	 */
1576 
1577 	/*
1578 	 * get dimensions of the list
1579 	 */
1580 	for (n = 0, nwidth = 0, pp = ap; *pp; n++, pp++) {
1581 		i = strlen(*pp);
1582 		nwidth = (i > nwidth) ? i : nwidth;
1583 	}
1584 	/*
1585 	 * we will print an index of the form
1586 	 *	%d)
1587 	 * in front of each entry
1588 	 * get the max width of this
1589 	 */
1590 	for (i = n, dwidth = 1; i >= 10; i /= 10)
1591 		dwidth++;
1592 
1593 	smi.args = ap;
1594 	smi.arg_width = nwidth;
1595 	smi.num_width = dwidth;
1596 	print_columns(shl_out, n, select_fmt_entry, (void *) &smi,
1597 		dwidth + nwidth + 2);
1598 
1599 	return n;
1600 }
1601 #endif /* KSH || EDIT */
1602 #ifdef KSH
1603 
1604 /*
1605  *	[[ ... ]] evaluation routines
1606  */
1607 
1608 extern const char *const dbtest_tokens[];
1609 extern const char db_close[];
1610 
1611 /* Test if the current token is a whatever.  Accepts the current token if
1612  * it is.  Returns 0 if it is not, non-zero if it is (in the case of
1613  * TM_UNOP and TM_BINOP, the returned value is a Test_op).
1614  */
1615 static int
1616 dbteste_isa(te, meta)
1617 	Test_env *te;
1618 	Test_meta meta;
1619 {
1620 	int ret = 0;
1621 	int uqword;
1622 	char *p;
1623 
1624 	if (!*te->pos.wp)
1625 		return meta == TM_END;
1626 
1627 	/* unquoted word? */
1628 	for (p = *te->pos.wp; *p == CHAR; p += 2)
1629 		;
1630 	uqword = *p == EOS;
1631 
1632 	if (meta == TM_UNOP || meta == TM_BINOP) {
1633 		if (uqword) {
1634 			char buf[8];	/* longer than the longest operator */
1635 			char *q = buf;
1636 			for (p = *te->pos.wp; *p == CHAR
1637 					      && q < &buf[sizeof(buf) - 1];
1638 					      p += 2)
1639 				*q++ = p[1];
1640 			*q = '\0';
1641 			ret = (int) test_isop(te, meta, buf);
1642 		}
1643 	} else if (meta == TM_END)
1644 		ret = 0;
1645 	else
1646 		ret = uqword
1647 			&& strcmp(*te->pos.wp, dbtest_tokens[(int) meta]) == 0;
1648 
1649 	/* Accept the token? */
1650 	if (ret)
1651 		te->pos.wp++;
1652 
1653 	return ret;
1654 }
1655 
1656 static const char *
1657 dbteste_getopnd(te, op, do_eval)
1658 	Test_env *te;
1659 	Test_op op;
1660 	int do_eval;
1661 {
1662 	char *s = *te->pos.wp;
1663 
1664 	if (!s)
1665 		return (char *) 0;
1666 
1667 	te->pos.wp++;
1668 
1669 	if (!do_eval)
1670 		return null;
1671 
1672 	if (op == TO_STEQL || op == TO_STNEQ)
1673 		s = evalstr(s, DOTILDE | DOPAT);
1674 	else
1675 		s = evalstr(s, DOTILDE);
1676 
1677 	return s;
1678 }
1679 
1680 static int
1681 dbteste_eval(te, op, opnd1, opnd2, do_eval)
1682 	Test_env *te;
1683 	Test_op op;
1684 	const char *opnd1;
1685 	const char *opnd2;
1686 	int do_eval;
1687 {
1688 	return test_eval(te, op, opnd1, opnd2, do_eval);
1689 }
1690 
1691 static void
1692 dbteste_error(te, offset, msg)
1693 	Test_env *te;
1694 	int offset;
1695 	const char *msg;
1696 {
1697 	te->flags |= TEF_ERROR;
1698 	internal_errorf(0, "dbteste_error: %s (offset %d)", msg, offset);
1699 }
1700 #endif /* KSH */
1701