xref: /openbsd-src/bin/ksh/exec.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: exec.c,v 1.24 2001/07/19 16:46:27 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((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 	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 & ~XTIME, -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 		current_lineno = t->lineno;	/* for $LINENO */
112 
113 		/* POSIX says expand command words first, then redirections,
114 		 * and assignments last..
115 		 */
116 		ap = eval(t->args, t->u.evalflags | DOBLANK | DOGLOB | DOTILDE);
117 		if (flags & XTIME)
118 			/* Allow option parsing (bizarre, but POSIX) */
119 			timex_hook(t, &ap);
120 		if (Flag(FXTRACE) && ap[0]) {
121 			shf_fprintf(shl_out, "%s",
122 				PS4_SUBSTITUTE(str_val(global("PS4"))));
123 			for (i = 0; ap[i]; i++)
124 				shf_fprintf(shl_out, "%s%s", ap[i],
125 					ap[i + 1] ? space : newline);
126 			shf_flush(shl_out);
127 		}
128 		if (ap[0])
129 			tp = findcom(ap[0], FC_BI|FC_FUNC);
130 	}
131 	flags &= ~XTIME;
132 
133 	if (t->ioact != NULL || t->type == TPIPE || t->type == TCOPROC) {
134 		e->savefd = (short *) alloc(sizeofN(short, NUFILE), ATEMP);
135 		/* initialize to not redirected */
136 		memset(e->savefd, 0, sizeofN(short, NUFILE));
137 	}
138 
139 	/* do redirection, to be restored in quitenv() */
140 	if (t->ioact != NULL)
141 		for (iowp = t->ioact; *iowp != NULL; iowp++) {
142 			if (iosetup(*iowp, tp) < 0) {
143 				exstat = rv = 1;
144 				/* Redirection failures for special commands
145 				 * cause (non-interactive) shell to exit.
146 				 */
147 				if (tp && tp->type == CSHELL
148 				    && (tp->flag & SPEC_BI))
149 					errorf(null);
150 				/* Deal with FERREXIT, quitenv(), etc. */
151 				goto Break;
152 			}
153 		}
154 
155 	switch(t->type) {
156 	  case TCOM:
157 		rv = comexec(t, tp, ap, flags);
158 		break;
159 
160 	  case TPAREN:
161 		rv = execute(t->left, flags|XFORK);
162 		break;
163 
164 	  case TPIPE:
165 		flags |= XFORK;
166 		flags &= ~XEXEC;
167 		e->savefd[0] = savefd(0, 0);
168 		(void) ksh_dup2(e->savefd[0], 0, FALSE); /* stdin of first */
169 		e->savefd[1] = savefd(1, 0);
170 		while (t->type == TPIPE) {
171 			openpipe(pv);
172 			(void) ksh_dup2(pv[1], 1, FALSE); /* stdout of curr */
173 			/* Let exchild() close pv[0] in child
174 			 * (if this isn't done, commands like
175 			 *    (: ; cat /etc/termcap) | sleep 1
176 			 *  will hang forever).
177 			 */
178 			exchild(t->left, flags|XPIPEO|XCCLOSE, pv[0]);
179 			(void) ksh_dup2(pv[0], 0, FALSE); /* stdin of next */
180 			closepipe(pv);
181 			flags |= XPIPEI;
182 			t = t->right;
183 		}
184 		restfd(1, e->savefd[1]); /* stdout of last */
185 		e->savefd[1] = 0; /* no need to re-restore this */
186 		/* Let exchild() close 0 in parent, after fork, before wait */
187 		i = exchild(t, flags|XPCLOSE, 0);
188 		if (!(flags&XBGND) && !(flags&XXCOM))
189 			rv = i;
190 		break;
191 
192 	  case TLIST:
193 		while (t->type == TLIST) {
194 			execute(t->left, flags & XERROK);
195 			t = t->right;
196 		}
197 		rv = execute(t, flags & XERROK);
198 		break;
199 
200 #ifdef KSH
201 	  case TCOPROC:
202 	  {
203 # ifdef JOB_SIGS
204 		sigset_t	omask;
205 # endif /* JOB_SIGS */
206 
207 # ifdef JOB_SIGS
208 		/* Block sigchild as we are using things changed in the
209 		 * signal handler
210 		 */
211 		sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
212 		e->type = E_ERRH;
213 		i = ksh_sigsetjmp(e->jbuf, 0);
214 		if (i) {
215 			sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
216 			quitenv();
217 			unwind(i);
218 			/*NOTREACHED*/
219 		}
220 # endif /* JOB_SIGS */
221 		/* Already have a (live) co-process? */
222 		if (coproc.job && coproc.write >= 0)
223 			errorf("coprocess already exists");
224 
225 		/* Can we re-use the existing co-process pipe? */
226 		coproc_cleanup(TRUE);
227 
228 		/* do this before opening pipes, in case these fail */
229 		e->savefd[0] = savefd(0, 0);
230 		e->savefd[1] = savefd(1, 0);
231 
232 		openpipe(pv);
233 		ksh_dup2(pv[0], 0, FALSE);
234 		close(pv[0]);
235 		coproc.write = pv[1];
236 		coproc.job = (void *) 0;
237 
238 		if (coproc.readw >= 0)
239 			ksh_dup2(coproc.readw, 1, FALSE);
240 		else {
241 			openpipe(pv);
242 			coproc.read = pv[0];
243 			ksh_dup2(pv[1], 1, FALSE);
244 			coproc.readw = pv[1];	 /* closed before first read */
245 			coproc.njobs = 0;
246 			/* create new coprocess id */
247 			++coproc.id;
248 		}
249 # ifdef JOB_SIGS
250 		sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
251 		e->type = E_EXEC; /* no more need for error handler */
252 # endif /* JOB_SIGS */
253 
254 		/* exchild() closes coproc.* in child after fork,
255 		 * will also increment coproc.njobs when the
256 		 * job is actually created.
257 		 */
258 		flags &= ~XEXEC;
259 		exchild(t->left, flags|XBGND|XFORK|XCOPROC|XCCLOSE,
260 			coproc.readw);
261 		break;
262 	  }
263 #endif /* KSH */
264 
265 	  case TASYNC:
266 		/* XXX non-optimal, I think - "(foo &)", forks for (),
267 		 * forks again for async...  parent should optimize
268 		 * this to "foo &"...
269 		 */
270 		rv = execute(t->left, (flags&~XEXEC)|XBGND|XFORK);
271 		break;
272 
273 	  case TOR:
274 	  case TAND:
275 		rv = execute(t->left, XERROK);
276 		if (t->right != NULL && (rv == 0) == (t->type == TAND))
277 			rv = execute(t->right, flags & XERROK);
278 		else
279 			flags |= XERROK;
280 		break;
281 
282 	  case TBANG:
283 		rv = !execute(t->right, XERROK);
284 		break;
285 
286 #ifdef KSH
287 	  case TDBRACKET:
288 	    {
289 		Test_env te;
290 
291 		te.flags = TEF_DBRACKET;
292 		te.pos.wp = t->args;
293 		te.isa = dbteste_isa;
294 		te.getopnd = dbteste_getopnd;
295 		te.eval = dbteste_eval;
296 		te.error = dbteste_error;
297 
298 		rv = test_parse(&te);
299 		break;
300 	    }
301 #endif /* KSH */
302 
303 	  case TFOR:
304 #ifdef KSH
305 	  case TSELECT:
306 	    {
307 		volatile bool_t is_first = TRUE;
308 #endif /* KSH */
309 		ap = (t->vars != NULL) ?
310 			  eval(t->vars, DOBLANK|DOGLOB|DOTILDE)
311 			: e->loc->argv + 1;
312 		e->type = E_LOOP;
313 		while (1) {
314 			i = ksh_sigsetjmp(e->jbuf, 0);
315 			if (!i)
316 				break;
317 			if ((e->flags&EF_BRKCONT_PASS)
318 			    || (i != LBREAK && i != LCONTIN))
319 			{
320 				quitenv();
321 				unwind(i);
322 			} else if (i == LBREAK) {
323 				rv = 0;
324 				goto Break;
325 			}
326 		}
327 		rv = 0; /* in case of a continue */
328 		if (t->type == TFOR) {
329 			while (*ap != NULL) {
330 				setstr(global(t->str), *ap++, KSH_UNWIND_ERROR);
331 				rv = execute(t->left, flags & XERROK);
332 			}
333 		}
334 #ifdef KSH
335 		else { /* TSELECT */
336 			for (;;) {
337 				if (!(cp = do_selectargs(ap, is_first))) {
338 					rv = 1;
339 					break;
340 				}
341 				is_first = FALSE;
342 				setstr(global(t->str), cp, KSH_UNWIND_ERROR);
343 				rv = execute(t->left, flags & XERROK);
344 			}
345 		}
346 	    }
347 #endif /* KSH */
348 		break;
349 
350 	  case TWHILE:
351 	  case TUNTIL:
352 		e->type = E_LOOP;
353 		while (1) {
354 			i = ksh_sigsetjmp(e->jbuf, 0);
355 			if (!i)
356 				break;
357 			if ((e->flags&EF_BRKCONT_PASS)
358 			    || (i != LBREAK && i != LCONTIN))
359 			{
360 				quitenv();
361 				unwind(i);
362 			} else if (i == LBREAK) {
363 				rv = 0;
364 				goto Break;
365 			}
366 		}
367 		rv = 0; /* in case of a continue */
368 		while ((execute(t->left, XERROK) == 0) == (t->type == TWHILE))
369 			rv = execute(t->right, flags & XERROK);
370 		break;
371 
372 	  case TIF:
373 	  case TELIF:
374 		if (t->right == NULL)
375 			break;	/* should be error */
376 		rv = execute(t->left, XERROK) == 0 ?
377 			execute(t->right->left, flags & XERROK) :
378 			execute(t->right->right, flags & XERROK);
379 		break;
380 
381 	  case TCASE:
382 		cp = evalstr(t->str, DOTILDE);
383 		for (t = t->left; t != NULL && t->type == TPAT; t = t->right)
384 		    for (ap = t->vars; *ap; ap++)
385 			if ((s = evalstr(*ap, DOTILDE|DOPAT))
386 			    && gmatch(cp, s, FALSE))
387 				goto Found;
388 		break;
389 	  Found:
390 		rv = execute(t->left, flags & XERROK);
391 		break;
392 
393 	  case TBRACE:
394 		rv = execute(t->left, flags & XERROK);
395 		break;
396 
397 	  case TFUNCT:
398 		rv = define(t->str, t);
399 		break;
400 
401 	  case TTIME:
402 		/* Clear XEXEC so nested execute() call doesn't exit
403 		 * (allows "ls -l | time grep foo").
404 		 */
405 		rv = timex(t, flags & ~XEXEC);
406 		break;
407 
408 	  case TEXEC:		/* an eval'd TCOM */
409 		s = t->args[0];
410 		ap = makenv();
411 #ifndef F_SETFD
412 		for (i = 0; i < sizeof(clexec_tab); i++)
413 			if (clexec_tab[i]) {
414 				close(i);
415 				clexec_tab[i] = 0;
416 			}
417 #endif
418 		restoresigs();
419 		cleanup_proc_env();
420 		/* XINTACT bit is for OS2 */
421 		ksh_execve(t->str, t->args, ap, (flags & XINTACT) ? 1 : 0);
422 		if (errno == ENOEXEC)
423 			scriptexec(t, ap);
424 		else
425 			errorf("%s: %s", s, strerror(errno));
426 	}
427     Break:
428 	exstat = rv;
429 
430 	quitenv();		/* restores IO */
431 	if ((flags&XEXEC))
432 		unwind(LEXIT);	/* exit child */
433 	if (rv != 0 && !(flags & XERROK)) {
434 		if (Flag(FERREXIT))
435 			unwind(LERROR);
436 		trapsig(SIGERR_);
437 	}
438 	return rv;
439 }
440 
441 /*
442  * execute simple command
443  */
444 
445 static int
446 comexec(t, tp, ap, flags)
447 	struct op *t;
448 	struct tbl *volatile tp;
449 	register char **ap;
450 	int volatile flags;
451 {
452 	int i;
453 	int rv = 0;
454 	register char *cp;
455 	register char **lastp;
456 	static struct op texec; /* Must be static (XXX but why?) */
457 	int type_flags;
458 	int keepasn_ok;
459 	int fcflags = FC_BI|FC_FUNC|FC_PATH;
460 
461 #ifdef __GNUC__
462 	(void)&rv;
463 #endif
464 
465 #ifdef KSH
466 	/* snag the last argument for $_ XXX not the same as at&t ksh,
467 	 * which only seems to set $_ after a newline (but not in
468 	 * functions/dot scripts, but in interactive and scipt) -
469 	 * perhaps save last arg here and set it in shell()?.
470 	 */
471 	if (!Flag(FSH) && Flag(FTALKING) && *(lastp = ap)) {
472 		while (*++lastp)
473 			;
474 		/* setstr() can't fail here */
475 		setstr(typeset("_", LOCAL, 0, INTEGER, 0), *--lastp,
476 		       KSH_RETURN_ERROR);
477 	}
478 #endif /* KSH */
479 
480 	/* Deal with the shell builtins builtin, exec and command since
481 	 * they can be followed by other commands.  This must be done before
482 	 * we know if we should create a local block, which must be done
483 	 * before we can do a path search (in case the assignments change
484 	 * PATH).
485 	 * Odd cases:
486 	 *   FOO=bar exec > /dev/null		FOO is kept but not exported
487 	 *   FOO=bar exec foobar		FOO is exported
488 	 *   FOO=bar command exec > /dev/null	FOO is neither kept nor exported
489 	 *   FOO=bar command			FOO is neither kept nor exported
490 	 *   PATH=... foobar			use new PATH in foobar search
491 	 */
492 	keepasn_ok = 1;
493 	while (tp && tp->type == CSHELL) {
494 		fcflags = FC_BI|FC_FUNC|FC_PATH;/* undo effects of command */
495 		if (tp->val.f == c_builtin) {
496 			if ((cp = *++ap) == NULL) {
497 				tp = NULL;
498 				break;
499 			}
500 			tp = findcom(cp, FC_BI);
501 			if (tp == NULL)
502 				errorf("builtin: %s: not a builtin", cp);
503 			continue;
504 		} else if (tp->val.f == c_exec) {
505 			if (ap[1] == NULL)
506 				break;
507 			ap++;
508 			flags |= XEXEC;
509 		} else if (tp->val.f == c_command) {
510 			int optc, saw_p = 0;
511 
512 			/* Ugly dealing with options in two places (here and
513 			 * in c_command(), but such is life)
514 			 */
515 			ksh_getopt_reset(&builtin_opt, 0);
516 			while ((optc = ksh_getopt(ap, &builtin_opt, ":p"))
517 									== 'p')
518 				saw_p = 1;
519 			if (optc != EOF)
520 				break;	/* command -vV or something */
521 			/* don't look for functions */
522 			fcflags = FC_BI|FC_PATH;
523 			if (saw_p) {
524 				if (Flag(FRESTRICTED)) {
525 					warningf(TRUE,
526 						"command -p: restricted");
527 					rv = 1;
528 					goto Leave;
529 				}
530 				fcflags |= FC_DEFPATH;
531 			}
532 			ap += builtin_opt.optind;
533 			/* POSIX says special builtins lose their status
534 			 * if accessed using command.
535 			 */
536 			keepasn_ok = 0;
537 			if (!ap[0]) {
538 				/* ensure command with no args exits with 0 */
539 				subst_exstat = 0;
540 				break;
541 			}
542 		} else
543 			break;
544 		tp = findcom(ap[0], fcflags & (FC_BI|FC_FUNC));
545 	}
546 	if (keepasn_ok && (!ap[0] || (tp && (tp->flag & KEEPASN))))
547 		type_flags = 0;
548 	else {
549 		/* create new variable/function block */
550 		newblock();
551 		/* ksh functions don't keep assignments, POSIX functions do. */
552 		if (keepasn_ok && tp && tp->type == CFUNC
553 		    && !(tp->flag & FKSH))
554 			type_flags = 0;
555 		else
556 			type_flags = LOCAL|LOCAL_COPY|EXPORT;
557 	}
558 	if (Flag(FEXPORT))
559 		type_flags |= EXPORT;
560 	for (i = 0; t->vars[i]; i++) {
561 		cp = evalstr(t->vars[i], DOASNTILDE);
562 		if (Flag(FXTRACE)) {
563 			if (i == 0)
564 				shf_fprintf(shl_out, "%s",
565 					PS4_SUBSTITUTE(str_val(global("PS4"))));
566 			shf_fprintf(shl_out, "%s%s", cp,
567 				t->vars[i + 1] ? space : newline);
568 			if (!t->vars[i + 1])
569 				shf_flush(shl_out);
570 		}
571 		typeset(cp, type_flags, 0, 0, 0);
572 	}
573 
574 	if ((cp = *ap) == NULL) {
575 		rv = subst_exstat;
576 		goto Leave;
577 	} else if (!tp) {
578 		if (Flag(FRESTRICTED) && ksh_strchr_dirsep(cp)) {
579 			warningf(TRUE, "%s: restricted", cp);
580 			rv = 1;
581 			goto Leave;
582 		}
583 		tp = findcom(cp, fcflags);
584 	}
585 
586 	switch (tp->type) {
587 	  case CSHELL:			/* shell built-in */
588 		rv = call_builtin(tp, ap);
589 		break;
590 
591 	  case CFUNC:			/* function call */
592 	  {
593 		volatile int old_xflag;
594 		volatile Tflag old_inuse;
595 		const char *volatile old_kshname;
596 
597 		if (!(tp->flag & ISSET)) {
598 			struct tbl *ftp;
599 
600 			if (!tp->u.fpath) {
601 				if (tp->u2.errno_) {
602 					warningf(TRUE,
603 				"%s: can't find function definition file - %s",
604 						cp, strerror(tp->u2.errno_));
605 					rv = 126;
606 				} else {
607 					warningf(TRUE,
608 				"%s: can't find function definition file", cp);
609 					rv = 127;
610 				}
611 				break;
612 			}
613 			if (include(tp->u.fpath, 0, (char **) 0, 0) < 0) {
614 				warningf(TRUE,
615 			    "%s: can't open function definition file %s - %s",
616 					cp, tp->u.fpath, strerror(errno));
617 				rv = 127;
618 				break;
619 			}
620 			if (!(ftp = findfunc(cp, hash(cp), FALSE))
621 			    || !(ftp->flag & ISSET))
622 			{
623 				warningf(TRUE,
624 					"%s: function not defined by %s",
625 					cp, tp->u.fpath);
626 				rv = 127;
627 				break;
628 			}
629 			tp = ftp;
630 		}
631 
632 		/* ksh functions set $0 to function name, POSIX functions leave
633 		 * $0 unchanged.
634 		 */
635 		old_kshname = kshname;
636 		if (tp->flag & FKSH)
637 			kshname = ap[0];
638 		else
639 			ap[0] = (char *) kshname;
640 		e->loc->argv = ap;
641 		for (i = 0; *ap++ != NULL; i++)
642 			;
643 		e->loc->argc = i - 1;
644 		/* ksh-style functions handle getopts sanely,
645 		 * bourne/posix functions are insane...
646 		 */
647 		if (tp->flag & FKSH) {
648 			e->loc->flags |= BF_DOGETOPTS;
649 			e->loc->getopts_state = user_opt;
650 			getopts_reset(1);
651 		}
652 
653 		old_xflag = Flag(FXTRACE);
654 		Flag(FXTRACE) = tp->flag & TRACE ? TRUE : FALSE;
655 
656 		old_inuse = tp->flag & FINUSE;
657 		tp->flag |= FINUSE;
658 
659 		e->type = E_FUNC;
660 		i = ksh_sigsetjmp(e->jbuf, 0);
661 		if (i == 0) {
662 			/* seems odd to pass XERROK here, but at&t ksh does */
663 			exstat = execute(tp->val.t, flags & XERROK);
664 			i = LRETURN;
665 		}
666 		kshname = old_kshname;
667 		Flag(FXTRACE) = old_xflag;
668 		tp->flag = (tp->flag & ~FINUSE) | old_inuse;
669 		/* Were we deleted while executing?  If so, free the execution
670 		 * tree.  todo: Unfortunately, the table entry is never re-used
671 		 * until the lookup table is expanded.
672 		 */
673 		if ((tp->flag & (FDELETE|FINUSE)) == FDELETE) {
674 			if (tp->flag & ALLOC) {
675 				tp->flag &= ~ALLOC;
676 				tfree(tp->val.t, tp->areap);
677 			}
678 			tp->flag = 0;
679 		}
680 		switch (i) {
681 		  case LRETURN:
682 		  case LERROR:
683 			rv = exstat;
684 			break;
685 		  case LINTR:
686 		  case LEXIT:
687 		  case LLEAVE:
688 		  case LSHELL:
689 			quitenv();
690 			unwind(i);
691 			/*NOTREACHED*/
692 		  default:
693 			quitenv();
694 			internal_errorf(1, "CFUNC %d", i);
695 		}
696 		break;
697 	  }
698 
699 	  case CEXEC:		/* executable command */
700 	  case CTALIAS:		/* tracked alias */
701 		if (!(tp->flag&ISSET)) {
702 			/* errno_ will be set if the named command was found
703 			 * but could not be executed (permissions, no execute
704 			 * bit, directory, etc).  Print out a (hopefully)
705 			 * useful error message and set the exit status to 126.
706 			 */
707 			if (tp->u2.errno_) {
708 				warningf(TRUE, "%s: cannot execute - %s", cp,
709 					strerror(tp->u2.errno_));
710 				rv = 126;	/* POSIX */
711 			} else {
712 				warningf(TRUE, "%s: not found", cp);
713 				rv = 127;
714 			}
715 			break;
716 		}
717 
718 #ifdef KSH
719 		if (!Flag(FSH)) {
720 			/* set $_ to program's full path */
721 			/* setstr() can't fail here */
722 			setstr(typeset("_", LOCAL|EXPORT, 0, INTEGER, 0),
723 			       tp->val.s, KSH_RETURN_ERROR);
724 		}
725 #endif /* KSH */
726 
727 		if (flags&XEXEC) {
728 			j_exit();
729 			if (!(flags&XBGND) || Flag(FMONITOR)) {
730 				setexecsig(&sigtraps[SIGINT], SS_RESTORE_ORIG);
731 				setexecsig(&sigtraps[SIGQUIT], SS_RESTORE_ORIG);
732 			}
733 		}
734 
735 		/* to fork we set up a TEXEC node and call execute */
736 		texec.type = TEXEC;
737 		texec.left = t;	/* for tprint */
738 		texec.str = tp->val.s;
739 		texec.args = ap;
740 		rv = exchild(&texec, flags, -1);
741 		break;
742 	}
743   Leave:
744 	if (flags & XEXEC) {
745 		exstat = rv;
746 		unwind(LLEAVE);
747 	}
748 	return rv;
749 }
750 
751 static void
752 scriptexec(tp, ap)
753 	register struct op *tp;
754 	register char **ap;
755 {
756 	char *shell;
757 
758 	shell = str_val(global(EXECSHELL_STR));
759 	if (shell && *shell)
760 		shell = search(shell, path, X_OK, (int *) 0);
761 	if (!shell || !*shell)
762 		shell = EXECSHELL;
763 
764 	*tp->args-- = tp->str;
765 #ifdef	SHARPBANG
766 	{
767 		char buf[LINE];
768 		register char *cp;
769 		register int fd, n;
770 
771 		buf[0] = '\0';
772 		if ((fd = open(tp->str, O_RDONLY)) >= 0) {
773 			if ((n = read(fd, buf, LINE - 1)) > 0)
774 				buf[n] = '\0';
775 			(void) close(fd);
776 		}
777 		if ((buf[0] == '#' && buf[1] == '!' && (cp = &buf[2]))
778 # ifdef OS2
779 		    || (strncmp(buf, "extproc", 7) == 0 && isspace(buf[7])
780 			&& (cp = &buf[7]))
781 # endif /* OS2 */
782 		    )
783 		{
784 			while (*cp && (*cp == ' ' || *cp == '\t'))
785 				cp++;
786 			if (*cp && *cp != '\n') {
787 				char *a0 = cp, *a1 = (char *) 0;
788 # ifdef OS2
789 				char *a2 = cp;
790 # endif /* OS2 */
791 
792 				while (*cp && *cp != '\n' && *cp != ' '
793 				       && *cp != '\t')
794 				{
795 # ifdef OS2
796 			/* Allow shell search without prepended path
797 			 * if shell with / in pathname cannot be found.
798 			 * Use / explicitly so \ can be used if explicit
799 			 * needs to be forced.
800 			 */
801 					if (*cp == '/')
802 						a2 = cp + 1;
803 # endif /* OS2 */
804 					cp++;
805 				}
806 				if (*cp && *cp != '\n') {
807 					*cp++ = '\0';
808 					while (*cp
809 					       && (*cp == ' ' || *cp == '\t'))
810 						cp++;
811 					if (*cp && *cp != '\n') {
812 						a1 = cp;
813 						/* all one argument */
814 						while (*cp && *cp != '\n')
815 							cp++;
816 					}
817 				}
818 				if (*cp == '\n') {
819 					*cp = '\0';
820 					if (a1)
821 						*tp->args-- = a1;
822 # ifdef OS2
823 					if (a0 != a2) {
824 						char *tmp_a0 = str_nsave(a0,
825 							strlen(a0) + 5, ATEMP);
826 						if (search_access(tmp_a0, X_OK,
827 								(int *) 0))
828 							a0 = a2;
829 						afree(tmp_a0, ATEMP);
830 					}
831 # endif /* OS2 */
832 					shell = a0;
833 				}
834 			}
835 # ifdef OS2
836 		} else {
837 		        /* Use ksh documented shell default if present
838 			 * else use OS2_SHELL which is assumed to need
839 			 * the /c option and '\' as dir separater.
840 			 */
841 		         char *p = shell;
842 
843 			 shell = str_val(global("EXECSHELL"));
844 			 if (shell && *shell)
845 				 shell = search(shell, path, X_OK, (int *) 0);
846 			 if (!shell || !*shell) {
847 				 shell = p;
848 				 *tp->args-- = "/c";
849 				 for (p = tp->str; *p; p++)
850 					 if (*p == '/')
851 						 *p = '\\';
852 			 }
853 # endif /* OS2 */
854 		}
855 	}
856 #endif	/* SHARPBANG */
857 	*tp->args = shell;
858 
859 	ksh_execve(tp->args[0], tp->args, ap, 0);
860 
861 	/* report both the program that was run and the bogus shell */
862 	errorf("%s: %s: %s", tp->str, shell, strerror(errno));
863 }
864 
865 int
866 shcomexec(wp)
867 	register char **wp;
868 {
869 	register struct tbl *tp;
870 
871 	tp = tsearch(&builtins, *wp, hash(*wp));
872 	if (tp == NULL)
873 		internal_errorf(1, "shcomexec: %s", *wp);
874 	return call_builtin(tp, wp);
875 }
876 
877 /*
878  * Search function tables for a function.  If create set, a table entry
879  * is created if none is found.
880  */
881 struct tbl *
882 findfunc(name, h, create)
883 	const char *name;
884 	unsigned int h;
885 	int create;
886 {
887 	struct block *l;
888 	struct tbl *tp = (struct tbl *) 0;
889 
890 	for (l = e->loc; l; l = l->next) {
891 		tp = tsearch(&l->funs, name, h);
892 		if (tp)
893 			break;
894 		if (!l->next && create) {
895 			tp = tenter(&l->funs, name, h);
896 			tp->flag = DEFINED;
897 			tp->type = CFUNC;
898 			tp->val.t = (struct op *) 0;
899 			break;
900 		}
901 	}
902 	return tp;
903 }
904 
905 /*
906  * define function.  Returns 1 if function is being undefined (t == 0) and
907  * function did not exist, returns 0 otherwise.
908  */
909 int
910 define(name, t)
911 	const char *name;
912 	struct op *t;
913 {
914 	struct tbl *tp;
915 	int was_set = 0;
916 
917 	while (1) {
918 		tp = findfunc(name, hash(name), TRUE);
919 
920 		if (tp->flag & ISSET)
921 			was_set = 1;
922 		/* If this function is currently being executed, we zap this
923 		 * table entry so findfunc() won't see it
924 		 */
925 		if (tp->flag & FINUSE) {
926 			tp->name[0] = '\0';
927 			tp->flag &= ~DEFINED; /* ensure it won't be found */
928 			tp->flag |= FDELETE;
929 		} else
930 			break;
931 	}
932 
933 	if (tp->flag & ALLOC) {
934 		tp->flag &= ~(ISSET|ALLOC);
935 		tfree(tp->val.t, tp->areap);
936 	}
937 
938 	if (t == NULL) {		/* undefine */
939 		tdelete(tp);
940 		return was_set ? 0 : 1;
941 	}
942 
943 	tp->val.t = tcopy(t->left, tp->areap);
944 	tp->flag |= (ISSET|ALLOC);
945 	if (t->u.ksh_func)
946 		tp->flag |= FKSH;
947 
948 	return 0;
949 }
950 
951 /*
952  * add builtin
953  */
954 void
955 builtin(name, func)
956 	const char *name;
957 	int (*func) ARGS((char **));
958 {
959 	register struct tbl *tp;
960 	Tflag flag;
961 
962 	/* see if any flags should be set for this builtin */
963 	for (flag = 0; ; name++) {
964 		if (*name == '=')	/* command does variable assignment */
965 			flag |= KEEPASN;
966 		else if (*name == '*')	/* POSIX special builtin */
967 			flag |= SPEC_BI;
968 		else if (*name == '+')	/* POSIX regular builtin */
969 			flag |= REG_BI;
970 		else
971 			break;
972 	}
973 
974 	tp = tenter(&builtins, name, hash(name));
975 	tp->flag = DEFINED | flag;
976 	tp->type = CSHELL;
977 	tp->val.f = func;
978 }
979 
980 /*
981  * find command
982  * either function, hashed command, or built-in (in that order)
983  */
984 struct tbl *
985 findcom(name, flags)
986 	const char *name;
987 	int	flags;		/* FC_* */
988 {
989 	static struct tbl temp;
990 	unsigned int h = hash(name);
991 	struct tbl *tp = NULL, *tbi;
992 	int insert = Flag(FTRACKALL);	/* insert if not found */
993 	char *fpath;			/* for function autoloading */
994 	char *npath;
995 
996 	if (ksh_strchr_dirsep(name) != NULL) {
997 		insert = 0;
998 		/* prevent FPATH search below */
999 		flags &= ~FC_FUNC;
1000 		goto Search;
1001 	}
1002 	tbi = (flags & FC_BI) ? tsearch(&builtins, name, h) : NULL;
1003 	/* POSIX says special builtins first, then functions, then
1004 	 * POSIX regular builtins, then search path...
1005 	 */
1006 	if ((flags & FC_SPECBI) && tbi && (tbi->flag & SPEC_BI))
1007 		tp = tbi;
1008 	if (!tp && (flags & FC_FUNC)) {
1009 		tp = findfunc(name, h, FALSE);
1010 		if (tp && !(tp->flag & ISSET)) {
1011 			if ((fpath = str_val(global("FPATH"))) == null) {
1012 				tp->u.fpath = (char *) 0;
1013 				tp->u2.errno_ = 0;
1014 			} else
1015 				tp->u.fpath = search(name, fpath, R_OK,
1016 					&tp->u2.errno_);
1017 		}
1018 	}
1019 	if (!tp && (flags & FC_REGBI) && tbi && (tbi->flag & REG_BI))
1020 		tp = tbi;
1021 	/* todo: posix says non-special/non-regular builtins must
1022 	 * be triggered by some user-controllable means like a
1023 	 * special directory in PATH.  Requires modifications to
1024 	 * the search() function.  Tracked aliases should be
1025 	 * modified to allow tracking of builtin commands.
1026 	 * This should be under control of the FPOSIX flag.
1027 	 * If this is changed, also change c_whence...
1028 	 */
1029 	if (!tp && (flags & FC_UNREGBI) && tbi)
1030 		tp = tbi;
1031 	if (!tp && (flags & FC_PATH) && !(flags & FC_DEFPATH)) {
1032 		tp = tsearch(&taliases, name, h);
1033 		if (tp && (tp->flag & ISSET) && eaccess(tp->val.s, X_OK) != 0) {
1034 			if (tp->flag & ALLOC) {
1035 				tp->flag &= ~ALLOC;
1036 				afree(tp->val.s, APERM);
1037 			}
1038 			tp->flag &= ~ISSET;
1039 		}
1040 	}
1041 
1042   Search:
1043 	if ((!tp || (tp->type == CTALIAS && !(tp->flag&ISSET)))
1044 	    && (flags & FC_PATH))
1045 	{
1046 		if (!tp) {
1047 			if (insert && !(flags & FC_DEFPATH)) {
1048 				tp = tenter(&taliases, name, h);
1049 				tp->type = CTALIAS;
1050 			} else {
1051 				tp = &temp;
1052 				tp->type = CEXEC;
1053 			}
1054 			tp->flag = DEFINED;	/* make ~ISSET */
1055 		}
1056 		npath = search(name, flags & FC_DEFPATH ? def_path : path,
1057 				X_OK, &tp->u2.errno_);
1058 		if (npath) {
1059 			tp->val.s = tp == &temp ? npath : str_save(npath, APERM);
1060 			tp->flag |= ISSET|ALLOC;
1061 		} else if ((flags & FC_FUNC)
1062 			   && (fpath = str_val(global("FPATH"))) != null
1063 			   && (npath = search(name, fpath, R_OK,
1064 					      &tp->u2.errno_)) != (char *) 0)
1065 		{
1066 			/* An undocumented feature of at&t ksh is that it
1067 			 * searches FPATH if a command is not found, even
1068 			 * if the command hasn't been set up as an autoloaded
1069 			 * function (ie, no typeset -uf).
1070 			 */
1071 			tp = &temp;
1072 			tp->type = CFUNC;
1073 			tp->flag = DEFINED; /* make ~ISSET */
1074 			tp->u.fpath = npath;
1075 		}
1076 	}
1077 	return tp;
1078 }
1079 
1080 /*
1081  * flush executable commands with relative paths
1082  */
1083 void
1084 flushcom(all)
1085 	int all;		/* just relative or all */
1086 {
1087 	struct tbl *tp;
1088 	struct tstate ts;
1089 
1090 	for (twalk(&ts, &taliases); (tp = tnext(&ts)) != NULL; )
1091 		if ((tp->flag&ISSET) && (all || !ISDIRSEP(tp->val.s[0]))) {
1092 			if (tp->flag&ALLOC) {
1093 				tp->flag &= ~(ALLOC|ISSET);
1094 				afree(tp->val.s, APERM);
1095 			}
1096 			tp->flag &= ~ISSET;
1097 		}
1098 }
1099 
1100 /* Check if path is something we want to find.  Returns -1 for failure. */
1101 int
1102 search_access(path, mode, errnop)
1103 	const char *path;
1104 	int mode;
1105 	int *errnop;		/* set if candidate found, but not suitable */
1106 {
1107 #ifndef OS2
1108 	int ret, err = 0;
1109 	struct stat statb;
1110 
1111 	if (stat(path, &statb) < 0)
1112 		return -1;
1113 	ret = eaccess(path, mode);
1114 	if (ret < 0)
1115 		err = errno; /* File exists, but we can't access it */
1116 	else if (mode == X_OK
1117 		 && (!S_ISREG(statb.st_mode)
1118 		     /* This 'cause access() says root can execute everything */
1119 		     || !(statb.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH))))
1120 	{
1121 		ret = -1;
1122 		err = S_ISDIR(statb.st_mode) ? EISDIR : EACCES;
1123 	}
1124 	if (err && errnop && !*errnop)
1125 		*errnop = err;
1126 	return ret;
1127 #else /* !OS2 */
1128 	/*
1129 	 * NOTE: ASSUMES path can be modified and has enough room at the
1130 	 *       end of the string for a suffix (ie, 4 extra characters).
1131 	 *	 Certain code knows this (eg, eval.c(globit()),
1132 	 *	 exec.c(search())).
1133 	 */
1134 	static char *xsuffixes[] = { ".ksh", ".exe", ".", ".sh", ".cmd",
1135 				     ".com", ".bat", (char *) 0
1136 				   };
1137 	static char *rsuffixes[] = { ".ksh", ".", ".sh", ".cmd", ".bat",
1138 				      (char *) 0
1139 				   };
1140 	int i;
1141 	char *mpath = (char *) path;
1142 	char *tp = mpath + strlen(mpath);
1143 	char *p;
1144 	char **sfx;
1145 
1146 	/* If a suffix has been specified, check if it is one of the
1147 	 * suffixes that indicate the file is executable - if so, change
1148 	 * the access test to R_OK...
1149 	 * This code assumes OS/2 files can have only one suffix...
1150 	 */
1151 	if ((p = strrchr((p = ksh_strrchr_dirsep(mpath)) ? p : mpath, '.'))) {
1152 		if (mode == X_OK)
1153 			mode = R_OK;
1154 		return search_access1(mpath, mode, errnop);
1155 	}
1156 	/* Try appending the various suffixes.  Different suffixes for
1157 	 * read and execute 'cause we don't want to read an executable...
1158 	 */
1159 	sfx = mode == R_OK ? rsuffixes : xsuffixes;
1160 	for (i = 0; sfx[i]; i++) {
1161 		strcpy(tp, p = sfx[i]);
1162 		if (search_access1(mpath, R_OK, errnop) == 0)
1163 			return 0;
1164 		*tp = '\0';
1165 	}
1166 	return -1;
1167 #endif /* !OS2 */
1168 }
1169 
1170 #ifdef OS2
1171 static int
1172 search_access1(path, mode, errnop)
1173 	const char *path;
1174 	int mode;
1175 	int *errnop;		/* set if candidate found, but not suitable */
1176 {
1177 	int ret, err = 0;
1178 	struct stat statb;
1179 
1180 	if (stat(path, &statb) < 0)
1181 		return -1;
1182 	ret = eaccess(path, mode);
1183 	if (ret < 0)
1184 		err = errno; /* File exists, but we can't access it */
1185 	else if (!S_ISREG(statb.st_mode)) {
1186 		ret = -1;
1187 		err = S_ISDIR(statb.st_mode) ? EISDIR : EACCES;
1188 	}
1189 	if (err && errnop && !*errnop)
1190 		*errnop = err;
1191 	return ret;
1192 }
1193 #endif /* OS2 */
1194 
1195 /*
1196  * search for command with PATH
1197  */
1198 char *
1199 search(name, path, mode, errnop)
1200 	const char *name;
1201 	const char *path;
1202 	int mode;		/* R_OK or X_OK */
1203 	int *errnop;		/* set if candidate found, but not suitable */
1204 {
1205 	const char *sp, *p;
1206 	char *xp;
1207 	XString xs;
1208 	int namelen;
1209 
1210 	if (errnop)
1211 		*errnop = 0;
1212 #ifdef OS2
1213 	/* Xinit() allocates 8 additional bytes, so appended suffixes won't
1214 	 * overflow the memory.
1215 	 */
1216 	namelen = strlen(name) + 1;
1217 	Xinit(xs, xp, namelen, ATEMP);
1218 	memcpy(Xstring(xs, xp), name, namelen);
1219 
1220  	if (ksh_strchr_dirsep(name)) {
1221 		if (search_access(Xstring(xs, xp), mode, errnop) >= 0)
1222 			return Xstring(xs, xp); /* not Xclose() - see above */
1223 		Xfree(xs, xp);
1224 		return NULL;
1225 	}
1226 
1227 	/* Look in current context always. (os2 style) */
1228 	if (search_access(Xstring(xs, xp), mode, errnop) == 0)
1229 		return Xstring(xs, xp); /* not Xclose() - xp may be wrong */
1230 #else /* OS2 */
1231 	if (ksh_strchr_dirsep(name)) {
1232 		if (search_access(name, mode, errnop) == 0)
1233 			return (char *) name;
1234 		return NULL;
1235 	}
1236 
1237 	namelen = strlen(name) + 1;
1238 	Xinit(xs, xp, 128, ATEMP);
1239 #endif /* OS2 */
1240 
1241 	sp = path;
1242 	while (sp != NULL) {
1243 		xp = Xstring(xs, xp);
1244 		if (!(p = strchr(sp, PATHSEP)))
1245 			p = sp + strlen(sp);
1246 		if (p != sp) {
1247 			XcheckN(xs, xp, p - sp);
1248 			memcpy(xp, sp, p - sp);
1249 			xp += p - sp;
1250 			*xp++ = DIRSEP;
1251 		}
1252 		sp = p;
1253 		XcheckN(xs, xp, namelen);
1254 		memcpy(xp, name, namelen);
1255  		if (search_access(Xstring(xs, xp), mode, errnop) == 0)
1256 #ifdef OS2
1257  			return Xstring(xs, xp); /* Not Xclose() - see above */
1258 #else /* OS2 */
1259 			return Xclose(xs, xp + namelen);
1260 #endif /* OS2 */
1261 		if (*sp++ == '\0')
1262 			sp = NULL;
1263 	}
1264 	Xfree(xs, xp);
1265 	return NULL;
1266 }
1267 
1268 static int
1269 call_builtin(tp, wp)
1270 	struct tbl *tp;
1271 	char **wp;
1272 {
1273 	int rv;
1274 
1275 	builtin_argv0 = wp[0];
1276 	builtin_flag = tp->flag;
1277 	shf_reopen(1, SHF_WR, shl_stdout);
1278 	shl_stdout_ok = 1;
1279 	ksh_getopt_reset(&builtin_opt, GF_ERROR);
1280 	rv = (*tp->val.f)(wp);
1281 	shf_flush(shl_stdout);
1282 	shl_stdout_ok = 0;
1283 	builtin_flag = 0;
1284 	builtin_argv0 = (char *) 0;
1285 	return rv;
1286 }
1287 
1288 /*
1289  * set up redirection, saving old fd's in e->savefd
1290  */
1291 static int
1292 iosetup(iop, tp)
1293 	register struct ioword *iop;
1294 	struct tbl *tp;
1295 {
1296 	register int u = -1;
1297 	char *cp = iop->name;
1298 	int iotype = iop->flag & IOTYPE;
1299 	int do_open = 1, do_close = 0, UNINITIALIZED(flags);
1300 	struct ioword iotmp;
1301 	struct stat statb;
1302 
1303 	if (iotype != IOHERE)
1304 		cp = evalonestr(cp, DOTILDE|(Flag(FTALKING_I) ? DOGLOB : 0));
1305 
1306 	/* Used for tracing and error messages to print expanded cp */
1307 	iotmp = *iop;
1308 	iotmp.name = (iotype == IOHERE) ? (char *) 0 : cp;
1309 	iotmp.flag |= IONAMEXP;
1310 
1311 	if (Flag(FXTRACE))
1312 		shellf("%s%s\n",
1313 			PS4_SUBSTITUTE(str_val(global("PS4"))),
1314 			snptreef((char *) 0, 32, "%R", &iotmp));
1315 
1316 	switch (iotype) {
1317 	  case IOREAD:
1318 		flags = O_RDONLY;
1319 		break;
1320 
1321 	  case IOCAT:
1322 		flags = O_WRONLY | O_APPEND | O_CREAT;
1323 		break;
1324 
1325 	  case IOWRITE:
1326 		flags = O_WRONLY | O_CREAT | O_TRUNC;
1327 		/* The stat() is here to allow redirections to
1328 		 * things like /dev/null without error.
1329 		 */
1330 		if (Flag(FNOCLOBBER) && !(iop->flag & IOCLOB)
1331 		    && (stat(cp, &statb) < 0 || S_ISREG(statb.st_mode)))
1332 			flags |= O_EXCL;
1333 		break;
1334 
1335 	  case IORDWR:
1336 		flags = O_RDWR | O_CREAT;
1337 		break;
1338 
1339 	  case IOHERE:
1340 		do_open = 0;
1341 		/* herein() returns -2 if error has been printed */
1342 		u = herein(iop->heredoc, iop->flag & IOEVAL);
1343 		/* cp may have wrong name */
1344 		break;
1345 
1346 	  case IODUP:
1347 	  {
1348 		const char *emsg;
1349 
1350 		do_open = 0;
1351 		if (*cp == '-' && !cp[1]) {
1352 			u = 1009;	 /* prevent error return below */
1353 			do_close = 1;
1354 		} else if ((u = check_fd(cp,
1355 				X_OK | ((iop->flag & IORDUP) ? R_OK : W_OK),
1356 				&emsg)) < 0)
1357 		{
1358 			warningf(TRUE, "%s: %s",
1359 				snptreef((char *) 0, 32, "%R", &iotmp), emsg);
1360 			return -1;
1361 		}
1362 		break;
1363 	  }
1364 	}
1365 	if (do_open) {
1366 		if (Flag(FRESTRICTED) && (flags & O_CREAT)) {
1367 			warningf(TRUE, "%s: restricted", cp);
1368 			return -1;
1369 		}
1370 		u = open(cp, flags, 0666);
1371 #ifdef OS2
1372 		if (u < 0 && strcmp(cp, "/dev/null") == 0)
1373 			u = open("nul", flags, 0666);
1374 #endif /* OS2 */
1375 	}
1376 	if (u < 0) {
1377 		/* herein() may already have printed message */
1378 		if (u == -1)
1379 			warningf(TRUE, "cannot %s %s: %s",
1380 			       iotype == IODUP ? "dup"
1381 				: (iotype == IOREAD || iotype == IOHERE) ?
1382 				    "open" : "create", cp, strerror(errno));
1383 		return -1;
1384 	}
1385 	/* Do not save if it has already been redirected (i.e. "cat >x >y"). */
1386 	if (e->savefd[iop->unit] == 0) {
1387 		/* If these are the same, it means unit was previously closed */
1388 		if (u == iop->unit)
1389 			e->savefd[iop->unit] = -1;
1390 		else
1391 			/* c_exec() assumes e->savefd[fd] set for any
1392 			 * redirections.  Ask savefd() not to close iop->unit;
1393 			 * this allows error messages to be seen if iop->unit
1394 			 * is 2; also means we can't lose the fd (eg, both
1395 			 * dup2 below and dup2 in restfd() failing).
1396 			 */
1397 			e->savefd[iop->unit] = savefd(iop->unit, 1);
1398 	}
1399 
1400 	if (do_close)
1401 		close(iop->unit);
1402 	else if (u != iop->unit) {
1403 		if (ksh_dup2(u, iop->unit, TRUE) < 0) {
1404 			warningf(TRUE,
1405 				"could not finish (dup) redirection %s: %s",
1406 				snptreef((char *) 0, 32, "%R", &iotmp),
1407 				strerror(errno));
1408 			if (iotype != IODUP)
1409 				close(u);
1410 			return -1;
1411 		}
1412 		if (iotype != IODUP)
1413 			close(u);
1414 #ifdef KSH
1415 		/* Touching any co-process fd in an empty exec
1416 		 * causes the shell to close its copies
1417 		 */
1418 		else if (tp && tp->type == CSHELL && tp->val.f == c_exec) {
1419 			if (iop->flag & IORDUP)	/* possible exec <&p */
1420 				coproc_read_close(u);
1421 			else			/* possible exec >&p */
1422 				coproc_write_close(u);
1423 		}
1424 #endif /* KSH */
1425 	}
1426 	if (u == 2) /* Clear any write errors */
1427 		shf_reopen(2, SHF_WR, shl_out);
1428 	return 0;
1429 }
1430 
1431 /*
1432  * open here document temp file.
1433  * if unquoted here, expand here temp file into second temp file.
1434  */
1435 static int
1436 herein(content, sub)
1437 	const char *content;
1438 	int sub;
1439 {
1440 	volatile int fd = -1;
1441 	struct source *s, *volatile osource;
1442 	struct shf *volatile shf;
1443 	struct temp *h;
1444 	int i;
1445 
1446 	/* ksh -c 'cat << EOF' can cause this... */
1447 	if (content == (char *) 0) {
1448 		warningf(TRUE, "here document missing");
1449 		return -2; /* special to iosetup(): don't print error */
1450 	}
1451 
1452 	/* Create temp file to hold content (done before newenv so temp
1453 	 * doesn't get removed too soon).
1454 	 */
1455 	h = maketemp(ATEMP, TT_HEREDOC_EXP, &e->temps);
1456 	if (!(shf = h->shf) || (fd = open(h->name, O_RDONLY, 0)) < 0) {
1457 		warningf(TRUE, "can't %s temporary file %s: %s",
1458 			!shf ? "create" : "open",
1459 			h->name, strerror(errno));
1460 		if (shf)
1461 			shf_close(shf);
1462 		return -2 /* special to iosetup(): don't print error */;
1463 	}
1464 
1465 	osource = source;
1466 	newenv(E_ERRH);
1467 	i = ksh_sigsetjmp(e->jbuf, 0);
1468 	if (i) {
1469 		source = osource;
1470 		quitenv();
1471 		shf_close(shf);	/* after quitenv */
1472 		close(fd);
1473 		return -2; /* special to iosetup(): don't print error */
1474 	}
1475 	if (sub) {
1476 		/* Do substitutions on the content of heredoc */
1477 		s = pushs(SSTRING, ATEMP);
1478 		s->start = s->str = content;
1479 		source = s;
1480 		if (yylex(ONEWORD) != LWORD)
1481 			internal_errorf(1, "herein: yylex");
1482 		source = osource;
1483 		shf_puts(evalstr(yylval.cp, 0), shf);
1484 	} else
1485 		shf_puts(content, shf);
1486 
1487 	quitenv();
1488 
1489 	if (shf_close(shf) == EOF) {
1490 		close(fd);
1491 		warningf(TRUE, "error writing %s: %s", h->name,
1492 			strerror(errno));
1493 		return -2; /* special to iosetup(): don't print error */
1494 	}
1495 
1496 	return fd;
1497 }
1498 
1499 #if defined(KSH) || defined(EDIT)
1500 /*
1501  *	ksh special - the select command processing section
1502  *	print the args in column form - assuming that we can
1503  */
1504 static char *
1505 do_selectargs(ap, print_menu)
1506 	register char **ap;
1507 	bool_t print_menu;
1508 {
1509 	static const char *const read_args[] = {
1510 					"read", "-r", "REPLY", (char *) 0
1511 				    };
1512 	char *s;
1513 	int i, argct;
1514 
1515 	for (argct = 0; ap[argct]; argct++)
1516 		;
1517 	while (1) {
1518 		/* Menu is printed if
1519 		 *	- this is the first time around the select loop
1520 		 *	- the user enters a blank line
1521 		 *	- the REPLY parameter is empty
1522 		 */
1523 		if (print_menu || !*str_val(global("REPLY")))
1524 			pr_menu(ap);
1525 		shellf("%s", str_val(global("PS3")));
1526 		if (call_builtin(findcom("read", FC_BI), (char **) read_args))
1527 			return (char *) 0;
1528 		s = str_val(global("REPLY"));
1529 		if (*s) {
1530 			i = atoi(s);
1531 			return (i >= 1 && i <= argct) ? ap[i - 1] : null;
1532 		}
1533 		print_menu = 1;
1534 	}
1535 }
1536 
1537 struct select_menu_info {
1538 	char	*const *args;
1539 	int	arg_width;
1540 	int	num_width;
1541 } info;
1542 
1543 static char *select_fmt_entry ARGS((void *arg, int i, char *buf, int buflen));
1544 
1545 /* format a single select menu item */
1546 static char *
1547 select_fmt_entry(arg, i, buf, buflen)
1548 	void *arg;
1549 	int i;
1550 	char *buf;
1551 	int buflen;
1552 {
1553 	struct select_menu_info *smi = (struct select_menu_info *) arg;
1554 
1555 	shf_snprintf(buf, buflen, "%*d) %s",
1556 		smi->num_width, i + 1, smi->args[i]);
1557 	return buf;
1558 }
1559 
1560 /*
1561  *	print a select style menu
1562  */
1563 int
1564 pr_menu(ap)
1565 	char *const *ap;
1566 {
1567 	struct select_menu_info smi;
1568 	char *const *pp;
1569 	int nwidth, dwidth;
1570 	int i, n;
1571 
1572 	/* Width/column calculations were done once and saved, but this
1573 	 * means select can't be used recursively so we re-calculate each
1574 	 * time (could save in a structure that is returned, but its probably
1575 	 * not worth the bother).
1576 	 */
1577 
1578 	/*
1579 	 * get dimensions of the list
1580 	 */
1581 	for (n = 0, nwidth = 0, pp = ap; *pp; n++, pp++) {
1582 		i = strlen(*pp);
1583 		nwidth = (i > nwidth) ? i : nwidth;
1584 	}
1585 	/*
1586 	 * we will print an index of the form
1587 	 *	%d)
1588 	 * in front of each entry
1589 	 * get the max width of this
1590 	 */
1591 	for (i = n, dwidth = 1; i >= 10; i /= 10)
1592 		dwidth++;
1593 
1594 	smi.args = ap;
1595 	smi.arg_width = nwidth;
1596 	smi.num_width = dwidth;
1597 	print_columns(shl_out, n, select_fmt_entry, (void *) &smi,
1598 		dwidth + nwidth + 2, 1);
1599 
1600 	return n;
1601 }
1602 
1603 /* XXX: horrible kludge to fit within the framework */
1604 
1605 static char *plain_fmt_entry ARGS((void *arg, int i, char *buf, int buflen));
1606 
1607 static char *
1608 plain_fmt_entry(arg, i, buf, buflen)
1609 	void *arg;
1610 	int i;
1611 	char *buf;
1612 	int buflen;
1613 {
1614 	shf_snprintf(buf, buflen, "%s", ((char *const *)arg)[i]);
1615 	return buf;
1616 }
1617 
1618 int
1619 pr_list(ap)
1620 	char *const *ap;
1621 {
1622 	char *const *pp;
1623 	int nwidth;
1624 	int i, n;
1625 
1626 	for (n = 0, nwidth = 0, pp = ap; *pp; n++, pp++) {
1627 		i = strlen(*pp);
1628 		nwidth = (i > nwidth) ? i : nwidth;
1629 	}
1630 	print_columns(shl_out, n, plain_fmt_entry, (void *) ap, nwidth + 1, 0);
1631 
1632 	return n;
1633 }
1634 #endif /* KSH || EDIT */
1635 #ifdef KSH
1636 
1637 /*
1638  *	[[ ... ]] evaluation routines
1639  */
1640 
1641 extern const char *const dbtest_tokens[];
1642 extern const char db_close[];
1643 
1644 /* Test if the current token is a whatever.  Accepts the current token if
1645  * it is.  Returns 0 if it is not, non-zero if it is (in the case of
1646  * TM_UNOP and TM_BINOP, the returned value is a Test_op).
1647  */
1648 static int
1649 dbteste_isa(te, meta)
1650 	Test_env *te;
1651 	Test_meta meta;
1652 {
1653 	int ret = 0;
1654 	int uqword;
1655 	char *p;
1656 
1657 	if (!*te->pos.wp)
1658 		return meta == TM_END;
1659 
1660 	/* unquoted word? */
1661 	for (p = *te->pos.wp; *p == CHAR; p += 2)
1662 		;
1663 	uqword = *p == EOS;
1664 
1665 	if (meta == TM_UNOP || meta == TM_BINOP) {
1666 		if (uqword) {
1667 			char buf[8];	/* longer than the longest operator */
1668 			char *q = buf;
1669 			for (p = *te->pos.wp; *p == CHAR
1670 					      && q < &buf[sizeof(buf) - 1];
1671 					      p += 2)
1672 				*q++ = p[1];
1673 			*q = '\0';
1674 			ret = (int) test_isop(te, meta, buf);
1675 		}
1676 	} else if (meta == TM_END)
1677 		ret = 0;
1678 	else
1679 		ret = uqword
1680 			&& strcmp(*te->pos.wp, dbtest_tokens[(int) meta]) == 0;
1681 
1682 	/* Accept the token? */
1683 	if (ret)
1684 		te->pos.wp++;
1685 
1686 	return ret;
1687 }
1688 
1689 static const char *
1690 dbteste_getopnd(te, op, do_eval)
1691 	Test_env *te;
1692 	Test_op op;
1693 	int do_eval;
1694 {
1695 	char *s = *te->pos.wp;
1696 
1697 	if (!s)
1698 		return (char *) 0;
1699 
1700 	te->pos.wp++;
1701 
1702 	if (!do_eval)
1703 		return null;
1704 
1705 	if (op == TO_STEQL || op == TO_STNEQ)
1706 		s = evalstr(s, DOTILDE | DOPAT);
1707 	else
1708 		s = evalstr(s, DOTILDE);
1709 
1710 	return s;
1711 }
1712 
1713 static int
1714 dbteste_eval(te, op, opnd1, opnd2, do_eval)
1715 	Test_env *te;
1716 	Test_op op;
1717 	const char *opnd1;
1718 	const char *opnd2;
1719 	int do_eval;
1720 {
1721 	return test_eval(te, op, opnd1, opnd2, do_eval);
1722 }
1723 
1724 static void
1725 dbteste_error(te, offset, msg)
1726 	Test_env *te;
1727 	int offset;
1728 	const char *msg;
1729 {
1730 	te->flags |= TEF_ERROR;
1731 	internal_errorf(0, "dbteste_error: %s (offset %d)", msg, offset);
1732 }
1733 #endif /* KSH */
1734