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1 /*	$OpenBSD: exec.c,v 1.52 2015/09/10 22:48:58 nicm Exp $	*/
2 
3 /*-
4  * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
5  *		 2011, 2012, 2013, 2014, 2015, 2016, 2017
6  *	mirabilos <m@mirbsd.org>
7  *
8  * Provided that these terms and disclaimer and all copyright notices
9  * are retained or reproduced in an accompanying document, permission
10  * is granted to deal in this work without restriction, including un-
11  * limited rights to use, publicly perform, distribute, sell, modify,
12  * merge, give away, or sublicence.
13  *
14  * This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
15  * the utmost extent permitted by applicable law, neither express nor
16  * implied; without malicious intent or gross negligence. In no event
17  * may a licensor, author or contributor be held liable for indirect,
18  * direct, other damage, loss, or other issues arising in any way out
19  * of dealing in the work, even if advised of the possibility of such
20  * damage or existence of a defect, except proven that it results out
21  * of said person's immediate fault when using the work as intended.
22  */
23 
24 #include "sh.h"
25 
26 __RCSID("$MirOS: src/bin/mksh/exec.c,v 1.196 2017/04/12 16:46:21 tg Exp $");
27 
28 #ifndef MKSH_DEFAULT_EXECSHELL
29 #define MKSH_DEFAULT_EXECSHELL	MKSH_UNIXROOT "/bin/sh"
30 #endif
31 
32 static int comexec(struct op *, struct tbl * volatile, const char **,
33     int volatile, volatile int *);
34 static void scriptexec(struct op *, const char **) MKSH_A_NORETURN;
35 static int call_builtin(struct tbl *, const char **, const char *, bool);
36 static int iosetup(struct ioword *, struct tbl *);
37 static const char *do_selectargs(const char **, bool);
38 static Test_op dbteste_isa(Test_env *, Test_meta);
39 static const char *dbteste_getopnd(Test_env *, Test_op, bool);
40 static void dbteste_error(Test_env *, int, const char *);
41 /* XXX: horrible kludge to fit within the framework */
42 static void plain_fmt_entry(char *, size_t, unsigned int, const void *);
43 static void select_fmt_entry(char *, size_t, unsigned int, const void *);
44 
45 /*
46  * execute command tree
47  */
48 int
execute(struct op * volatile t,volatile int flags,volatile int * volatile xerrok)49 execute(struct op * volatile t,
50     /* if XEXEC don't fork */
51     volatile int flags,
52     volatile int * volatile xerrok)
53 {
54 	int i;
55 	volatile int rv = 0, dummy = 0;
56 	int pv[2];
57 	const char ** volatile ap = NULL;
58 	char ** volatile up;
59 	const char *s, *ccp;
60 	struct ioword **iowp;
61 	struct tbl *tp = NULL;
62 
63 	if (t == NULL)
64 		return (0);
65 
66 	/* Caller doesn't care if XERROK should propagate. */
67 	if (xerrok == NULL)
68 		xerrok = &dummy;
69 
70 	if ((flags&XFORK) && !(flags&XEXEC) && t->type != TPIPE)
71 		/* run in sub-process */
72 		return (exchild(t, flags & ~XTIME, xerrok, -1));
73 
74 	newenv(E_EXEC);
75 	if (trap)
76 		runtraps(0);
77 
78 	/* we want to run an executable, do some variance checks */
79 	if (t->type == TCOM) {
80 		/*
81 		 * Clear subst_exstat before argument expansion. Used by
82 		 * null commands (see comexec() and c_eval()) and by c_set().
83 		 */
84 		subst_exstat = 0;
85 
86 		/* for $LINENO */
87 		current_lineno = t->lineno;
88 
89 		/* check if this is 'var=<<EOF' */
90 		if (
91 		    /* we have zero arguments, i.e. no program to run */
92 		    t->args[0] == NULL &&
93 		    /* we have exactly one variable assignment */
94 		    t->vars[0] != NULL && t->vars[1] == NULL &&
95 		    /* we have exactly one I/O redirection */
96 		    t->ioact != NULL && t->ioact[0] != NULL &&
97 		    t->ioact[1] == NULL &&
98 		    /* of type "here document" (or "here string") */
99 		    (t->ioact[0]->ioflag & IOTYPE) == IOHERE &&
100 		    /* the variable assignment begins with a valid varname */
101 		    (ccp = skip_wdvarname(t->vars[0], true)) != t->vars[0] &&
102 		    /* and has no right-hand side (i.e. "varname=") */
103 		    ccp[0] == CHAR && ((ccp[1] == '=' && ccp[2] == EOS) ||
104 		    /* or "varname+=" */ (ccp[1] == '+' && ccp[2] == CHAR &&
105 		    ccp[3] == '=' && ccp[4] == EOS))) {
106 			char *cp, *dp;
107 
108 			if ((rv = herein(t->ioact[0], &cp) /*? 1 : 0*/))
109 				cp = NULL;
110 			dp = shf_smprintf(Tf_ss, evalstr(t->vars[0],
111 			    DOASNTILDE | DOSCALAR), rv ? null : cp);
112 			typeset(dp, Flag(FEXPORT) ? EXPORT : 0, 0, 0, 0);
113 			/* free the expanded value */
114 			afree(cp, APERM);
115 			afree(dp, ATEMP);
116 			goto Break;
117 		}
118 
119 		/*
120 		 * POSIX says expand command words first, then redirections,
121 		 * and assignments last..
122 		 */
123 		up = eval(t->args, t->u.evalflags | DOBLANK | DOGLOB | DOTILDE);
124 		if (flags & XTIME)
125 			/* Allow option parsing (bizarre, but POSIX) */
126 			timex_hook(t, &up);
127 		ap = (const char **)up;
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 = alloc2(NUFILE, sizeof(short), ATEMP);
135 		/* initialise to not redirected */
136 		memset(e->savefd, 0, NUFILE * sizeof(short));
137 	}
138 
139 	/* mark for replacement later (unless TPIPE) */
140 	vp_pipest->flag |= INT_L;
141 
142 	/* do redirection, to be restored in quitenv() */
143 	if (t->ioact != NULL)
144 		for (iowp = t->ioact; *iowp != NULL; iowp++) {
145 			if (iosetup(*iowp, tp) < 0) {
146 				exstat = rv = 1;
147 				/*
148 				 * Redirection failures for special commands
149 				 * cause (non-interactive) shell to exit.
150 				 */
151 				if (tp && tp->type == CSHELL &&
152 				    (tp->flag & SPEC_BI))
153 					errorfz();
154 				/* Deal with FERREXIT, quitenv(), etc. */
155 				goto Break;
156 			}
157 		}
158 
159 	switch (t->type) {
160 	case TCOM:
161 		rv = comexec(t, tp, (const char **)ap, flags, xerrok);
162 		break;
163 
164 	case TPAREN:
165 		rv = execute(t->left, flags | XFORK, xerrok);
166 		break;
167 
168 	case TPIPE:
169 		flags |= XFORK;
170 		flags &= ~XEXEC;
171 		e->savefd[0] = savefd(0);
172 		e->savefd[1] = savefd(1);
173 		while (t->type == TPIPE) {
174 			openpipe(pv);
175 			/* stdout of curr */
176 			ksh_dup2(pv[1], 1, false);
177 			/**
178 			 * Let exchild() close pv[0] in child
179 			 * (if this isn't done, commands like
180 			 *	(: ; cat /etc/termcap) | sleep 1
181 			 * will hang forever).
182 			 */
183 			exchild(t->left, flags | XPIPEO | XCCLOSE,
184 			    NULL, pv[0]);
185 			/* stdin of next */
186 			ksh_dup2(pv[0], 0, false);
187 			closepipe(pv);
188 			flags |= XPIPEI;
189 			t = t->right;
190 		}
191 		/* stdout of last */
192 		restfd(1, e->savefd[1]);
193 		/* no need to re-restore this */
194 		e->savefd[1] = 0;
195 		/* Let exchild() close 0 in parent, after fork, before wait */
196 		i = exchild(t, flags | XPCLOSE | XPIPEST, xerrok, 0);
197 		if (!(flags&XBGND) && !(flags&XXCOM))
198 			rv = i;
199 		break;
200 
201 	case TLIST:
202 		while (t->type == TLIST) {
203 			execute(t->left, flags & XERROK, NULL);
204 			t = t->right;
205 		}
206 		rv = execute(t, flags & XERROK, xerrok);
207 		break;
208 
209 	case TCOPROC: {
210 #ifndef MKSH_NOPROSPECTOFWORK
211 		sigset_t omask;
212 
213 		/*
214 		 * Block sigchild as we are using things changed in the
215 		 * signal handler
216 		 */
217 		sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
218 		e->type = E_ERRH;
219 		if ((i = kshsetjmp(e->jbuf))) {
220 			sigprocmask(SIG_SETMASK, &omask, NULL);
221 			quitenv(NULL);
222 			unwind(i);
223 			/* NOTREACHED */
224 		}
225 #endif
226 		/* Already have a (live) co-process? */
227 		if (coproc.job && coproc.write >= 0)
228 			errorf("coprocess already exists");
229 
230 		/* Can we re-use the existing co-process pipe? */
231 		coproc_cleanup(true);
232 
233 		/* do this before opening pipes, in case these fail */
234 		e->savefd[0] = savefd(0);
235 		e->savefd[1] = savefd(1);
236 
237 		openpipe(pv);
238 		if (pv[0] != 0) {
239 			ksh_dup2(pv[0], 0, false);
240 			close(pv[0]);
241 		}
242 		coproc.write = pv[1];
243 		coproc.job = NULL;
244 
245 		if (coproc.readw >= 0)
246 			ksh_dup2(coproc.readw, 1, false);
247 		else {
248 			openpipe(pv);
249 			coproc.read = pv[0];
250 			ksh_dup2(pv[1], 1, false);
251 			/* closed before first read */
252 			coproc.readw = pv[1];
253 			coproc.njobs = 0;
254 			/* create new coprocess id */
255 			++coproc.id;
256 		}
257 #ifndef MKSH_NOPROSPECTOFWORK
258 		sigprocmask(SIG_SETMASK, &omask, NULL);
259 		/* no more need for error handler */
260 		e->type = E_EXEC;
261 #endif
262 
263 		/*
264 		 * exchild() closes coproc.* in child after fork,
265 		 * will also increment coproc.njobs when the
266 		 * job is actually created.
267 		 */
268 		flags &= ~XEXEC;
269 		exchild(t->left, flags | XBGND | XFORK | XCOPROC | XCCLOSE,
270 		    NULL, coproc.readw);
271 		break;
272 	}
273 
274 	case TASYNC:
275 		/*
276 		 * XXX non-optimal, I think - "(foo &)", forks for (),
277 		 * forks again for async... parent should optimise
278 		 * this to "foo &"...
279 		 */
280 		rv = execute(t->left, (flags&~XEXEC)|XBGND|XFORK, xerrok);
281 		break;
282 
283 	case TOR:
284 	case TAND:
285 		rv = execute(t->left, XERROK, NULL);
286 		if ((rv == 0) == (t->type == TAND))
287 			rv = execute(t->right, flags & XERROK, xerrok);
288 		else {
289 			flags |= XERROK;
290 			if (xerrok)
291 				*xerrok = 1;
292 		}
293 		break;
294 
295 	case TBANG:
296 		rv = !execute(t->right, XERROK, xerrok);
297 		flags |= XERROK;
298 		if (xerrok)
299 			*xerrok = 1;
300 		break;
301 
302 	case TDBRACKET: {
303 		Test_env te;
304 
305 		te.flags = TEF_DBRACKET;
306 		te.pos.wp = t->args;
307 		te.isa = dbteste_isa;
308 		te.getopnd = dbteste_getopnd;
309 		te.eval = test_eval;
310 		te.error = dbteste_error;
311 
312 		rv = test_parse(&te);
313 		break;
314 	}
315 
316 	case TFOR:
317 	case TSELECT: {
318 		volatile bool is_first = true;
319 
320 		ap = (t->vars == NULL) ? e->loc->argv + 1 :
321 		    (const char **)eval((const char **)t->vars,
322 		    DOBLANK | DOGLOB | DOTILDE);
323 		e->type = E_LOOP;
324 		while ((i = kshsetjmp(e->jbuf))) {
325 			if ((e->flags&EF_BRKCONT_PASS) ||
326 			    (i != LBREAK && i != LCONTIN)) {
327 				quitenv(NULL);
328 				unwind(i);
329 			} else if (i == LBREAK) {
330 				rv = 0;
331 				goto Break;
332 			}
333 		}
334 		/* in case of a continue */
335 		rv = 0;
336 		if (t->type == TFOR) {
337 			while (*ap != NULL) {
338 				setstr(global(t->str), *ap++, KSH_UNWIND_ERROR);
339 				rv = execute(t->left, flags & XERROK, xerrok);
340 			}
341 		} else {
342  do_TSELECT:
343 			if ((ccp = do_selectargs(ap, is_first))) {
344 				is_first = false;
345 				setstr(global(t->str), ccp, KSH_UNWIND_ERROR);
346 				execute(t->left, flags & XERROK, xerrok);
347 				goto do_TSELECT;
348 			}
349 			rv = 1;
350 		}
351 		break;
352 	}
353 
354 	case TWHILE:
355 	case TUNTIL:
356 		e->type = E_LOOP;
357 		while ((i = kshsetjmp(e->jbuf))) {
358 			if ((e->flags&EF_BRKCONT_PASS) ||
359 			    (i != LBREAK && i != LCONTIN)) {
360 				quitenv(NULL);
361 				unwind(i);
362 			} else if (i == LBREAK) {
363 				rv = 0;
364 				goto Break;
365 			}
366 		}
367 		/* in case of a continue */
368 		rv = 0;
369 		while ((execute(t->left, XERROK, NULL) == 0) ==
370 		    (t->type == TWHILE))
371 			rv = execute(t->right, flags & XERROK, xerrok);
372 		break;
373 
374 	case TIF:
375 	case TELIF:
376 		if (t->right == NULL)
377 			/* should be error */
378 			break;
379 		rv = execute(execute(t->left, XERROK, NULL) == 0 ?
380 		    t->right->left : t->right->right, flags & XERROK, xerrok);
381 		break;
382 
383 	case TCASE:
384 		i = 0;
385 		ccp = evalstr(t->str, DOTILDE | DOSCALAR);
386 		for (t = t->left; t != NULL && t->type == TPAT; t = t->right) {
387 			for (ap = (const char **)t->vars; *ap; ap++) {
388 				if (i || ((s = evalstr(*ap, DOTILDE|DOPAT)) &&
389 				    gmatchx(ccp, s, false))) {
390 					record_match(ccp);
391 					rv = execute(t->left, flags & XERROK,
392 					    xerrok);
393 					i = 0;
394 					switch (t->u.charflag) {
395 					case '&':
396 						i = 1;
397 						/* FALLTHROUGH */
398 					case '|':
399 						goto TCASE_next;
400 					}
401 					goto TCASE_out;
402 				}
403 			}
404 			i = 0;
405  TCASE_next:
406 			/* empty */;
407 		}
408  TCASE_out:
409 		break;
410 
411 	case TBRACE:
412 		rv = execute(t->left, flags & XERROK, xerrok);
413 		break;
414 
415 	case TFUNCT:
416 		rv = define(t->str, t);
417 		break;
418 
419 	case TTIME:
420 		/*
421 		 * Clear XEXEC so nested execute() call doesn't exit
422 		 * (allows "ls -l | time grep foo").
423 		 */
424 		rv = timex(t, flags & ~XEXEC, xerrok);
425 		break;
426 
427 	case TEXEC:
428 		/* an eval'd TCOM */
429 		up = makenv();
430 		restoresigs();
431 		cleanup_proc_env();
432 		{
433 			union mksh_ccphack cargs;
434 
435 			cargs.ro = t->args;
436 			execve(t->str, cargs.rw, up);
437 			rv = errno;
438 		}
439 		if (rv == ENOEXEC)
440 			scriptexec(t, (const char **)up);
441 		else
442 			errorf(Tf_sD_s, t->str, cstrerror(rv));
443 	}
444  Break:
445 	exstat = rv & 0xFF;
446 	if (vp_pipest->flag & INT_L) {
447 		unset(vp_pipest, 1);
448 		vp_pipest->flag = DEFINED | ISSET | INTEGER | RDONLY |
449 		    ARRAY | INT_U | INT_L;
450 		vp_pipest->val.i = rv;
451 	}
452 
453 	/* restores IO */
454 	quitenv(NULL);
455 	if ((flags&XEXEC))
456 		/* exit child */
457 		unwind(LEXIT);
458 	if (rv != 0 && !(flags & XERROK) &&
459 	    (xerrok == NULL || !*xerrok)) {
460 		if (Flag(FERREXIT) & 0x80) {
461 			/* inside eval */
462 			Flag(FERREXIT) = 0;
463 		} else {
464 			trapsig(ksh_SIGERR);
465 			if (Flag(FERREXIT))
466 				unwind(LERROR);
467 		}
468 	}
469 	return (rv);
470 }
471 
472 /*
473  * execute simple command
474  */
475 
476 static int
comexec(struct op * t,struct tbl * volatile tp,const char ** ap,volatile int flags,volatile int * xerrok)477 comexec(struct op *t, struct tbl * volatile tp, const char **ap,
478     volatile int flags, volatile int *xerrok)
479 {
480 	int i;
481 	volatile int rv = 0;
482 	const char *cp;
483 	const char **lastp;
484 	/* Must be static (XXX but why?) */
485 	static struct op texec;
486 	int type_flags;
487 	bool resetspec;
488 	int fcflags = FC_BI|FC_FUNC|FC_PATH;
489 	struct block *l_expand, *l_assign;
490 	int optc;
491 	const char *exec_argv0 = NULL;
492 	bool exec_clrenv = false;
493 
494 	/* snag the last argument for $_ */
495 	if (Flag(FTALKING) && *(lastp = ap)) {
496 		/*
497 		 * XXX not the same as AT&T ksh, which only seems to set $_
498 		 * after a newline (but not in functions/dot scripts, but in
499 		 * interactive and script) - perhaps save last arg here and
500 		 * set it in shell()?.
501 		 */
502 		while (*++lastp)
503 			;
504 		/* setstr() can't fail here */
505 		setstr(typeset("_", LOCAL, 0, INTEGER, 0), *--lastp,
506 		    KSH_RETURN_ERROR);
507 	}
508 
509 	/**
510 	 * Deal with the shell builtins builtin, exec and command since
511 	 * they can be followed by other commands. This must be done before
512 	 * we know if we should create a local block which must be done
513 	 * before we can do a path search (in case the assignments change
514 	 * PATH).
515 	 * Odd cases:
516 	 *	FOO=bar exec >/dev/null		FOO is kept but not exported
517 	 *	FOO=bar exec foobar		FOO is exported
518 	 *	FOO=bar command exec >/dev/null	FOO is neither kept nor exported
519 	 *	FOO=bar command			FOO is neither kept nor exported
520 	 *	PATH=... foobar			use new PATH in foobar search
521 	 */
522 	resetspec = false;
523 	while (tp && tp->type == CSHELL) {
524 		/* undo effects of command */
525 		fcflags = FC_BI|FC_FUNC|FC_PATH;
526 		if (tp->val.f == c_builtin) {
527 			if ((cp = *++ap) == NULL ||
528 			    (!strcmp(cp, "--") && (cp = *++ap) == NULL)) {
529 				tp = NULL;
530 				break;
531 			}
532 			if ((tp = findcom(cp, FC_BI)) == NULL)
533 				errorf(Tf_sD_sD_s, Tbuiltin, cp, Tnot_found);
534 			if (tp->type == CSHELL && (tp->flag & LOW_BI))
535 				break;
536 			continue;
537 		} else if (tp->val.f == c_exec) {
538 			if (ap[1] == NULL)
539 				break;
540 			ksh_getopt_reset(&builtin_opt, GF_ERROR);
541 			while ((optc = ksh_getopt(ap, &builtin_opt, "a:c")) != -1)
542 				switch (optc) {
543 				case 'a':
544 					exec_argv0 = builtin_opt.optarg;
545 					break;
546 				case 'c':
547 					exec_clrenv = true;
548 					/* ensure we can actually do this */
549 					resetspec = true;
550 					break;
551 				default:
552 					rv = 2;
553 					goto Leave;
554 				}
555 			ap += builtin_opt.optind;
556 			flags |= XEXEC;
557 		} else if (tp->val.f == c_command) {
558 			bool saw_p = false;
559 
560 			/*
561 			 * Ugly dealing with options in two places (here
562 			 * and in c_command(), but such is life)
563 			 */
564 			ksh_getopt_reset(&builtin_opt, 0);
565 			while ((optc = ksh_getopt(ap, &builtin_opt, ":p")) == 'p')
566 				saw_p = true;
567 			if (optc != -1)
568 				/* command -vV or something */
569 				break;
570 			/* don't look for functions */
571 			fcflags = FC_BI|FC_PATH;
572 			if (saw_p) {
573 				if (Flag(FRESTRICTED)) {
574 					warningf(true, Tf_sD_s,
575 					    "command -p", "restricted");
576 					rv = 1;
577 					goto Leave;
578 				}
579 				fcflags |= FC_DEFPATH;
580 			}
581 			ap += builtin_opt.optind;
582 			/*
583 			 * POSIX says special builtins lose their status
584 			 * if accessed using command.
585 			 */
586 			resetspec = true;
587 			if (!ap[0]) {
588 				/* ensure command with no args exits with 0 */
589 				subst_exstat = 0;
590 				break;
591 			}
592 		} else if (tp->flag & LOW_BI) {
593 			/* if we have any flags, do not use the builtin */
594 			if ((ap[1] && ap[1][0] == '-' && ap[1][1] != '\0' &&
595 			    /* argument, begins with -, is not - or -- */
596 			    (ap[1][1] != '-' || ap[1][2] != '\0')) ||
597 			    /* always prefer the external utility */
598 			    (tp->flag & LOWER_BI)) {
599 				struct tbl *ext_cmd;
600 
601 				ext_cmd = findcom(tp->name, FC_PATH | FC_FUNC);
602 				if (ext_cmd && (ext_cmd->type != CTALIAS ||
603 				    (ext_cmd->flag & ISSET)))
604 					tp = ext_cmd;
605 			}
606 			break;
607 		} else if (tp->val.f == c_trap) {
608 			t->u.evalflags &= ~DOTCOMEXEC;
609 			break;
610 		} else
611 			break;
612 		tp = findcom(ap[0], fcflags & (FC_BI|FC_FUNC));
613 	}
614 	if (t->u.evalflags & DOTCOMEXEC)
615 		flags |= XEXEC;
616 	l_expand = e->loc;
617 	if (!resetspec && (!ap[0] || (tp && (tp->flag & KEEPASN))))
618 		type_flags = 0;
619 	else {
620 		/* create new variable/function block */
621 		newblock();
622 		/* ksh functions don't keep assignments, POSIX functions do. */
623 		if (!resetspec && tp && tp->type == CFUNC &&
624 		    !(tp->flag & FKSH))
625 			type_flags = EXPORT;
626 		else
627 			type_flags = LOCAL|LOCAL_COPY|EXPORT;
628 	}
629 	l_assign = e->loc;
630 	if (exec_clrenv)
631 		l_assign->flags |= BF_STOPENV;
632 	if (Flag(FEXPORT))
633 		type_flags |= EXPORT;
634 	if (Flag(FXTRACE))
635 		change_xtrace(2, false);
636 	for (i = 0; t->vars[i]; i++) {
637 		/* do NOT lookup in the new var/fn block just created */
638 		e->loc = l_expand;
639 		cp = evalstr(t->vars[i], DOASNTILDE | DOSCALAR);
640 		e->loc = l_assign;
641 		if (Flag(FXTRACE)) {
642 			const char *ccp;
643 
644 			ccp = skip_varname(cp, true);
645 			if (*ccp == '+')
646 				++ccp;
647 			if (*ccp == '=')
648 				++ccp;
649 			shf_write(cp, ccp - cp, shl_xtrace);
650 			print_value_quoted(shl_xtrace, ccp);
651 			shf_putc(' ', shl_xtrace);
652 		}
653 		/* but assign in there as usual */
654 		typeset(cp, type_flags, 0, 0, 0);
655 	}
656 
657 	if (Flag(FXTRACE)) {
658 		change_xtrace(2, false);
659 		if (ap[rv = 0]) {
660  xtrace_ap_loop:
661 			print_value_quoted(shl_xtrace, ap[rv]);
662 			if (ap[++rv]) {
663 				shf_putc(' ', shl_xtrace);
664 				goto xtrace_ap_loop;
665 			}
666 		}
667 		change_xtrace(1, false);
668 	}
669 
670 	if ((cp = *ap) == NULL) {
671 		rv = subst_exstat;
672 		goto Leave;
673 	} else if (!tp) {
674 		if (Flag(FRESTRICTED) && mksh_vdirsep(cp)) {
675 			warningf(true, Tf_sD_s, cp, "restricted");
676 			rv = 1;
677 			goto Leave;
678 		}
679 		tp = findcom(cp, fcflags);
680 	}
681 
682 	switch (tp->type) {
683 
684 	/* shell built-in */
685 	case CSHELL:
686  do_call_builtin:
687 		rv = call_builtin(tp, (const char **)ap, null, resetspec);
688 		if (resetspec && tp->val.f == c_shift) {
689 			l_expand->argc = l_assign->argc;
690 			l_expand->argv = l_assign->argv;
691 		}
692 		break;
693 
694 	/* function call */
695 	case CFUNC: {
696 		volatile uint32_t old_inuse;
697 		const char * volatile old_kshname;
698 		volatile uint8_t old_flags[FNFLAGS];
699 
700 		if (!(tp->flag & ISSET)) {
701 			struct tbl *ftp;
702 
703 			if (!tp->u.fpath) {
704  fpath_error:
705 				rv = (tp->u2.errnov == ENOENT) ? 127 : 126;
706 				warningf(true, Tf_sD_s_sD_s, cp,
707 				    Tcant_find, Tfile_fd,
708 				    cstrerror(tp->u2.errnov));
709 				break;
710 			}
711 			errno = 0;
712 			if (include(tp->u.fpath, 0, NULL, false) < 0 ||
713 			    !(ftp = findfunc(cp, hash(cp), false)) ||
714 			    !(ftp->flag & ISSET)) {
715 				rv = errno;
716 				if ((ftp = findcom(cp, FC_BI)) &&
717 				    (ftp->type == CSHELL) &&
718 				    (ftp->flag & LOW_BI)) {
719 					tp = ftp;
720 					goto do_call_builtin;
721 				}
722 				if (rv) {
723 					tp->u2.errnov = rv;
724 					cp = tp->u.fpath;
725 					goto fpath_error;
726 				}
727 				warningf(true, Tf_sD_s_s, cp,
728 				    "function not defined by", tp->u.fpath);
729 				rv = 127;
730 				break;
731 			}
732 			tp = ftp;
733 		}
734 
735 		/*
736 		 * ksh functions set $0 to function name, POSIX
737 		 * functions leave $0 unchanged.
738 		 */
739 		old_kshname = kshname;
740 		if (tp->flag & FKSH)
741 			kshname = ap[0];
742 		else
743 			ap[0] = kshname;
744 		e->loc->argv = ap;
745 		for (i = 0; *ap++ != NULL; i++)
746 			;
747 		e->loc->argc = i - 1;
748 		/*
749 		 * ksh-style functions handle getopts sanely,
750 		 * Bourne/POSIX functions are insane...
751 		 */
752 		if (tp->flag & FKSH) {
753 			e->loc->flags |= BF_DOGETOPTS;
754 			e->loc->getopts_state = user_opt;
755 			getopts_reset(1);
756 		}
757 
758 		for (type_flags = 0; type_flags < FNFLAGS; ++type_flags)
759 			old_flags[type_flags] = shell_flags[type_flags];
760 		change_xtrace((Flag(FXTRACEREC) ? Flag(FXTRACE) : 0) |
761 		    ((tp->flag & TRACE) ? 1 : 0), false);
762 		old_inuse = tp->flag & FINUSE;
763 		tp->flag |= FINUSE;
764 
765 		e->type = E_FUNC;
766 		if (!(i = kshsetjmp(e->jbuf))) {
767 			execute(tp->val.t, flags & XERROK, NULL);
768 			i = LRETURN;
769 		}
770 
771 		kshname = old_kshname;
772 		change_xtrace(old_flags[(int)FXTRACE], false);
773 #ifndef MKSH_LEGACY_MODE
774 		if (tp->flag & FKSH) {
775 			/* Korn style functions restore Flags on return */
776 			old_flags[(int)FXTRACE] = Flag(FXTRACE);
777 			for (type_flags = 0; type_flags < FNFLAGS; ++type_flags)
778 				shell_flags[type_flags] = old_flags[type_flags];
779 		}
780 #endif
781 		tp->flag = (tp->flag & ~FINUSE) | old_inuse;
782 
783 		/*
784 		 * Were we deleted while executing? If so, free the
785 		 * execution tree.
786 		 */
787 		if ((tp->flag & (FDELETE|FINUSE)) == FDELETE) {
788 			if (tp->flag & ALLOC) {
789 				tp->flag &= ~ALLOC;
790 				tfree(tp->val.t, tp->areap);
791 			}
792 			tp->flag = 0;
793 		}
794 		switch (i) {
795 		case LRETURN:
796 		case LERROR:
797 			rv = exstat & 0xFF;
798 			break;
799 		case LINTR:
800 		case LEXIT:
801 		case LLEAVE:
802 		case LSHELL:
803 			quitenv(NULL);
804 			unwind(i);
805 			/* NOTREACHED */
806 		default:
807 			quitenv(NULL);
808 			internal_errorf(Tunexpected_type, Tunwind, Tfunction, i);
809 		}
810 		break;
811 	}
812 
813 	/* executable command */
814 	case CEXEC:
815 	/* tracked alias */
816 	case CTALIAS:
817 		if (!(tp->flag&ISSET)) {
818 			if (tp->u2.errnov == ENOENT) {
819 				rv = 127;
820 				warningf(true, Tf_sD_s, cp, Tnot_found);
821 			} else {
822 				rv = 126;
823 				warningf(true, Tf_sD_sD_s, cp, "can't execute",
824 				    cstrerror(tp->u2.errnov));
825 			}
826 			break;
827 		}
828 
829 		/* set $_ to program's full path */
830 		/* setstr() can't fail here */
831 		setstr(typeset("_", LOCAL | EXPORT, 0, INTEGER, 0),
832 		    tp->val.s, KSH_RETURN_ERROR);
833 
834 		/* to fork, we set up a TEXEC node and call execute */
835 		texec.type = TEXEC;
836 		/* for vistree/dumptree */
837 		texec.left = t;
838 		texec.str = tp->val.s;
839 		texec.args = ap;
840 
841 		/* in this case we do not fork, of course */
842 		if (flags & XEXEC) {
843 			if (exec_argv0)
844 				texec.args[0] = exec_argv0;
845 			j_exit();
846 			if (!(flags & XBGND)
847 #ifndef MKSH_UNEMPLOYED
848 			    || Flag(FMONITOR)
849 #endif
850 			    ) {
851 				setexecsig(&sigtraps[SIGINT], SS_RESTORE_ORIG);
852 				setexecsig(&sigtraps[SIGQUIT], SS_RESTORE_ORIG);
853 			}
854 		}
855 
856 		rv = exchild(&texec, flags, xerrok, -1);
857 		break;
858 	}
859  Leave:
860 	if (flags & XEXEC) {
861 		exstat = rv & 0xFF;
862 		unwind(LLEAVE);
863 	}
864 	return (rv);
865 }
866 
867 static void
scriptexec(struct op * tp,const char ** ap)868 scriptexec(struct op *tp, const char **ap)
869 {
870 	const char *sh;
871 #ifndef MKSH_SMALL
872 	int fd;
873 	unsigned char buf[68];
874 #endif
875 	union mksh_ccphack args, cap;
876 
877 	sh = str_val(global(TEXECSHELL));
878 	if (sh && *sh)
879 		sh = search_path(sh, path, X_OK, NULL);
880 	if (!sh || !*sh)
881 		sh = MKSH_DEFAULT_EXECSHELL;
882 
883 	*tp->args-- = tp->str;
884 
885 #ifndef MKSH_SMALL
886 	if ((fd = binopen2(tp->str, O_RDONLY)) >= 0) {
887 		unsigned char *cp;
888 		unsigned short m;
889 		ssize_t n;
890 
891 #if defined(__OS2__) && defined(MKSH_WITH_TEXTMODE)
892 		setmode(fd, O_TEXT);
893 #endif
894 		/* read first couple of octets from file */
895 		n = read(fd, buf, sizeof(buf) - 1);
896 		close(fd);
897 		/* read error or short read? */
898 		if (n < 5)
899 			goto nomagic;
900 		/* terminate buffer */
901 		buf[n] = '\0';
902 
903 		/* skip UTF-8 Byte Order Mark, if present */
904 		cp = buf + (n = ((buf[0] == 0xEF) && (buf[1] == 0xBB) &&
905 		    (buf[2] == 0xBF)) ? 3 : 0);
906 
907 		/* scan for newline or NUL (end of buffer) */
908 		while (*cp && *cp != '\n')
909 			++cp;
910 		/* if the shebang line is longer than MAXINTERP, bail out */
911 		if (!*cp)
912 			goto noshebang;
913 		/* replace newline by NUL */
914 		*cp = '\0';
915 
916 		/* restore start of shebang position (buf+0 or buf+3) */
917 		cp = buf + n;
918 		/* bail out if no shebang magic found */
919 		if (cp[0] == '#' && cp[1] == '!')
920 			cp += 2;
921 #ifdef __OS2__
922 		else if (!strncmp(cp, Textproc, 7) &&
923 		    (cp[7] == ' ' || cp[7] == '\t'))
924 			cp += 8;
925 #endif
926 		else
927 			goto noshebang;
928 		/* skip whitespace before shell name */
929 		while (*cp == ' ' || *cp == '\t')
930 			++cp;
931 		/* just whitespace on the line? */
932 		if (*cp == '\0')
933 			goto noshebang;
934 		/* no, we actually found an interpreter name */
935 		sh = (char *)cp;
936 		/* look for end of shell/interpreter name */
937 		while (*cp != ' ' && *cp != '\t' && *cp != '\0')
938 			++cp;
939 		/* any arguments? */
940 		if (*cp) {
941 			*cp++ = '\0';
942 			/* skip spaces before arguments */
943 			while (*cp == ' ' || *cp == '\t')
944 				++cp;
945 			/* pass it all in ONE argument (historic reasons) */
946 			if (*cp)
947 				*tp->args-- = (char *)cp;
948 		}
949 #ifdef __OS2__
950 		/*
951 		 * Search shell/interpreter name without directory in PATH
952 		 * if specified path does not exist
953 		 */
954 		if (mksh_vdirsep(sh) && !search_path(sh, path, X_OK, NULL)) {
955 			cp = search_path(_getname(sh), path, X_OK, NULL);
956 			if (cp)
957 				sh = cp;
958 		}
959 #endif
960 		goto nomagic;
961  noshebang:
962 		m = buf[0] << 8 | buf[1];
963 		if (m == 0x7F45 && buf[2] == 'L' && buf[3] == 'F')
964 			errorf("%s: not executable: %d-bit ELF file", tp->str,
965 			    32 * buf[4]);
966 		if ((m == /* OMAGIC */ 0407) ||
967 		    (m == /* NMAGIC */ 0410) ||
968 		    (m == /* ZMAGIC */ 0413) ||
969 		    (m == /* QMAGIC */ 0314) ||
970 		    (m == /* ECOFF_I386 */ 0x4C01) ||
971 		    (m == /* ECOFF_M68K */ 0x0150 || m == 0x5001) ||
972 		    (m == /* ECOFF_SH */   0x0500 || m == 0x0005) ||
973 		    (m == /* bzip */ 0x425A) || (m == /* "MZ" */ 0x4D5A) ||
974 		    (m == /* "NE" */ 0x4E45) || (m == /* "LX" */ 0x4C58) ||
975 		    (m == /* ksh93 */ 0x0B13) || (m == /* LZIP */ 0x4C5A) ||
976 		    (m == /* xz */ 0xFD37 && buf[2] == 'z' && buf[3] == 'X' &&
977 		    buf[4] == 'Z') || (m == /* 7zip */ 0x377A) ||
978 		    (m == /* gzip */ 0x1F8B) || (m == /* .Z */ 0x1F9D))
979 			errorf("%s: not executable: magic %04X", tp->str, m);
980 #ifdef __OS2__
981 		cp = _getext(tp->str);
982 		if (cp && (!stricmp(cp, ".cmd") || !stricmp(cp, ".bat"))) {
983 			/* execute .cmd and .bat with OS2_SHELL, usually CMD.EXE */
984 			sh = str_val(global("OS2_SHELL"));
985 			*tp->args-- = "/c";
986 			/* convert slahes to backslashes */
987 			for (cp = tp->str; *cp; cp++) {
988 				if (*cp == '/')
989 					*cp = '\\';
990 			}
991 		}
992 #endif
993  nomagic:
994 		;
995 	}
996 #endif
997 	args.ro = tp->args;
998 	*args.ro = sh;
999 
1000 	cap.ro = ap;
1001 	execve(args.rw[0], args.rw, cap.rw);
1002 
1003 	/* report both the programme that was run and the bogus interpreter */
1004 	errorf(Tf_sD_sD_s, tp->str, sh, cstrerror(errno));
1005 }
1006 
1007 /* actual 'builtin' built-in utility call is handled in comexec() */
1008 int
c_builtin(const char ** wp)1009 c_builtin(const char **wp)
1010 {
1011 	return (call_builtin(get_builtin(*wp), wp, Tbuiltin, false));
1012 }
1013 
1014 struct tbl *
get_builtin(const char * s)1015 get_builtin(const char *s)
1016 {
1017 	return (s && *s ? ktsearch(&builtins, s, hash(s)) : NULL);
1018 }
1019 
1020 /*
1021  * Search function tables for a function. If create set, a table entry
1022  * is created if none is found.
1023  */
1024 struct tbl *
findfunc(const char * name,uint32_t h,bool create)1025 findfunc(const char *name, uint32_t h, bool create)
1026 {
1027 	struct block *l;
1028 	struct tbl *tp = NULL;
1029 
1030 	for (l = e->loc; l; l = l->next) {
1031 		tp = ktsearch(&l->funs, name, h);
1032 		if (tp)
1033 			break;
1034 		if (!l->next && create) {
1035 			tp = ktenter(&l->funs, name, h);
1036 			tp->flag = DEFINED;
1037 			tp->type = CFUNC;
1038 			tp->val.t = NULL;
1039 			break;
1040 		}
1041 	}
1042 	return (tp);
1043 }
1044 
1045 /*
1046  * define function. Returns 1 if function is being undefined (t == 0) and
1047  * function did not exist, returns 0 otherwise.
1048  */
1049 int
define(const char * name,struct op * t)1050 define(const char *name, struct op *t)
1051 {
1052 	uint32_t nhash;
1053 	struct tbl *tp;
1054 	bool was_set = false;
1055 
1056 	nhash = hash(name);
1057 
1058 	while (/* CONSTCOND */ 1) {
1059 		tp = findfunc(name, nhash, true);
1060 
1061 		if (tp->flag & ISSET)
1062 			was_set = true;
1063 		/*
1064 		 * If this function is currently being executed, we zap
1065 		 * this table entry so findfunc() won't see it
1066 		 */
1067 		if (tp->flag & FINUSE) {
1068 			tp->name[0] = '\0';
1069 			/* ensure it won't be found */
1070 			tp->flag &= ~DEFINED;
1071 			tp->flag |= FDELETE;
1072 		} else
1073 			break;
1074 	}
1075 
1076 	if (tp->flag & ALLOC) {
1077 		tp->flag &= ~(ISSET|ALLOC|FKSH);
1078 		tfree(tp->val.t, tp->areap);
1079 	}
1080 
1081 	if (t == NULL) {
1082 		/* undefine */
1083 		ktdelete(tp);
1084 		return (was_set ? 0 : 1);
1085 	}
1086 
1087 	tp->val.t = tcopy(t->left, tp->areap);
1088 	tp->flag |= (ISSET|ALLOC);
1089 	if (t->u.ksh_func)
1090 		tp->flag |= FKSH;
1091 
1092 	return (0);
1093 }
1094 
1095 /*
1096  * add builtin
1097  */
1098 const char *
builtin(const char * name,int (* func)(const char **))1099 builtin(const char *name, int (*func) (const char **))
1100 {
1101 	struct tbl *tp;
1102 	uint32_t flag = DEFINED;
1103 
1104 	/* see if any flags should be set for this builtin */
1105  flags_loop:
1106 	switch (*name) {
1107 	case '=':
1108 		/* command does variable assignment */
1109 		flag |= KEEPASN;
1110 		break;
1111 	case '*':
1112 		/* POSIX special builtin */
1113 		flag |= SPEC_BI;
1114 		break;
1115 	case '~':
1116 		/* external utility overrides built-in utility, always */
1117 		flag |= LOWER_BI;
1118 		/* FALLTHROUGH */
1119 	case '!':
1120 		/* external utility overrides built-in utility, with flags */
1121 		flag |= LOW_BI;
1122 		break;
1123 	case '-':
1124 		/* is declaration utility if argv[1] is one (POSIX: command) */
1125 		flag |= DECL_FWDR;
1126 		break;
1127 	case '^':
1128 		/* is declaration utility (POSIX: export, readonly) */
1129 		flag |= DECL_UTIL;
1130 		break;
1131 	default:
1132 		goto flags_seen;
1133 	}
1134 	++name;
1135 	goto flags_loop;
1136  flags_seen:
1137 
1138 	/* enter into the builtins hash table */
1139 	tp = ktenter(&builtins, name, hash(name));
1140 	tp->flag = flag;
1141 	tp->type = CSHELL;
1142 	tp->val.f = func;
1143 
1144 	/* return name, for direct builtin call check in main.c */
1145 	return (name);
1146 }
1147 
1148 /*
1149  * find command
1150  * either function, hashed command, or built-in (in that order)
1151  */
1152 struct tbl *
findcom(const char * name,int flags)1153 findcom(const char *name, int flags)
1154 {
1155 	static struct tbl temp;
1156 	uint32_t h = hash(name);
1157 	struct tbl *tp = NULL, *tbi;
1158 	/* insert if not found */
1159 	unsigned char insert = Flag(FTRACKALL);
1160 	/* for function autoloading */
1161 	char *fpath;
1162 	union mksh_cchack npath;
1163 
1164 	if (mksh_vdirsep(name)
1165 #ifdef MKSH_DOSPATH
1166 	    && (strcmp(name, T_builtin) != 0)
1167 #endif
1168 	    ) {
1169 		insert = 0;
1170 		/* prevent FPATH search below */
1171 		flags &= ~FC_FUNC;
1172 		goto Search;
1173 	}
1174 	tbi = (flags & FC_BI) ? ktsearch(&builtins, name, h) : NULL;
1175 	/*
1176 	 * POSIX says special builtins first, then functions, then
1177 	 * regular builtins, then search path...
1178 	 */
1179 	if ((flags & FC_SPECBI) && tbi && (tbi->flag & SPEC_BI))
1180 		tp = tbi;
1181 	if (!tp && (flags & FC_FUNC)) {
1182 		tp = findfunc(name, h, false);
1183 		if (tp && !(tp->flag & ISSET)) {
1184 			if ((fpath = str_val(global(TFPATH))) == null) {
1185 				tp->u.fpath = NULL;
1186 				tp->u2.errnov = ENOENT;
1187 			} else
1188 				tp->u.fpath = search_path(name, fpath, R_OK,
1189 				    &tp->u2.errnov);
1190 		}
1191 	}
1192 	if (!tp && (flags & FC_NORMBI) && tbi)
1193 		tp = tbi;
1194 	if (!tp && (flags & FC_PATH) && !(flags & FC_DEFPATH)) {
1195 		tp = ktsearch(&taliases, name, h);
1196 		if (tp && (tp->flag & ISSET) &&
1197 		    ksh_access(tp->val.s, X_OK) != 0) {
1198 			if (tp->flag & ALLOC) {
1199 				tp->flag &= ~ALLOC;
1200 				afree(tp->val.s, APERM);
1201 			}
1202 			tp->flag &= ~ISSET;
1203 		}
1204 	}
1205 
1206  Search:
1207 	if ((!tp || (tp->type == CTALIAS && !(tp->flag&ISSET))) &&
1208 	    (flags & FC_PATH)) {
1209 		if (!tp) {
1210 			if (insert && !(flags & FC_DEFPATH)) {
1211 				tp = ktenter(&taliases, name, h);
1212 				tp->type = CTALIAS;
1213 			} else {
1214 				tp = &temp;
1215 				tp->type = CEXEC;
1216 			}
1217 			/* make ~ISSET */
1218 			tp->flag = DEFINED;
1219 		}
1220 		npath.ro = search_path(name,
1221 		    (flags & FC_DEFPATH) ? def_path : path,
1222 		    X_OK, &tp->u2.errnov);
1223 		if (npath.ro) {
1224 			strdupx(tp->val.s, npath.ro, APERM);
1225 			if (npath.ro != name)
1226 				afree(npath.rw, ATEMP);
1227 			tp->flag |= ISSET|ALLOC;
1228 		} else if ((flags & FC_FUNC) &&
1229 		    (fpath = str_val(global(TFPATH))) != null &&
1230 		    (npath.ro = search_path(name, fpath, R_OK,
1231 		    &tp->u2.errnov)) != NULL) {
1232 			/*
1233 			 * An undocumented feature of AT&T ksh is that
1234 			 * it searches FPATH if a command is not found,
1235 			 * even if the command hasn't been set up as an
1236 			 * autoloaded function (ie, no typeset -uf).
1237 			 */
1238 			tp = &temp;
1239 			tp->type = CFUNC;
1240 			/* make ~ISSET */
1241 			tp->flag = DEFINED;
1242 			tp->u.fpath = npath.ro;
1243 		}
1244 	}
1245 	return (tp);
1246 }
1247 
1248 /*
1249  * flush executable commands with relative paths
1250  * (just relative or all?)
1251  */
1252 void
flushcom(bool all)1253 flushcom(bool all)
1254 {
1255 	struct tbl *tp;
1256 	struct tstate ts;
1257 
1258 	for (ktwalk(&ts, &taliases); (tp = ktnext(&ts)) != NULL; )
1259 		if ((tp->flag&ISSET) && (all || !mksh_abspath(tp->val.s))) {
1260 			if (tp->flag&ALLOC) {
1261 				tp->flag &= ~(ALLOC|ISSET);
1262 				afree(tp->val.s, APERM);
1263 			}
1264 			tp->flag &= ~ISSET;
1265 		}
1266 }
1267 
1268 /* check if path is something we want to find */
1269 int
search_access(const char * fn,int mode)1270 search_access(const char *fn, int mode)
1271 {
1272 	struct stat sb;
1273 
1274 	if (stat(fn, &sb) < 0)
1275 		/* file does not exist */
1276 		return (ENOENT);
1277 	/* LINTED use of access */
1278 	if (access(fn, mode) < 0) {
1279 		/* file exists, but we can't access it */
1280 		int eno;
1281 
1282 		eno = errno;
1283 		return (eno ? eno : EACCES);
1284 	}
1285 #ifdef __OS2__
1286 	/* treat all files as executable on OS/2 */
1287 	sb.st_mode |= S_IXUSR | S_IXGRP | S_IXOTH;
1288 #endif
1289 	if (mode == X_OK && (!S_ISREG(sb.st_mode) ||
1290 	    !(sb.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))))
1291 		/* access(2) may say root can execute everything */
1292 		return (S_ISDIR(sb.st_mode) ? EISDIR : EACCES);
1293 	return (0);
1294 }
1295 
1296 #ifdef __OS2__
1297 /* check if path is something we want to find, adding executable extensions */
1298 #define search_access(fn, mode)	access_ex((search_access), (fn), (mode))
1299 #else
1300 #define search_access(fn, mode)	(search_access)((fn), (mode))
1301 #endif
1302 
1303 /*
1304  * search for command with PATH
1305  */
1306 const char *
search_path(const char * name,const char * lpath,int mode,int * errnop)1307 search_path(const char *name, const char *lpath,
1308     /* R_OK or X_OK */
1309     int mode,
1310     /* set if candidate found, but not suitable */
1311     int *errnop)
1312 {
1313 	const char *sp, *p;
1314 	char *xp;
1315 	XString xs;
1316 	size_t namelen;
1317 	int ec = 0, ev;
1318 
1319 	if (mksh_vdirsep(name)) {
1320 		if ((ec = search_access(name, mode)) == 0) {
1321  search_path_ok:
1322 			if (errnop)
1323 				*errnop = 0;
1324 #ifndef __OS2__
1325 			return (name);
1326 #else
1327 			return (real_exec_name(name));
1328 #endif
1329 		}
1330 		goto search_path_err;
1331 	}
1332 
1333 	namelen = strlen(name) + 1;
1334 	Xinit(xs, xp, 128, ATEMP);
1335 
1336 	sp = lpath;
1337 	while (sp != NULL) {
1338 		xp = Xstring(xs, xp);
1339 		if (!(p = cstrchr(sp, MKSH_PATHSEPC)))
1340 			p = sp + strlen(sp);
1341 		if (p != sp) {
1342 			XcheckN(xs, xp, p - sp);
1343 			memcpy(xp, sp, p - sp);
1344 			xp += p - sp;
1345 #ifdef __OS2__
1346 			if (xp > Xstring(xs, xp) && mksh_cdirsep(xp[-1]))
1347 				xp--;
1348 #endif
1349 			*xp++ = '/';
1350 		}
1351 		sp = p;
1352 		XcheckN(xs, xp, namelen);
1353 		memcpy(xp, name, namelen);
1354 		if ((ev = search_access(Xstring(xs, xp), mode)) == 0) {
1355 			name = Xclose(xs, xp + namelen);
1356 			goto search_path_ok;
1357 		}
1358 		/* accumulate non-ENOENT errors only */
1359 		if (ev != ENOENT && ec == 0)
1360 			ec = ev;
1361 		if (*sp++ == '\0')
1362 			sp = NULL;
1363 	}
1364 	Xfree(xs, xp);
1365  search_path_err:
1366 	if (errnop)
1367 		*errnop = ec ? ec : ENOENT;
1368 	return (NULL);
1369 }
1370 
1371 static int
call_builtin(struct tbl * tp,const char ** wp,const char * where,bool resetspec)1372 call_builtin(struct tbl *tp, const char **wp, const char *where, bool resetspec)
1373 {
1374 	int rv;
1375 
1376 	if (!tp)
1377 		internal_errorf(Tf_sD_s, where, wp[0]);
1378 	builtin_argv0 = wp[0];
1379 	builtin_spec = tobool(!resetspec && (tp->flag & SPEC_BI));
1380 	shf_reopen(1, SHF_WR, shl_stdout);
1381 	shl_stdout_ok = true;
1382 	ksh_getopt_reset(&builtin_opt, GF_ERROR);
1383 	rv = (*tp->val.f)(wp);
1384 	shf_flush(shl_stdout);
1385 	shl_stdout_ok = false;
1386 	builtin_argv0 = NULL;
1387 	builtin_spec = false;
1388 	return (rv);
1389 }
1390 
1391 /*
1392  * set up redirection, saving old fds in e->savefd
1393  */
1394 static int
iosetup(struct ioword * iop,struct tbl * tp)1395 iosetup(struct ioword *iop, struct tbl *tp)
1396 {
1397 	int u = -1;
1398 	char *cp = iop->ioname;
1399 	int iotype = iop->ioflag & IOTYPE;
1400 	bool do_open = true, do_close = false, do_fstat = false;
1401 	int flags = 0;
1402 	struct ioword iotmp;
1403 	struct stat statb;
1404 
1405 	if (iotype != IOHERE)
1406 		cp = evalonestr(cp, DOTILDE|(Flag(FTALKING_I) ? DOGLOB : 0));
1407 
1408 	/* Used for tracing and error messages to print expanded cp */
1409 	iotmp = *iop;
1410 	iotmp.ioname = (iotype == IOHERE) ? NULL : cp;
1411 	iotmp.ioflag |= IONAMEXP;
1412 
1413 	if (Flag(FXTRACE)) {
1414 		change_xtrace(2, false);
1415 		fptreef(shl_xtrace, 0, Tft_R, &iotmp);
1416 		change_xtrace(1, false);
1417 	}
1418 
1419 	switch (iotype) {
1420 	case IOREAD:
1421 		flags = O_RDONLY;
1422 		break;
1423 
1424 	case IOCAT:
1425 		flags = O_WRONLY | O_APPEND | O_CREAT;
1426 		break;
1427 
1428 	case IOWRITE:
1429 		if (Flag(FNOCLOBBER) && !(iop->ioflag & IOCLOB)) {
1430 			/* >file under set -C */
1431 			if (stat(cp, &statb)) {
1432 				/* nonexistent file */
1433 				flags = O_WRONLY | O_CREAT | O_EXCL;
1434 			} else if (S_ISREG(statb.st_mode)) {
1435 				/* regular file, refuse clobbering */
1436 				goto clobber_refused;
1437 			} else {
1438 				/*
1439 				 * allow redirections to things
1440 				 * like /dev/null without error
1441 				 */
1442 				flags = O_WRONLY;
1443 				/* but check again after opening */
1444 				do_fstat = true;
1445 			}
1446 		} else {
1447 			/* >|file or set +C */
1448 			flags = O_WRONLY | O_CREAT | O_TRUNC;
1449 		}
1450 		break;
1451 
1452 	case IORDWR:
1453 		flags = O_RDWR | O_CREAT;
1454 		break;
1455 
1456 	case IOHERE:
1457 		do_open = false;
1458 		/* herein() returns -2 if error has been printed */
1459 		u = herein(iop, NULL);
1460 		/* cp may have wrong name */
1461 		break;
1462 
1463 	case IODUP: {
1464 		const char *emsg;
1465 
1466 		do_open = false;
1467 		if (ksh_isdash(cp)) {
1468 			/* prevent error return below */
1469 			u = 1009;
1470 			do_close = true;
1471 		} else if ((u = check_fd(cp,
1472 		    X_OK | ((iop->ioflag & IORDUP) ? R_OK : W_OK),
1473 		    &emsg)) < 0) {
1474 			char *sp;
1475 
1476 			warningf(true, Tf_sD_s,
1477 			    (sp = snptreef(NULL, 32, Tft_R, &iotmp)), emsg);
1478 			afree(sp, ATEMP);
1479 			return (-1);
1480 		}
1481 		if (u == (int)iop->unit)
1482 			/* "dup from" == "dup to" */
1483 			return (0);
1484 		break;
1485 	    }
1486 	}
1487 
1488 	if (do_open) {
1489 		if (Flag(FRESTRICTED) && (flags & O_CREAT)) {
1490 			warningf(true, Tf_sD_s, cp, "restricted");
1491 			return (-1);
1492 		}
1493 		u = binopen3(cp, flags, 0666);
1494 		if (do_fstat && u >= 0) {
1495 			/* prevent race conditions */
1496 			if (fstat(u, &statb) || S_ISREG(statb.st_mode)) {
1497 				close(u);
1498  clobber_refused:
1499 				u = -1;
1500 				errno = EEXIST;
1501 			}
1502 		}
1503 	}
1504 	if (u < 0) {
1505 		/* herein() may already have printed message */
1506 		if (u == -1) {
1507 			u = errno;
1508 			warningf(true, Tf_cant_ss_s,
1509 #if 0
1510 			    /* can't happen */
1511 			    iotype == IODUP ? "dup" :
1512 #endif
1513 			    (iotype == IOREAD || iotype == IOHERE) ?
1514 			    Topen : Tcreate, cp, cstrerror(u));
1515 		}
1516 		return (-1);
1517 	}
1518 	/* Do not save if it has already been redirected (i.e. "cat >x >y"). */
1519 	if (e->savefd[iop->unit] == 0) {
1520 		/* If these are the same, it means unit was previously closed */
1521 		if (u == (int)iop->unit)
1522 			e->savefd[iop->unit] = -1;
1523 		else
1524 			/*
1525 			 * c_exec() assumes e->savefd[fd] set for any
1526 			 * redirections. Ask savefd() not to close iop->unit;
1527 			 * this allows error messages to be seen if iop->unit
1528 			 * is 2; also means we can't lose the fd (eg, both
1529 			 * dup2 below and dup2 in restfd() failing).
1530 			 */
1531 			e->savefd[iop->unit] = savefd(iop->unit);
1532 	}
1533 
1534 	if (do_close)
1535 		close(iop->unit);
1536 	else if (u != (int)iop->unit) {
1537 		if (ksh_dup2(u, iop->unit, true) < 0) {
1538 			int eno;
1539 			char *sp;
1540 
1541 			eno = errno;
1542 			warningf(true, Tf_s_sD_s, Tredirection_dup,
1543 			    (sp = snptreef(NULL, 32, Tft_R, &iotmp)),
1544 			    cstrerror(eno));
1545 			afree(sp, ATEMP);
1546 			if (iotype != IODUP)
1547 				close(u);
1548 			return (-1);
1549 		}
1550 		if (iotype != IODUP)
1551 			close(u);
1552 		/*
1553 		 * Touching any co-process fd in an empty exec
1554 		 * causes the shell to close its copies
1555 		 */
1556 		else if (tp && tp->type == CSHELL && tp->val.f == c_exec) {
1557 			if (iop->ioflag & IORDUP)
1558 				/* possible exec <&p */
1559 				coproc_read_close(u);
1560 			else
1561 				/* possible exec >&p */
1562 				coproc_write_close(u);
1563 		}
1564 	}
1565 	if (u == 2)
1566 		/* Clear any write errors */
1567 		shf_reopen(2, SHF_WR, shl_out);
1568 	return (0);
1569 }
1570 
1571 /*
1572  * Process here documents by providing the content, either as
1573  * result (globally allocated) string or in a temp file; if
1574  * unquoted, the string is expanded first.
1575  */
1576 static int
hereinval(struct ioword * iop,int sub,char ** resbuf,struct shf * shf)1577 hereinval(struct ioword *iop, int sub, char **resbuf, struct shf *shf)
1578 {
1579 	const char * volatile ccp = iop->heredoc;
1580 	struct source *s, *osource;
1581 
1582 	osource = source;
1583 	newenv(E_ERRH);
1584 	if (kshsetjmp(e->jbuf)) {
1585 		source = osource;
1586 		quitenv(shf);
1587 		/* special to iosetup(): don't print error */
1588 		return (-2);
1589 	}
1590 	if (iop->ioflag & IOHERESTR) {
1591 		ccp = evalstr(iop->delim, DOHERESTR | DOSCALAR | DOHEREDOC);
1592 	} else if (sub) {
1593 		/* do substitutions on the content of heredoc */
1594 		s = pushs(SSTRING, ATEMP);
1595 		s->start = s->str = ccp;
1596 		source = s;
1597 		if (yylex(sub) != LWORD)
1598 			internal_errorf("herein: yylex");
1599 		source = osource;
1600 		ccp = evalstr(yylval.cp, DOSCALAR | DOHEREDOC);
1601 	}
1602 
1603 	if (resbuf == NULL)
1604 		shf_puts(ccp, shf);
1605 	else
1606 		strdupx(*resbuf, ccp, APERM);
1607 
1608 	quitenv(NULL);
1609 	return (0);
1610 }
1611 
1612 int
herein(struct ioword * iop,char ** resbuf)1613 herein(struct ioword *iop, char **resbuf)
1614 {
1615 	int fd = -1;
1616 	struct shf *shf;
1617 	struct temp *h;
1618 	int i;
1619 
1620 	/* lexer substitution flags */
1621 	i = (iop->ioflag & IOEVAL) ? (ONEWORD | HEREDOC) : 0;
1622 
1623 	/* skip all the fd setup if we just want the value */
1624 	if (resbuf != NULL)
1625 		return (hereinval(iop, i, resbuf, NULL));
1626 
1627 	/*
1628 	 * Create temp file to hold content (done before newenv
1629 	 * so temp doesn't get removed too soon).
1630 	 */
1631 	h = maketemp(ATEMP, TT_HEREDOC_EXP, &e->temps);
1632 	if (!(shf = h->shf) || (fd = binopen3(h->tffn, O_RDONLY, 0)) < 0) {
1633 		i = errno;
1634 		warningf(true, Tf_temp,
1635 		    !shf ? Tcreate : Topen, h->tffn, cstrerror(i));
1636 		if (shf)
1637 			shf_close(shf);
1638 		/* special to iosetup(): don't print error */
1639 		return (-2);
1640 	}
1641 
1642 	if (hereinval(iop, i, NULL, shf) == -2) {
1643 		close(fd);
1644 		/* special to iosetup(): don't print error */
1645 		return (-2);
1646 	}
1647 
1648 	if (shf_close(shf) == -1) {
1649 		i = errno;
1650 		close(fd);
1651 		warningf(true, Tf_temp,
1652 		    Twrite, h->tffn, cstrerror(i));
1653 		/* special to iosetup(): don't print error */
1654 		return (-2);
1655 	}
1656 
1657 	return (fd);
1658 }
1659 
1660 /*
1661  *	ksh special - the select command processing section
1662  *	print the args in column form - assuming that we can
1663  */
1664 static const char *
do_selectargs(const char ** ap,bool print_menu)1665 do_selectargs(const char **ap, bool print_menu)
1666 {
1667 	static const char *read_args[] = {
1668 		Tread, "-r", "REPLY", NULL
1669 	};
1670 	char *s;
1671 	int i, argct;
1672 
1673 	for (argct = 0; ap[argct]; argct++)
1674 		;
1675 	while (/* CONSTCOND */ 1) {
1676 		/*-
1677 		 * Menu is printed if
1678 		 *	- this is the first time around the select loop
1679 		 *	- the user enters a blank line
1680 		 *	- the REPLY parameter is empty
1681 		 */
1682 		if (print_menu || !*str_val(global("REPLY")))
1683 			pr_menu(ap);
1684 		shellf(Tf_s, str_val(global("PS3")));
1685 		if (call_builtin(findcom(Tread, FC_BI), read_args, Tselect,
1686 		    false))
1687 			return (NULL);
1688 		if (*(s = str_val(global("REPLY"))))
1689 			return ((getn(s, &i) && i >= 1 && i <= argct) ?
1690 			    ap[i - 1] : null);
1691 		print_menu = true;
1692 	}
1693 }
1694 
1695 struct select_menu_info {
1696 	const char * const *args;
1697 	int num_width;
1698 };
1699 
1700 /* format a single select menu item */
1701 static void
select_fmt_entry(char * buf,size_t buflen,unsigned int i,const void * arg)1702 select_fmt_entry(char *buf, size_t buflen, unsigned int i, const void *arg)
1703 {
1704 	const struct select_menu_info *smi =
1705 	    (const struct select_menu_info *)arg;
1706 
1707 	shf_snprintf(buf, buflen, "%*u) %s",
1708 	    smi->num_width, i + 1, smi->args[i]);
1709 }
1710 
1711 /*
1712  *	print a select style menu
1713  */
1714 void
pr_menu(const char * const * ap)1715 pr_menu(const char * const *ap)
1716 {
1717 	struct select_menu_info smi;
1718 	const char * const *pp;
1719 	size_t acols = 0, aocts = 0, i;
1720 	unsigned int n;
1721 	struct columnise_opts co;
1722 
1723 	/*
1724 	 * width/column calculations were done once and saved, but this
1725 	 * means select can't be used recursively so we re-calculate
1726 	 * each time (could save in a structure that is returned, but
1727 	 * it's probably not worth the bother)
1728 	 */
1729 
1730 	/*
1731 	 * get dimensions of the list
1732 	 */
1733 	for (n = 0, pp = ap; *pp; n++, pp++) {
1734 		i = strlen(*pp);
1735 		if (i > aocts)
1736 			aocts = i;
1737 		i = utf_mbswidth(*pp);
1738 		if (i > acols)
1739 			acols = i;
1740 	}
1741 
1742 	/*
1743 	 * we will print an index of the form "%d) " in front of
1744 	 * each entry, so get the maximum width of this
1745 	 */
1746 	for (i = n, smi.num_width = 1; i >= 10; i /= 10)
1747 		smi.num_width++;
1748 
1749 	smi.args = ap;
1750 	co.shf = shl_out;
1751 	co.linesep = '\n';
1752 	co.prefcol = co.do_last = true;
1753 	print_columns(&co, n, select_fmt_entry, (void *)&smi,
1754 	    smi.num_width + 2 + aocts, smi.num_width + 2 + acols);
1755 }
1756 
1757 static void
plain_fmt_entry(char * buf,size_t buflen,unsigned int i,const void * arg)1758 plain_fmt_entry(char *buf, size_t buflen, unsigned int i, const void *arg)
1759 {
1760 	strlcpy(buf, ((const char * const *)arg)[i], buflen);
1761 }
1762 
1763 void
pr_list(struct columnise_opts * cop,char * const * ap)1764 pr_list(struct columnise_opts *cop, char * const *ap)
1765 {
1766 	size_t acols = 0, aocts = 0, i;
1767 	unsigned int n;
1768 	char * const *pp;
1769 
1770 	for (n = 0, pp = ap; *pp; n++, pp++) {
1771 		i = strlen(*pp);
1772 		if (i > aocts)
1773 			aocts = i;
1774 		i = utf_mbswidth(*pp);
1775 		if (i > acols)
1776 			acols = i;
1777 	}
1778 
1779 	print_columns(cop, n, plain_fmt_entry, (const void *)ap,
1780 	    aocts, acols);
1781 }
1782 
1783 /*
1784  *	[[ ... ]] evaluation routines
1785  */
1786 
1787 /*
1788  * Test if the current token is a whatever. Accepts the current token if
1789  * it is. Returns 0 if it is not, non-zero if it is (in the case of
1790  * TM_UNOP and TM_BINOP, the returned value is a Test_op).
1791  */
1792 static Test_op
dbteste_isa(Test_env * te,Test_meta meta)1793 dbteste_isa(Test_env *te, Test_meta meta)
1794 {
1795 	Test_op ret = TO_NONOP;
1796 	bool uqword;
1797 	const char *p;
1798 
1799 	if (!*te->pos.wp)
1800 		return (meta == TM_END ? TO_NONNULL : TO_NONOP);
1801 
1802 	/* unquoted word? */
1803 	for (p = *te->pos.wp; *p == CHAR; p += 2)
1804 		;
1805 	uqword = *p == EOS;
1806 
1807 	if (meta == TM_UNOP || meta == TM_BINOP) {
1808 		if (uqword) {
1809 			/* longer than the longest operator */
1810 			char buf[8];
1811 			char *q = buf;
1812 
1813 			p = *te->pos.wp;
1814 			while (*p++ == CHAR &&
1815 			    (size_t)(q - buf) < sizeof(buf) - 1)
1816 				*q++ = *p++;
1817 			*q = '\0';
1818 			ret = test_isop(meta, buf);
1819 		}
1820 	} else if (meta == TM_END)
1821 		ret = TO_NONOP;
1822 	else
1823 		ret = (uqword && !strcmp(*te->pos.wp,
1824 		    dbtest_tokens[(int)meta])) ? TO_NONNULL : TO_NONOP;
1825 
1826 	/* Accept the token? */
1827 	if (ret != TO_NONOP)
1828 		te->pos.wp++;
1829 
1830 	return (ret);
1831 }
1832 
1833 static const char *
dbteste_getopnd(Test_env * te,Test_op op,bool do_eval)1834 dbteste_getopnd(Test_env *te, Test_op op, bool do_eval)
1835 {
1836 	const char *s = *te->pos.wp;
1837 	int flags = DOTILDE | DOSCALAR;
1838 
1839 	if (!s)
1840 		return (NULL);
1841 
1842 	te->pos.wp++;
1843 
1844 	if (!do_eval)
1845 		return (null);
1846 
1847 	if (op == TO_STEQL || op == TO_STNEQ)
1848 		flags |= DOPAT;
1849 
1850 	return (evalstr(s, flags));
1851 }
1852 
1853 static void
dbteste_error(Test_env * te,int offset,const char * msg)1854 dbteste_error(Test_env *te, int offset, const char *msg)
1855 {
1856 	te->flags |= TEF_ERROR;
1857 	internal_warningf("dbteste_error: %s (offset %d)", msg, offset);
1858 }
1859