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1 /*	$NetBSD: parser.c,v 1.57 2004/06/27 10:27:57 dsl Exp $	*/
2 
3 /*-
4  * Copyright (c) 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Kenneth Almquist.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)parser.c	8.7 (Berkeley) 5/16/95";
39 #else
40 __RCSID("$NetBSD: parser.c,v 1.57 2004/06/27 10:27:57 dsl Exp $");
41 #endif
42 #endif /* not lint */
43 
44 #include <stdlib.h>
45 
46 #include "shell.h"
47 #include "parser.h"
48 #include "nodes.h"
49 #include "expand.h"	/* defines rmescapes() */
50 #include "eval.h"	/* defines commandname */
51 #include "redir.h"	/* defines copyfd() */
52 #include "syntax.h"
53 #include "options.h"
54 #include "input.h"
55 #include "output.h"
56 #include "var.h"
57 #include "error.h"
58 #include "memalloc.h"
59 #include "mystring.h"
60 #include "alias.h"
61 #include "show.h"
62 #ifndef SMALL
63 #include "myhistedit.h"
64 #endif
65 
66 /*
67  * Shell command parser.
68  */
69 
70 #define EOFMARKLEN 79
71 
72 /* values returned by readtoken */
73 #include "token.h"
74 
75 #define OPENBRACE '{'
76 #define CLOSEBRACE '}'
77 
78 
79 struct heredoc {
80 	struct heredoc *next;	/* next here document in list */
81 	union node *here;		/* redirection node */
82 	char *eofmark;		/* string indicating end of input */
83 	int striptabs;		/* if set, strip leading tabs */
84 };
85 
86 
87 
88 static int noalias = 0;		/* when set, don't handle aliases */
89 struct heredoc *heredoclist;	/* list of here documents to read */
90 int parsebackquote;		/* nonzero if we are inside backquotes */
91 int doprompt;			/* if set, prompt the user */
92 int needprompt;			/* true if interactive and at start of line */
93 int lasttoken;			/* last token read */
94 MKINIT int tokpushback;		/* last token pushed back */
95 char *wordtext;			/* text of last word returned by readtoken */
96 MKINIT int checkkwd;            /* 1 == check for kwds, 2 == also eat newlines */
97 struct nodelist *backquotelist;
98 union node *redirnode;
99 struct heredoc *heredoc;
100 int quoteflag;			/* set if (part of) last token was quoted */
101 int startlinno;			/* line # where last token started */
102 
103 
104 STATIC union node *list(int);
105 STATIC union node *andor(void);
106 STATIC union node *pipeline(void);
107 STATIC union node *command(void);
108 STATIC union node *simplecmd(union node **, union node *);
109 STATIC union node *makename(void);
110 STATIC void parsefname(void);
111 STATIC void parseheredoc(void);
112 STATIC int peektoken(void);
113 STATIC int readtoken(void);
114 STATIC int xxreadtoken(void);
115 STATIC int readtoken1(int, char const *, char *, int);
116 STATIC int noexpand(char *);
117 STATIC void synexpect(int) __attribute__((__noreturn__));
118 STATIC void synerror(const char *) __attribute__((__noreturn__));
119 STATIC void setprompt(int);
120 
121 
122 /*
123  * Read and parse a command.  Returns NEOF on end of file.  (NULL is a
124  * valid parse tree indicating a blank line.)
125  */
126 
127 union node *
parsecmd(int interact)128 parsecmd(int interact)
129 {
130 	int t;
131 
132 	tokpushback = 0;
133 	doprompt = interact;
134 	if (doprompt)
135 		setprompt(1);
136 	else
137 		setprompt(0);
138 	needprompt = 0;
139 	t = readtoken();
140 	if (t == TEOF)
141 		return NEOF;
142 	if (t == TNL)
143 		return NULL;
144 	tokpushback++;
145 	return list(1);
146 }
147 
148 
149 STATIC union node *
list(int nlflag)150 list(int nlflag)
151 {
152 	union node *n1, *n2, *n3;
153 	int tok;
154 
155 	checkkwd = 2;
156 	if (nlflag == 0 && tokendlist[peektoken()])
157 		return NULL;
158 	n1 = NULL;
159 	for (;;) {
160 		n2 = andor();
161 		tok = readtoken();
162 		if (tok == TBACKGND) {
163 			if (n2->type == NCMD || n2->type == NPIPE) {
164 				n2->ncmd.backgnd = 1;
165 			} else if (n2->type == NREDIR) {
166 				n2->type = NBACKGND;
167 			} else {
168 				n3 = (union node *)stalloc(sizeof (struct nredir));
169 				n3->type = NBACKGND;
170 				n3->nredir.n = n2;
171 				n3->nredir.redirect = NULL;
172 				n2 = n3;
173 			}
174 		}
175 		if (n1 == NULL) {
176 			n1 = n2;
177 		}
178 		else {
179 			n3 = (union node *)stalloc(sizeof (struct nbinary));
180 			n3->type = NSEMI;
181 			n3->nbinary.ch1 = n1;
182 			n3->nbinary.ch2 = n2;
183 			n1 = n3;
184 		}
185 		switch (tok) {
186 		case TBACKGND:
187 		case TSEMI:
188 			tok = readtoken();
189 			/* fall through */
190 		case TNL:
191 			if (tok == TNL) {
192 				parseheredoc();
193 				if (nlflag)
194 					return n1;
195 			} else {
196 				tokpushback++;
197 			}
198 			checkkwd = 2;
199 			if (tokendlist[peektoken()])
200 				return n1;
201 			break;
202 		case TEOF:
203 			if (heredoclist)
204 				parseheredoc();
205 			else
206 				pungetc();		/* push back EOF on input */
207 			return n1;
208 		default:
209 			if (nlflag)
210 				synexpect(-1);
211 			tokpushback++;
212 			return n1;
213 		}
214 	}
215 }
216 
217 
218 
219 STATIC union node *
andor(void)220 andor(void)
221 {
222 	union node *n1, *n2, *n3;
223 	int t;
224 
225 	n1 = pipeline();
226 	for (;;) {
227 		if ((t = readtoken()) == TAND) {
228 			t = NAND;
229 		} else if (t == TOR) {
230 			t = NOR;
231 		} else {
232 			tokpushback++;
233 			return n1;
234 		}
235 		n2 = pipeline();
236 		n3 = (union node *)stalloc(sizeof (struct nbinary));
237 		n3->type = t;
238 		n3->nbinary.ch1 = n1;
239 		n3->nbinary.ch2 = n2;
240 		n1 = n3;
241 	}
242 }
243 
244 
245 
246 STATIC union node *
pipeline(void)247 pipeline(void)
248 {
249 	union node *n1, *n2, *pipenode;
250 	struct nodelist *lp, *prev;
251 	int negate;
252 
253 	negate = 0;
254 	TRACE(("pipeline: entered\n"));
255 	while (readtoken() == TNOT)
256 		negate = !negate;
257 	tokpushback++;
258 	n1 = command();
259 	if (readtoken() == TPIPE) {
260 		pipenode = (union node *)stalloc(sizeof (struct npipe));
261 		pipenode->type = NPIPE;
262 		pipenode->npipe.backgnd = 0;
263 		lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
264 		pipenode->npipe.cmdlist = lp;
265 		lp->n = n1;
266 		do {
267 			prev = lp;
268 			lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
269 			lp->n = command();
270 			prev->next = lp;
271 		} while (readtoken() == TPIPE);
272 		lp->next = NULL;
273 		n1 = pipenode;
274 	}
275 	tokpushback++;
276 	if (negate) {
277 		n2 = (union node *)stalloc(sizeof (struct nnot));
278 		n2->type = NNOT;
279 		n2->nnot.com = n1;
280 		return n2;
281 	} else
282 		return n1;
283 }
284 
285 
286 
287 STATIC union node *
command(void)288 command(void)
289 {
290 	union node *n1, *n2;
291 	union node *ap, **app;
292 	union node *cp, **cpp;
293 	union node *redir, **rpp;
294 	int t, negate = 0;
295 
296 	checkkwd = 2;
297 	redir = NULL;
298 	n1 = NULL;
299 	rpp = &redir;
300 
301 	/* Check for redirection which may precede command */
302 	while (readtoken() == TREDIR) {
303 		*rpp = n2 = redirnode;
304 		rpp = &n2->nfile.next;
305 		parsefname();
306 	}
307 	tokpushback++;
308 
309 	while (readtoken() == TNOT) {
310 		TRACE(("command: TNOT recognized\n"));
311 		negate = !negate;
312 	}
313 	tokpushback++;
314 
315 	switch (readtoken()) {
316 	case TIF:
317 		n1 = (union node *)stalloc(sizeof (struct nif));
318 		n1->type = NIF;
319 		n1->nif.test = list(0);
320 		if (readtoken() != TTHEN)
321 			synexpect(TTHEN);
322 		n1->nif.ifpart = list(0);
323 		n2 = n1;
324 		while (readtoken() == TELIF) {
325 			n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif));
326 			n2 = n2->nif.elsepart;
327 			n2->type = NIF;
328 			n2->nif.test = list(0);
329 			if (readtoken() != TTHEN)
330 				synexpect(TTHEN);
331 			n2->nif.ifpart = list(0);
332 		}
333 		if (lasttoken == TELSE)
334 			n2->nif.elsepart = list(0);
335 		else {
336 			n2->nif.elsepart = NULL;
337 			tokpushback++;
338 		}
339 		if (readtoken() != TFI)
340 			synexpect(TFI);
341 		checkkwd = 1;
342 		break;
343 	case TWHILE:
344 	case TUNTIL: {
345 		int got;
346 		n1 = (union node *)stalloc(sizeof (struct nbinary));
347 		n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL;
348 		n1->nbinary.ch1 = list(0);
349 		if ((got=readtoken()) != TDO) {
350 TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : ""));
351 			synexpect(TDO);
352 		}
353 		n1->nbinary.ch2 = list(0);
354 		if (readtoken() != TDONE)
355 			synexpect(TDONE);
356 		checkkwd = 1;
357 		break;
358 	}
359 	case TFOR:
360 		if (readtoken() != TWORD || quoteflag || ! goodname(wordtext))
361 			synerror("Bad for loop variable");
362 		n1 = (union node *)stalloc(sizeof (struct nfor));
363 		n1->type = NFOR;
364 		n1->nfor.var = wordtext;
365 		if (readtoken() == TWORD && ! quoteflag && equal(wordtext, "in")) {
366 			app = &ap;
367 			while (readtoken() == TWORD) {
368 				n2 = (union node *)stalloc(sizeof (struct narg));
369 				n2->type = NARG;
370 				n2->narg.text = wordtext;
371 				n2->narg.backquote = backquotelist;
372 				*app = n2;
373 				app = &n2->narg.next;
374 			}
375 			*app = NULL;
376 			n1->nfor.args = ap;
377 			if (lasttoken != TNL && lasttoken != TSEMI)
378 				synexpect(-1);
379 		} else {
380 			static char argvars[5] = {CTLVAR, VSNORMAL|VSQUOTE,
381 								   '@', '=', '\0'};
382 			n2 = (union node *)stalloc(sizeof (struct narg));
383 			n2->type = NARG;
384 			n2->narg.text = argvars;
385 			n2->narg.backquote = NULL;
386 			n2->narg.next = NULL;
387 			n1->nfor.args = n2;
388 			/*
389 			 * Newline or semicolon here is optional (but note
390 			 * that the original Bourne shell only allowed NL).
391 			 */
392 			if (lasttoken != TNL && lasttoken != TSEMI)
393 				tokpushback++;
394 		}
395 		checkkwd = 2;
396 		if ((t = readtoken()) == TDO)
397 			t = TDONE;
398 		else if (t == TBEGIN)
399 			t = TEND;
400 		else
401 			synexpect(-1);
402 		n1->nfor.body = list(0);
403 		if (readtoken() != t)
404 			synexpect(t);
405 		checkkwd = 1;
406 		break;
407 	case TCASE:
408 		n1 = (union node *)stalloc(sizeof (struct ncase));
409 		n1->type = NCASE;
410 		if (readtoken() != TWORD)
411 			synexpect(TWORD);
412 		n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg));
413 		n2->type = NARG;
414 		n2->narg.text = wordtext;
415 		n2->narg.backquote = backquotelist;
416 		n2->narg.next = NULL;
417 		while (readtoken() == TNL);
418 		if (lasttoken != TWORD || ! equal(wordtext, "in"))
419 			synerror("expecting \"in\"");
420 		cpp = &n1->ncase.cases;
421 		noalias = 1;
422 		checkkwd = 2, readtoken();
423 		do {
424 			*cpp = cp = (union node *)stalloc(sizeof (struct nclist));
425 			cp->type = NCLIST;
426 			app = &cp->nclist.pattern;
427 			for (;;) {
428 				*app = ap = (union node *)stalloc(sizeof (struct narg));
429 				ap->type = NARG;
430 				ap->narg.text = wordtext;
431 				ap->narg.backquote = backquotelist;
432 				if (checkkwd = 2, readtoken() != TPIPE)
433 					break;
434 				app = &ap->narg.next;
435 				readtoken();
436 			}
437 			ap->narg.next = NULL;
438 			noalias = 0;
439 			if (lasttoken != TRP) {
440 				synexpect(TRP);
441 			}
442 			cp->nclist.body = list(0);
443 
444 			checkkwd = 2;
445 			if ((t = readtoken()) != TESAC) {
446 				if (t != TENDCASE) {
447 					noalias = 0;
448 					synexpect(TENDCASE);
449 				} else {
450 					noalias = 1;
451 					checkkwd = 2;
452 					readtoken();
453 				}
454 			}
455 			cpp = &cp->nclist.next;
456 		} while(lasttoken != TESAC);
457 		noalias = 0;
458 		*cpp = NULL;
459 		checkkwd = 1;
460 		break;
461 	case TLP:
462 		n1 = (union node *)stalloc(sizeof (struct nredir));
463 		n1->type = NSUBSHELL;
464 		n1->nredir.n = list(0);
465 		n1->nredir.redirect = NULL;
466 		if (readtoken() != TRP)
467 			synexpect(TRP);
468 		checkkwd = 1;
469 		break;
470 	case TBEGIN:
471 		n1 = list(0);
472 		if (readtoken() != TEND)
473 			synexpect(TEND);
474 		checkkwd = 1;
475 		break;
476 	/* Handle an empty command like other simple commands.  */
477 	case TSEMI:
478 		/*
479 		 * An empty command before a ; doesn't make much sense, and
480 		 * should certainly be disallowed in the case of `if ;'.
481 		 */
482 		if (!redir)
483 			synexpect(-1);
484 	case TAND:
485 	case TOR:
486 	case TNL:
487 	case TEOF:
488 	case TWORD:
489 	case TRP:
490 		tokpushback++;
491 		n1 = simplecmd(rpp, redir);
492 		goto checkneg;
493 	default:
494 		synexpect(-1);
495 		/* NOTREACHED */
496 	}
497 
498 	/* Now check for redirection which may follow command */
499 	while (readtoken() == TREDIR) {
500 		*rpp = n2 = redirnode;
501 		rpp = &n2->nfile.next;
502 		parsefname();
503 	}
504 	tokpushback++;
505 	*rpp = NULL;
506 	if (redir) {
507 		if (n1->type != NSUBSHELL) {
508 			n2 = (union node *)stalloc(sizeof (struct nredir));
509 			n2->type = NREDIR;
510 			n2->nredir.n = n1;
511 			n1 = n2;
512 		}
513 		n1->nredir.redirect = redir;
514 	}
515 
516 checkneg:
517 	if (negate) {
518 		n2 = (union node *)stalloc(sizeof (struct nnot));
519 		n2->type = NNOT;
520 		n2->nnot.com = n1;
521 		return n2;
522 	}
523 	else
524 		return n1;
525 }
526 
527 
528 STATIC union node *
simplecmd(union node ** rpp,union node * redir)529 simplecmd(union node **rpp, union node *redir)
530 {
531 	union node *args, **app;
532 	union node **orig_rpp = rpp;
533 	union node *n = NULL, *n2;
534 	int negate = 0;
535 
536 	/* If we don't have any redirections already, then we must reset */
537 	/* rpp to be the address of the local redir variable.  */
538 	if (redir == 0)
539 		rpp = &redir;
540 
541 	args = NULL;
542 	app = &args;
543 	/*
544 	 * We save the incoming value, because we need this for shell
545 	 * functions.  There can not be a redirect or an argument between
546 	 * the function name and the open parenthesis.
547 	 */
548 	orig_rpp = rpp;
549 
550 	while (readtoken() == TNOT) {
551 		TRACE(("command: TNOT recognized\n"));
552 		negate = !negate;
553 	}
554 	tokpushback++;
555 
556 	for (;;) {
557 		if (readtoken() == TWORD) {
558 			n = (union node *)stalloc(sizeof (struct narg));
559 			n->type = NARG;
560 			n->narg.text = wordtext;
561 			n->narg.backquote = backquotelist;
562 			*app = n;
563 			app = &n->narg.next;
564 		} else if (lasttoken == TREDIR) {
565 			*rpp = n = redirnode;
566 			rpp = &n->nfile.next;
567 			parsefname();	/* read name of redirection file */
568 		} else if (lasttoken == TLP && app == &args->narg.next
569 					    && rpp == orig_rpp) {
570 			/* We have a function */
571 			if (readtoken() != TRP)
572 				synexpect(TRP);
573 #ifdef notdef
574 			if (! goodname(n->narg.text))
575 				synerror("Bad function name");
576 #endif
577 			n->type = NDEFUN;
578 			n->narg.next = command();
579 			goto checkneg;
580 		} else {
581 			tokpushback++;
582 			break;
583 		}
584 	}
585 	*app = NULL;
586 	*rpp = NULL;
587 	n = (union node *)stalloc(sizeof (struct ncmd));
588 	n->type = NCMD;
589 	n->ncmd.backgnd = 0;
590 	n->ncmd.args = args;
591 	n->ncmd.redirect = redir;
592 
593 checkneg:
594 	if (negate) {
595 		n2 = (union node *)stalloc(sizeof (struct nnot));
596 		n2->type = NNOT;
597 		n2->nnot.com = n;
598 		return n2;
599 	}
600 	else
601 		return n;
602 }
603 
604 STATIC union node *
makename(void)605 makename(void)
606 {
607 	union node *n;
608 
609 	n = (union node *)stalloc(sizeof (struct narg));
610 	n->type = NARG;
611 	n->narg.next = NULL;
612 	n->narg.text = wordtext;
613 	n->narg.backquote = backquotelist;
614 	return n;
615 }
616 
fixredir(union node * n,const char * text,int err)617 void fixredir(union node *n, const char *text, int err)
618 	{
619 	TRACE(("Fix redir %s %d\n", text, err));
620 	if (!err)
621 		n->ndup.vname = NULL;
622 
623 	if (is_digit(text[0]) && text[1] == '\0')
624 		n->ndup.dupfd = digit_val(text[0]);
625 	else if (text[0] == '-' && text[1] == '\0')
626 		n->ndup.dupfd = -1;
627 	else {
628 
629 		if (err)
630 			synerror("Bad fd number");
631 		else
632 			n->ndup.vname = makename();
633 	}
634 }
635 
636 
637 STATIC void
parsefname(void)638 parsefname(void)
639 {
640 	union node *n = redirnode;
641 
642 	if (readtoken() != TWORD)
643 		synexpect(-1);
644 	if (n->type == NHERE) {
645 		struct heredoc *here = heredoc;
646 		struct heredoc *p;
647 		int i;
648 
649 		if (quoteflag == 0)
650 			n->type = NXHERE;
651 		TRACE(("Here document %d\n", n->type));
652 		if (here->striptabs) {
653 			while (*wordtext == '\t')
654 				wordtext++;
655 		}
656 		if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN)
657 			synerror("Illegal eof marker for << redirection");
658 		rmescapes(wordtext);
659 		here->eofmark = wordtext;
660 		here->next = NULL;
661 		if (heredoclist == NULL)
662 			heredoclist = here;
663 		else {
664 			for (p = heredoclist ; p->next ; p = p->next);
665 			p->next = here;
666 		}
667 	} else if (n->type == NTOFD || n->type == NFROMFD) {
668 		fixredir(n, wordtext, 0);
669 	} else {
670 		n->nfile.fname = makename();
671 	}
672 }
673 
674 
675 /*
676  * Input any here documents.
677  */
678 
679 STATIC void
parseheredoc(void)680 parseheredoc(void)
681 {
682 	struct heredoc *here;
683 	union node *n;
684 
685 	while (heredoclist) {
686 		here = heredoclist;
687 		heredoclist = here->next;
688 		if (needprompt) {
689 			setprompt(2);
690 			needprompt = 0;
691 		}
692 		readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX,
693 				here->eofmark, here->striptabs);
694 		n = (union node *)stalloc(sizeof (struct narg));
695 		n->narg.type = NARG;
696 		n->narg.next = NULL;
697 		n->narg.text = wordtext;
698 		n->narg.backquote = backquotelist;
699 		here->here->nhere.doc = n;
700 	}
701 }
702 
703 STATIC int
peektoken(void)704 peektoken(void)
705 {
706 	int t;
707 
708 	t = readtoken();
709 	tokpushback++;
710 	return (t);
711 }
712 
713 STATIC int
readtoken(void)714 readtoken(void)
715 {
716 	int t;
717 	int savecheckkwd = checkkwd;
718 #ifdef DEBUG
719 	int alreadyseen = tokpushback;
720 #endif
721 	struct alias *ap;
722 
723 	top:
724 	t = xxreadtoken();
725 
726 	if (checkkwd) {
727 		/*
728 		 * eat newlines
729 		 */
730 		if (checkkwd == 2) {
731 			checkkwd = 0;
732 			while (t == TNL) {
733 				parseheredoc();
734 				t = xxreadtoken();
735 			}
736 		} else
737 			checkkwd = 0;
738 		/*
739 		 * check for keywords and aliases
740 		 */
741 		if (t == TWORD && !quoteflag)
742 		{
743 			const char *const *pp;
744 
745 			for (pp = parsekwd; *pp; pp++) {
746 				if (**pp == *wordtext && equal(*pp, wordtext))
747 				{
748 					lasttoken = t = pp -
749 					    parsekwd + KWDOFFSET;
750 					TRACE(("keyword %s recognized\n", tokname[t]));
751 					goto out;
752 				}
753 			}
754 			if(!noalias &&
755 			    (ap = lookupalias(wordtext, 1)) != NULL) {
756 				pushstring(ap->val, strlen(ap->val), ap);
757 				checkkwd = savecheckkwd;
758 				goto top;
759 			}
760 		}
761 out:
762 		checkkwd = (t == TNOT) ? savecheckkwd : 0;
763 	}
764 #ifdef DEBUG
765 	if (!alreadyseen)
766 	    TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
767 	else
768 	    TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
769 #endif
770 	return (t);
771 }
772 
773 
774 /*
775  * Read the next input token.
776  * If the token is a word, we set backquotelist to the list of cmds in
777  *	backquotes.  We set quoteflag to true if any part of the word was
778  *	quoted.
779  * If the token is TREDIR, then we set redirnode to a structure containing
780  *	the redirection.
781  * In all cases, the variable startlinno is set to the number of the line
782  *	on which the token starts.
783  *
784  * [Change comment:  here documents and internal procedures]
785  * [Readtoken shouldn't have any arguments.  Perhaps we should make the
786  *  word parsing code into a separate routine.  In this case, readtoken
787  *  doesn't need to have any internal procedures, but parseword does.
788  *  We could also make parseoperator in essence the main routine, and
789  *  have parseword (readtoken1?) handle both words and redirection.]
790  */
791 
792 #define RETURN(token)	return lasttoken = token
793 
794 STATIC int
xxreadtoken(void)795 xxreadtoken(void)
796 {
797 	int c;
798 
799 	if (tokpushback) {
800 		tokpushback = 0;
801 		return lasttoken;
802 	}
803 	if (needprompt) {
804 		setprompt(2);
805 		needprompt = 0;
806 	}
807 	startlinno = plinno;
808 	for (;;) {	/* until token or start of word found */
809 		c = pgetc_macro();
810 		if (c == ' ' || c == '\t')
811 			continue;		/* quick check for white space first */
812 		switch (c) {
813 		case ' ': case '\t':
814 			continue;
815 		case '#':
816 			while ((c = pgetc()) != '\n' && c != PEOF);
817 			pungetc();
818 			continue;
819 		case '\\':
820 			if (pgetc() == '\n') {
821 				startlinno = ++plinno;
822 				if (doprompt)
823 					setprompt(2);
824 				else
825 					setprompt(0);
826 				continue;
827 			}
828 			pungetc();
829 			goto breakloop;
830 		case '\n':
831 			plinno++;
832 			needprompt = doprompt;
833 			RETURN(TNL);
834 		case PEOF:
835 			RETURN(TEOF);
836 		case '&':
837 			if (pgetc() == '&')
838 				RETURN(TAND);
839 			pungetc();
840 			RETURN(TBACKGND);
841 		case '|':
842 			if (pgetc() == '|')
843 				RETURN(TOR);
844 			pungetc();
845 			RETURN(TPIPE);
846 		case ';':
847 			if (pgetc() == ';')
848 				RETURN(TENDCASE);
849 			pungetc();
850 			RETURN(TSEMI);
851 		case '(':
852 			RETURN(TLP);
853 		case ')':
854 			RETURN(TRP);
855 		default:
856 			goto breakloop;
857 		}
858 	}
859 breakloop:
860 	return readtoken1(c, BASESYNTAX, (char *)NULL, 0);
861 #undef RETURN
862 }
863 
864 
865 
866 /*
867  * If eofmark is NULL, read a word or a redirection symbol.  If eofmark
868  * is not NULL, read a here document.  In the latter case, eofmark is the
869  * word which marks the end of the document and striptabs is true if
870  * leading tabs should be stripped from the document.  The argument firstc
871  * is the first character of the input token or document.
872  *
873  * Because C does not have internal subroutines, I have simulated them
874  * using goto's to implement the subroutine linkage.  The following macros
875  * will run code that appears at the end of readtoken1.
876  */
877 
878 #define CHECKEND()	{goto checkend; checkend_return:;}
879 #define PARSEREDIR()	{goto parseredir; parseredir_return:;}
880 #define PARSESUB()	{goto parsesub; parsesub_return:;}
881 #define PARSEBACKQOLD()	{oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;}
882 #define PARSEBACKQNEW()	{oldstyle = 0; goto parsebackq; parsebackq_newreturn:;}
883 #define	PARSEARITH()	{goto parsearith; parsearith_return:;}
884 
885 /*
886  * Keep track of nested doublequotes in dblquote and doublequotep.
887  * We use dblquote for the first 32 levels, and we expand to a malloc'ed
888  * region for levels above that. Usually we never need to malloc.
889  * This code assumes that an int is 32 bits. We don't use uint32_t,
890  * because the rest of the code does not.
891  */
892 #define ISDBLQUOTE() ((varnest < 32) ? (dblquote & (1 << varnest)) : \
893     (dblquotep[(varnest / 32) - 1] & (1 << (varnest % 32))))
894 
895 #define SETDBLQUOTE() \
896     if (varnest < 32) \
897 	dblquote |= (1 << varnest); \
898     else \
899 	dblquotep[(varnest / 32) - 1] |= (1 << (varnest % 32))
900 
901 #define CLRDBLQUOTE() \
902     if (varnest < 32) \
903 	dblquote &= ~(1 << varnest); \
904     else \
905 	dblquotep[(varnest / 32) - 1] &= ~(1 << (varnest % 32))
906 
907 STATIC int
readtoken1(int firstc,char const * syntax,char * eofmark,int striptabs)908 readtoken1(int firstc, char const *syntax, char *eofmark, int striptabs)
909 {
910 	int c = firstc;
911 	char *out;
912 	int len;
913 	char line[EOFMARKLEN + 1];
914 	struct nodelist *bqlist;
915 	int quotef;
916 	int *dblquotep = NULL;
917 	size_t maxnest = 32;
918 	int dblquote;
919 	int varnest;	/* levels of variables expansion */
920 	int arinest;	/* levels of arithmetic expansion */
921 	int parenlevel;	/* levels of parens in arithmetic */
922 	int oldstyle;
923 	char const *prevsyntax = NULL;	/* syntax before arithmetic */
924 #if __GNUC__
925 	/* Avoid longjmp clobbering */
926 	(void) &maxnest;
927 	(void) &dblquotep;
928 	(void) &out;
929 	(void) &quotef;
930 	(void) &dblquote;
931 	(void) &varnest;
932 	(void) &arinest;
933 	(void) &parenlevel;
934 	(void) &oldstyle;
935 	(void) &prevsyntax;
936 	(void) &syntax;
937 #endif
938 
939 	startlinno = plinno;
940 	dblquote = 0;
941 	varnest = 0;
942 	if (syntax == DQSYNTAX) {
943 		SETDBLQUOTE();
944 	}
945 	quotef = 0;
946 	bqlist = NULL;
947 	arinest = 0;
948 	parenlevel = 0;
949 
950 	STARTSTACKSTR(out);
951 	loop: {	/* for each line, until end of word */
952 #if ATTY
953 		if (c == '\034' && doprompt
954 		 && attyset() && ! equal(termval(), "emacs")) {
955 			attyline();
956 			if (syntax == BASESYNTAX)
957 				return readtoken();
958 			c = pgetc();
959 			goto loop;
960 		}
961 #endif
962 		CHECKEND();	/* set c to PEOF if at end of here document */
963 		for (;;) {	/* until end of line or end of word */
964 			CHECKSTRSPACE(4, out);	/* permit 4 calls to USTPUTC */
965 			switch(syntax[c]) {
966 			case CNL:	/* '\n' */
967 				if (syntax == BASESYNTAX)
968 					goto endword;	/* exit outer loop */
969 				USTPUTC(c, out);
970 				plinno++;
971 				if (doprompt)
972 					setprompt(2);
973 				else
974 					setprompt(0);
975 				c = pgetc();
976 				goto loop;		/* continue outer loop */
977 			case CWORD:
978 				USTPUTC(c, out);
979 				break;
980 			case CCTL:
981 				if (eofmark == NULL || ISDBLQUOTE())
982 					USTPUTC(CTLESC, out);
983 				USTPUTC(c, out);
984 				break;
985 			case CBACK:	/* backslash */
986 				c = pgetc();
987 				if (c == PEOF) {
988 					USTPUTC('\\', out);
989 					pungetc();
990 					break;
991 				}
992 				if (c == '\n') {
993 					if (doprompt)
994 						setprompt(2);
995 					else
996 						setprompt(0);
997 					break;
998 				}
999 				quotef = 1;
1000 				if (ISDBLQUOTE() && c != '\\' &&
1001 				    c != '`' && c != '$' &&
1002 				    (c != '"' || eofmark != NULL))
1003 					USTPUTC('\\', out);
1004 				if (SQSYNTAX[c] == CCTL)
1005 					USTPUTC(CTLESC, out);
1006 				else if (eofmark == NULL) {
1007 					USTPUTC(CTLQUOTEMARK, out);
1008 					USTPUTC(c, out);
1009 					if (varnest != 0)
1010 						USTPUTC(CTLQUOTEEND, out);
1011 					break;
1012 				}
1013 				USTPUTC(c, out);
1014 				break;
1015 			case CSQUOTE:
1016 				if (syntax != SQSYNTAX) {
1017 					if (eofmark == NULL)
1018 						USTPUTC(CTLQUOTEMARK, out);
1019 					quotef = 1;
1020 					syntax = SQSYNTAX;
1021 					break;
1022 				}
1023 				if (eofmark != NULL && arinest == 0 &&
1024 				    varnest == 0) {
1025 					/* Ignore inside quoted here document */
1026 					USTPUTC(c, out);
1027 					break;
1028 				}
1029 				/* End of single quotes... */
1030 				if (arinest)
1031 					syntax = ARISYNTAX;
1032 				else {
1033 					syntax = BASESYNTAX;
1034 					if (varnest != 0)
1035 						USTPUTC(CTLQUOTEEND, out);
1036 				}
1037 				break;
1038 			case CDQUOTE:
1039 				if (eofmark != NULL && arinest == 0 &&
1040 				    varnest == 0) {
1041 					/* Ignore inside here document */
1042 					USTPUTC(c, out);
1043 					break;
1044 				}
1045 				quotef = 1;
1046 				if (arinest) {
1047 					if (ISDBLQUOTE()) {
1048 						syntax = ARISYNTAX;
1049 						CLRDBLQUOTE();
1050 					} else {
1051 						syntax = DQSYNTAX;
1052 						SETDBLQUOTE();
1053 						USTPUTC(CTLQUOTEMARK, out);
1054 					}
1055 					break;
1056 				}
1057 				if (eofmark != NULL)
1058 					break;
1059 				if (ISDBLQUOTE()) {
1060 					if (varnest != 0)
1061 						USTPUTC(CTLQUOTEEND, out);
1062 					syntax = BASESYNTAX;
1063 					CLRDBLQUOTE();
1064 				} else {
1065 					syntax = DQSYNTAX;
1066 					SETDBLQUOTE();
1067 					USTPUTC(CTLQUOTEMARK, out);
1068 				}
1069 				break;
1070 			case CVAR:	/* '$' */
1071 				PARSESUB();		/* parse substitution */
1072 				break;
1073 			case CENDVAR:	/* CLOSEBRACE */
1074 				if (varnest > 0 && !ISDBLQUOTE()) {
1075 					varnest--;
1076 					USTPUTC(CTLENDVAR, out);
1077 				} else {
1078 					USTPUTC(c, out);
1079 				}
1080 				break;
1081 			case CLP:	/* '(' in arithmetic */
1082 				parenlevel++;
1083 				USTPUTC(c, out);
1084 				break;
1085 			case CRP:	/* ')' in arithmetic */
1086 				if (parenlevel > 0) {
1087 					USTPUTC(c, out);
1088 					--parenlevel;
1089 				} else {
1090 					if (pgetc() == ')') {
1091 						if (--arinest == 0) {
1092 							USTPUTC(CTLENDARI, out);
1093 							syntax = prevsyntax;
1094 							if (syntax == DQSYNTAX)
1095 								SETDBLQUOTE();
1096 							else
1097 								CLRDBLQUOTE();
1098 						} else
1099 							USTPUTC(')', out);
1100 					} else {
1101 						/*
1102 						 * unbalanced parens
1103 						 *  (don't 2nd guess - no error)
1104 						 */
1105 						pungetc();
1106 						USTPUTC(')', out);
1107 					}
1108 				}
1109 				break;
1110 			case CBQUOTE:	/* '`' */
1111 				PARSEBACKQOLD();
1112 				break;
1113 			case CEOF:
1114 				goto endword;		/* exit outer loop */
1115 			default:
1116 				if (varnest == 0)
1117 					goto endword;	/* exit outer loop */
1118 				USTPUTC(c, out);
1119 			}
1120 			c = pgetc_macro();
1121 		}
1122 	}
1123 endword:
1124 	if (syntax == ARISYNTAX)
1125 		synerror("Missing '))'");
1126 	if (syntax != BASESYNTAX && ! parsebackquote && eofmark == NULL)
1127 		synerror("Unterminated quoted string");
1128 	if (varnest != 0) {
1129 		startlinno = plinno;
1130 		/* { */
1131 		synerror("Missing '}'");
1132 	}
1133 	USTPUTC('\0', out);
1134 	len = out - stackblock();
1135 	out = stackblock();
1136 	if (eofmark == NULL) {
1137 		if ((c == '>' || c == '<')
1138 		 && quotef == 0
1139 		 && len <= 2
1140 		 && (*out == '\0' || is_digit(*out))) {
1141 			PARSEREDIR();
1142 			return lasttoken = TREDIR;
1143 		} else {
1144 			pungetc();
1145 		}
1146 	}
1147 	quoteflag = quotef;
1148 	backquotelist = bqlist;
1149 	grabstackblock(len);
1150 	wordtext = out;
1151 	if (dblquotep != NULL)
1152 	    ckfree(dblquotep);
1153 	return lasttoken = TWORD;
1154 /* end of readtoken routine */
1155 
1156 
1157 
1158 /*
1159  * Check to see whether we are at the end of the here document.  When this
1160  * is called, c is set to the first character of the next input line.  If
1161  * we are at the end of the here document, this routine sets the c to PEOF.
1162  */
1163 
1164 checkend: {
1165 	if (eofmark) {
1166 		if (striptabs) {
1167 			while (c == '\t')
1168 				c = pgetc();
1169 		}
1170 		if (c == *eofmark) {
1171 			if (pfgets(line, sizeof line) != NULL) {
1172 				char *p, *q;
1173 
1174 				p = line;
1175 				for (q = eofmark + 1 ; *q && *p == *q ; p++, q++);
1176 				if (*p == '\n' && *q == '\0') {
1177 					c = PEOF;
1178 					plinno++;
1179 					needprompt = doprompt;
1180 				} else {
1181 					pushstring(line, strlen(line), NULL);
1182 				}
1183 			}
1184 		}
1185 	}
1186 	goto checkend_return;
1187 }
1188 
1189 
1190 /*
1191  * Parse a redirection operator.  The variable "out" points to a string
1192  * specifying the fd to be redirected.  The variable "c" contains the
1193  * first character of the redirection operator.
1194  */
1195 
1196 parseredir: {
1197 	char fd = *out;
1198 	union node *np;
1199 
1200 	np = (union node *)stalloc(sizeof (struct nfile));
1201 	if (c == '>') {
1202 		np->nfile.fd = 1;
1203 		c = pgetc();
1204 		if (c == '>')
1205 			np->type = NAPPEND;
1206 		else if (c == '|')
1207 			np->type = NCLOBBER;
1208 		else if (c == '&')
1209 			np->type = NTOFD;
1210 		else {
1211 			np->type = NTO;
1212 			pungetc();
1213 		}
1214 	} else {	/* c == '<' */
1215 		np->nfile.fd = 0;
1216 		switch (c = pgetc()) {
1217 		case '<':
1218 			if (sizeof (struct nfile) != sizeof (struct nhere)) {
1219 				np = (union node *)stalloc(sizeof (struct nhere));
1220 				np->nfile.fd = 0;
1221 			}
1222 			np->type = NHERE;
1223 			heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc));
1224 			heredoc->here = np;
1225 			if ((c = pgetc()) == '-') {
1226 				heredoc->striptabs = 1;
1227 			} else {
1228 				heredoc->striptabs = 0;
1229 				pungetc();
1230 			}
1231 			break;
1232 
1233 		case '&':
1234 			np->type = NFROMFD;
1235 			break;
1236 
1237 		case '>':
1238 			np->type = NFROMTO;
1239 			break;
1240 
1241 		default:
1242 			np->type = NFROM;
1243 			pungetc();
1244 			break;
1245 		}
1246 	}
1247 	if (fd != '\0')
1248 		np->nfile.fd = digit_val(fd);
1249 	redirnode = np;
1250 	goto parseredir_return;
1251 }
1252 
1253 
1254 /*
1255  * Parse a substitution.  At this point, we have read the dollar sign
1256  * and nothing else.
1257  */
1258 
1259 parsesub: {
1260 	int subtype;
1261 	int typeloc;
1262 	int flags;
1263 	char *p;
1264 	static const char types[] = "}-+?=";
1265 
1266 	c = pgetc();
1267 	if (c != '(' && c != OPENBRACE && !is_name(c) && !is_special(c)) {
1268 		USTPUTC('$', out);
1269 		pungetc();
1270 	} else if (c == '(') {	/* $(command) or $((arith)) */
1271 		if (pgetc() == '(') {
1272 			PARSEARITH();
1273 		} else {
1274 			pungetc();
1275 			PARSEBACKQNEW();
1276 		}
1277 	} else {
1278 		USTPUTC(CTLVAR, out);
1279 		typeloc = out - stackblock();
1280 		USTPUTC(VSNORMAL, out);
1281 		subtype = VSNORMAL;
1282 		if (c == OPENBRACE) {
1283 			c = pgetc();
1284 			if (c == '#') {
1285 				if ((c = pgetc()) == CLOSEBRACE)
1286 					c = '#';
1287 				else
1288 					subtype = VSLENGTH;
1289 			}
1290 			else
1291 				subtype = 0;
1292 		}
1293 		if (is_name(c)) {
1294 			do {
1295 				STPUTC(c, out);
1296 				c = pgetc();
1297 			} while (is_in_name(c));
1298 		} else if (is_digit(c)) {
1299 			do {
1300 				USTPUTC(c, out);
1301 				c = pgetc();
1302 			} while (is_digit(c));
1303 		}
1304 		else if (is_special(c)) {
1305 			USTPUTC(c, out);
1306 			c = pgetc();
1307 		}
1308 		else
1309 badsub:			synerror("Bad substitution");
1310 
1311 		STPUTC('=', out);
1312 		flags = 0;
1313 		if (subtype == 0) {
1314 			switch (c) {
1315 			case ':':
1316 				flags = VSNUL;
1317 				c = pgetc();
1318 				/*FALLTHROUGH*/
1319 			default:
1320 				p = strchr(types, c);
1321 				if (p == NULL)
1322 					goto badsub;
1323 				subtype = p - types + VSNORMAL;
1324 				break;
1325 			case '%':
1326 			case '#':
1327 				{
1328 					int cc = c;
1329 					subtype = c == '#' ? VSTRIMLEFT :
1330 							     VSTRIMRIGHT;
1331 					c = pgetc();
1332 					if (c == cc)
1333 						subtype++;
1334 					else
1335 						pungetc();
1336 					break;
1337 				}
1338 			}
1339 		} else {
1340 			pungetc();
1341 		}
1342 		if (ISDBLQUOTE() || arinest)
1343 			flags |= VSQUOTE;
1344 		*(stackblock() + typeloc) = subtype | flags;
1345 		if (subtype != VSNORMAL) {
1346 			varnest++;
1347 			if (varnest >= maxnest) {
1348 				dblquotep = ckrealloc(dblquotep, maxnest / 8);
1349 				dblquotep[(maxnest / 32) - 1] = 0;
1350 				maxnest += 32;
1351 			}
1352 		}
1353 	}
1354 	goto parsesub_return;
1355 }
1356 
1357 
1358 /*
1359  * Called to parse command substitutions.  Newstyle is set if the command
1360  * is enclosed inside $(...); nlpp is a pointer to the head of the linked
1361  * list of commands (passed by reference), and savelen is the number of
1362  * characters on the top of the stack which must be preserved.
1363  */
1364 
1365 parsebackq: {
1366 	struct nodelist **nlpp;
1367 	int savepbq;
1368 	union node *n;
1369 	char *volatile str;
1370 	struct jmploc jmploc;
1371 	struct jmploc *volatile savehandler;
1372 	int savelen;
1373 	int saveprompt;
1374 #ifdef __GNUC__
1375 	(void) &saveprompt;
1376 #endif
1377 
1378 	savepbq = parsebackquote;
1379 	if (setjmp(jmploc.loc)) {
1380 		if (str)
1381 			ckfree(str);
1382 		parsebackquote = 0;
1383 		handler = savehandler;
1384 		longjmp(handler->loc, 1);
1385 	}
1386 	INTOFF;
1387 	str = NULL;
1388 	savelen = out - stackblock();
1389 	if (savelen > 0) {
1390 		str = ckmalloc(savelen);
1391 		memcpy(str, stackblock(), savelen);
1392 	}
1393 	savehandler = handler;
1394 	handler = &jmploc;
1395 	INTON;
1396         if (oldstyle) {
1397                 /* We must read until the closing backquote, giving special
1398                    treatment to some slashes, and then push the string and
1399                    reread it as input, interpreting it normally.  */
1400                 char *pout;
1401                 int pc;
1402                 int psavelen;
1403                 char *pstr;
1404 
1405 
1406                 STARTSTACKSTR(pout);
1407 		for (;;) {
1408 			if (needprompt) {
1409 				setprompt(2);
1410 				needprompt = 0;
1411 			}
1412 			switch (pc = pgetc()) {
1413 			case '`':
1414 				goto done;
1415 
1416 			case '\\':
1417                                 if ((pc = pgetc()) == '\n') {
1418 					plinno++;
1419 					if (doprompt)
1420 						setprompt(2);
1421 					else
1422 						setprompt(0);
1423 					/*
1424 					 * If eating a newline, avoid putting
1425 					 * the newline into the new character
1426 					 * stream (via the STPUTC after the
1427 					 * switch).
1428 					 */
1429 					continue;
1430 				}
1431                                 if (pc != '\\' && pc != '`' && pc != '$'
1432                                     && (!ISDBLQUOTE() || pc != '"'))
1433                                         STPUTC('\\', pout);
1434 				break;
1435 
1436 			case '\n':
1437 				plinno++;
1438 				needprompt = doprompt;
1439 				break;
1440 
1441 			case PEOF:
1442 			        startlinno = plinno;
1443 				synerror("EOF in backquote substitution");
1444  				break;
1445 
1446 			default:
1447 				break;
1448 			}
1449 			STPUTC(pc, pout);
1450                 }
1451 done:
1452                 STPUTC('\0', pout);
1453                 psavelen = pout - stackblock();
1454                 if (psavelen > 0) {
1455 			pstr = grabstackstr(pout);
1456 			setinputstring(pstr, 1);
1457                 }
1458         }
1459 	nlpp = &bqlist;
1460 	while (*nlpp)
1461 		nlpp = &(*nlpp)->next;
1462 	*nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist));
1463 	(*nlpp)->next = NULL;
1464 	parsebackquote = oldstyle;
1465 
1466 	if (oldstyle) {
1467 		saveprompt = doprompt;
1468 		doprompt = 0;
1469 	}
1470 
1471 	n = list(0);
1472 
1473 	if (oldstyle)
1474 		doprompt = saveprompt;
1475 	else {
1476 		if (readtoken() != TRP)
1477 			synexpect(TRP);
1478 	}
1479 
1480 	(*nlpp)->n = n;
1481         if (oldstyle) {
1482 		/*
1483 		 * Start reading from old file again, ignoring any pushed back
1484 		 * tokens left from the backquote parsing
1485 		 */
1486                 popfile();
1487 		tokpushback = 0;
1488 	}
1489 	while (stackblocksize() <= savelen)
1490 		growstackblock();
1491 	STARTSTACKSTR(out);
1492 	if (str) {
1493 		memcpy(out, str, savelen);
1494 		STADJUST(savelen, out);
1495 		INTOFF;
1496 		ckfree(str);
1497 		str = NULL;
1498 		INTON;
1499 	}
1500 	parsebackquote = savepbq;
1501 	handler = savehandler;
1502 	if (arinest || ISDBLQUOTE())
1503 		USTPUTC(CTLBACKQ | CTLQUOTE, out);
1504 	else
1505 		USTPUTC(CTLBACKQ, out);
1506 	if (oldstyle)
1507 		goto parsebackq_oldreturn;
1508 	else
1509 		goto parsebackq_newreturn;
1510 }
1511 
1512 /*
1513  * Parse an arithmetic expansion (indicate start of one and set state)
1514  */
1515 parsearith: {
1516 
1517 	if (++arinest == 1) {
1518 		prevsyntax = syntax;
1519 		syntax = ARISYNTAX;
1520 		USTPUTC(CTLARI, out);
1521 		if (ISDBLQUOTE())
1522 			USTPUTC('"',out);
1523 		else
1524 			USTPUTC(' ',out);
1525 	} else {
1526 		/*
1527 		 * we collapse embedded arithmetic expansion to
1528 		 * parenthesis, which should be equivalent
1529 		 */
1530 		USTPUTC('(', out);
1531 	}
1532 	goto parsearith_return;
1533 }
1534 
1535 } /* end of readtoken */
1536 
1537 
1538 
1539 #ifdef mkinit
1540 RESET {
1541 	tokpushback = 0;
1542 	checkkwd = 0;
1543 }
1544 #endif
1545 
1546 /*
1547  * Returns true if the text contains nothing to expand (no dollar signs
1548  * or backquotes).
1549  */
1550 
1551 STATIC int
noexpand(char * text)1552 noexpand(char *text)
1553 {
1554 	char *p;
1555 	char c;
1556 
1557 	p = text;
1558 	while ((c = *p++) != '\0') {
1559 		if (c == CTLQUOTEMARK)
1560 			continue;
1561 		if (c == CTLESC)
1562 			p++;
1563 		else if (BASESYNTAX[(int)c] == CCTL)
1564 			return 0;
1565 	}
1566 	return 1;
1567 }
1568 
1569 
1570 /*
1571  * Return true if the argument is a legal variable name (a letter or
1572  * underscore followed by zero or more letters, underscores, and digits).
1573  */
1574 
1575 int
goodname(char * name)1576 goodname(char *name)
1577 	{
1578 	char *p;
1579 
1580 	p = name;
1581 	if (! is_name(*p))
1582 		return 0;
1583 	while (*++p) {
1584 		if (! is_in_name(*p))
1585 			return 0;
1586 	}
1587 	return 1;
1588 }
1589 
1590 
1591 /*
1592  * Called when an unexpected token is read during the parse.  The argument
1593  * is the token that is expected, or -1 if more than one type of token can
1594  * occur at this point.
1595  */
1596 
1597 STATIC void
synexpect(int token)1598 synexpect(int token)
1599 {
1600 	char msg[64];
1601 
1602 	if (token >= 0) {
1603 		fmtstr(msg, 64, "%s unexpected (expecting %s)",
1604 			tokname[lasttoken], tokname[token]);
1605 	} else {
1606 		fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]);
1607 	}
1608 	synerror(msg);
1609 	/* NOTREACHED */
1610 }
1611 
1612 
1613 STATIC void
synerror(const char * msg)1614 synerror(const char *msg)
1615 {
1616 	if (commandname)
1617 		outfmt(&errout, "%s: %d: ", commandname, startlinno);
1618 	outfmt(&errout, "Syntax error: %s\n", msg);
1619 	error((char *)NULL);
1620 	/* NOTREACHED */
1621 }
1622 
1623 STATIC void
setprompt(int which)1624 setprompt(int which)
1625 {
1626 	whichprompt = which;
1627 
1628 #ifdef WITH_HISTORY
1629 	if (!el)
1630 #endif
1631 #ifdef WITH_LINENOISE
1632         if (! in_interactive_mode() )
1633 #endif
1634 		out2str(getprompt(NULL));
1635 }
1636 
1637 /*
1638  * called by editline -- any expansions to the prompt
1639  *    should be added here.
1640  */
1641 const char *
getprompt(void * unused)1642 getprompt(void *unused)
1643 	{
1644 	switch (whichprompt) {
1645 	case 0:
1646 		return "";
1647 	case 1:
1648 		return ps1val();
1649 	case 2:
1650 		return ps2val();
1651 	default:
1652 		return "<internal prompt error>";
1653 	}
1654 }
1655