xref: /dflybsd-src/bin/sh/parser.c (revision 744c01d0dc2aa1481a40e5b0988d15691602f5c9)
1 /*-
2  * Copyright (c) 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Kenneth Almquist.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  * @(#)parser.c	8.7 (Berkeley) 5/16/95
37  * $FreeBSD: src/bin/sh/parser.c,v 1.58 2006/11/05 18:36:05 stefanf Exp $
38  * $DragonFly: src/bin/sh/parser.c,v 1.11 2007/01/14 17:29:58 pavalos Exp $
39  */
40 
41 #include <stdlib.h>
42 #include <unistd.h>
43 
44 #include "shell.h"
45 #include "parser.h"
46 #include "nodes.h"
47 #include "expand.h"	/* defines rmescapes() */
48 #include "syntax.h"
49 #include "options.h"
50 #include "input.h"
51 #include "output.h"
52 #include "var.h"
53 #include "error.h"
54 #include "memalloc.h"
55 #include "mystring.h"
56 #include "alias.h"
57 #include "show.h"
58 #include "eval.h"
59 #ifndef NO_HISTORY
60 #include "myhistedit.h"
61 #endif
62 
63 /*
64  * Shell command parser.
65  */
66 
67 #define	EOFMARKLEN	79
68 #define	PROMPTLEN	128
69 
70 /* values returned by readtoken */
71 #include "token.h"
72 
73 
74 
75 struct heredoc {
76 	struct heredoc *next;	/* next here document in list */
77 	union node *here;		/* redirection node */
78 	char *eofmark;		/* string indicating end of input */
79 	int striptabs;		/* if set, strip leading tabs */
80 };
81 
82 
83 
84 STATIC struct heredoc *heredoclist;	/* list of here documents to read */
85 STATIC int parsebackquote;	/* nonzero if we are inside backquotes */
86 STATIC int doprompt;		/* if set, prompt the user */
87 STATIC int needprompt;		/* true if interactive and at start of line */
88 STATIC int lasttoken;		/* last token read */
89 MKINIT int tokpushback;		/* last token pushed back */
90 STATIC char *wordtext;		/* text of last word returned by readtoken */
91 MKINIT int checkkwd;            /* 1 == check for kwds, 2 == also eat newlines */
92 STATIC struct nodelist *backquotelist;
93 STATIC union node *redirnode;
94 STATIC struct heredoc *heredoc;
95 STATIC int quoteflag;		/* set if (part of) last token was quoted */
96 STATIC int startlinno;		/* line # where last token started */
97 
98 /* XXX When 'noaliases' is set to one, no alias expansion takes place. */
99 static int noaliases = 0;
100 
101 
102 STATIC union node *list(int);
103 STATIC union node *andor(void);
104 STATIC union node *pipeline(void);
105 STATIC union node *command(void);
106 STATIC union node *simplecmd(union node **, union node *);
107 STATIC union node *makename(void);
108 STATIC void parsefname(void);
109 STATIC void parseheredoc(void);
110 STATIC int peektoken(void);
111 STATIC int readtoken(void);
112 STATIC int xxreadtoken(void);
113 STATIC int readtoken1(int, char const *, char *, int);
114 STATIC int noexpand(char *);
115 STATIC void synexpect(int);
116 STATIC void synerror(const char *);
117 STATIC void setprompt(int);
118 
119 
120 /*
121  * Read and parse a command.  Returns NEOF on end of file.  (NULL is a
122  * valid parse tree indicating a blank line.)
123  */
124 
125 union node *
126 parsecmd(int interact)
127 {
128 	int t;
129 
130 	tokpushback = 0;
131 	doprompt = interact;
132 	if (doprompt)
133 		setprompt(1);
134 	else
135 		setprompt(0);
136 	needprompt = 0;
137 	t = readtoken();
138 	if (t == TEOF)
139 		return NEOF;
140 	if (t == TNL)
141 		return NULL;
142 	tokpushback++;
143 	return list(1);
144 }
145 
146 
147 STATIC union node *
148 list(int nlflag)
149 {
150 	union node *n1, *n2, *n3;
151 	int tok;
152 
153 	checkkwd = 2;
154 	if (nlflag == 0 && tokendlist[peektoken()])
155 		return NULL;
156 	n1 = NULL;
157 	for (;;) {
158 		n2 = andor();
159 		tok = readtoken();
160 		if (tok == TBACKGND) {
161 			if (n2->type == NCMD || n2->type == NPIPE) {
162 				n2->ncmd.backgnd = 1;
163 			} else if (n2->type == NREDIR) {
164 				n2->type = NBACKGND;
165 			} else {
166 				n3 = (union node *)stalloc(sizeof (struct nredir));
167 				n3->type = NBACKGND;
168 				n3->nredir.n = n2;
169 				n3->nredir.redirect = NULL;
170 				n2 = n3;
171 			}
172 		}
173 		if (n1 == NULL) {
174 			n1 = n2;
175 		}
176 		else {
177 			n3 = (union node *)stalloc(sizeof (struct nbinary));
178 			n3->type = NSEMI;
179 			n3->nbinary.ch1 = n1;
180 			n3->nbinary.ch2 = n2;
181 			n1 = n3;
182 		}
183 		switch (tok) {
184 		case TBACKGND:
185 		case TSEMI:
186 			tok = readtoken();
187 			/* FALLTHROUGH */
188 		case TNL:
189 			if (tok == TNL) {
190 				parseheredoc();
191 				if (nlflag)
192 					return n1;
193 			} else {
194 				tokpushback++;
195 			}
196 			checkkwd = 2;
197 			if (tokendlist[peektoken()])
198 				return n1;
199 			break;
200 		case TEOF:
201 			if (heredoclist)
202 				parseheredoc();
203 			else
204 				pungetc();		/* push back EOF on input */
205 			return n1;
206 		default:
207 			if (nlflag)
208 				synexpect(-1);
209 			tokpushback++;
210 			return n1;
211 		}
212 	}
213 }
214 
215 
216 
217 STATIC union node *
218 andor(void)
219 {
220 	union node *n1, *n2, *n3;
221 	int t;
222 
223 	n1 = pipeline();
224 	for (;;) {
225 		if ((t = readtoken()) == TAND) {
226 			t = NAND;
227 		} else if (t == TOR) {
228 			t = NOR;
229 		} else {
230 			tokpushback++;
231 			return n1;
232 		}
233 		n2 = pipeline();
234 		n3 = (union node *)stalloc(sizeof (struct nbinary));
235 		n3->type = t;
236 		n3->nbinary.ch1 = n1;
237 		n3->nbinary.ch2 = n2;
238 		n1 = n3;
239 	}
240 }
241 
242 
243 
244 STATIC union node *
245 pipeline(void)
246 {
247 	union node *n1, *n2, *pipenode;
248 	struct nodelist *lp, *prev;
249 	int negate;
250 
251 	negate = 0;
252 	TRACE(("pipeline: entered\n"));
253 	while (readtoken() == TNOT)
254 		negate = !negate;
255 	tokpushback++;
256 	n1 = command();
257 	if (readtoken() == TPIPE) {
258 		pipenode = (union node *)stalloc(sizeof (struct npipe));
259 		pipenode->type = NPIPE;
260 		pipenode->npipe.backgnd = 0;
261 		lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
262 		pipenode->npipe.cmdlist = lp;
263 		lp->n = n1;
264 		do {
265 			prev = lp;
266 			lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
267 			lp->n = command();
268 			prev->next = lp;
269 		} while (readtoken() == TPIPE);
270 		lp->next = NULL;
271 		n1 = pipenode;
272 	}
273 	tokpushback++;
274 	if (negate) {
275 		n2 = (union node *)stalloc(sizeof (struct nnot));
276 		n2->type = NNOT;
277 		n2->nnot.com = n1;
278 		return n2;
279 	} else
280 		return n1;
281 }
282 
283 
284 
285 STATIC union node *
286 command(void)
287 {
288 	union node *n1, *n2;
289 	union node *ap, **app;
290 	union node *cp, **cpp;
291 	union node *redir, **rpp;
292 	int t, negate = 0;
293 
294 	checkkwd = 2;
295 	redir = NULL;
296 	n1 = NULL;
297 	rpp = &redir;
298 
299 	/* Check for redirection which may precede command */
300 	while (readtoken() == TREDIR) {
301 		*rpp = n2 = redirnode;
302 		rpp = &n2->nfile.next;
303 		parsefname();
304 	}
305 	tokpushback++;
306 
307 	while (readtoken() == TNOT) {
308 		TRACE(("command: TNOT recognized\n"));
309 		negate = !negate;
310 	}
311 	tokpushback++;
312 
313 	switch (readtoken()) {
314 	case TIF:
315 		n1 = (union node *)stalloc(sizeof (struct nif));
316 		n1->type = NIF;
317 		if ((n1->nif.test = list(0)) == NULL)
318 			synexpect(-1);
319 		if (readtoken() != TTHEN)
320 			synexpect(TTHEN);
321 		n1->nif.ifpart = list(0);
322 		n2 = n1;
323 		while (readtoken() == TELIF) {
324 			n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif));
325 			n2 = n2->nif.elsepart;
326 			n2->type = NIF;
327 			if ((n2->nif.test = list(0)) == NULL)
328 				synexpect(-1);
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 		if ((n1->nbinary.ch1 = list(0)) == NULL)
349 			synexpect(-1);
350 		if ((got=readtoken()) != TDO) {
351 TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : ""));
352 			synexpect(TDO);
353 		}
354 		n1->nbinary.ch2 = list(0);
355 		if (readtoken() != TDONE)
356 			synexpect(TDONE);
357 		checkkwd = 1;
358 		break;
359 	}
360 	case TFOR:
361 		if (readtoken() != TWORD || quoteflag || ! goodname(wordtext))
362 			synerror("Bad for loop variable");
363 		n1 = (union node *)stalloc(sizeof (struct nfor));
364 		n1->type = NFOR;
365 		n1->nfor.var = wordtext;
366 		if (readtoken() == TWORD && ! quoteflag && equal(wordtext, "in")) {
367 			app = &ap;
368 			while (readtoken() == TWORD) {
369 				n2 = (union node *)stalloc(sizeof (struct narg));
370 				n2->type = NARG;
371 				n2->narg.text = wordtext;
372 				n2->narg.backquote = backquotelist;
373 				*app = n2;
374 				app = &n2->narg.next;
375 			}
376 			*app = NULL;
377 			n1->nfor.args = ap;
378 			if (lasttoken != TNL && lasttoken != TSEMI)
379 				synexpect(-1);
380 		} else {
381 			static char argvars[5] = {
382 				CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0'
383 			};
384 			n2 = (union node *)stalloc(sizeof (struct narg));
385 			n2->type = NARG;
386 			n2->narg.text = argvars;
387 			n2->narg.backquote = NULL;
388 			n2->narg.next = NULL;
389 			n1->nfor.args = n2;
390 			/*
391 			 * Newline or semicolon here is optional (but note
392 			 * that the original Bourne shell only allowed NL).
393 			 */
394 			if (lasttoken != TNL && lasttoken != TSEMI)
395 				tokpushback++;
396 		}
397 		checkkwd = 2;
398 		if ((t = readtoken()) == TDO)
399 			t = TDONE;
400 		else if (t == TBEGIN)
401 			t = TEND;
402 		else
403 			synexpect(-1);
404 		n1->nfor.body = list(0);
405 		if (readtoken() != t)
406 			synexpect(t);
407 		checkkwd = 1;
408 		break;
409 	case TCASE:
410 		n1 = (union node *)stalloc(sizeof (struct ncase));
411 		n1->type = NCASE;
412 		if (readtoken() != TWORD)
413 			synexpect(TWORD);
414 		n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg));
415 		n2->type = NARG;
416 		n2->narg.text = wordtext;
417 		n2->narg.backquote = backquotelist;
418 		n2->narg.next = NULL;
419 		while (readtoken() == TNL);
420 		if (lasttoken != TWORD || ! equal(wordtext, "in"))
421 			synerror("expecting \"in\"");
422 		cpp = &n1->ncase.cases;
423 		noaliases = 1;	/* turn off alias expansion */
424 		checkkwd = 2, readtoken();
425 		while (lasttoken != TESAC) {
426 			*cpp = cp = (union node *)stalloc(sizeof (struct nclist));
427 			cp->type = NCLIST;
428 			app = &cp->nclist.pattern;
429 			if (lasttoken == TLP)
430 				readtoken();
431 			for (;;) {
432 				*app = ap = (union node *)stalloc(sizeof (struct narg));
433 				ap->type = NARG;
434 				ap->narg.text = wordtext;
435 				ap->narg.backquote = backquotelist;
436 				if (checkkwd = 2, readtoken() != TPIPE)
437 					break;
438 				app = &ap->narg.next;
439 				readtoken();
440 			}
441 			ap->narg.next = NULL;
442 			if (lasttoken != TRP)
443 				noaliases = 0, synexpect(TRP);
444 			cp->nclist.body = list(0);
445 
446 			checkkwd = 2;
447 			if ((t = readtoken()) != TESAC) {
448 				if (t != TENDCASE)
449 					noaliases = 0, synexpect(TENDCASE);
450 				else
451 					checkkwd = 2, readtoken();
452 			}
453 			cpp = &cp->nclist.next;
454 		}
455 		noaliases = 0;	/* reset alias expansion */
456 		*cpp = NULL;
457 		checkkwd = 1;
458 		break;
459 	case TLP:
460 		n1 = (union node *)stalloc(sizeof (struct nredir));
461 		n1->type = NSUBSHELL;
462 		n1->nredir.n = list(0);
463 		n1->nredir.redirect = NULL;
464 		if (readtoken() != TRP)
465 			synexpect(TRP);
466 		checkkwd = 1;
467 		break;
468 	case TBEGIN:
469 		n1 = list(0);
470 		if (readtoken() != TEND)
471 			synexpect(TEND);
472 		checkkwd = 1;
473 		break;
474 	/* Handle an empty command like other simple commands.  */
475 	case TSEMI:
476 	case TAND:
477 	case TOR:
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 TNL:
485 	case TEOF:
486 	case TWORD:
487 	case TRP:
488 		tokpushback++;
489 		n1 = simplecmd(rpp, redir);
490 		goto checkneg;
491 	default:
492 		synexpect(-1);
493 	}
494 
495 	/* Now check for redirection which may follow command */
496 	while (readtoken() == TREDIR) {
497 		*rpp = n2 = redirnode;
498 		rpp = &n2->nfile.next;
499 		parsefname();
500 	}
501 	tokpushback++;
502 	*rpp = NULL;
503 	if (redir) {
504 		if (n1->type != NSUBSHELL) {
505 			n2 = (union node *)stalloc(sizeof (struct nredir));
506 			n2->type = NREDIR;
507 			n2->nredir.n = n1;
508 			n1 = n2;
509 		}
510 		n1->nredir.redirect = redir;
511 	}
512 
513 checkneg:
514 	if (negate) {
515 		n2 = (union node *)stalloc(sizeof (struct nnot));
516 		n2->type = NNOT;
517 		n2->nnot.com = n1;
518 		return n2;
519 	}
520 	else
521 		return n1;
522 }
523 
524 
525 STATIC union node *
526 simplecmd(union node **rpp, union node *redir)
527 {
528 	union node *args, **app;
529 	union node **orig_rpp = rpp;
530 	union node *n = NULL, *n2;
531 	int negate = 0;
532 
533 	/* If we don't have any redirections already, then we must reset */
534 	/* rpp to be the address of the local redir variable.  */
535 	if (redir == 0)
536 		rpp = &redir;
537 
538 	args = NULL;
539 	app = &args;
540 	/*
541 	 * We save the incoming value, because we need this for shell
542 	 * functions.  There can not be a redirect or an argument between
543 	 * the function name and the open parenthesis.
544 	 */
545 	orig_rpp = rpp;
546 
547 	while (readtoken() == TNOT) {
548 		TRACE(("command: TNOT recognized\n"));
549 		negate = !negate;
550 	}
551 	tokpushback++;
552 
553 	for (;;) {
554 		if (readtoken() == TWORD) {
555 			n = (union node *)stalloc(sizeof (struct narg));
556 			n->type = NARG;
557 			n->narg.text = wordtext;
558 			n->narg.backquote = backquotelist;
559 			*app = n;
560 			app = &n->narg.next;
561 		} else if (lasttoken == TREDIR) {
562 			*rpp = n = redirnode;
563 			rpp = &n->nfile.next;
564 			parsefname();	/* read name of redirection file */
565 		} else if (lasttoken == TLP && app == &args->narg.next
566 					    && rpp == orig_rpp) {
567 			/* We have a function */
568 			if (readtoken() != TRP)
569 				synexpect(TRP);
570 #ifdef notdef
571 			if (! goodname(n->narg.text))
572 				synerror("Bad function name");
573 #endif
574 			n->type = NDEFUN;
575 			n->narg.next = command();
576 			goto checkneg;
577 		} else {
578 			tokpushback++;
579 			break;
580 		}
581 	}
582 	*app = NULL;
583 	*rpp = NULL;
584 	n = (union node *)stalloc(sizeof (struct ncmd));
585 	n->type = NCMD;
586 	n->ncmd.backgnd = 0;
587 	n->ncmd.args = args;
588 	n->ncmd.redirect = redir;
589 
590 checkneg:
591 	if (negate) {
592 		n2 = (union node *)stalloc(sizeof (struct nnot));
593 		n2->type = NNOT;
594 		n2->nnot.com = n;
595 		return n2;
596 	}
597 	else
598 		return n;
599 }
600 
601 STATIC union node *
602 makename(void)
603 {
604 	union node *n;
605 
606 	n = (union node *)stalloc(sizeof (struct narg));
607 	n->type = NARG;
608 	n->narg.next = NULL;
609 	n->narg.text = wordtext;
610 	n->narg.backquote = backquotelist;
611 	return n;
612 }
613 
614 void
615 fixredir(union node *n, const char *text, int err)
616 {
617 	TRACE(("Fix redir %s %d\n", text, err));
618 	if (!err)
619 		n->ndup.vname = NULL;
620 
621 	if (is_digit(text[0]) && text[1] == '\0')
622 		n->ndup.dupfd = digit_val(text[0]);
623 	else if (text[0] == '-' && text[1] == '\0')
624 		n->ndup.dupfd = -1;
625 	else {
626 
627 		if (err)
628 			synerror("Bad fd number");
629 		else
630 			n->ndup.vname = makename();
631 	}
632 }
633 
634 
635 STATIC void
636 parsefname(void)
637 {
638 	union node *n = redirnode;
639 
640 	if (readtoken() != TWORD)
641 		synexpect(-1);
642 	if (n->type == NHERE) {
643 		struct heredoc *here = heredoc;
644 		struct heredoc *p;
645 		int i;
646 
647 		if (quoteflag == 0)
648 			n->type = NXHERE;
649 		TRACE(("Here document %d\n", n->type));
650 		if (here->striptabs) {
651 			while (*wordtext == '\t')
652 				wordtext++;
653 		}
654 		if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN)
655 			synerror("Illegal eof marker for << redirection");
656 		rmescapes(wordtext);
657 		here->eofmark = wordtext;
658 		here->next = NULL;
659 		if (heredoclist == NULL)
660 			heredoclist = here;
661 		else {
662 			for (p = heredoclist ; p->next ; p = p->next);
663 			p->next = here;
664 		}
665 	} else if (n->type == NTOFD || n->type == NFROMFD) {
666 		fixredir(n, wordtext, 0);
667 	} else {
668 		n->nfile.fname = makename();
669 	}
670 }
671 
672 
673 /*
674  * Input any here documents.
675  */
676 
677 STATIC void
678 parseheredoc(void)
679 {
680 	struct heredoc *here;
681 	union node *n;
682 
683 	while (heredoclist) {
684 		here = heredoclist;
685 		heredoclist = here->next;
686 		if (needprompt) {
687 			setprompt(2);
688 			needprompt = 0;
689 		}
690 		readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX,
691 				here->eofmark, here->striptabs);
692 		n = (union node *)stalloc(sizeof (struct narg));
693 		n->narg.type = NARG;
694 		n->narg.next = NULL;
695 		n->narg.text = wordtext;
696 		n->narg.backquote = backquotelist;
697 		here->here->nhere.doc = n;
698 	}
699 }
700 
701 STATIC int
702 peektoken(void)
703 {
704 	int t;
705 
706 	t = readtoken();
707 	tokpushback++;
708 	return (t);
709 }
710 
711 STATIC int
712 readtoken(void)
713 {
714 	int t;
715 	int savecheckkwd = checkkwd;
716 	struct alias *ap;
717 #ifdef DEBUG
718 	int alreadyseen = tokpushback;
719 #endif
720 
721 	top:
722 	t = xxreadtoken();
723 
724 	if (checkkwd) {
725 		/*
726 		 * eat newlines
727 		 */
728 		if (checkkwd == 2) {
729 			checkkwd = 0;
730 			while (t == TNL) {
731 				parseheredoc();
732 				t = xxreadtoken();
733 			}
734 		} else
735 			checkkwd = 0;
736 		/*
737 		 * check for keywords and aliases
738 		 */
739 		if (t == TWORD && !quoteflag)
740 		{
741 			const char * const *pp;
742 
743 			for (pp = parsekwd; *pp; pp++) {
744 				if (**pp == *wordtext && equal(*pp, wordtext))
745 				{
746 					lasttoken = t = pp - parsekwd + KWDOFFSET;
747 					TRACE(("keyword %s recognized\n", tokname[t]));
748 					goto out;
749 				}
750 			}
751 			if (noaliases == 0 &&
752 			    (ap = lookupalias(wordtext, 1)) != NULL) {
753 				pushstring(ap->val, strlen(ap->val), ap);
754 				checkkwd = savecheckkwd;
755 				goto top;
756 			}
757 		}
758 out:
759 		checkkwd = (t == TNOT) ? savecheckkwd : 0;
760 	}
761 #ifdef DEBUG
762 	if (!alreadyseen)
763 	    TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
764 	else
765 	    TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
766 #endif
767 	return (t);
768 }
769 
770 
771 /*
772  * Read the next input token.
773  * If the token is a word, we set backquotelist to the list of cmds in
774  *	backquotes.  We set quoteflag to true if any part of the word was
775  *	quoted.
776  * If the token is TREDIR, then we set redirnode to a structure containing
777  *	the redirection.
778  * In all cases, the variable startlinno is set to the number of the line
779  *	on which the token starts.
780  *
781  * [Change comment:  here documents and internal procedures]
782  * [Readtoken shouldn't have any arguments.  Perhaps we should make the
783  *  word parsing code into a separate routine.  In this case, readtoken
784  *  doesn't need to have any internal procedures, but parseword does.
785  *  We could also make parseoperator in essence the main routine, and
786  *  have parseword (readtoken1?) handle both words and redirection.]
787  */
788 
789 #define RETURN(token)	return lasttoken = token
790 
791 STATIC int
792 xxreadtoken(void)
793 {
794 	int c;
795 
796 	if (tokpushback) {
797 		tokpushback = 0;
798 		return lasttoken;
799 	}
800 	if (needprompt) {
801 		setprompt(2);
802 		needprompt = 0;
803 	}
804 	startlinno = plinno;
805 	for (;;) {	/* until token or start of word found */
806 		c = pgetc_macro();
807 		if (c == ' ' || c == '\t')
808 			continue;		/* quick check for white space first */
809 		switch (c) {
810 		case ' ': case '\t':
811 			continue;
812 		case '#':
813 			while ((c = pgetc()) != '\n' && c != PEOF);
814 			pungetc();
815 			continue;
816 		case '\\':
817 			if (pgetc() == '\n') {
818 				startlinno = ++plinno;
819 				if (doprompt)
820 					setprompt(2);
821 				else
822 					setprompt(0);
823 				continue;
824 			}
825 			pungetc();
826 			goto breakloop;
827 		case '\n':
828 			plinno++;
829 			needprompt = doprompt;
830 			RETURN(TNL);
831 		case PEOF:
832 			RETURN(TEOF);
833 		case '&':
834 			if (pgetc() == '&')
835 				RETURN(TAND);
836 			pungetc();
837 			RETURN(TBACKGND);
838 		case '|':
839 			if (pgetc() == '|')
840 				RETURN(TOR);
841 			pungetc();
842 			RETURN(TPIPE);
843 		case ';':
844 			if (pgetc() == ';')
845 				RETURN(TENDCASE);
846 			pungetc();
847 			RETURN(TSEMI);
848 		case '(':
849 			RETURN(TLP);
850 		case ')':
851 			RETURN(TRP);
852 		default:
853 			goto breakloop;
854 		}
855 	}
856 breakloop:
857 	return readtoken1(c, BASESYNTAX, (char *)NULL, 0);
858 #undef RETURN
859 }
860 
861 
862 
863 /*
864  * If eofmark is NULL, read a word or a redirection symbol.  If eofmark
865  * is not NULL, read a here document.  In the latter case, eofmark is the
866  * word which marks the end of the document and striptabs is true if
867  * leading tabs should be stripped from the document.  The argument firstc
868  * is the first character of the input token or document.
869  *
870  * Because C does not have internal subroutines, I have simulated them
871  * using goto's to implement the subroutine linkage.  The following macros
872  * will run code that appears at the end of readtoken1.
873  */
874 
875 #define CHECKEND()	{goto checkend; checkend_return:;}
876 #define PARSEREDIR()	{goto parseredir; parseredir_return:;}
877 #define PARSESUB()	{goto parsesub; parsesub_return:;}
878 #define PARSEBACKQOLD()	{oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;}
879 #define PARSEBACKQNEW()	{oldstyle = 0; goto parsebackq; parsebackq_newreturn:;}
880 #define	PARSEARITH()	{goto parsearith; parsearith_return:;}
881 
882 STATIC int
883 readtoken1(int firstc, char const *syn, char *eofmark, int striptabs)
884 {
885 	int c = firstc;
886 	char const * volatile syntax = syn;
887 	char * volatile out;
888 	int len;
889 	char line[EOFMARKLEN + 1];
890 	struct nodelist *bqlist;
891 	volatile int quotef;
892 	volatile int dblquote;
893 	volatile int varnest;	/* levels of variables expansion */
894 	volatile int arinest;	/* levels of arithmetic expansion */
895 	volatile int parenlevel;	/* levels of parens in arithmetic */
896 	volatile int oldstyle;
897 	char const * volatile prevsyntax = NULL;	/* syntax before arithmetic */
898 	int synentry;
899 
900 	startlinno = plinno;
901 	dblquote = 0;
902 	if (syntax == DQSYNTAX)
903 		dblquote = 1;
904 	quotef = 0;
905 	bqlist = NULL;
906 	varnest = 0;
907 	arinest = 0;
908 	parenlevel = 0;
909 
910 	STARTSTACKSTR(out);
911 	loop: {	/* for each line, until end of word */
912 		CHECKEND();	/* set c to PEOF if at end of here document */
913 		for (;;) {	/* until end of line or end of word */
914 			CHECKSTRSPACE(3, out);	/* permit 3 calls to USTPUTC */
915 
916 			synentry = syntax[c];
917 
918 			switch(synentry) {
919 			case CNL:	/* '\n' */
920 				if (syntax == BASESYNTAX)
921 					goto endword;	/* exit outer loop */
922 				USTPUTC(c, out);
923 				plinno++;
924 				if (doprompt)
925 					setprompt(2);
926 				else
927 					setprompt(0);
928 				c = pgetc();
929 				goto loop;		/* continue outer loop */
930 			case CWORD:
931 				USTPUTC(c, out);
932 				break;
933 			case CCTL:
934 				if (eofmark == NULL || dblquote)
935 					USTPUTC(CTLESC, out);
936 				USTPUTC(c, out);
937 				break;
938 			case CBACK:	/* backslash */
939 				c = pgetc();
940 				if (c == PEOF) {
941 					USTPUTC('\\', out);
942 					pungetc();
943 				} else if (c == '\n') {
944 					plinno++;
945 					if (doprompt)
946 						setprompt(2);
947 					else
948 						setprompt(0);
949 				} else {
950 					if (dblquote && c != '\\' &&
951 					    c != '`' && c != '$' &&
952 					    (c != '"' || eofmark != NULL))
953 						USTPUTC('\\', out);
954 					if (SQSYNTAX[c] == CCTL)
955 						USTPUTC(CTLESC, out);
956 					else if (eofmark == NULL)
957 						USTPUTC(CTLQUOTEMARK, out);
958 					USTPUTC(c, out);
959 					quotef++;
960 				}
961 				break;
962 			case CSQUOTE:
963 				if (eofmark == NULL)
964 					USTPUTC(CTLQUOTEMARK, out);
965 				syntax = SQSYNTAX;
966 				break;
967 			case CDQUOTE:
968 				if (eofmark == NULL)
969 					USTPUTC(CTLQUOTEMARK, out);
970 				syntax = DQSYNTAX;
971 				dblquote = 1;
972 				break;
973 			case CENDQUOTE:
974 				if (eofmark != NULL && arinest == 0 &&
975 				    varnest == 0) {
976 					USTPUTC(c, out);
977 				} else {
978 					if (arinest) {
979 						syntax = ARISYNTAX;
980 						dblquote = 0;
981 					} else if (eofmark == NULL) {
982 						syntax = BASESYNTAX;
983 						dblquote = 0;
984 					}
985 					quotef++;
986 				}
987 				break;
988 			case CVAR:	/* '$' */
989 				PARSESUB();		/* parse substitution */
990 				break;
991 			case CENDVAR:	/* '}' */
992 				if (varnest > 0) {
993 					varnest--;
994 					USTPUTC(CTLENDVAR, out);
995 				} else {
996 					USTPUTC(c, out);
997 				}
998 				break;
999 			case CLP:	/* '(' in arithmetic */
1000 				parenlevel++;
1001 				USTPUTC(c, out);
1002 				break;
1003 			case CRP:	/* ')' in arithmetic */
1004 				if (parenlevel > 0) {
1005 					USTPUTC(c, out);
1006 					--parenlevel;
1007 				} else {
1008 					if (pgetc() == ')') {
1009 						if (--arinest == 0) {
1010 							USTPUTC(CTLENDARI, out);
1011 							syntax = prevsyntax;
1012 							if (syntax == DQSYNTAX)
1013 								dblquote = 1;
1014 							else
1015 								dblquote = 0;
1016 						} else
1017 							USTPUTC(')', out);
1018 					} else {
1019 						/*
1020 						 * unbalanced parens
1021 						 *  (don't 2nd guess - no error)
1022 						 */
1023 						pungetc();
1024 						USTPUTC(')', out);
1025 					}
1026 				}
1027 				break;
1028 			case CBQUOTE:	/* '`' */
1029 				PARSEBACKQOLD();
1030 				break;
1031 			case CEOF:
1032 				goto endword;		/* exit outer loop */
1033 			default:
1034 				if (varnest == 0)
1035 					goto endword;	/* exit outer loop */
1036 				USTPUTC(c, out);
1037 			}
1038 			c = pgetc_macro();
1039 		}
1040 	}
1041 endword:
1042 	if (syntax == ARISYNTAX)
1043 		synerror("Missing '))'");
1044 	if (syntax != BASESYNTAX && ! parsebackquote && eofmark == NULL)
1045 		synerror("Unterminated quoted string");
1046 	if (varnest != 0) {
1047 		startlinno = plinno;
1048 		synerror("Missing '}'");
1049 	}
1050 	USTPUTC('\0', out);
1051 	len = out - stackblock();
1052 	out = stackblock();
1053 	if (eofmark == NULL) {
1054 		if ((c == '>' || c == '<')
1055 		 && quotef == 0
1056 		 && len <= 2
1057 		 && (*out == '\0' || is_digit(*out))) {
1058 			PARSEREDIR();
1059 			return lasttoken = TREDIR;
1060 		} else {
1061 			pungetc();
1062 		}
1063 	}
1064 	quoteflag = quotef;
1065 	backquotelist = bqlist;
1066 	grabstackblock(len);
1067 	wordtext = out;
1068 	return lasttoken = TWORD;
1069 /* end of readtoken routine */
1070 
1071 
1072 
1073 /*
1074  * Check to see whether we are at the end of the here document.  When this
1075  * is called, c is set to the first character of the next input line.  If
1076  * we are at the end of the here document, this routine sets the c to PEOF.
1077  */
1078 
1079 checkend: {
1080 	if (eofmark) {
1081 		if (striptabs) {
1082 			while (c == '\t')
1083 				c = pgetc();
1084 		}
1085 		if (c == *eofmark) {
1086 			if (pfgets(line, sizeof line) != NULL) {
1087 				char *p, *q;
1088 
1089 				p = line;
1090 				for (q = eofmark + 1 ; *q && *p == *q ; p++, q++);
1091 				if (*p == '\n' && *q == '\0') {
1092 					c = PEOF;
1093 					plinno++;
1094 					needprompt = doprompt;
1095 				} else {
1096 					pushstring(line, strlen(line), NULL);
1097 				}
1098 			}
1099 		}
1100 	}
1101 	goto checkend_return;
1102 }
1103 
1104 
1105 /*
1106  * Parse a redirection operator.  The variable "out" points to a string
1107  * specifying the fd to be redirected.  The variable "c" contains the
1108  * first character of the redirection operator.
1109  */
1110 
1111 parseredir: {
1112 	char fd = *out;
1113 	union node *np;
1114 
1115 	np = (union node *)stalloc(sizeof (struct nfile));
1116 	if (c == '>') {
1117 		np->nfile.fd = 1;
1118 		c = pgetc();
1119 		if (c == '>')
1120 			np->type = NAPPEND;
1121 		else if (c == '&')
1122 			np->type = NTOFD;
1123 		else if (c == '|')
1124 			np->type = NCLOBBER;
1125 		else {
1126 			np->type = NTO;
1127 			pungetc();
1128 		}
1129 	} else {	/* c == '<' */
1130 		np->nfile.fd = 0;
1131 		c = pgetc();
1132 		if (c == '<') {
1133 			if (sizeof (struct nfile) != sizeof (struct nhere)) {
1134 				np = (union node *)stalloc(sizeof (struct nhere));
1135 				np->nfile.fd = 0;
1136 			}
1137 			np->type = NHERE;
1138 			heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc));
1139 			heredoc->here = np;
1140 			if ((c = pgetc()) == '-') {
1141 				heredoc->striptabs = 1;
1142 			} else {
1143 				heredoc->striptabs = 0;
1144 				pungetc();
1145 			}
1146 		} else if (c == '&')
1147 			np->type = NFROMFD;
1148 		else if (c == '>')
1149 			np->type = NFROMTO;
1150 		else {
1151 			np->type = NFROM;
1152 			pungetc();
1153 		}
1154 	}
1155 	if (fd != '\0')
1156 		np->nfile.fd = digit_val(fd);
1157 	redirnode = np;
1158 	goto parseredir_return;
1159 }
1160 
1161 
1162 /*
1163  * Parse a substitution.  At this point, we have read the dollar sign
1164  * and nothing else.
1165  */
1166 
1167 parsesub: {
1168 	int subtype;
1169 	int typeloc;
1170 	int flags;
1171 	char *p;
1172 	static const char types[] = "}-+?=";
1173        int bracketed_name = 0; /* used to handle ${[0-9]*} variables */
1174 
1175 	c = pgetc();
1176 	if (c != '(' && c != '{' && (is_eof(c) || !is_name(c)) &&
1177 	    !is_special(c)) {
1178 		USTPUTC('$', out);
1179 		pungetc();
1180 	} else if (c == '(') {	/* $(command) or $((arith)) */
1181 		if (pgetc() == '(') {
1182 			PARSEARITH();
1183 		} else {
1184 			pungetc();
1185 			PARSEBACKQNEW();
1186 		}
1187 	} else {
1188 		USTPUTC(CTLVAR, out);
1189 		typeloc = out - stackblock();
1190 		USTPUTC(VSNORMAL, out);
1191 		subtype = VSNORMAL;
1192 		if (c == '{') {
1193 			bracketed_name = 1;
1194 			c = pgetc();
1195 			if (c == '#') {
1196 				if ((c = pgetc()) == '}')
1197 					c = '#';
1198 				else
1199 					subtype = VSLENGTH;
1200 			}
1201 			else
1202 				subtype = 0;
1203 		}
1204 		if (!is_eof(c) && is_name(c)) {
1205 			do {
1206 				STPUTC(c, out);
1207 				c = pgetc();
1208 			} while (!is_eof(c) && is_in_name(c));
1209 		} else if (is_digit(c)) {
1210 			if (bracketed_name) {
1211 				do {
1212 					STPUTC(c, out);
1213 					c = pgetc();
1214 				} while (is_digit(c));
1215 			} else {
1216 				STPUTC(c, out);
1217 				c = pgetc();
1218 			}
1219 		} else {
1220 			if (! is_special(c)) {
1221 				subtype = VSERROR;
1222 				if (c == '}')
1223 					pungetc();
1224 				else
1225 					USTPUTC(c, out);
1226 			} else {
1227 				USTPUTC(c, out);
1228 				c = pgetc();
1229 			}
1230 		}
1231 		flags = 0;
1232 		if (subtype == 0) {
1233 			switch (c) {
1234 			case ':':
1235 				flags = VSNUL;
1236 				c = pgetc();
1237 				/*FALLTHROUGH*/
1238 			default:
1239 				p = strchr(types, c);
1240 				if (p == NULL) {
1241 					if (flags == VSNUL)
1242 						STPUTC(':', out);
1243 					STPUTC(c, out);
1244 					subtype = VSERROR;
1245 				} else
1246 					subtype = p - types + VSNORMAL;
1247 				break;
1248 			case '%':
1249 			case '#':
1250 				{
1251 					int cc = c;
1252 					subtype = c == '#' ? VSTRIMLEFT :
1253 							     VSTRIMRIGHT;
1254 					c = pgetc();
1255 					if (c == cc)
1256 						subtype++;
1257 					else
1258 						pungetc();
1259 					break;
1260 				}
1261 			}
1262 		} else if (subtype != VSERROR) {
1263 			pungetc();
1264 		}
1265 		STPUTC('=', out);
1266 		if (subtype != VSLENGTH && (dblquote || arinest))
1267 			flags |= VSQUOTE;
1268 		*(stackblock() + typeloc) = subtype | flags;
1269 		if (subtype != VSNORMAL)
1270 			varnest++;
1271 	}
1272 	goto parsesub_return;
1273 }
1274 
1275 
1276 /*
1277  * Called to parse command substitutions.  Newstyle is set if the command
1278  * is enclosed inside $(...); nlpp is a pointer to the head of the linked
1279  * list of commands (passed by reference), and savelen is the number of
1280  * characters on the top of the stack which must be preserved.
1281  */
1282 
1283 parsebackq: {
1284 	struct nodelist **nlpp;
1285 	int savepbq;
1286 	union node *n;
1287 	char *volatile str;
1288 	struct jmploc jmploc;
1289 	struct jmploc *volatile savehandler;
1290 	int savelen;
1291 	volatile int saveprompt;
1292 
1293 	savepbq = parsebackquote;
1294 	if (setjmp(jmploc.loc)) {
1295 		if (str)
1296 			ckfree(str);
1297 		parsebackquote = 0;
1298 		handler = savehandler;
1299 		longjmp(handler->loc, 1);
1300 	}
1301 	INTOFF;
1302 	str = NULL;
1303 	savelen = out - stackblock();
1304 	if (savelen > 0) {
1305 		str = ckmalloc(savelen);
1306 		memcpy(str, stackblock(), savelen);
1307 	}
1308 	savehandler = handler;
1309 	handler = &jmploc;
1310 	INTON;
1311         if (oldstyle) {
1312                 /* We must read until the closing backquote, giving special
1313                    treatment to some slashes, and then push the string and
1314                    reread it as input, interpreting it normally.  */
1315                 char *pout;
1316                 int pc;
1317                 int psavelen;
1318                 char *pstr;
1319 
1320 
1321                 STARTSTACKSTR(pout);
1322 		for (;;) {
1323 			if (needprompt) {
1324 				setprompt(2);
1325 				needprompt = 0;
1326 			}
1327 			switch (pc = pgetc()) {
1328 			case '`':
1329 				goto done;
1330 
1331 			case '\\':
1332                                 if ((pc = pgetc()) == '\n') {
1333 					plinno++;
1334 					if (doprompt)
1335 						setprompt(2);
1336 					else
1337 						setprompt(0);
1338 					/*
1339 					 * If eating a newline, avoid putting
1340 					 * the newline into the new character
1341 					 * stream (via the STPUTC after the
1342 					 * switch).
1343 					 */
1344 					continue;
1345 				}
1346                                 if (pc != '\\' && pc != '`' && pc != '$'
1347                                     && (!dblquote || pc != '"'))
1348                                         STPUTC('\\', pout);
1349 				break;
1350 
1351 			case '\n':
1352 				plinno++;
1353 				needprompt = doprompt;
1354 				break;
1355 
1356 			case PEOF:
1357 			        startlinno = plinno;
1358 				synerror("EOF in backquote substitution");
1359  				break;
1360 
1361 			default:
1362 				break;
1363 			}
1364 			STPUTC(pc, pout);
1365                 }
1366 done:
1367                 STPUTC('\0', pout);
1368                 psavelen = pout - stackblock();
1369                 if (psavelen > 0) {
1370                         pstr = ckmalloc(psavelen);
1371                         memcpy(pstr, stackblock(), psavelen);
1372 			setinputstring(pstr, 1);
1373                 }
1374         }
1375 	nlpp = &bqlist;
1376 	while (*nlpp)
1377 		nlpp = &(*nlpp)->next;
1378 	*nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist));
1379 	(*nlpp)->next = NULL;
1380 	parsebackquote = oldstyle;
1381 
1382 	if (oldstyle) {
1383 		saveprompt = doprompt;
1384 		doprompt = 0;
1385 	}
1386 
1387 	n = list(0);
1388 
1389 	if (oldstyle)
1390 		doprompt = saveprompt;
1391 	else {
1392 		if (readtoken() != TRP)
1393 			synexpect(TRP);
1394 	}
1395 
1396 	(*nlpp)->n = n;
1397         if (oldstyle) {
1398 		/*
1399 		 * Start reading from old file again, ignoring any pushed back
1400 		 * tokens left from the backquote parsing
1401 		 */
1402                 popfile();
1403 		tokpushback = 0;
1404 	}
1405 	while (stackblocksize() <= savelen)
1406 		growstackblock();
1407 	STARTSTACKSTR(out);
1408 	if (str) {
1409 		memcpy(out, str, savelen);
1410 		STADJUST(savelen, out);
1411 		INTOFF;
1412 		ckfree(str);
1413 		str = NULL;
1414 		INTON;
1415 	}
1416 	parsebackquote = savepbq;
1417 	handler = savehandler;
1418 	if (arinest || dblquote)
1419 		USTPUTC(CTLBACKQ | CTLQUOTE, out);
1420 	else
1421 		USTPUTC(CTLBACKQ, out);
1422 	if (oldstyle)
1423 		goto parsebackq_oldreturn;
1424 	else
1425 		goto parsebackq_newreturn;
1426 }
1427 
1428 /*
1429  * Parse an arithmetic expansion (indicate start of one and set state)
1430  */
1431 parsearith: {
1432 
1433 	if (++arinest == 1) {
1434 		prevsyntax = syntax;
1435 		syntax = ARISYNTAX;
1436 		USTPUTC(CTLARI, out);
1437 		if (dblquote)
1438 			USTPUTC('"',out);
1439 		else
1440 			USTPUTC(' ',out);
1441 	} else {
1442 		/*
1443 		 * we collapse embedded arithmetic expansion to
1444 		 * parenthesis, which should be equivalent
1445 		 */
1446 		USTPUTC('(', out);
1447 	}
1448 	goto parsearith_return;
1449 }
1450 
1451 } /* end of readtoken */
1452 
1453 
1454 
1455 #ifdef mkinit
1456 RESET {
1457 	tokpushback = 0;
1458 	checkkwd = 0;
1459 }
1460 #endif
1461 
1462 /*
1463  * Returns true if the text contains nothing to expand (no dollar signs
1464  * or backquotes).
1465  */
1466 
1467 STATIC int
1468 noexpand(char *text)
1469 {
1470 	char *p;
1471 	char c;
1472 
1473 	p = text;
1474 	while ((c = *p++) != '\0') {
1475 		if ( c == CTLQUOTEMARK)
1476 			continue;
1477 		if (c == CTLESC)
1478 			p++;
1479 		else if (BASESYNTAX[(int)c] == CCTL)
1480 			return 0;
1481 	}
1482 	return 1;
1483 }
1484 
1485 
1486 /*
1487  * Return true if the argument is a legal variable name (a letter or
1488  * underscore followed by zero or more letters, underscores, and digits).
1489  */
1490 
1491 int
1492 goodname(char *name)
1493 {
1494 	char *p;
1495 
1496 	p = name;
1497 	if (! is_name(*p))
1498 		return 0;
1499 	while (*++p) {
1500 		if (! is_in_name(*p))
1501 			return 0;
1502 	}
1503 	return 1;
1504 }
1505 
1506 
1507 /*
1508  * Called when an unexpected token is read during the parse.  The argument
1509  * is the token that is expected, or -1 if more than one type of token can
1510  * occur at this point.
1511  */
1512 
1513 STATIC void
1514 synexpect(int token)
1515 {
1516 	char msg[64];
1517 
1518 	if (token >= 0) {
1519 		fmtstr(msg, 64, "%s unexpected (expecting %s)",
1520 			tokname[lasttoken], tokname[token]);
1521 	} else {
1522 		fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]);
1523 	}
1524 	synerror(msg);
1525 }
1526 
1527 
1528 STATIC void
1529 synerror(const char *msg)
1530 {
1531 	if (commandname)
1532 		outfmt(&errout, "%s: %d: ", commandname, startlinno);
1533 	outfmt(&errout, "Syntax error: %s\n", msg);
1534 	error((char *)NULL);
1535 }
1536 
1537 STATIC void
1538 setprompt(int which)
1539 {
1540 	whichprompt = which;
1541 
1542 #ifndef NO_HISTORY
1543 	if (!el)
1544 #endif
1545 		out2str(getprompt(NULL));
1546 }
1547 
1548 /*
1549  * called by editline -- any expansions to the prompt
1550  *    should be added here.
1551  */
1552 const char *
1553 getprompt(void *unused __unused)
1554 {
1555 	static char ps[PROMPTLEN];
1556 	const char *fmt;
1557 	int i, j, trim;
1558 
1559 	/*
1560 	 * Select prompt format.
1561 	 */
1562 	switch (whichprompt) {
1563 	case 0:
1564 		fmt = "";
1565 		break;
1566 	case 1:
1567 		fmt = ps1val();
1568 		break;
1569 	case 2:
1570 		fmt = ps2val();
1571 		break;
1572 	default:
1573 		return "<internal prompt error>";
1574 	}
1575 
1576 	/*
1577 	 * Format prompt string.
1578 	 */
1579 	for (i = 0; (i < 127) && (*fmt != '\0'); i++, fmt++)
1580 		if (*fmt == '\\')
1581 			switch (*++fmt) {
1582 
1583 				/*
1584 				 * Hostname.
1585 				 *
1586 				 * \h specifies just the local hostname,
1587 				 * \H specifies fully-qualified hostname.
1588 				 */
1589 			case 'h':
1590 			case 'H':
1591 				ps[i] = '\0';
1592 				gethostname(&ps[i], PROMPTLEN - i);
1593 				/* Skip to end of hostname. */
1594 				trim = (*fmt == 'h') ? '.' : '\0';
1595 				while ((ps[i+1] != '\0') && (ps[i+1] != trim))
1596 					i++;
1597 				break;
1598 
1599 				/*
1600 				 * Working directory.
1601 				 *
1602 				 * \W specifies just the final component,
1603 				 * \w specifies the entire path.
1604 				 */
1605 			case 'W':
1606 			case 'w':
1607 				ps[i] = '\0';
1608 				getcwd(&ps[i], PROMPTLEN - i);
1609 				if (*fmt == 'W') {
1610 					/* Final path component only. */
1611 					trim = 1;
1612 					for (j = i; ps[j] != '\0'; j++)
1613 					  if (ps[j] == '/')
1614 						trim = j + 1;
1615 					memmove(&ps[i], &ps[trim],
1616 					    j - trim + 1);
1617 				}
1618 				/* Skip to end of path. */
1619 				while (ps[i + 1] != '\0')
1620 					i++;
1621 				break;
1622 
1623 				/*
1624 				 * Superuser status.
1625 				 *
1626 				 * '$' for normal users, '#' for root.
1627 				 */
1628 			case '$':
1629 				ps[i] = (geteuid() != 0) ? '$' : '#';
1630 				break;
1631 
1632 				/*
1633 				 * A literal \.
1634 				 */
1635 			case '\\':
1636 				ps[i] = '\\';
1637 				break;
1638 
1639 				/*
1640 				 * Emit unrecognized formats verbatim.
1641 				 */
1642 			default:
1643 				ps[i++] = '\\';
1644 				ps[i] = *fmt;
1645 				break;
1646 			}
1647 		else
1648 			ps[i] = *fmt;
1649 	ps[i] = '\0';
1650 	return (ps);
1651 }
1652