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 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)parser.c 8.7 (Berkeley) 5/16/95";
36 #endif
37 #endif /* not lint */
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40
41 #include <stdlib.h>
42 #include <unistd.h>
43 #include <stdio.h>
44
45 #include "shell.h"
46 #include "parser.h"
47 #include "nodes.h"
48 #include "expand.h" /* defines rmescapes() */
49 #include "syntax.h"
50 #include "options.h"
51 #include "input.h"
52 #include "output.h"
53 #include "var.h"
54 #include "error.h"
55 #include "memalloc.h"
56 #include "mystring.h"
57 #include "alias.h"
58 #include "show.h"
59 #include "eval.h"
60 #include "exec.h" /* to check for special builtins */
61 #ifndef NO_HISTORY
62 #include "myhistedit.h"
63 #endif
64
65 /*
66 * Shell command parser.
67 */
68
69 #define EOFMARKLEN 79
70 #define PROMPTLEN 128
71
72 /* values of checkkwd variable */
73 #define CHKALIAS 0x1
74 #define CHKKWD 0x2
75 #define CHKNL 0x4
76
77 /* values returned by readtoken */
78 #include "token.h"
79
80
81
82 struct heredoc {
83 struct heredoc *next; /* next here document in list */
84 union node *here; /* redirection node */
85 char *eofmark; /* string indicating end of input */
86 int striptabs; /* if set, strip leading tabs */
87 };
88
89 struct parser_temp {
90 struct parser_temp *next;
91 void *data;
92 };
93
94
95 static struct heredoc *heredoclist; /* list of here documents to read */
96 static int doprompt; /* if set, prompt the user */
97 static int needprompt; /* true if interactive and at start of line */
98 static int lasttoken; /* last token read */
99 static int tokpushback; /* last token pushed back */
100 static char *wordtext; /* text of last word returned by readtoken */
101 static int checkkwd;
102 static struct nodelist *backquotelist;
103 static union node *redirnode;
104 static struct heredoc *heredoc;
105 static int quoteflag; /* set if (part of) last token was quoted */
106 static int startlinno; /* line # where last token started */
107 static int funclinno; /* line # where the current function started */
108 static struct parser_temp *parser_temp;
109
110
111 static union node *list(int);
112 static union node *andor(void);
113 static union node *pipeline(void);
114 static union node *command(void);
115 static union node *simplecmd(union node **, union node *);
116 static union node *makename(void);
117 static union node *makebinary(int type, union node *n1, union node *n2);
118 static void parsefname(void);
119 static void parseheredoc(void);
120 static int peektoken(void);
121 static int readtoken(void);
122 static int xxreadtoken(void);
123 static int readtoken1(int, const char *, const char *, int);
124 static int noexpand(char *);
125 static void consumetoken(int);
126 static void synexpect(int) __dead2;
127 static void synerror(const char *) __dead2;
128 static void setprompt(int);
129
130
131 static void *
parser_temp_alloc(size_t len)132 parser_temp_alloc(size_t len)
133 {
134 struct parser_temp *t;
135
136 INTOFF;
137 t = ckmalloc(sizeof(*t));
138 t->data = NULL;
139 t->next = parser_temp;
140 parser_temp = t;
141 t->data = ckmalloc(len);
142 INTON;
143 return t->data;
144 }
145
146
147 static void *
parser_temp_realloc(void * ptr,size_t len)148 parser_temp_realloc(void *ptr, size_t len)
149 {
150 struct parser_temp *t;
151
152 INTOFF;
153 t = parser_temp;
154 if (ptr != t->data)
155 error("bug: parser_temp_realloc misused");
156 t->data = ckrealloc(t->data, len);
157 INTON;
158 return t->data;
159 }
160
161
162 static void
parser_temp_free_upto(void * ptr)163 parser_temp_free_upto(void *ptr)
164 {
165 struct parser_temp *t;
166 int done = 0;
167
168 INTOFF;
169 while (parser_temp != NULL && !done) {
170 t = parser_temp;
171 parser_temp = t->next;
172 done = t->data == ptr;
173 ckfree(t->data);
174 ckfree(t);
175 }
176 INTON;
177 if (!done)
178 error("bug: parser_temp_free_upto misused");
179 }
180
181
182 static void
parser_temp_free_all(void)183 parser_temp_free_all(void)
184 {
185 struct parser_temp *t;
186
187 INTOFF;
188 while (parser_temp != NULL) {
189 t = parser_temp;
190 parser_temp = t->next;
191 ckfree(t->data);
192 ckfree(t);
193 }
194 INTON;
195 }
196
197
198 /*
199 * Read and parse a command. Returns NEOF on end of file. (NULL is a
200 * valid parse tree indicating a blank line.)
201 */
202
203 union node *
parsecmd(int interact)204 parsecmd(int interact)
205 {
206 int t;
207
208 /* This assumes the parser is not re-entered,
209 * which could happen if we add command substitution on PS1/PS2.
210 */
211 parser_temp_free_all();
212 heredoclist = NULL;
213
214 tokpushback = 0;
215 checkkwd = 0;
216 doprompt = interact;
217 if (doprompt)
218 setprompt(1);
219 else
220 setprompt(0);
221 needprompt = 0;
222 t = readtoken();
223 if (t == TEOF)
224 return NEOF;
225 if (t == TNL)
226 return NULL;
227 tokpushback++;
228 return list(1);
229 }
230
231
232 static union node *
list(int nlflag)233 list(int nlflag)
234 {
235 union node *ntop, *n1, *n2, *n3;
236 int tok;
237
238 checkkwd = CHKNL | CHKKWD | CHKALIAS;
239 if (!nlflag && tokendlist[peektoken()])
240 return NULL;
241 ntop = n1 = NULL;
242 for (;;) {
243 n2 = andor();
244 tok = readtoken();
245 if (tok == TBACKGND) {
246 if (n2 != NULL && n2->type == NPIPE) {
247 n2->npipe.backgnd = 1;
248 } else if (n2 != NULL && n2->type == NREDIR) {
249 n2->type = NBACKGND;
250 } else {
251 n3 = (union node *)stalloc(sizeof (struct nredir));
252 n3->type = NBACKGND;
253 n3->nredir.n = n2;
254 n3->nredir.redirect = NULL;
255 n2 = n3;
256 }
257 }
258 if (ntop == NULL)
259 ntop = n2;
260 else if (n1 == NULL) {
261 n1 = makebinary(NSEMI, ntop, n2);
262 ntop = n1;
263 }
264 else {
265 n3 = makebinary(NSEMI, n1->nbinary.ch2, n2);
266 n1->nbinary.ch2 = n3;
267 n1 = n3;
268 }
269 switch (tok) {
270 case TBACKGND:
271 case TSEMI:
272 tok = readtoken();
273 /* FALLTHROUGH */
274 case TNL:
275 if (tok == TNL) {
276 parseheredoc();
277 if (nlflag)
278 return ntop;
279 } else if (tok == TEOF && nlflag) {
280 parseheredoc();
281 return ntop;
282 } else {
283 tokpushback++;
284 }
285 checkkwd = CHKNL | CHKKWD | CHKALIAS;
286 if (!nlflag && tokendlist[peektoken()])
287 return ntop;
288 break;
289 case TEOF:
290 if (heredoclist)
291 parseheredoc();
292 else
293 pungetc(); /* push back EOF on input */
294 return ntop;
295 default:
296 if (nlflag)
297 synexpect(-1);
298 tokpushback++;
299 return ntop;
300 }
301 }
302 }
303
304
305
306 static union node *
andor(void)307 andor(void)
308 {
309 union node *n;
310 int t;
311
312 n = pipeline();
313 for (;;) {
314 if ((t = readtoken()) == TAND) {
315 t = NAND;
316 } else if (t == TOR) {
317 t = NOR;
318 } else {
319 tokpushback++;
320 return n;
321 }
322 n = makebinary(t, n, pipeline());
323 }
324 }
325
326
327
328 static union node *
pipeline(void)329 pipeline(void)
330 {
331 union node *n1, *n2, *pipenode;
332 struct nodelist *lp, *prev;
333 int negate, t;
334
335 negate = 0;
336 checkkwd = CHKNL | CHKKWD | CHKALIAS;
337 TRACE(("pipeline: entered\n"));
338 while (readtoken() == TNOT)
339 negate = !negate;
340 tokpushback++;
341 n1 = command();
342 if (readtoken() == TPIPE) {
343 pipenode = (union node *)stalloc(sizeof (struct npipe));
344 pipenode->type = NPIPE;
345 pipenode->npipe.backgnd = 0;
346 lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
347 pipenode->npipe.cmdlist = lp;
348 lp->n = n1;
349 do {
350 prev = lp;
351 lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
352 checkkwd = CHKNL | CHKKWD | CHKALIAS;
353 t = readtoken();
354 tokpushback++;
355 if (t == TNOT)
356 lp->n = pipeline();
357 else
358 lp->n = command();
359 prev->next = lp;
360 } while (readtoken() == TPIPE);
361 lp->next = NULL;
362 n1 = pipenode;
363 }
364 tokpushback++;
365 if (negate) {
366 n2 = (union node *)stalloc(sizeof (struct nnot));
367 n2->type = NNOT;
368 n2->nnot.com = n1;
369 return n2;
370 } else
371 return n1;
372 }
373
374
375
376 static union node *
command(void)377 command(void)
378 {
379 union node *n1, *n2;
380 union node *ap, **app;
381 union node *cp, **cpp;
382 union node *redir, **rpp;
383 int t;
384 int is_subshell;
385
386 checkkwd = CHKNL | CHKKWD | CHKALIAS;
387 is_subshell = 0;
388 redir = NULL;
389 n1 = NULL;
390 rpp = &redir;
391
392 /* Check for redirection which may precede command */
393 while (readtoken() == TREDIR) {
394 *rpp = n2 = redirnode;
395 rpp = &n2->nfile.next;
396 parsefname();
397 }
398 tokpushback++;
399
400 switch (readtoken()) {
401 case TIF:
402 n1 = (union node *)stalloc(sizeof (struct nif));
403 n1->type = NIF;
404 if ((n1->nif.test = list(0)) == NULL)
405 synexpect(-1);
406 consumetoken(TTHEN);
407 n1->nif.ifpart = list(0);
408 n2 = n1;
409 while (readtoken() == TELIF) {
410 n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif));
411 n2 = n2->nif.elsepart;
412 n2->type = NIF;
413 if ((n2->nif.test = list(0)) == NULL)
414 synexpect(-1);
415 consumetoken(TTHEN);
416 n2->nif.ifpart = list(0);
417 }
418 if (lasttoken == TELSE)
419 n2->nif.elsepart = list(0);
420 else {
421 n2->nif.elsepart = NULL;
422 tokpushback++;
423 }
424 consumetoken(TFI);
425 checkkwd = CHKKWD | CHKALIAS;
426 break;
427 case TWHILE:
428 case TUNTIL:
429 t = lasttoken;
430 if ((n1 = list(0)) == NULL)
431 synexpect(-1);
432 consumetoken(TDO);
433 n1 = makebinary((t == TWHILE)? NWHILE : NUNTIL, n1, list(0));
434 consumetoken(TDONE);
435 checkkwd = CHKKWD | CHKALIAS;
436 break;
437 case TFOR:
438 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext))
439 synerror("Bad for loop variable");
440 n1 = (union node *)stalloc(sizeof (struct nfor));
441 n1->type = NFOR;
442 n1->nfor.var = wordtext;
443 while (readtoken() == TNL)
444 ;
445 if (lasttoken == TWORD && ! quoteflag && equal(wordtext, "in")) {
446 app = ≈
447 while (readtoken() == TWORD) {
448 n2 = makename();
449 *app = n2;
450 app = &n2->narg.next;
451 }
452 *app = NULL;
453 n1->nfor.args = ap;
454 if (lasttoken != TNL && lasttoken != TSEMI)
455 synexpect(-1);
456 } else {
457 static char argvars[5] = {
458 CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0'
459 };
460 n2 = (union node *)stalloc(sizeof (struct narg));
461 n2->type = NARG;
462 n2->narg.text = argvars;
463 n2->narg.backquote = NULL;
464 n2->narg.next = NULL;
465 n1->nfor.args = n2;
466 /*
467 * Newline or semicolon here is optional (but note
468 * that the original Bourne shell only allowed NL).
469 */
470 if (lasttoken != TNL && lasttoken != TSEMI)
471 tokpushback++;
472 }
473 checkkwd = CHKNL | CHKKWD | CHKALIAS;
474 if ((t = readtoken()) == TDO)
475 t = TDONE;
476 else if (t == TBEGIN)
477 t = TEND;
478 else
479 synexpect(-1);
480 n1->nfor.body = list(0);
481 consumetoken(t);
482 checkkwd = CHKKWD | CHKALIAS;
483 break;
484 case TCASE:
485 n1 = (union node *)stalloc(sizeof (struct ncase));
486 n1->type = NCASE;
487 consumetoken(TWORD);
488 n1->ncase.expr = makename();
489 while (readtoken() == TNL);
490 if (lasttoken != TWORD || ! equal(wordtext, "in"))
491 synerror("expecting \"in\"");
492 cpp = &n1->ncase.cases;
493 checkkwd = CHKNL | CHKKWD, readtoken();
494 while (lasttoken != TESAC) {
495 *cpp = cp = (union node *)stalloc(sizeof (struct nclist));
496 cp->type = NCLIST;
497 app = &cp->nclist.pattern;
498 if (lasttoken == TLP)
499 readtoken();
500 for (;;) {
501 *app = ap = makename();
502 checkkwd = CHKNL | CHKKWD;
503 if (readtoken() != TPIPE)
504 break;
505 app = &ap->narg.next;
506 readtoken();
507 }
508 ap->narg.next = NULL;
509 if (lasttoken != TRP)
510 synexpect(TRP);
511 cp->nclist.body = list(0);
512
513 checkkwd = CHKNL | CHKKWD | CHKALIAS;
514 if ((t = readtoken()) != TESAC) {
515 if (t == TENDCASE)
516 ;
517 else if (t == TFALLTHRU)
518 cp->type = NCLISTFALLTHRU;
519 else
520 synexpect(TENDCASE);
521 checkkwd = CHKNL | CHKKWD, readtoken();
522 }
523 cpp = &cp->nclist.next;
524 }
525 *cpp = NULL;
526 checkkwd = CHKKWD | CHKALIAS;
527 break;
528 case TLP:
529 n1 = (union node *)stalloc(sizeof (struct nredir));
530 n1->type = NSUBSHELL;
531 n1->nredir.n = list(0);
532 n1->nredir.redirect = NULL;
533 consumetoken(TRP);
534 checkkwd = CHKKWD | CHKALIAS;
535 is_subshell = 1;
536 break;
537 case TBEGIN:
538 n1 = list(0);
539 consumetoken(TEND);
540 checkkwd = CHKKWD | CHKALIAS;
541 break;
542 /* A simple command must have at least one redirection or word. */
543 case TBACKGND:
544 case TSEMI:
545 case TAND:
546 case TOR:
547 case TPIPE:
548 case TENDCASE:
549 case TFALLTHRU:
550 case TEOF:
551 case TNL:
552 case TRP:
553 if (!redir)
554 synexpect(-1);
555 case TWORD:
556 tokpushback++;
557 n1 = simplecmd(rpp, redir);
558 return n1;
559 default:
560 synexpect(-1);
561 }
562
563 /* Now check for redirection which may follow command */
564 while (readtoken() == TREDIR) {
565 *rpp = n2 = redirnode;
566 rpp = &n2->nfile.next;
567 parsefname();
568 }
569 tokpushback++;
570 *rpp = NULL;
571 if (redir) {
572 if (!is_subshell) {
573 n2 = (union node *)stalloc(sizeof (struct nredir));
574 n2->type = NREDIR;
575 n2->nredir.n = n1;
576 n1 = n2;
577 }
578 n1->nredir.redirect = redir;
579 }
580
581 return n1;
582 }
583
584
585 static union node *
simplecmd(union node ** rpp,union node * redir)586 simplecmd(union node **rpp, union node *redir)
587 {
588 union node *args, **app;
589 union node **orig_rpp = rpp;
590 union node *n = NULL;
591 int special;
592 int savecheckkwd;
593
594 /* If we don't have any redirections already, then we must reset */
595 /* rpp to be the address of the local redir variable. */
596 if (redir == 0)
597 rpp = &redir;
598
599 args = NULL;
600 app = &args;
601 /*
602 * We save the incoming value, because we need this for shell
603 * functions. There can not be a redirect or an argument between
604 * the function name and the open parenthesis.
605 */
606 orig_rpp = rpp;
607
608 savecheckkwd = CHKALIAS;
609
610 for (;;) {
611 checkkwd = savecheckkwd;
612 if (readtoken() == TWORD) {
613 n = makename();
614 *app = n;
615 app = &n->narg.next;
616 if (savecheckkwd != 0 && !isassignment(wordtext))
617 savecheckkwd = 0;
618 } else if (lasttoken == TREDIR) {
619 *rpp = n = redirnode;
620 rpp = &n->nfile.next;
621 parsefname(); /* read name of redirection file */
622 } else if (lasttoken == TLP && app == &args->narg.next
623 && rpp == orig_rpp) {
624 /* We have a function */
625 consumetoken(TRP);
626 funclinno = plinno;
627 /*
628 * - Require plain text.
629 * - Functions with '/' cannot be called.
630 * - Reject name=().
631 * - Reject ksh extended glob patterns.
632 */
633 if (!noexpand(n->narg.text) || quoteflag ||
634 strchr(n->narg.text, '/') ||
635 strchr("!%*+-=?@}~",
636 n->narg.text[strlen(n->narg.text) - 1]))
637 synerror("Bad function name");
638 rmescapes(n->narg.text);
639 if (find_builtin(n->narg.text, &special) >= 0 &&
640 special)
641 synerror("Cannot override a special builtin with a function");
642 n->type = NDEFUN;
643 n->narg.next = command();
644 funclinno = 0;
645 return n;
646 } else {
647 tokpushback++;
648 break;
649 }
650 }
651 *app = NULL;
652 *rpp = NULL;
653 n = (union node *)stalloc(sizeof (struct ncmd));
654 n->type = NCMD;
655 n->ncmd.args = args;
656 n->ncmd.redirect = redir;
657 return n;
658 }
659
660 static union node *
makename(void)661 makename(void)
662 {
663 union node *n;
664
665 n = (union node *)stalloc(sizeof (struct narg));
666 n->type = NARG;
667 n->narg.next = NULL;
668 n->narg.text = wordtext;
669 n->narg.backquote = backquotelist;
670 return n;
671 }
672
673 static union node *
makebinary(int type,union node * n1,union node * n2)674 makebinary(int type, union node *n1, union node *n2)
675 {
676 union node *n;
677
678 n = (union node *)stalloc(sizeof (struct nbinary));
679 n->type = type;
680 n->nbinary.ch1 = n1;
681 n->nbinary.ch2 = n2;
682 return (n);
683 }
684
685 void
forcealias(void)686 forcealias(void)
687 {
688 checkkwd |= CHKALIAS;
689 }
690
691 void
fixredir(union node * n,const char * text,int err)692 fixredir(union node *n, const char *text, int err)
693 {
694 TRACE(("Fix redir %s %d\n", text, err));
695 if (!err)
696 n->ndup.vname = NULL;
697
698 if (is_digit(text[0]) && text[1] == '\0')
699 n->ndup.dupfd = digit_val(text[0]);
700 else if (text[0] == '-' && text[1] == '\0')
701 n->ndup.dupfd = -1;
702 else {
703
704 if (err)
705 synerror("Bad fd number");
706 else
707 n->ndup.vname = makename();
708 }
709 }
710
711
712 static void
parsefname(void)713 parsefname(void)
714 {
715 union node *n = redirnode;
716
717 consumetoken(TWORD);
718 if (n->type == NHERE) {
719 struct heredoc *here = heredoc;
720 struct heredoc *p;
721 int i;
722
723 if (quoteflag == 0)
724 n->type = NXHERE;
725 TRACE(("Here document %d\n", n->type));
726 if (here->striptabs) {
727 while (*wordtext == '\t')
728 wordtext++;
729 }
730 if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN)
731 synerror("Illegal eof marker for << redirection");
732 rmescapes(wordtext);
733 here->eofmark = wordtext;
734 here->next = NULL;
735 if (heredoclist == NULL)
736 heredoclist = here;
737 else {
738 for (p = heredoclist ; p->next ; p = p->next);
739 p->next = here;
740 }
741 } else if (n->type == NTOFD || n->type == NFROMFD) {
742 fixredir(n, wordtext, 0);
743 } else {
744 n->nfile.fname = makename();
745 }
746 }
747
748
749 /*
750 * Input any here documents.
751 */
752
753 static void
parseheredoc(void)754 parseheredoc(void)
755 {
756 struct heredoc *here;
757 union node *n;
758
759 while (heredoclist) {
760 here = heredoclist;
761 heredoclist = here->next;
762 if (needprompt) {
763 setprompt(2);
764 needprompt = 0;
765 }
766 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX,
767 here->eofmark, here->striptabs);
768 n = makename();
769 here->here->nhere.doc = n;
770 }
771 }
772
773 static int
peektoken(void)774 peektoken(void)
775 {
776 int t;
777
778 t = readtoken();
779 tokpushback++;
780 return (t);
781 }
782
783 static int
readtoken(void)784 readtoken(void)
785 {
786 int t;
787 struct alias *ap;
788 #ifdef DEBUG
789 int alreadyseen = tokpushback;
790 #endif
791
792 top:
793 t = xxreadtoken();
794
795 /*
796 * eat newlines
797 */
798 if (checkkwd & CHKNL) {
799 while (t == TNL) {
800 parseheredoc();
801 t = xxreadtoken();
802 }
803 }
804
805 /*
806 * check for keywords and aliases
807 */
808 if (t == TWORD && !quoteflag)
809 {
810 const char * const *pp;
811
812 if (checkkwd & CHKKWD)
813 for (pp = parsekwd; *pp; pp++) {
814 if (**pp == *wordtext && equal(*pp, wordtext))
815 {
816 lasttoken = t = pp - parsekwd + KWDOFFSET;
817 TRACE(("keyword %s recognized\n", tokname[t]));
818 goto out;
819 }
820 }
821 if (checkkwd & CHKALIAS &&
822 (ap = lookupalias(wordtext, 1)) != NULL) {
823 pushstring(ap->val, strlen(ap->val), ap);
824 goto top;
825 }
826 }
827 out:
828 if (t != TNOT)
829 checkkwd = 0;
830
831 #ifdef DEBUG
832 if (!alreadyseen)
833 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
834 else
835 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
836 #endif
837 return (t);
838 }
839
840
841 /*
842 * Read the next input token.
843 * If the token is a word, we set backquotelist to the list of cmds in
844 * backquotes. We set quoteflag to true if any part of the word was
845 * quoted.
846 * If the token is TREDIR, then we set redirnode to a structure containing
847 * the redirection.
848 * In all cases, the variable startlinno is set to the number of the line
849 * on which the token starts.
850 *
851 * [Change comment: here documents and internal procedures]
852 * [Readtoken shouldn't have any arguments. Perhaps we should make the
853 * word parsing code into a separate routine. In this case, readtoken
854 * doesn't need to have any internal procedures, but parseword does.
855 * We could also make parseoperator in essence the main routine, and
856 * have parseword (readtoken1?) handle both words and redirection.]
857 */
858
859 #define RETURN(token) return lasttoken = token
860
861 static int
xxreadtoken(void)862 xxreadtoken(void)
863 {
864 int c;
865
866 if (tokpushback) {
867 tokpushback = 0;
868 return lasttoken;
869 }
870 if (needprompt) {
871 setprompt(2);
872 needprompt = 0;
873 }
874 startlinno = plinno;
875 for (;;) { /* until token or start of word found */
876 c = pgetc_macro();
877 switch (c) {
878 case ' ': case '\t':
879 continue;
880 case '#':
881 while ((c = pgetc()) != '\n' && c != PEOF);
882 pungetc();
883 continue;
884 case '\\':
885 if (pgetc() == '\n') {
886 startlinno = ++plinno;
887 if (doprompt)
888 setprompt(2);
889 else
890 setprompt(0);
891 continue;
892 }
893 pungetc();
894 goto breakloop;
895 case '\n':
896 plinno++;
897 needprompt = doprompt;
898 RETURN(TNL);
899 case PEOF:
900 RETURN(TEOF);
901 case '&':
902 if (pgetc() == '&')
903 RETURN(TAND);
904 pungetc();
905 RETURN(TBACKGND);
906 case '|':
907 if (pgetc() == '|')
908 RETURN(TOR);
909 pungetc();
910 RETURN(TPIPE);
911 case ';':
912 c = pgetc();
913 if (c == ';')
914 RETURN(TENDCASE);
915 else if (c == '&')
916 RETURN(TFALLTHRU);
917 pungetc();
918 RETURN(TSEMI);
919 case '(':
920 RETURN(TLP);
921 case ')':
922 RETURN(TRP);
923 default:
924 goto breakloop;
925 }
926 }
927 breakloop:
928 return readtoken1(c, BASESYNTAX, (char *)NULL, 0);
929 #undef RETURN
930 }
931
932
933 #define MAXNEST_static 8
934 struct tokenstate
935 {
936 const char *syntax; /* *SYNTAX */
937 int parenlevel; /* levels of parentheses in arithmetic */
938 enum tokenstate_category
939 {
940 TSTATE_TOP,
941 TSTATE_VAR_OLD, /* ${var+-=?}, inherits dquotes */
942 TSTATE_VAR_NEW, /* other ${var...}, own dquote state */
943 TSTATE_ARITH
944 } category;
945 };
946
947
948 /*
949 * Called to parse command substitutions.
950 */
951
952 static char *
parsebackq(char * out,struct nodelist ** pbqlist,int oldstyle,int dblquote,int quoted)953 parsebackq(char *out, struct nodelist **pbqlist,
954 int oldstyle, int dblquote, int quoted)
955 {
956 struct nodelist **nlpp;
957 union node *n;
958 char *volatile str;
959 struct jmploc jmploc;
960 struct jmploc *const savehandler = handler;
961 size_t savelen;
962 int saveprompt;
963 const int bq_startlinno = plinno;
964 char *volatile ostr = NULL;
965 struct parsefile *const savetopfile = getcurrentfile();
966 struct heredoc *const saveheredoclist = heredoclist;
967 struct heredoc *here;
968
969 str = NULL;
970 if (setjmp(jmploc.loc)) {
971 popfilesupto(savetopfile);
972 if (str)
973 ckfree(str);
974 if (ostr)
975 ckfree(ostr);
976 heredoclist = saveheredoclist;
977 handler = savehandler;
978 if (exception == EXERROR) {
979 startlinno = bq_startlinno;
980 synerror("Error in command substitution");
981 }
982 longjmp(handler->loc, 1);
983 }
984 INTOFF;
985 savelen = out - stackblock();
986 if (savelen > 0) {
987 str = ckmalloc(savelen);
988 memcpy(str, stackblock(), savelen);
989 }
990 handler = &jmploc;
991 heredoclist = NULL;
992 INTON;
993 if (oldstyle) {
994 /* We must read until the closing backquote, giving special
995 treatment to some slashes, and then push the string and
996 reread it as input, interpreting it normally. */
997 char *oout;
998 int c;
999 int olen;
1000
1001
1002 STARTSTACKSTR(oout);
1003 for (;;) {
1004 if (needprompt) {
1005 setprompt(2);
1006 needprompt = 0;
1007 }
1008 CHECKSTRSPACE(2, oout);
1009 switch (c = pgetc()) {
1010 case '`':
1011 goto done;
1012
1013 case '\\':
1014 if ((c = pgetc()) == '\n') {
1015 plinno++;
1016 if (doprompt)
1017 setprompt(2);
1018 else
1019 setprompt(0);
1020 /*
1021 * If eating a newline, avoid putting
1022 * the newline into the new character
1023 * stream (via the USTPUTC after the
1024 * switch).
1025 */
1026 continue;
1027 }
1028 if (c != '\\' && c != '`' && c != '$'
1029 && (!dblquote || c != '"'))
1030 USTPUTC('\\', oout);
1031 break;
1032
1033 case '\n':
1034 plinno++;
1035 needprompt = doprompt;
1036 break;
1037
1038 case PEOF:
1039 startlinno = plinno;
1040 synerror("EOF in backquote substitution");
1041 break;
1042
1043 default:
1044 break;
1045 }
1046 USTPUTC(c, oout);
1047 }
1048 done:
1049 USTPUTC('\0', oout);
1050 olen = oout - stackblock();
1051 INTOFF;
1052 ostr = ckmalloc(olen);
1053 memcpy(ostr, stackblock(), olen);
1054 setinputstring(ostr, 1);
1055 INTON;
1056 }
1057 nlpp = pbqlist;
1058 while (*nlpp)
1059 nlpp = &(*nlpp)->next;
1060 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist));
1061 (*nlpp)->next = NULL;
1062
1063 if (oldstyle) {
1064 saveprompt = doprompt;
1065 doprompt = 0;
1066 }
1067
1068 n = list(0);
1069
1070 if (oldstyle) {
1071 if (peektoken() != TEOF)
1072 synexpect(-1);
1073 doprompt = saveprompt;
1074 } else
1075 consumetoken(TRP);
1076
1077 (*nlpp)->n = n;
1078 if (oldstyle) {
1079 /*
1080 * Start reading from old file again, ignoring any pushed back
1081 * tokens left from the backquote parsing
1082 */
1083 popfile();
1084 tokpushback = 0;
1085 }
1086 STARTSTACKSTR(out);
1087 CHECKSTRSPACE(savelen + 1, out);
1088 INTOFF;
1089 if (str) {
1090 memcpy(out, str, savelen);
1091 STADJUST(savelen, out);
1092 ckfree(str);
1093 str = NULL;
1094 }
1095 if (ostr) {
1096 ckfree(ostr);
1097 ostr = NULL;
1098 }
1099 here = saveheredoclist;
1100 if (here != NULL) {
1101 while (here->next != NULL)
1102 here = here->next;
1103 here->next = heredoclist;
1104 heredoclist = saveheredoclist;
1105 }
1106 handler = savehandler;
1107 INTON;
1108 if (quoted)
1109 USTPUTC(CTLBACKQ | CTLQUOTE, out);
1110 else
1111 USTPUTC(CTLBACKQ, out);
1112 return out;
1113 }
1114
1115
1116 /*
1117 * Called to parse a backslash escape sequence inside $'...'.
1118 * The backslash has already been read.
1119 */
1120 static char *
readcstyleesc(char * out)1121 readcstyleesc(char *out)
1122 {
1123 int c, v, i, n;
1124
1125 c = pgetc();
1126 switch (c) {
1127 case '\0':
1128 synerror("Unterminated quoted string");
1129 case '\n':
1130 plinno++;
1131 if (doprompt)
1132 setprompt(2);
1133 else
1134 setprompt(0);
1135 return out;
1136 case '\\':
1137 case '\'':
1138 case '"':
1139 v = c;
1140 break;
1141 case 'a': v = '\a'; break;
1142 case 'b': v = '\b'; break;
1143 case 'e': v = '\033'; break;
1144 case 'f': v = '\f'; break;
1145 case 'n': v = '\n'; break;
1146 case 'r': v = '\r'; break;
1147 case 't': v = '\t'; break;
1148 case 'v': v = '\v'; break;
1149 case 'x':
1150 v = 0;
1151 for (;;) {
1152 c = pgetc();
1153 if (c >= '0' && c <= '9')
1154 v = (v << 4) + c - '0';
1155 else if (c >= 'A' && c <= 'F')
1156 v = (v << 4) + c - 'A' + 10;
1157 else if (c >= 'a' && c <= 'f')
1158 v = (v << 4) + c - 'a' + 10;
1159 else
1160 break;
1161 }
1162 pungetc();
1163 break;
1164 case '0': case '1': case '2': case '3':
1165 case '4': case '5': case '6': case '7':
1166 v = c - '0';
1167 c = pgetc();
1168 if (c >= '0' && c <= '7') {
1169 v <<= 3;
1170 v += c - '0';
1171 c = pgetc();
1172 if (c >= '0' && c <= '7') {
1173 v <<= 3;
1174 v += c - '0';
1175 } else
1176 pungetc();
1177 } else
1178 pungetc();
1179 break;
1180 case 'c':
1181 c = pgetc();
1182 if (c < 0x3f || c > 0x7a || c == 0x60)
1183 synerror("Bad escape sequence");
1184 if (c == '\\' && pgetc() != '\\')
1185 synerror("Bad escape sequence");
1186 if (c == '?')
1187 v = 127;
1188 else
1189 v = c & 0x1f;
1190 break;
1191 case 'u':
1192 case 'U':
1193 n = c == 'U' ? 8 : 4;
1194 v = 0;
1195 for (i = 0; i < n; i++) {
1196 c = pgetc();
1197 if (c >= '0' && c <= '9')
1198 v = (v << 4) + c - '0';
1199 else if (c >= 'A' && c <= 'F')
1200 v = (v << 4) + c - 'A' + 10;
1201 else if (c >= 'a' && c <= 'f')
1202 v = (v << 4) + c - 'a' + 10;
1203 else
1204 synerror("Bad escape sequence");
1205 }
1206 if (v == 0 || (v >= 0xd800 && v <= 0xdfff))
1207 synerror("Bad escape sequence");
1208 /* We really need iconv here. */
1209 if (initial_localeisutf8 && v > 127) {
1210 CHECKSTRSPACE(4, out);
1211 /*
1212 * We cannot use wctomb() as the locale may have
1213 * changed.
1214 */
1215 if (v <= 0x7ff) {
1216 USTPUTC(0xc0 | v >> 6, out);
1217 USTPUTC(0x80 | (v & 0x3f), out);
1218 return out;
1219 } else if (v <= 0xffff) {
1220 USTPUTC(0xe0 | v >> 12, out);
1221 USTPUTC(0x80 | ((v >> 6) & 0x3f), out);
1222 USTPUTC(0x80 | (v & 0x3f), out);
1223 return out;
1224 } else if (v <= 0x10ffff) {
1225 USTPUTC(0xf0 | v >> 18, out);
1226 USTPUTC(0x80 | ((v >> 12) & 0x3f), out);
1227 USTPUTC(0x80 | ((v >> 6) & 0x3f), out);
1228 USTPUTC(0x80 | (v & 0x3f), out);
1229 return out;
1230 }
1231 }
1232 if (v > 127)
1233 v = '?';
1234 break;
1235 default:
1236 synerror("Bad escape sequence");
1237 }
1238 v = (char)v;
1239 /*
1240 * We can't handle NUL bytes.
1241 * POSIX says we should skip till the closing quote.
1242 */
1243 if (v == '\0') {
1244 while ((c = pgetc()) != '\'') {
1245 if (c == '\\')
1246 c = pgetc();
1247 if (c == PEOF)
1248 synerror("Unterminated quoted string");
1249 }
1250 pungetc();
1251 return out;
1252 }
1253 if (SQSYNTAX[v] == CCTL)
1254 USTPUTC(CTLESC, out);
1255 USTPUTC(v, out);
1256 return out;
1257 }
1258
1259
1260 /*
1261 * If eofmark is NULL, read a word or a redirection symbol. If eofmark
1262 * is not NULL, read a here document. In the latter case, eofmark is the
1263 * word which marks the end of the document and striptabs is true if
1264 * leading tabs should be stripped from the document. The argument firstc
1265 * is the first character of the input token or document.
1266 *
1267 * Because C does not have internal subroutines, I have simulated them
1268 * using goto's to implement the subroutine linkage. The following macros
1269 * will run code that appears at the end of readtoken1.
1270 */
1271
1272 #define CHECKEND() {goto checkend; checkend_return:;}
1273 #define PARSEREDIR() {goto parseredir; parseredir_return:;}
1274 #define PARSESUB() {goto parsesub; parsesub_return:;}
1275 #define PARSEARITH() {goto parsearith; parsearith_return:;}
1276
1277 static int
readtoken1(int firstc,char const * initialsyntax,const char * eofmark,int striptabs)1278 readtoken1(int firstc, char const *initialsyntax, const char *eofmark,
1279 int striptabs)
1280 {
1281 int c = firstc;
1282 char *out;
1283 int len;
1284 char line[EOFMARKLEN + 1];
1285 struct nodelist *bqlist;
1286 int quotef;
1287 int newvarnest;
1288 int level;
1289 int synentry;
1290 struct tokenstate state_static[MAXNEST_static];
1291 int maxnest = MAXNEST_static;
1292 struct tokenstate *state = state_static;
1293 int sqiscstyle = 0;
1294
1295 startlinno = plinno;
1296 quotef = 0;
1297 bqlist = NULL;
1298 newvarnest = 0;
1299 level = 0;
1300 state[level].syntax = initialsyntax;
1301 state[level].parenlevel = 0;
1302 state[level].category = TSTATE_TOP;
1303
1304 STARTSTACKSTR(out);
1305 loop: { /* for each line, until end of word */
1306 CHECKEND(); /* set c to PEOF if at end of here document */
1307 for (;;) { /* until end of line or end of word */
1308 CHECKSTRSPACE(4, out); /* permit 4 calls to USTPUTC */
1309
1310 synentry = state[level].syntax[c];
1311
1312 switch(synentry) {
1313 case CNL: /* '\n' */
1314 if (state[level].syntax == BASESYNTAX)
1315 goto endword; /* exit outer loop */
1316 USTPUTC(c, out);
1317 plinno++;
1318 if (doprompt)
1319 setprompt(2);
1320 else
1321 setprompt(0);
1322 c = pgetc();
1323 goto loop; /* continue outer loop */
1324 case CSBACK:
1325 if (sqiscstyle) {
1326 out = readcstyleesc(out);
1327 break;
1328 }
1329 /* FALLTHROUGH */
1330 case CWORD:
1331 USTPUTC(c, out);
1332 break;
1333 case CCTL:
1334 if (eofmark == NULL || initialsyntax != SQSYNTAX)
1335 USTPUTC(CTLESC, out);
1336 USTPUTC(c, out);
1337 break;
1338 case CBACK: /* backslash */
1339 c = pgetc();
1340 if (c == PEOF) {
1341 USTPUTC('\\', out);
1342 pungetc();
1343 } else if (c == '\n') {
1344 plinno++;
1345 if (doprompt)
1346 setprompt(2);
1347 else
1348 setprompt(0);
1349 } else {
1350 if (state[level].syntax == DQSYNTAX &&
1351 c != '\\' && c != '`' && c != '$' &&
1352 (c != '"' || (eofmark != NULL &&
1353 newvarnest == 0)) &&
1354 (c != '}' || state[level].category != TSTATE_VAR_OLD))
1355 USTPUTC('\\', out);
1356 if ((eofmark == NULL ||
1357 newvarnest > 0) &&
1358 state[level].syntax == BASESYNTAX)
1359 USTPUTC(CTLQUOTEMARK, out);
1360 if (SQSYNTAX[c] == CCTL)
1361 USTPUTC(CTLESC, out);
1362 USTPUTC(c, out);
1363 if ((eofmark == NULL ||
1364 newvarnest > 0) &&
1365 state[level].syntax == BASESYNTAX &&
1366 state[level].category == TSTATE_VAR_OLD)
1367 USTPUTC(CTLQUOTEEND, out);
1368 quotef++;
1369 }
1370 break;
1371 case CSQUOTE:
1372 USTPUTC(CTLQUOTEMARK, out);
1373 state[level].syntax = SQSYNTAX;
1374 sqiscstyle = 0;
1375 break;
1376 case CDQUOTE:
1377 USTPUTC(CTLQUOTEMARK, out);
1378 state[level].syntax = DQSYNTAX;
1379 break;
1380 case CENDQUOTE:
1381 if (eofmark != NULL && newvarnest == 0)
1382 USTPUTC(c, out);
1383 else {
1384 if (state[level].category == TSTATE_VAR_OLD)
1385 USTPUTC(CTLQUOTEEND, out);
1386 state[level].syntax = BASESYNTAX;
1387 quotef++;
1388 }
1389 break;
1390 case CVAR: /* '$' */
1391 PARSESUB(); /* parse substitution */
1392 break;
1393 case CENDVAR: /* '}' */
1394 if (level > 0 &&
1395 ((state[level].category == TSTATE_VAR_OLD &&
1396 state[level].syntax ==
1397 state[level - 1].syntax) ||
1398 (state[level].category == TSTATE_VAR_NEW &&
1399 state[level].syntax == BASESYNTAX))) {
1400 if (state[level].category == TSTATE_VAR_NEW)
1401 newvarnest--;
1402 level--;
1403 USTPUTC(CTLENDVAR, out);
1404 } else {
1405 USTPUTC(c, out);
1406 }
1407 break;
1408 case CLP: /* '(' in arithmetic */
1409 state[level].parenlevel++;
1410 USTPUTC(c, out);
1411 break;
1412 case CRP: /* ')' in arithmetic */
1413 if (state[level].parenlevel > 0) {
1414 USTPUTC(c, out);
1415 --state[level].parenlevel;
1416 } else {
1417 if (pgetc() == ')') {
1418 if (level > 0 &&
1419 state[level].category == TSTATE_ARITH) {
1420 level--;
1421 USTPUTC(CTLENDARI, out);
1422 } else
1423 USTPUTC(')', out);
1424 } else {
1425 /*
1426 * unbalanced parens
1427 * (don't 2nd guess - no error)
1428 */
1429 pungetc();
1430 USTPUTC(')', out);
1431 }
1432 }
1433 break;
1434 case CBQUOTE: /* '`' */
1435 out = parsebackq(out, &bqlist, 1,
1436 state[level].syntax == DQSYNTAX &&
1437 (eofmark == NULL || newvarnest > 0),
1438 state[level].syntax == DQSYNTAX || state[level].syntax == ARISYNTAX);
1439 break;
1440 case CEOF:
1441 goto endword; /* exit outer loop */
1442 case CIGN:
1443 break;
1444 default:
1445 if (level == 0)
1446 goto endword; /* exit outer loop */
1447 USTPUTC(c, out);
1448 }
1449 c = pgetc_macro();
1450 }
1451 }
1452 endword:
1453 if (state[level].syntax == ARISYNTAX)
1454 synerror("Missing '))'");
1455 if (state[level].syntax != BASESYNTAX && eofmark == NULL)
1456 synerror("Unterminated quoted string");
1457 if (state[level].category == TSTATE_VAR_OLD ||
1458 state[level].category == TSTATE_VAR_NEW) {
1459 startlinno = plinno;
1460 synerror("Missing '}'");
1461 }
1462 if (state != state_static)
1463 parser_temp_free_upto(state);
1464 USTPUTC('\0', out);
1465 len = out - stackblock();
1466 out = stackblock();
1467 if (eofmark == NULL) {
1468 if ((c == '>' || c == '<')
1469 && quotef == 0
1470 && len <= 2
1471 && (*out == '\0' || is_digit(*out))) {
1472 PARSEREDIR();
1473 return lasttoken = TREDIR;
1474 } else {
1475 pungetc();
1476 }
1477 }
1478 quoteflag = quotef;
1479 backquotelist = bqlist;
1480 grabstackblock(len);
1481 wordtext = out;
1482 return lasttoken = TWORD;
1483 /* end of readtoken routine */
1484
1485
1486 /*
1487 * Check to see whether we are at the end of the here document. When this
1488 * is called, c is set to the first character of the next input line. If
1489 * we are at the end of the here document, this routine sets the c to PEOF.
1490 */
1491
1492 checkend: {
1493 if (eofmark) {
1494 if (striptabs) {
1495 while (c == '\t')
1496 c = pgetc();
1497 }
1498 if (c == *eofmark) {
1499 if (pfgets(line, sizeof line) != NULL) {
1500 const char *p, *q;
1501
1502 p = line;
1503 for (q = eofmark + 1 ; *q && *p == *q ; p++, q++);
1504 if ((*p == '\0' || *p == '\n') && *q == '\0') {
1505 c = PEOF;
1506 if (*p == '\n') {
1507 plinno++;
1508 needprompt = doprompt;
1509 }
1510 } else {
1511 pushstring(line, strlen(line), NULL);
1512 }
1513 }
1514 }
1515 }
1516 goto checkend_return;
1517 }
1518
1519
1520 /*
1521 * Parse a redirection operator. The variable "out" points to a string
1522 * specifying the fd to be redirected. The variable "c" contains the
1523 * first character of the redirection operator.
1524 */
1525
1526 parseredir: {
1527 char fd = *out;
1528 union node *np;
1529
1530 np = (union node *)stalloc(sizeof (struct nfile));
1531 if (c == '>') {
1532 np->nfile.fd = 1;
1533 c = pgetc();
1534 if (c == '>')
1535 np->type = NAPPEND;
1536 else if (c == '&')
1537 np->type = NTOFD;
1538 else if (c == '|')
1539 np->type = NCLOBBER;
1540 else {
1541 np->type = NTO;
1542 pungetc();
1543 }
1544 } else { /* c == '<' */
1545 np->nfile.fd = 0;
1546 c = pgetc();
1547 if (c == '<') {
1548 if (sizeof (struct nfile) != sizeof (struct nhere)) {
1549 np = (union node *)stalloc(sizeof (struct nhere));
1550 np->nfile.fd = 0;
1551 }
1552 np->type = NHERE;
1553 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc));
1554 heredoc->here = np;
1555 if ((c = pgetc()) == '-') {
1556 heredoc->striptabs = 1;
1557 } else {
1558 heredoc->striptabs = 0;
1559 pungetc();
1560 }
1561 } else if (c == '&')
1562 np->type = NFROMFD;
1563 else if (c == '>')
1564 np->type = NFROMTO;
1565 else {
1566 np->type = NFROM;
1567 pungetc();
1568 }
1569 }
1570 if (fd != '\0')
1571 np->nfile.fd = digit_val(fd);
1572 redirnode = np;
1573 goto parseredir_return;
1574 }
1575
1576
1577 /*
1578 * Parse a substitution. At this point, we have read the dollar sign
1579 * and nothing else.
1580 */
1581
1582 parsesub: {
1583 char buf[10];
1584 int subtype;
1585 int typeloc;
1586 int flags;
1587 char *p;
1588 static const char types[] = "}-+?=";
1589 int bracketed_name = 0; /* used to handle ${[0-9]*} variables */
1590 int linno;
1591 int length;
1592 int c1;
1593
1594 c = pgetc();
1595 if (c == '(') { /* $(command) or $((arith)) */
1596 if (pgetc() == '(') {
1597 PARSEARITH();
1598 } else {
1599 pungetc();
1600 out = parsebackq(out, &bqlist, 0,
1601 state[level].syntax == DQSYNTAX &&
1602 (eofmark == NULL || newvarnest > 0),
1603 state[level].syntax == DQSYNTAX ||
1604 state[level].syntax == ARISYNTAX);
1605 }
1606 } else if (c == '{' || is_name(c) || is_special(c)) {
1607 USTPUTC(CTLVAR, out);
1608 typeloc = out - stackblock();
1609 USTPUTC(VSNORMAL, out);
1610 subtype = VSNORMAL;
1611 flags = 0;
1612 if (c == '{') {
1613 bracketed_name = 1;
1614 c = pgetc();
1615 subtype = 0;
1616 }
1617 varname:
1618 if (!is_eof(c) && is_name(c)) {
1619 length = 0;
1620 do {
1621 STPUTC(c, out);
1622 c = pgetc();
1623 length++;
1624 } while (!is_eof(c) && is_in_name(c));
1625 if (length == 6 &&
1626 strncmp(out - length, "LINENO", length) == 0) {
1627 /* Replace the variable name with the
1628 * current line number. */
1629 linno = plinno;
1630 if (funclinno != 0)
1631 linno -= funclinno - 1;
1632 snprintf(buf, sizeof(buf), "%d", linno);
1633 STADJUST(-6, out);
1634 STPUTS(buf, out);
1635 flags |= VSLINENO;
1636 }
1637 } else if (is_digit(c)) {
1638 if (bracketed_name) {
1639 do {
1640 STPUTC(c, out);
1641 c = pgetc();
1642 } while (is_digit(c));
1643 } else {
1644 STPUTC(c, out);
1645 c = pgetc();
1646 }
1647 } else if (is_special(c)) {
1648 c1 = c;
1649 c = pgetc();
1650 if (subtype == 0 && c1 == '#') {
1651 subtype = VSLENGTH;
1652 if (strchr(types, c) == NULL && c != ':' &&
1653 c != '#' && c != '%')
1654 goto varname;
1655 c1 = c;
1656 c = pgetc();
1657 if (c1 != '}' && c == '}') {
1658 pungetc();
1659 c = c1;
1660 goto varname;
1661 }
1662 pungetc();
1663 c = c1;
1664 c1 = '#';
1665 subtype = 0;
1666 }
1667 USTPUTC(c1, out);
1668 } else {
1669 subtype = VSERROR;
1670 if (c == '}')
1671 pungetc();
1672 else if (c == '\n' || c == PEOF)
1673 synerror("Unexpected end of line in substitution");
1674 else
1675 USTPUTC(c, out);
1676 }
1677 if (subtype == 0) {
1678 switch (c) {
1679 case ':':
1680 flags |= VSNUL;
1681 c = pgetc();
1682 /*FALLTHROUGH*/
1683 default:
1684 p = strchr(types, c);
1685 if (p == NULL) {
1686 if (c == '\n' || c == PEOF)
1687 synerror("Unexpected end of line in substitution");
1688 if (flags == VSNUL)
1689 STPUTC(':', out);
1690 STPUTC(c, out);
1691 subtype = VSERROR;
1692 } else
1693 subtype = p - types + VSNORMAL;
1694 break;
1695 case '%':
1696 case '#':
1697 {
1698 int cc = c;
1699 subtype = c == '#' ? VSTRIMLEFT :
1700 VSTRIMRIGHT;
1701 c = pgetc();
1702 if (c == cc)
1703 subtype++;
1704 else
1705 pungetc();
1706 break;
1707 }
1708 }
1709 } else if (subtype != VSERROR) {
1710 if (subtype == VSLENGTH && c != '}')
1711 subtype = VSERROR;
1712 pungetc();
1713 }
1714 STPUTC('=', out);
1715 if (state[level].syntax == DQSYNTAX ||
1716 state[level].syntax == ARISYNTAX)
1717 flags |= VSQUOTE;
1718 *(stackblock() + typeloc) = subtype | flags;
1719 if (subtype != VSNORMAL) {
1720 if (level + 1 >= maxnest) {
1721 maxnest *= 2;
1722 if (state == state_static) {
1723 state = parser_temp_alloc(
1724 maxnest * sizeof(*state));
1725 memcpy(state, state_static,
1726 MAXNEST_static * sizeof(*state));
1727 } else
1728 state = parser_temp_realloc(state,
1729 maxnest * sizeof(*state));
1730 }
1731 level++;
1732 state[level].parenlevel = 0;
1733 if (subtype == VSMINUS || subtype == VSPLUS ||
1734 subtype == VSQUESTION || subtype == VSASSIGN) {
1735 /*
1736 * For operators that were in the Bourne shell,
1737 * inherit the double-quote state.
1738 */
1739 state[level].syntax = state[level - 1].syntax;
1740 state[level].category = TSTATE_VAR_OLD;
1741 } else {
1742 /*
1743 * The other operators take a pattern,
1744 * so go to BASESYNTAX.
1745 * Also, ' and " are now special, even
1746 * in here documents.
1747 */
1748 state[level].syntax = BASESYNTAX;
1749 state[level].category = TSTATE_VAR_NEW;
1750 newvarnest++;
1751 }
1752 }
1753 } else if (c == '\'' && state[level].syntax == BASESYNTAX) {
1754 /* $'cstylequotes' */
1755 USTPUTC(CTLQUOTEMARK, out);
1756 state[level].syntax = SQSYNTAX;
1757 sqiscstyle = 1;
1758 } else {
1759 USTPUTC('$', out);
1760 pungetc();
1761 }
1762 goto parsesub_return;
1763 }
1764
1765
1766 /*
1767 * Parse an arithmetic expansion (indicate start of one and set state)
1768 */
1769 parsearith: {
1770
1771 if (level + 1 >= maxnest) {
1772 maxnest *= 2;
1773 if (state == state_static) {
1774 state = parser_temp_alloc(
1775 maxnest * sizeof(*state));
1776 memcpy(state, state_static,
1777 MAXNEST_static * sizeof(*state));
1778 } else
1779 state = parser_temp_realloc(state,
1780 maxnest * sizeof(*state));
1781 }
1782 level++;
1783 state[level].syntax = ARISYNTAX;
1784 state[level].parenlevel = 0;
1785 state[level].category = TSTATE_ARITH;
1786 USTPUTC(CTLARI, out);
1787 if (state[level - 1].syntax == DQSYNTAX)
1788 USTPUTC('"',out);
1789 else
1790 USTPUTC(' ',out);
1791 goto parsearith_return;
1792 }
1793
1794 } /* end of readtoken */
1795
1796
1797 /*
1798 * Returns true if the text contains nothing to expand (no dollar signs
1799 * or backquotes).
1800 */
1801
1802 static int
noexpand(char * text)1803 noexpand(char *text)
1804 {
1805 char *p;
1806 char c;
1807
1808 p = text;
1809 while ((c = *p++) != '\0') {
1810 if ( c == CTLQUOTEMARK)
1811 continue;
1812 if (c == CTLESC)
1813 p++;
1814 else if (BASESYNTAX[(int)c] == CCTL)
1815 return 0;
1816 }
1817 return 1;
1818 }
1819
1820
1821 /*
1822 * Return true if the argument is a legal variable name (a letter or
1823 * underscore followed by zero or more letters, underscores, and digits).
1824 */
1825
1826 int
goodname(const char * name)1827 goodname(const char *name)
1828 {
1829 const char *p;
1830
1831 p = name;
1832 if (! is_name(*p))
1833 return 0;
1834 while (*++p) {
1835 if (! is_in_name(*p))
1836 return 0;
1837 }
1838 return 1;
1839 }
1840
1841
1842 int
isassignment(const char * p)1843 isassignment(const char *p)
1844 {
1845 if (!is_name(*p))
1846 return 0;
1847 p++;
1848 for (;;) {
1849 if (*p == '=')
1850 return 1;
1851 else if (!is_in_name(*p))
1852 return 0;
1853 p++;
1854 }
1855 }
1856
1857
1858 static void
consumetoken(int token)1859 consumetoken(int token)
1860 {
1861 if (readtoken() != token)
1862 synexpect(token);
1863 }
1864
1865
1866 /*
1867 * Called when an unexpected token is read during the parse. The argument
1868 * is the token that is expected, or -1 if more than one type of token can
1869 * occur at this point.
1870 */
1871
1872 static void
synexpect(int token)1873 synexpect(int token)
1874 {
1875 char msg[64];
1876
1877 if (token >= 0) {
1878 fmtstr(msg, 64, "%s unexpected (expecting %s)",
1879 tokname[lasttoken], tokname[token]);
1880 } else {
1881 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]);
1882 }
1883 synerror(msg);
1884 }
1885
1886
1887 static void
synerror(const char * msg)1888 synerror(const char *msg)
1889 {
1890 if (commandname)
1891 outfmt(out2, "%s: %d: ", commandname, startlinno);
1892 outfmt(out2, "Syntax error: %s\n", msg);
1893 error((char *)NULL);
1894 }
1895
1896 static void
setprompt(int which)1897 setprompt(int which)
1898 {
1899 whichprompt = which;
1900
1901 #ifndef NO_HISTORY
1902 if (!el)
1903 #endif
1904 {
1905 out2str(getprompt(NULL));
1906 flushout(out2);
1907 }
1908 }
1909
1910 /*
1911 * called by editline -- any expansions to the prompt
1912 * should be added here.
1913 */
1914 char *
getprompt(void * unused __unused)1915 getprompt(void *unused __unused)
1916 {
1917 static char ps[PROMPTLEN];
1918 char *fmt;
1919 const char *pwd;
1920 int i, trim;
1921 static char internal_error[] = "??";
1922
1923 /*
1924 * Select prompt format.
1925 */
1926 switch (whichprompt) {
1927 case 0:
1928 fmt = nullstr;
1929 break;
1930 case 1:
1931 fmt = ps1val();
1932 break;
1933 case 2:
1934 fmt = ps2val();
1935 break;
1936 default:
1937 return internal_error;
1938 }
1939
1940 /*
1941 * Format prompt string.
1942 */
1943 for (i = 0; (i < 127) && (*fmt != '\0'); i++, fmt++)
1944 if (*fmt == '\\')
1945 switch (*++fmt) {
1946
1947 /*
1948 * Hostname.
1949 *
1950 * \h specifies just the local hostname,
1951 * \H specifies fully-qualified hostname.
1952 */
1953 case 'h':
1954 case 'H':
1955 ps[i] = '\0';
1956 gethostname(&ps[i], PROMPTLEN - i);
1957 /* Skip to end of hostname. */
1958 trim = (*fmt == 'h') ? '.' : '\0';
1959 while ((ps[i+1] != '\0') && (ps[i+1] != trim))
1960 i++;
1961 break;
1962
1963 /*
1964 * Working directory.
1965 *
1966 * \W specifies just the final component,
1967 * \w specifies the entire path.
1968 */
1969 case 'W':
1970 case 'w':
1971 pwd = lookupvar("PWD");
1972 if (pwd == NULL)
1973 pwd = "?";
1974 if (*fmt == 'W' &&
1975 *pwd == '/' && pwd[1] != '\0')
1976 strlcpy(&ps[i], strrchr(pwd, '/') + 1,
1977 PROMPTLEN - i);
1978 else
1979 strlcpy(&ps[i], pwd, PROMPTLEN - i);
1980 /* Skip to end of path. */
1981 while (ps[i + 1] != '\0')
1982 i++;
1983 break;
1984
1985 /*
1986 * Superuser status.
1987 *
1988 * '$' for normal users, '#' for root.
1989 */
1990 case '$':
1991 ps[i] = (geteuid() != 0) ? '$' : '#';
1992 break;
1993
1994 /*
1995 * A literal \.
1996 */
1997 case '\\':
1998 ps[i] = '\\';
1999 break;
2000
2001 /*
2002 * Emit unrecognized formats verbatim.
2003 */
2004 default:
2005 ps[i++] = '\\';
2006 ps[i] = *fmt;
2007 break;
2008 }
2009 else
2010 ps[i] = *fmt;
2011 ps[i] = '\0';
2012 return (ps);
2013 }
2014
2015
2016 const char *
expandstr(const char * ps)2017 expandstr(const char *ps)
2018 {
2019 union node n;
2020 struct jmploc jmploc;
2021 struct jmploc *const savehandler = handler;
2022 const int saveprompt = doprompt;
2023 struct parsefile *const savetopfile = getcurrentfile();
2024 struct parser_temp *const saveparser_temp = parser_temp;
2025 const char *result = NULL;
2026
2027 if (!setjmp(jmploc.loc)) {
2028 handler = &jmploc;
2029 parser_temp = NULL;
2030 setinputstring(ps, 1);
2031 doprompt = 0;
2032 readtoken1(pgetc(), DQSYNTAX, "\n\n", 0);
2033 if (backquotelist != NULL)
2034 error("Command substitution not allowed here");
2035
2036 n.narg.type = NARG;
2037 n.narg.next = NULL;
2038 n.narg.text = wordtext;
2039 n.narg.backquote = backquotelist;
2040
2041 expandarg(&n, NULL, 0);
2042 result = stackblock();
2043 INTOFF;
2044 }
2045 handler = savehandler;
2046 doprompt = saveprompt;
2047 popfilesupto(savetopfile);
2048 if (parser_temp != saveparser_temp) {
2049 parser_temp_free_all();
2050 parser_temp = saveparser_temp;
2051 }
2052 if (result != NULL) {
2053 INTON;
2054 } else if (exception == EXINT)
2055 raise(SIGINT);
2056 return result;
2057 }
2058