1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Kenneth Almquist.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #ifndef lint
36 #if 0
37 static char sccsid[] = "@(#)parser.c 8.7 (Berkeley) 5/16/95";
38 #endif
39 #endif /* not lint */
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD: head/bin/sh/parser.c 343399 2019-01-24 11:59:46Z trasz $");
42
43 #include <sys/param.h>
44 #include <pwd.h>
45 #include <stdlib.h>
46 #include <unistd.h>
47 #include <stdio.h>
48
49 #include "shell.h"
50 #include "parser.h"
51 #include "nodes.h"
52 #include "expand.h" /* defines rmescapes() */
53 #include "syntax.h"
54 #include "options.h"
55 #include "input.h"
56 #include "output.h"
57 #include "var.h"
58 #include "error.h"
59 #include "memalloc.h"
60 #include "mystring.h"
61 #include "alias.h"
62 #include "show.h"
63 #include "eval.h"
64 #include "exec.h" /* to check for special builtins */
65 #ifndef NO_HISTORY
66 #include "myhistedit.h"
67 #endif
68
69 /*
70 * Shell command parser.
71 */
72
73 #define PROMPTLEN 128
74
75 /* values of checkkwd variable */
76 #define CHKALIAS 0x1
77 #define CHKKWD 0x2
78 #define CHKNL 0x4
79
80 /* values returned by readtoken */
81 #include "token.h"
82
83
84
85 struct heredoc {
86 struct heredoc *next; /* next here document in list */
87 union node *here; /* redirection node */
88 char *eofmark; /* string indicating end of input */
89 int striptabs; /* if set, strip leading tabs */
90 };
91
92 struct parser_temp {
93 struct parser_temp *next;
94 void *data;
95 };
96
97
98 static struct heredoc *heredoclist; /* list of here documents to read */
99 static int doprompt; /* if set, prompt the user */
100 static int needprompt; /* true if interactive and at start of line */
101 static int lasttoken; /* last token read */
102 static int tokpushback; /* last token pushed back */
103 static char *wordtext; /* text of last word returned by readtoken */
104 static int checkkwd;
105 static struct nodelist *backquotelist;
106 static union node *redirnode;
107 static struct heredoc *heredoc;
108 static int quoteflag; /* set if (part of) last token was quoted */
109 static int startlinno; /* line # where last token started */
110 static int funclinno; /* line # where the current function started */
111 static struct parser_temp *parser_temp;
112
113 #define NOEOFMARK ((const char *)&heredoclist)
114
115
116 static union node *list(int);
117 static union node *andor(void);
118 static union node *pipeline(void);
119 static union node *command(void);
120 static union node *simplecmd(union node **, union node *);
121 static union node *makename(void);
122 static union node *makebinary(int type, union node *n1, union node *n2);
123 static void parsefname(void);
124 static void parseheredoc(void);
125 static int peektoken(void);
126 static int readtoken(void);
127 static int xxreadtoken(void);
128 static int readtoken1(int, const char *, const char *, int);
129 static int noexpand(char *);
130 static void consumetoken(int);
131 static void synexpect(int) __dead2;
132 static void synerror(const char *) __dead2;
133 static void setprompt(int);
134 static int pgetc_linecont(void);
135 static void getusername(char *, size_t);
136
137
138 static void *
parser_temp_alloc(size_t len)139 parser_temp_alloc(size_t len)
140 {
141 struct parser_temp *t;
142
143 INTOFF;
144 t = ckmalloc(sizeof(*t));
145 t->data = NULL;
146 t->next = parser_temp;
147 parser_temp = t;
148 t->data = ckmalloc(len);
149 INTON;
150 return t->data;
151 }
152
153
154 static void *
parser_temp_realloc(void * ptr,size_t len)155 parser_temp_realloc(void *ptr, size_t len)
156 {
157 struct parser_temp *t;
158
159 INTOFF;
160 t = parser_temp;
161 if (ptr != t->data)
162 error("bug: parser_temp_realloc misused");
163 t->data = ckrealloc(t->data, len);
164 INTON;
165 return t->data;
166 }
167
168
169 static void
parser_temp_free_upto(void * ptr)170 parser_temp_free_upto(void *ptr)
171 {
172 struct parser_temp *t;
173 int done = 0;
174
175 INTOFF;
176 while (parser_temp != NULL && !done) {
177 t = parser_temp;
178 parser_temp = t->next;
179 done = t->data == ptr;
180 ckfree(t->data);
181 ckfree(t);
182 }
183 INTON;
184 if (!done)
185 error("bug: parser_temp_free_upto misused");
186 }
187
188
189 static void
parser_temp_free_all(void)190 parser_temp_free_all(void)
191 {
192 struct parser_temp *t;
193
194 INTOFF;
195 while (parser_temp != NULL) {
196 t = parser_temp;
197 parser_temp = t->next;
198 ckfree(t->data);
199 ckfree(t);
200 }
201 INTON;
202 }
203
204
205 /*
206 * Read and parse a command. Returns NEOF on end of file. (NULL is a
207 * valid parse tree indicating a blank line.)
208 */
209
210 union node *
parsecmd(int interact)211 parsecmd(int interact)
212 {
213 int t;
214
215 /* This assumes the parser is not re-entered,
216 * which could happen if we add command substitution on PS1/PS2.
217 */
218 parser_temp_free_all();
219 heredoclist = NULL;
220
221 tokpushback = 0;
222 checkkwd = 0;
223 doprompt = interact;
224 if (doprompt)
225 setprompt(1);
226 else
227 setprompt(0);
228 needprompt = 0;
229 t = readtoken();
230 if (t == TEOF)
231 return NEOF;
232 if (t == TNL)
233 return NULL;
234 tokpushback++;
235 return list(1);
236 }
237
238
239 /*
240 * Read and parse words for wordexp.
241 * Returns a list of NARG nodes; NULL if there are no words.
242 */
243 union node *
parsewordexp(void)244 parsewordexp(void)
245 {
246 union node *n, *first = NULL, **pnext;
247 int t;
248
249 /* This assumes the parser is not re-entered,
250 * which could happen if we add command substitution on PS1/PS2.
251 */
252 parser_temp_free_all();
253 heredoclist = NULL;
254
255 tokpushback = 0;
256 checkkwd = 0;
257 doprompt = 0;
258 setprompt(0);
259 needprompt = 0;
260 pnext = &first;
261 while ((t = readtoken()) != TEOF) {
262 if (t != TWORD)
263 synexpect(TWORD);
264 n = makename();
265 *pnext = n;
266 pnext = &n->narg.next;
267 }
268 return first;
269 }
270
271
272 static union node *
list(int nlflag)273 list(int nlflag)
274 {
275 union node *ntop, *n1, *n2, *n3;
276 int tok;
277
278 checkkwd = CHKNL | CHKKWD | CHKALIAS;
279 if (!nlflag && tokendlist[peektoken()])
280 return NULL;
281 ntop = n1 = NULL;
282 for (;;) {
283 n2 = andor();
284 tok = readtoken();
285 if (tok == TBACKGND) {
286 if (n2 != NULL && n2->type == NPIPE) {
287 n2->npipe.backgnd = 1;
288 } else if (n2 != NULL && n2->type == NREDIR) {
289 n2->type = NBACKGND;
290 } else {
291 n3 = (union node *)stalloc(sizeof (struct nredir));
292 n3->type = NBACKGND;
293 n3->nredir.n = n2;
294 n3->nredir.redirect = NULL;
295 n2 = n3;
296 }
297 }
298 if (ntop == NULL)
299 ntop = n2;
300 else if (n1 == NULL) {
301 n1 = makebinary(NSEMI, ntop, n2);
302 ntop = n1;
303 }
304 else {
305 n3 = makebinary(NSEMI, n1->nbinary.ch2, n2);
306 n1->nbinary.ch2 = n3;
307 n1 = n3;
308 }
309 switch (tok) {
310 case TBACKGND:
311 case TSEMI:
312 tok = readtoken();
313 /* FALLTHROUGH */
314 case TNL:
315 if (tok == TNL) {
316 parseheredoc();
317 if (nlflag)
318 return ntop;
319 } else if (tok == TEOF && nlflag) {
320 parseheredoc();
321 return ntop;
322 } else {
323 tokpushback++;
324 }
325 checkkwd = CHKNL | CHKKWD | CHKALIAS;
326 if (!nlflag && tokendlist[peektoken()])
327 return ntop;
328 break;
329 case TEOF:
330 if (heredoclist)
331 parseheredoc();
332 else
333 pungetc(); /* push back EOF on input */
334 return ntop;
335 default:
336 if (nlflag)
337 synexpect(-1);
338 tokpushback++;
339 return ntop;
340 }
341 }
342 }
343
344
345
346 static union node *
andor(void)347 andor(void)
348 {
349 union node *n;
350 int t;
351
352 n = pipeline();
353 for (;;) {
354 if ((t = readtoken()) == TAND) {
355 t = NAND;
356 } else if (t == TOR) {
357 t = NOR;
358 } else {
359 tokpushback++;
360 return n;
361 }
362 n = makebinary(t, n, pipeline());
363 }
364 }
365
366
367
368 static union node *
pipeline(void)369 pipeline(void)
370 {
371 union node *n1, *n2, *pipenode;
372 struct nodelist *lp, *prev;
373 int negate, t;
374
375 negate = 0;
376 checkkwd = CHKNL | CHKKWD | CHKALIAS;
377 TRACE(("pipeline: entered\n"));
378 while (readtoken() == TNOT)
379 negate = !negate;
380 tokpushback++;
381 n1 = command();
382 if (readtoken() == TPIPE) {
383 pipenode = (union node *)stalloc(sizeof (struct npipe));
384 pipenode->type = NPIPE;
385 pipenode->npipe.backgnd = 0;
386 lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
387 pipenode->npipe.cmdlist = lp;
388 lp->n = n1;
389 do {
390 prev = lp;
391 lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
392 checkkwd = CHKNL | CHKKWD | CHKALIAS;
393 t = readtoken();
394 tokpushback++;
395 if (t == TNOT)
396 lp->n = pipeline();
397 else
398 lp->n = command();
399 prev->next = lp;
400 } while (readtoken() == TPIPE);
401 lp->next = NULL;
402 n1 = pipenode;
403 }
404 tokpushback++;
405 if (negate) {
406 n2 = (union node *)stalloc(sizeof (struct nnot));
407 n2->type = NNOT;
408 n2->nnot.com = n1;
409 return n2;
410 } else
411 return n1;
412 }
413
414
415
416 static union node *
command(void)417 command(void)
418 {
419 union node *n1, *n2;
420 union node *ap, **app;
421 union node *cp, **cpp;
422 union node *redir, **rpp;
423 int t;
424 int is_subshell;
425
426 checkkwd = CHKNL | CHKKWD | CHKALIAS;
427 is_subshell = 0;
428 redir = NULL;
429 n1 = NULL;
430 rpp = &redir;
431
432 /* Check for redirection which may precede command */
433 while (readtoken() == TREDIR) {
434 *rpp = n2 = redirnode;
435 rpp = &n2->nfile.next;
436 parsefname();
437 }
438 tokpushback++;
439
440 switch (readtoken()) {
441 case TIF:
442 n1 = (union node *)stalloc(sizeof (struct nif));
443 n1->type = NIF;
444 if ((n1->nif.test = list(0)) == NULL)
445 synexpect(-1);
446 consumetoken(TTHEN);
447 n1->nif.ifpart = list(0);
448 n2 = n1;
449 while (readtoken() == TELIF) {
450 n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif));
451 n2 = n2->nif.elsepart;
452 n2->type = NIF;
453 if ((n2->nif.test = list(0)) == NULL)
454 synexpect(-1);
455 consumetoken(TTHEN);
456 n2->nif.ifpart = list(0);
457 }
458 if (lasttoken == TELSE)
459 n2->nif.elsepart = list(0);
460 else {
461 n2->nif.elsepart = NULL;
462 tokpushback++;
463 }
464 consumetoken(TFI);
465 checkkwd = CHKKWD | CHKALIAS;
466 break;
467 case TWHILE:
468 case TUNTIL:
469 t = lasttoken;
470 if ((n1 = list(0)) == NULL)
471 synexpect(-1);
472 consumetoken(TDO);
473 n1 = makebinary((t == TWHILE)? NWHILE : NUNTIL, n1, list(0));
474 consumetoken(TDONE);
475 checkkwd = CHKKWD | CHKALIAS;
476 break;
477 case TFOR:
478 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext))
479 synerror("Bad for loop variable");
480 n1 = (union node *)stalloc(sizeof (struct nfor));
481 n1->type = NFOR;
482 n1->nfor.var = wordtext;
483 while (readtoken() == TNL)
484 ;
485 if (lasttoken == TWORD && ! quoteflag && equal(wordtext, "in")) {
486 app = ≈
487 while (readtoken() == TWORD) {
488 n2 = makename();
489 *app = n2;
490 app = &n2->narg.next;
491 }
492 *app = NULL;
493 n1->nfor.args = ap;
494 if (lasttoken != TNL && lasttoken != TSEMI)
495 synexpect(-1);
496 } else {
497 static char argvars[5] = {
498 CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0'
499 };
500 n2 = (union node *)stalloc(sizeof (struct narg));
501 n2->type = NARG;
502 n2->narg.text = argvars;
503 n2->narg.backquote = NULL;
504 n2->narg.next = NULL;
505 n1->nfor.args = n2;
506 /*
507 * Newline or semicolon here is optional (but note
508 * that the original Bourne shell only allowed NL).
509 */
510 if (lasttoken != TNL && lasttoken != TSEMI)
511 tokpushback++;
512 }
513 checkkwd = CHKNL | CHKKWD | CHKALIAS;
514 if ((t = readtoken()) == TDO)
515 t = TDONE;
516 else if (t == TBEGIN)
517 t = TEND;
518 else
519 synexpect(-1);
520 n1->nfor.body = list(0);
521 consumetoken(t);
522 checkkwd = CHKKWD | CHKALIAS;
523 break;
524 case TCASE:
525 n1 = (union node *)stalloc(sizeof (struct ncase));
526 n1->type = NCASE;
527 consumetoken(TWORD);
528 n1->ncase.expr = makename();
529 while (readtoken() == TNL);
530 if (lasttoken != TWORD || ! equal(wordtext, "in"))
531 synerror("expecting \"in\"");
532 cpp = &n1->ncase.cases;
533 checkkwd = CHKNL | CHKKWD, readtoken();
534 while (lasttoken != TESAC) {
535 *cpp = cp = (union node *)stalloc(sizeof (struct nclist));
536 cp->type = NCLIST;
537 app = &cp->nclist.pattern;
538 if (lasttoken == TLP)
539 readtoken();
540 for (;;) {
541 *app = ap = makename();
542 checkkwd = CHKNL | CHKKWD;
543 if (readtoken() != TPIPE)
544 break;
545 app = &ap->narg.next;
546 readtoken();
547 }
548 ap->narg.next = NULL;
549 if (lasttoken != TRP)
550 synexpect(TRP);
551 cp->nclist.body = list(0);
552
553 checkkwd = CHKNL | CHKKWD | CHKALIAS;
554 if ((t = readtoken()) != TESAC) {
555 if (t == TENDCASE)
556 ;
557 else if (t == TFALLTHRU)
558 cp->type = NCLISTFALLTHRU;
559 else
560 synexpect(TENDCASE);
561 checkkwd = CHKNL | CHKKWD, readtoken();
562 }
563 cpp = &cp->nclist.next;
564 }
565 *cpp = NULL;
566 checkkwd = CHKKWD | CHKALIAS;
567 break;
568 case TLP:
569 n1 = (union node *)stalloc(sizeof (struct nredir));
570 n1->type = NSUBSHELL;
571 n1->nredir.n = list(0);
572 n1->nredir.redirect = NULL;
573 consumetoken(TRP);
574 checkkwd = CHKKWD | CHKALIAS;
575 is_subshell = 1;
576 break;
577 case TBEGIN:
578 n1 = list(0);
579 consumetoken(TEND);
580 checkkwd = CHKKWD | CHKALIAS;
581 break;
582 /* A simple command must have at least one redirection or word. */
583 case TBACKGND:
584 case TSEMI:
585 case TAND:
586 case TOR:
587 case TPIPE:
588 case TENDCASE:
589 case TFALLTHRU:
590 case TEOF:
591 case TNL:
592 case TRP:
593 if (!redir)
594 synexpect(-1);
595 /* FALLTHROUGH */
596 case TWORD:
597 tokpushback++;
598 n1 = simplecmd(rpp, redir);
599 return n1;
600 default:
601 synexpect(-1);
602 }
603
604 /* Now check for redirection which may follow command */
605 while (readtoken() == TREDIR) {
606 *rpp = n2 = redirnode;
607 rpp = &n2->nfile.next;
608 parsefname();
609 }
610 tokpushback++;
611 *rpp = NULL;
612 if (redir) {
613 if (!is_subshell) {
614 n2 = (union node *)stalloc(sizeof (struct nredir));
615 n2->type = NREDIR;
616 n2->nredir.n = n1;
617 n1 = n2;
618 }
619 n1->nredir.redirect = redir;
620 }
621
622 return n1;
623 }
624
625
626 static union node *
simplecmd(union node ** rpp,union node * redir)627 simplecmd(union node **rpp, union node *redir)
628 {
629 union node *args, **app;
630 union node **orig_rpp = rpp;
631 union node *n = NULL;
632 int special;
633 int savecheckkwd;
634
635 /* If we don't have any redirections already, then we must reset */
636 /* rpp to be the address of the local redir variable. */
637 if (redir == NULL)
638 rpp = &redir;
639
640 args = NULL;
641 app = &args;
642 /*
643 * We save the incoming value, because we need this for shell
644 * functions. There can not be a redirect or an argument between
645 * the function name and the open parenthesis.
646 */
647 orig_rpp = rpp;
648
649 savecheckkwd = CHKALIAS;
650
651 for (;;) {
652 checkkwd = savecheckkwd;
653 if (readtoken() == TWORD) {
654 n = makename();
655 *app = n;
656 app = &n->narg.next;
657 if (savecheckkwd != 0 && !isassignment(wordtext))
658 savecheckkwd = 0;
659 } else if (lasttoken == TREDIR) {
660 *rpp = n = redirnode;
661 rpp = &n->nfile.next;
662 parsefname(); /* read name of redirection file */
663 } else if (lasttoken == TLP && app == &args->narg.next
664 && rpp == orig_rpp) {
665 /* We have a function */
666 consumetoken(TRP);
667 funclinno = plinno;
668 /*
669 * - Require plain text.
670 * - Functions with '/' cannot be called.
671 * - Reject name=().
672 * - Reject ksh extended glob patterns.
673 */
674 if (!noexpand(n->narg.text) || quoteflag ||
675 strchr(n->narg.text, '/') ||
676 strchr("!%*+-=?@}~",
677 n->narg.text[strlen(n->narg.text) - 1]))
678 synerror("Bad function name");
679 rmescapes(n->narg.text);
680 if (find_builtin(n->narg.text, &special) >= 0 &&
681 special)
682 synerror("Cannot override a special builtin with a function");
683 n->type = NDEFUN;
684 n->narg.next = command();
685 funclinno = 0;
686 return n;
687 } else {
688 tokpushback++;
689 break;
690 }
691 }
692 *app = NULL;
693 *rpp = NULL;
694 n = (union node *)stalloc(sizeof (struct ncmd));
695 n->type = NCMD;
696 n->ncmd.args = args;
697 n->ncmd.redirect = redir;
698 return n;
699 }
700
701 static union node *
makename(void)702 makename(void)
703 {
704 union node *n;
705
706 n = (union node *)stalloc(sizeof (struct narg));
707 n->type = NARG;
708 n->narg.next = NULL;
709 n->narg.text = wordtext;
710 n->narg.backquote = backquotelist;
711 return n;
712 }
713
714 static union node *
makebinary(int type,union node * n1,union node * n2)715 makebinary(int type, union node *n1, union node *n2)
716 {
717 union node *n;
718
719 n = (union node *)stalloc(sizeof (struct nbinary));
720 n->type = type;
721 n->nbinary.ch1 = n1;
722 n->nbinary.ch2 = n2;
723 return (n);
724 }
725
726 void
forcealias(void)727 forcealias(void)
728 {
729 checkkwd |= CHKALIAS;
730 }
731
732 void
fixredir(union node * n,const char * text,int err)733 fixredir(union node *n, const char *text, int err)
734 {
735 TRACE(("Fix redir %s %d\n", text, err));
736 if (!err)
737 n->ndup.vname = NULL;
738
739 if (is_digit(text[0]) && text[1] == '\0')
740 n->ndup.dupfd = digit_val(text[0]);
741 else if (text[0] == '-' && text[1] == '\0')
742 n->ndup.dupfd = -1;
743 else {
744
745 if (err)
746 synerror("Bad fd number");
747 else
748 n->ndup.vname = makename();
749 }
750 }
751
752
753 static void
parsefname(void)754 parsefname(void)
755 {
756 union node *n = redirnode;
757
758 consumetoken(TWORD);
759 if (n->type == NHERE) {
760 struct heredoc *here = heredoc;
761 struct heredoc *p;
762
763 if (quoteflag == 0)
764 n->type = NXHERE;
765 TRACE(("Here document %d\n", n->type));
766 if (here->striptabs) {
767 while (*wordtext == '\t')
768 wordtext++;
769 }
770 if (! noexpand(wordtext))
771 synerror("Illegal eof marker for << redirection");
772 rmescapes(wordtext);
773 here->eofmark = wordtext;
774 here->next = NULL;
775 if (heredoclist == NULL)
776 heredoclist = here;
777 else {
778 for (p = heredoclist ; p->next ; p = p->next);
779 p->next = here;
780 }
781 } else if (n->type == NTOFD || n->type == NFROMFD) {
782 fixredir(n, wordtext, 0);
783 } else {
784 n->nfile.fname = makename();
785 }
786 }
787
788
789 /*
790 * Input any here documents.
791 */
792
793 static void
parseheredoc(void)794 parseheredoc(void)
795 {
796 struct heredoc *here;
797 union node *n;
798
799 while (heredoclist) {
800 here = heredoclist;
801 heredoclist = here->next;
802 if (needprompt) {
803 setprompt(2);
804 needprompt = 0;
805 }
806 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX,
807 here->eofmark, here->striptabs);
808 n = makename();
809 here->here->nhere.doc = n;
810 }
811 }
812
813 static int
peektoken(void)814 peektoken(void)
815 {
816 int t;
817
818 t = readtoken();
819 tokpushback++;
820 return (t);
821 }
822
823 static int
readtoken(void)824 readtoken(void)
825 {
826 int t;
827 struct alias *ap;
828 #ifdef DEBUG
829 int alreadyseen = tokpushback;
830 #endif
831
832 top:
833 t = xxreadtoken();
834
835 /*
836 * eat newlines
837 */
838 if (checkkwd & CHKNL) {
839 while (t == TNL) {
840 parseheredoc();
841 t = xxreadtoken();
842 }
843 }
844
845 /*
846 * check for keywords and aliases
847 */
848 if (t == TWORD && !quoteflag)
849 {
850 const char * const *pp;
851
852 if (checkkwd & CHKKWD)
853 for (pp = parsekwd; *pp; pp++) {
854 if (**pp == *wordtext && equal(*pp, wordtext))
855 {
856 lasttoken = t = pp - parsekwd + KWDOFFSET;
857 TRACE(("keyword %s recognized\n", tokname[t]));
858 goto out;
859 }
860 }
861 if (checkkwd & CHKALIAS &&
862 (ap = lookupalias(wordtext, 1)) != NULL) {
863 pushstring(ap->val, strlen(ap->val), ap);
864 goto top;
865 }
866 }
867 out:
868 if (t != TNOT)
869 checkkwd = 0;
870
871 #ifdef DEBUG
872 if (!alreadyseen)
873 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
874 else
875 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
876 #endif
877 return (t);
878 }
879
880
881 /*
882 * Read the next input token.
883 * If the token is a word, we set backquotelist to the list of cmds in
884 * backquotes. We set quoteflag to true if any part of the word was
885 * quoted.
886 * If the token is TREDIR, then we set redirnode to a structure containing
887 * the redirection.
888 * In all cases, the variable startlinno is set to the number of the line
889 * on which the token starts.
890 *
891 * [Change comment: here documents and internal procedures]
892 * [Readtoken shouldn't have any arguments. Perhaps we should make the
893 * word parsing code into a separate routine. In this case, readtoken
894 * doesn't need to have any internal procedures, but parseword does.
895 * We could also make parseoperator in essence the main routine, and
896 * have parseword (readtoken1?) handle both words and redirection.]
897 */
898
899 #define RETURN(token) return lasttoken = token
900
901 static int
xxreadtoken(void)902 xxreadtoken(void)
903 {
904 int c;
905
906 if (tokpushback) {
907 tokpushback = 0;
908 return lasttoken;
909 }
910 if (needprompt) {
911 setprompt(2);
912 needprompt = 0;
913 }
914 startlinno = plinno;
915 for (;;) { /* until token or start of word found */
916 c = pgetc_macro();
917 switch (c) {
918 case ' ': case '\t':
919 continue;
920 case '#':
921 while ((c = pgetc()) != '\n' && c != PEOF);
922 pungetc();
923 continue;
924 case '\\':
925 if (pgetc() == '\n') {
926 startlinno = ++plinno;
927 if (doprompt)
928 setprompt(2);
929 else
930 setprompt(0);
931 continue;
932 }
933 pungetc();
934 /* FALLTHROUGH */
935 default:
936 return readtoken1(c, BASESYNTAX, (char *)NULL, 0);
937 case '\n':
938 plinno++;
939 needprompt = doprompt;
940 RETURN(TNL);
941 case PEOF:
942 RETURN(TEOF);
943 case '&':
944 if (pgetc_linecont() == '&')
945 RETURN(TAND);
946 pungetc();
947 RETURN(TBACKGND);
948 case '|':
949 if (pgetc_linecont() == '|')
950 RETURN(TOR);
951 pungetc();
952 RETURN(TPIPE);
953 case ';':
954 c = pgetc_linecont();
955 if (c == ';')
956 RETURN(TENDCASE);
957 else if (c == '&')
958 RETURN(TFALLTHRU);
959 pungetc();
960 RETURN(TSEMI);
961 case '(':
962 RETURN(TLP);
963 case ')':
964 RETURN(TRP);
965 }
966 }
967 #undef RETURN
968 }
969
970
971 #define MAXNEST_static 8
972 struct tokenstate
973 {
974 const char *syntax; /* *SYNTAX */
975 int parenlevel; /* levels of parentheses in arithmetic */
976 enum tokenstate_category
977 {
978 TSTATE_TOP,
979 TSTATE_VAR_OLD, /* ${var+-=?}, inherits dquotes */
980 TSTATE_VAR_NEW, /* other ${var...}, own dquote state */
981 TSTATE_ARITH
982 } category;
983 };
984
985
986 /*
987 * Check to see whether we are at the end of the here document. When this
988 * is called, c is set to the first character of the next input line. If
989 * we are at the end of the here document, this routine sets the c to PEOF.
990 * The new value of c is returned.
991 */
992
993 static int
checkend(int c,const char * eofmark,int striptabs)994 checkend(int c, const char *eofmark, int striptabs)
995 {
996 if (striptabs) {
997 while (c == '\t')
998 c = pgetc();
999 }
1000 if (c == *eofmark) {
1001 int c2;
1002 const char *q;
1003
1004 for (q = eofmark + 1; c2 = pgetc(), *q != '\0' && c2 == *q; q++)
1005 ;
1006 if ((c2 == PEOF || c2 == '\n') && *q == '\0') {
1007 c = PEOF;
1008 if (c2 == '\n') {
1009 plinno++;
1010 needprompt = doprompt;
1011 }
1012 } else {
1013 pungetc();
1014 pushstring(eofmark + 1, q - (eofmark + 1), NULL);
1015 }
1016 } else if (c == '\n' && *eofmark == '\0') {
1017 c = PEOF;
1018 plinno++;
1019 needprompt = doprompt;
1020 }
1021 return (c);
1022 }
1023
1024
1025 /*
1026 * Parse a redirection operator. The variable "out" points to a string
1027 * specifying the fd to be redirected. The variable "c" contains the
1028 * first character of the redirection operator.
1029 */
1030
1031 static void
parseredir(char * out,int c)1032 parseredir(char *out, int c)
1033 {
1034 char fd = *out;
1035 union node *np;
1036
1037 np = (union node *)stalloc(sizeof (struct nfile));
1038 if (c == '>') {
1039 np->nfile.fd = 1;
1040 c = pgetc_linecont();
1041 if (c == '>')
1042 np->type = NAPPEND;
1043 else if (c == '&')
1044 np->type = NTOFD;
1045 else if (c == '|')
1046 np->type = NCLOBBER;
1047 else {
1048 np->type = NTO;
1049 pungetc();
1050 }
1051 } else { /* c == '<' */
1052 np->nfile.fd = 0;
1053 c = pgetc_linecont();
1054 if (c == '<') {
1055 if (sizeof (struct nfile) != sizeof (struct nhere)) {
1056 np = (union node *)stalloc(sizeof (struct nhere));
1057 np->nfile.fd = 0;
1058 }
1059 np->type = NHERE;
1060 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc));
1061 heredoc->here = np;
1062 if ((c = pgetc_linecont()) == '-') {
1063 heredoc->striptabs = 1;
1064 } else {
1065 heredoc->striptabs = 0;
1066 pungetc();
1067 }
1068 } else if (c == '&')
1069 np->type = NFROMFD;
1070 else if (c == '>')
1071 np->type = NFROMTO;
1072 else {
1073 np->type = NFROM;
1074 pungetc();
1075 }
1076 }
1077 if (fd != '\0')
1078 np->nfile.fd = digit_val(fd);
1079 redirnode = np;
1080 }
1081
1082 /*
1083 * Called to parse command substitutions.
1084 */
1085
1086 static char *
parsebackq(char * out,struct nodelist ** pbqlist,int oldstyle,int dblquote,int quoted)1087 parsebackq(char *out, struct nodelist **pbqlist,
1088 int oldstyle, int dblquote, int quoted)
1089 {
1090 struct nodelist **nlpp;
1091 union node *n;
1092 char *volatile str;
1093 struct jmploc jmploc;
1094 struct jmploc *const savehandler = handler;
1095 size_t savelen;
1096 int saveprompt;
1097 const int bq_startlinno = plinno;
1098 char *volatile ostr = NULL;
1099 struct parsefile *const savetopfile = getcurrentfile();
1100 struct heredoc *const saveheredoclist = heredoclist;
1101 struct heredoc *here;
1102
1103 str = NULL;
1104 if (setjmp(jmploc.loc)) {
1105 popfilesupto(savetopfile);
1106 if (str)
1107 ckfree(str);
1108 if (ostr)
1109 ckfree(ostr);
1110 heredoclist = saveheredoclist;
1111 handler = savehandler;
1112 if (exception == EXERROR) {
1113 startlinno = bq_startlinno;
1114 synerror("Error in command substitution");
1115 }
1116 longjmp(handler->loc, 1);
1117 }
1118 INTOFF;
1119 savelen = out - stackblock();
1120 if (savelen > 0) {
1121 str = ckmalloc(savelen);
1122 memcpy(str, stackblock(), savelen);
1123 }
1124 handler = &jmploc;
1125 heredoclist = NULL;
1126 INTON;
1127 if (oldstyle) {
1128 /* We must read until the closing backquote, giving special
1129 treatment to some slashes, and then push the string and
1130 reread it as input, interpreting it normally. */
1131 char *oout;
1132 int c;
1133 int olen;
1134
1135
1136 STARTSTACKSTR(oout);
1137 for (;;) {
1138 if (needprompt) {
1139 setprompt(2);
1140 needprompt = 0;
1141 }
1142 CHECKSTRSPACE(2, oout);
1143 c = pgetc_linecont();
1144 if (c == '`')
1145 break;
1146 switch (c) {
1147 case '\\':
1148 c = pgetc();
1149 if (c != '\\' && c != '`' && c != '$'
1150 && (!dblquote || c != '"'))
1151 USTPUTC('\\', oout);
1152 break;
1153
1154 case '\n':
1155 plinno++;
1156 needprompt = doprompt;
1157 break;
1158
1159 case PEOF:
1160 startlinno = plinno;
1161 synerror("EOF in backquote substitution");
1162 break;
1163
1164 default:
1165 break;
1166 }
1167 USTPUTC(c, oout);
1168 }
1169 USTPUTC('\0', oout);
1170 olen = oout - stackblock();
1171 INTOFF;
1172 ostr = ckmalloc(olen);
1173 memcpy(ostr, stackblock(), olen);
1174 setinputstring(ostr, 1);
1175 INTON;
1176 }
1177 nlpp = pbqlist;
1178 while (*nlpp)
1179 nlpp = &(*nlpp)->next;
1180 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist));
1181 (*nlpp)->next = NULL;
1182
1183 if (oldstyle) {
1184 saveprompt = doprompt;
1185 doprompt = 0;
1186 }
1187
1188 n = list(0);
1189
1190 if (oldstyle) {
1191 if (peektoken() != TEOF)
1192 synexpect(-1);
1193 doprompt = saveprompt;
1194 } else
1195 consumetoken(TRP);
1196
1197 (*nlpp)->n = n;
1198 if (oldstyle) {
1199 /*
1200 * Start reading from old file again, ignoring any pushed back
1201 * tokens left from the backquote parsing
1202 */
1203 popfile();
1204 tokpushback = 0;
1205 }
1206 STARTSTACKSTR(out);
1207 CHECKSTRSPACE(savelen + 1, out);
1208 INTOFF;
1209 if (str) {
1210 memcpy(out, str, savelen);
1211 STADJUST(savelen, out);
1212 ckfree(str);
1213 str = NULL;
1214 }
1215 if (ostr) {
1216 ckfree(ostr);
1217 ostr = NULL;
1218 }
1219 here = saveheredoclist;
1220 if (here != NULL) {
1221 while (here->next != NULL)
1222 here = here->next;
1223 here->next = heredoclist;
1224 heredoclist = saveheredoclist;
1225 }
1226 handler = savehandler;
1227 INTON;
1228 if (quoted)
1229 USTPUTC(CTLBACKQ | CTLQUOTE, out);
1230 else
1231 USTPUTC(CTLBACKQ, out);
1232 return out;
1233 }
1234
1235
1236 /*
1237 * Called to parse a backslash escape sequence inside $'...'.
1238 * The backslash has already been read.
1239 */
1240 static char *
readcstyleesc(char * out)1241 readcstyleesc(char *out)
1242 {
1243 int c, vc, i, n;
1244 unsigned int v;
1245
1246 c = pgetc();
1247 switch (c) {
1248 case '\0':
1249 synerror("Unterminated quoted string");
1250 case '\n':
1251 plinno++;
1252 if (doprompt)
1253 setprompt(2);
1254 else
1255 setprompt(0);
1256 return out;
1257 case '\\':
1258 case '\'':
1259 case '"':
1260 v = c;
1261 break;
1262 case 'a': v = '\a'; break;
1263 case 'b': v = '\b'; break;
1264 case 'e': v = '\033'; break;
1265 case 'f': v = '\f'; break;
1266 case 'n': v = '\n'; break;
1267 case 'r': v = '\r'; break;
1268 case 't': v = '\t'; break;
1269 case 'v': v = '\v'; break;
1270 case 'x':
1271 v = 0;
1272 for (;;) {
1273 c = pgetc();
1274 if (c >= '0' && c <= '9')
1275 v = (v << 4) + c - '0';
1276 else if (c >= 'A' && c <= 'F')
1277 v = (v << 4) + c - 'A' + 10;
1278 else if (c >= 'a' && c <= 'f')
1279 v = (v << 4) + c - 'a' + 10;
1280 else
1281 break;
1282 }
1283 pungetc();
1284 break;
1285 case '0': case '1': case '2': case '3':
1286 case '4': case '5': case '6': case '7':
1287 v = c - '0';
1288 c = pgetc();
1289 if (c >= '0' && c <= '7') {
1290 v <<= 3;
1291 v += c - '0';
1292 c = pgetc();
1293 if (c >= '0' && c <= '7') {
1294 v <<= 3;
1295 v += c - '0';
1296 } else
1297 pungetc();
1298 } else
1299 pungetc();
1300 break;
1301 case 'c':
1302 c = pgetc();
1303 if (c < 0x3f || c > 0x7a || c == 0x60)
1304 synerror("Bad escape sequence");
1305 if (c == '\\' && pgetc() != '\\')
1306 synerror("Bad escape sequence");
1307 if (c == '?')
1308 v = 127;
1309 else
1310 v = c & 0x1f;
1311 break;
1312 case 'u':
1313 case 'U':
1314 n = c == 'U' ? 8 : 4;
1315 v = 0;
1316 for (i = 0; i < n; i++) {
1317 c = pgetc();
1318 if (c >= '0' && c <= '9')
1319 v = (v << 4) + c - '0';
1320 else if (c >= 'A' && c <= 'F')
1321 v = (v << 4) + c - 'A' + 10;
1322 else if (c >= 'a' && c <= 'f')
1323 v = (v << 4) + c - 'a' + 10;
1324 else
1325 synerror("Bad escape sequence");
1326 }
1327 if (v == 0 || (v >= 0xd800 && v <= 0xdfff))
1328 synerror("Bad escape sequence");
1329 /* We really need iconv here. */
1330 if (initial_localeisutf8 && v > 127) {
1331 CHECKSTRSPACE(4, out);
1332 /*
1333 * We cannot use wctomb() as the locale may have
1334 * changed.
1335 */
1336 if (v <= 0x7ff) {
1337 USTPUTC(0xc0 | v >> 6, out);
1338 USTPUTC(0x80 | (v & 0x3f), out);
1339 return out;
1340 } else if (v <= 0xffff) {
1341 USTPUTC(0xe0 | v >> 12, out);
1342 USTPUTC(0x80 | ((v >> 6) & 0x3f), out);
1343 USTPUTC(0x80 | (v & 0x3f), out);
1344 return out;
1345 } else if (v <= 0x10ffff) {
1346 USTPUTC(0xf0 | v >> 18, out);
1347 USTPUTC(0x80 | ((v >> 12) & 0x3f), out);
1348 USTPUTC(0x80 | ((v >> 6) & 0x3f), out);
1349 USTPUTC(0x80 | (v & 0x3f), out);
1350 return out;
1351 }
1352 }
1353 if (v > 127)
1354 v = '?';
1355 break;
1356 default:
1357 synerror("Bad escape sequence");
1358 }
1359 vc = (char)v;
1360 /*
1361 * We can't handle NUL bytes.
1362 * POSIX says we should skip till the closing quote.
1363 */
1364 if (vc == '\0') {
1365 while ((c = pgetc()) != '\'') {
1366 if (c == '\\')
1367 c = pgetc();
1368 if (c == PEOF)
1369 synerror("Unterminated quoted string");
1370 if (c == '\n') {
1371 plinno++;
1372 if (doprompt)
1373 setprompt(2);
1374 else
1375 setprompt(0);
1376 }
1377 }
1378 pungetc();
1379 return out;
1380 }
1381 if (SQSYNTAX[vc] == CCTL)
1382 USTPUTC(CTLESC, out);
1383 USTPUTC(vc, out);
1384 return out;
1385 }
1386
1387
1388 /*
1389 * If eofmark is NULL, read a word or a redirection symbol. If eofmark
1390 * is not NULL, read a here document. In the latter case, eofmark is the
1391 * word which marks the end of the document and striptabs is true if
1392 * leading tabs should be stripped from the document. The argument firstc
1393 * is the first character of the input token or document.
1394 *
1395 * Because C does not have internal subroutines, I have simulated them
1396 * using goto's to implement the subroutine linkage. The following macros
1397 * will run code that appears at the end of readtoken1.
1398 */
1399
1400 #define PARSESUB() {goto parsesub; parsesub_return:;}
1401 #define PARSEARITH() {goto parsearith; parsearith_return:;}
1402
1403 static int
readtoken1(int firstc,char const * initialsyntax,const char * eofmark,int striptabs)1404 readtoken1(int firstc, char const *initialsyntax, const char *eofmark,
1405 int striptabs)
1406 {
1407 int c = firstc;
1408 char *out;
1409 int len;
1410 struct nodelist *bqlist;
1411 int quotef;
1412 int newvarnest;
1413 int level;
1414 int synentry;
1415 struct tokenstate state_static[MAXNEST_static];
1416 int maxnest = MAXNEST_static;
1417 struct tokenstate *state = state_static;
1418 int sqiscstyle = 0;
1419
1420 startlinno = plinno;
1421 quotef = 0;
1422 bqlist = NULL;
1423 newvarnest = 0;
1424 level = 0;
1425 state[level].syntax = initialsyntax;
1426 state[level].parenlevel = 0;
1427 state[level].category = TSTATE_TOP;
1428
1429 STARTSTACKSTR(out);
1430 loop: { /* for each line, until end of word */
1431 if (eofmark && eofmark != NOEOFMARK)
1432 /* set c to PEOF if at end of here document */
1433 c = checkend(c, eofmark, striptabs);
1434 for (;;) { /* until end of line or end of word */
1435 CHECKSTRSPACE(4, out); /* permit 4 calls to USTPUTC */
1436
1437 synentry = state[level].syntax[c];
1438
1439 switch(synentry) {
1440 case CNL: /* '\n' */
1441 if (level == 0)
1442 goto endword; /* exit outer loop */
1443 /* FALLTHROUGH */
1444 case CQNL:
1445 USTPUTC(c, out);
1446 plinno++;
1447 if (doprompt)
1448 setprompt(2);
1449 else
1450 setprompt(0);
1451 c = pgetc();
1452 goto loop; /* continue outer loop */
1453 case CSBACK:
1454 if (sqiscstyle) {
1455 out = readcstyleesc(out);
1456 break;
1457 }
1458 /* FALLTHROUGH */
1459 case CWORD:
1460 USTPUTC(c, out);
1461 break;
1462 case CCTL:
1463 if (eofmark == NULL || initialsyntax != SQSYNTAX)
1464 USTPUTC(CTLESC, out);
1465 USTPUTC(c, out);
1466 break;
1467 case CBACK: /* backslash */
1468 c = pgetc();
1469 if (c == PEOF) {
1470 USTPUTC('\\', out);
1471 pungetc();
1472 } else if (c == '\n') {
1473 plinno++;
1474 if (doprompt)
1475 setprompt(2);
1476 else
1477 setprompt(0);
1478 } else {
1479 if (state[level].syntax == DQSYNTAX &&
1480 c != '\\' && c != '`' && c != '$' &&
1481 (c != '"' || (eofmark != NULL &&
1482 newvarnest == 0)) &&
1483 (c != '}' || state[level].category != TSTATE_VAR_OLD))
1484 USTPUTC('\\', out);
1485 if ((eofmark == NULL ||
1486 newvarnest > 0) &&
1487 state[level].syntax == BASESYNTAX)
1488 USTPUTC(CTLQUOTEMARK, out);
1489 if (SQSYNTAX[c] == CCTL)
1490 USTPUTC(CTLESC, out);
1491 USTPUTC(c, out);
1492 if ((eofmark == NULL ||
1493 newvarnest > 0) &&
1494 state[level].syntax == BASESYNTAX &&
1495 state[level].category == TSTATE_VAR_OLD)
1496 USTPUTC(CTLQUOTEEND, out);
1497 quotef++;
1498 }
1499 break;
1500 case CSQUOTE:
1501 USTPUTC(CTLQUOTEMARK, out);
1502 state[level].syntax = SQSYNTAX;
1503 sqiscstyle = 0;
1504 break;
1505 case CDQUOTE:
1506 USTPUTC(CTLQUOTEMARK, out);
1507 state[level].syntax = DQSYNTAX;
1508 break;
1509 case CENDQUOTE:
1510 if (eofmark != NULL && newvarnest == 0)
1511 USTPUTC(c, out);
1512 else {
1513 if (state[level].category == TSTATE_VAR_OLD)
1514 USTPUTC(CTLQUOTEEND, out);
1515 state[level].syntax = BASESYNTAX;
1516 quotef++;
1517 }
1518 break;
1519 case CVAR: /* '$' */
1520 PARSESUB(); /* parse substitution */
1521 break;
1522 case CENDVAR: /* '}' */
1523 if (level > 0 &&
1524 ((state[level].category == TSTATE_VAR_OLD &&
1525 state[level].syntax ==
1526 state[level - 1].syntax) ||
1527 (state[level].category == TSTATE_VAR_NEW &&
1528 state[level].syntax == BASESYNTAX))) {
1529 if (state[level].category == TSTATE_VAR_NEW)
1530 newvarnest--;
1531 level--;
1532 USTPUTC(CTLENDVAR, out);
1533 } else {
1534 USTPUTC(c, out);
1535 }
1536 break;
1537 case CLP: /* '(' in arithmetic */
1538 state[level].parenlevel++;
1539 USTPUTC(c, out);
1540 break;
1541 case CRP: /* ')' in arithmetic */
1542 if (state[level].parenlevel > 0) {
1543 USTPUTC(c, out);
1544 --state[level].parenlevel;
1545 } else {
1546 if (pgetc_linecont() == ')') {
1547 if (level > 0 &&
1548 state[level].category == TSTATE_ARITH) {
1549 level--;
1550 USTPUTC(CTLENDARI, out);
1551 } else
1552 USTPUTC(')', out);
1553 } else {
1554 /*
1555 * unbalanced parens
1556 * (don't 2nd guess - no error)
1557 */
1558 pungetc();
1559 USTPUTC(')', out);
1560 }
1561 }
1562 break;
1563 case CBQUOTE: /* '`' */
1564 out = parsebackq(out, &bqlist, 1,
1565 state[level].syntax == DQSYNTAX &&
1566 (eofmark == NULL || newvarnest > 0),
1567 state[level].syntax == DQSYNTAX || state[level].syntax == ARISYNTAX);
1568 break;
1569 case CEOF:
1570 goto endword; /* exit outer loop */
1571 case CIGN:
1572 break;
1573 default:
1574 if (level == 0)
1575 goto endword; /* exit outer loop */
1576 USTPUTC(c, out);
1577 }
1578 c = pgetc_macro();
1579 }
1580 }
1581 endword:
1582 if (state[level].syntax == ARISYNTAX)
1583 synerror("Missing '))'");
1584 if (state[level].syntax != BASESYNTAX && eofmark == NULL)
1585 synerror("Unterminated quoted string");
1586 if (state[level].category == TSTATE_VAR_OLD ||
1587 state[level].category == TSTATE_VAR_NEW) {
1588 startlinno = plinno;
1589 synerror("Missing '}'");
1590 }
1591 if (state != state_static)
1592 parser_temp_free_upto(state);
1593 USTPUTC('\0', out);
1594 len = out - stackblock();
1595 out = stackblock();
1596 if (eofmark == NULL) {
1597 if ((c == '>' || c == '<')
1598 && quotef == 0
1599 && len <= 2
1600 && (*out == '\0' || is_digit(*out))) {
1601 parseredir(out, c);
1602 return lasttoken = TREDIR;
1603 } else {
1604 pungetc();
1605 }
1606 }
1607 quoteflag = quotef;
1608 backquotelist = bqlist;
1609 grabstackblock(len);
1610 wordtext = out;
1611 return lasttoken = TWORD;
1612 /* end of readtoken routine */
1613
1614
1615 /*
1616 * Parse a substitution. At this point, we have read the dollar sign
1617 * and nothing else.
1618 */
1619
1620 parsesub: {
1621 int subtype;
1622 int typeloc;
1623 int flags;
1624 char *p;
1625 static const char types[] = "}-+?=";
1626 int linno;
1627 int length;
1628 int c1;
1629
1630 c = pgetc_linecont();
1631 if (c == '(') { /* $(command) or $((arith)) */
1632 if (pgetc_linecont() == '(') {
1633 PARSEARITH();
1634 } else {
1635 pungetc();
1636 out = parsebackq(out, &bqlist, 0,
1637 state[level].syntax == DQSYNTAX &&
1638 (eofmark == NULL || newvarnest > 0),
1639 state[level].syntax == DQSYNTAX ||
1640 state[level].syntax == ARISYNTAX);
1641 }
1642 } else if (c == '{' || is_name(c) || is_special(c)) {
1643 USTPUTC(CTLVAR, out);
1644 typeloc = out - stackblock();
1645 USTPUTC(VSNORMAL, out);
1646 subtype = VSNORMAL;
1647 flags = 0;
1648 if (c == '{') {
1649 c = pgetc_linecont();
1650 subtype = 0;
1651 }
1652 varname:
1653 if (!is_eof(c) && is_name(c)) {
1654 length = 0;
1655 do {
1656 STPUTC(c, out);
1657 c = pgetc_linecont();
1658 length++;
1659 } while (!is_eof(c) && is_in_name(c));
1660 if (length == 6 &&
1661 strncmp(out - length, "LINENO", length) == 0) {
1662 /* Replace the variable name with the
1663 * current line number. */
1664 STADJUST(-6, out);
1665 CHECKSTRSPACE(11, out);
1666 linno = plinno;
1667 if (funclinno != 0)
1668 linno -= funclinno - 1;
1669 length = snprintf(out, 11, "%d", linno);
1670 if (length > 10)
1671 length = 10;
1672 out += length;
1673 flags |= VSLINENO;
1674 }
1675 } else if (is_digit(c)) {
1676 if (subtype != VSNORMAL) {
1677 do {
1678 STPUTC(c, out);
1679 c = pgetc_linecont();
1680 } while (is_digit(c));
1681 } else {
1682 USTPUTC(c, out);
1683 c = pgetc_linecont();
1684 }
1685 } else if (is_special(c)) {
1686 c1 = c;
1687 c = pgetc_linecont();
1688 if (subtype == 0 && c1 == '#') {
1689 subtype = VSLENGTH;
1690 if (strchr(types, c) == NULL && c != ':' &&
1691 c != '#' && c != '%')
1692 goto varname;
1693 c1 = c;
1694 c = pgetc_linecont();
1695 if (c1 != '}' && c == '}') {
1696 pungetc();
1697 c = c1;
1698 goto varname;
1699 }
1700 pungetc();
1701 c = c1;
1702 c1 = '#';
1703 subtype = 0;
1704 }
1705 USTPUTC(c1, out);
1706 } else {
1707 subtype = VSERROR;
1708 if (c == '}')
1709 pungetc();
1710 else if (c == '\n' || c == PEOF)
1711 synerror("Unexpected end of line in substitution");
1712 else if (BASESYNTAX[c] != CCTL)
1713 USTPUTC(c, out);
1714 }
1715 if (subtype == 0) {
1716 switch (c) {
1717 case ':':
1718 flags |= VSNUL;
1719 c = pgetc_linecont();
1720 /*FALLTHROUGH*/
1721 default:
1722 p = strchr(types, c);
1723 if (p == NULL) {
1724 if (c == '\n' || c == PEOF)
1725 synerror("Unexpected end of line in substitution");
1726 if (flags == VSNUL)
1727 STPUTC(':', out);
1728 if (BASESYNTAX[c] != CCTL)
1729 STPUTC(c, out);
1730 subtype = VSERROR;
1731 } else
1732 subtype = p - types + VSNORMAL;
1733 break;
1734 case '%':
1735 case '#':
1736 {
1737 int cc = c;
1738 subtype = c == '#' ? VSTRIMLEFT :
1739 VSTRIMRIGHT;
1740 c = pgetc_linecont();
1741 if (c == cc)
1742 subtype++;
1743 else
1744 pungetc();
1745 break;
1746 }
1747 }
1748 } else if (subtype != VSERROR) {
1749 if (subtype == VSLENGTH && c != '}')
1750 subtype = VSERROR;
1751 pungetc();
1752 }
1753 STPUTC('=', out);
1754 if (state[level].syntax == DQSYNTAX ||
1755 state[level].syntax == ARISYNTAX)
1756 flags |= VSQUOTE;
1757 *(stackblock() + typeloc) = subtype | flags;
1758 if (subtype != VSNORMAL) {
1759 if (level + 1 >= maxnest) {
1760 maxnest *= 2;
1761 if (state == state_static) {
1762 state = parser_temp_alloc(
1763 maxnest * sizeof(*state));
1764 memcpy(state, state_static,
1765 MAXNEST_static * sizeof(*state));
1766 } else
1767 state = parser_temp_realloc(state,
1768 maxnest * sizeof(*state));
1769 }
1770 level++;
1771 state[level].parenlevel = 0;
1772 if (subtype == VSMINUS || subtype == VSPLUS ||
1773 subtype == VSQUESTION || subtype == VSASSIGN) {
1774 /*
1775 * For operators that were in the Bourne shell,
1776 * inherit the double-quote state.
1777 */
1778 state[level].syntax = state[level - 1].syntax;
1779 state[level].category = TSTATE_VAR_OLD;
1780 } else {
1781 /*
1782 * The other operators take a pattern,
1783 * so go to BASESYNTAX.
1784 * Also, ' and " are now special, even
1785 * in here documents.
1786 */
1787 state[level].syntax = BASESYNTAX;
1788 state[level].category = TSTATE_VAR_NEW;
1789 newvarnest++;
1790 }
1791 }
1792 } else if (c == '\'' && state[level].syntax == BASESYNTAX) {
1793 /* $'cstylequotes' */
1794 USTPUTC(CTLQUOTEMARK, out);
1795 state[level].syntax = SQSYNTAX;
1796 sqiscstyle = 1;
1797 } else {
1798 USTPUTC('$', out);
1799 pungetc();
1800 }
1801 goto parsesub_return;
1802 }
1803
1804
1805 /*
1806 * Parse an arithmetic expansion (indicate start of one and set state)
1807 */
1808 parsearith: {
1809
1810 if (level + 1 >= maxnest) {
1811 maxnest *= 2;
1812 if (state == state_static) {
1813 state = parser_temp_alloc(
1814 maxnest * sizeof(*state));
1815 memcpy(state, state_static,
1816 MAXNEST_static * sizeof(*state));
1817 } else
1818 state = parser_temp_realloc(state,
1819 maxnest * sizeof(*state));
1820 }
1821 level++;
1822 state[level].syntax = ARISYNTAX;
1823 state[level].parenlevel = 0;
1824 state[level].category = TSTATE_ARITH;
1825 USTPUTC(CTLARI, out);
1826 if (state[level - 1].syntax == DQSYNTAX)
1827 USTPUTC('"',out);
1828 else
1829 USTPUTC(' ',out);
1830 goto parsearith_return;
1831 }
1832
1833 } /* end of readtoken */
1834
1835
1836 /*
1837 * Returns true if the text contains nothing to expand (no dollar signs
1838 * or backquotes).
1839 */
1840
1841 static int
noexpand(char * text)1842 noexpand(char *text)
1843 {
1844 char *p;
1845 char c;
1846
1847 p = text;
1848 while ((c = *p++) != '\0') {
1849 if ( c == CTLQUOTEMARK)
1850 continue;
1851 if (c == CTLESC)
1852 p++;
1853 else if (BASESYNTAX[(int)c] == CCTL)
1854 return 0;
1855 }
1856 return 1;
1857 }
1858
1859
1860 /*
1861 * Return true if the argument is a legal variable name (a letter or
1862 * underscore followed by zero or more letters, underscores, and digits).
1863 */
1864
1865 int
goodname(const char * name)1866 goodname(const char *name)
1867 {
1868 const char *p;
1869
1870 p = name;
1871 if (! is_name(*p))
1872 return 0;
1873 while (*++p) {
1874 if (! is_in_name(*p))
1875 return 0;
1876 }
1877 return 1;
1878 }
1879
1880
1881 int
isassignment(const char * p)1882 isassignment(const char *p)
1883 {
1884 if (!is_name(*p))
1885 return 0;
1886 p++;
1887 for (;;) {
1888 if (*p == '=')
1889 return 1;
1890 else if (!is_in_name(*p))
1891 return 0;
1892 p++;
1893 }
1894 }
1895
1896
1897 static void
consumetoken(int token)1898 consumetoken(int token)
1899 {
1900 if (readtoken() != token)
1901 synexpect(token);
1902 }
1903
1904
1905 /*
1906 * Called when an unexpected token is read during the parse. The argument
1907 * is the token that is expected, or -1 if more than one type of token can
1908 * occur at this point.
1909 */
1910
1911 static void
synexpect(int token)1912 synexpect(int token)
1913 {
1914 char msg[64];
1915
1916 if (token >= 0) {
1917 fmtstr(msg, 64, "%s unexpected (expecting %s)",
1918 tokname[lasttoken], tokname[token]);
1919 } else {
1920 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]);
1921 }
1922 synerror(msg);
1923 }
1924
1925
1926 static void
synerror(const char * msg)1927 synerror(const char *msg)
1928 {
1929 if (commandname)
1930 outfmt(out2, "%s: %d: ", commandname, startlinno);
1931 else if (arg0)
1932 outfmt(out2, "%s: ", arg0);
1933 outfmt(out2, "Syntax error: %s\n", msg);
1934 error((char *)NULL);
1935 }
1936
1937 static void
setprompt(int which)1938 setprompt(int which)
1939 {
1940 whichprompt = which;
1941 if (which == 0)
1942 return;
1943
1944 #ifndef NO_HISTORY
1945 if (!el)
1946 #endif
1947 {
1948 out2str(getprompt(NULL));
1949 flushout(out2);
1950 }
1951 }
1952
1953 static int
pgetc_linecont(void)1954 pgetc_linecont(void)
1955 {
1956 int c;
1957
1958 while ((c = pgetc_macro()) == '\\') {
1959 c = pgetc();
1960 if (c == '\n') {
1961 plinno++;
1962 if (doprompt)
1963 setprompt(2);
1964 else
1965 setprompt(0);
1966 } else {
1967 pungetc();
1968 /* Allow the backslash to be pushed back. */
1969 pushstring("\\", 1, NULL);
1970 return (pgetc());
1971 }
1972 }
1973 return (c);
1974 }
1975
1976
1977 static struct passwd *
getpwlogin(void)1978 getpwlogin(void)
1979 {
1980 const char *login;
1981
1982 login = getlogin();
1983 if (login == NULL)
1984 return (NULL);
1985
1986 return (getpwnam(login));
1987 }
1988
1989
1990 static void
getusername(char * name,size_t namelen)1991 getusername(char *name, size_t namelen)
1992 {
1993 static char cached_name[MAXLOGNAME];
1994 struct passwd *pw;
1995 uid_t euid;
1996
1997 if (cached_name[0] == '\0') {
1998 euid = geteuid();
1999
2000 /*
2001 * Handle the case when there is more than one
2002 * login with the same UID, or when the login
2003 * returned by getlogin(2) does no longer match
2004 * the current UID.
2005 */
2006 pw = getpwlogin();
2007 if (pw == NULL || pw->pw_uid != euid)
2008 pw = getpwuid(euid);
2009
2010 if (pw != NULL) {
2011 strlcpy(cached_name, pw->pw_name,
2012 sizeof(cached_name));
2013 } else {
2014 snprintf(cached_name, sizeof(cached_name),
2015 "%u", euid);
2016 }
2017 }
2018
2019 strlcpy(name, cached_name, namelen);
2020 }
2021
2022
2023 /*
2024 * called by editline -- any expansions to the prompt
2025 * should be added here.
2026 */
2027 char *
getprompt(void * unused __unused)2028 getprompt(void *unused __unused)
2029 {
2030 static char ps[PROMPTLEN];
2031 const char *fmt;
2032 const char *home;
2033 const char *pwd;
2034 size_t homelen;
2035 int i, trim;
2036 static char internal_error[] = "??";
2037
2038 /*
2039 * Select prompt format.
2040 */
2041 switch (whichprompt) {
2042 case 0:
2043 fmt = "";
2044 break;
2045 case 1:
2046 fmt = ps1val();
2047 break;
2048 case 2:
2049 fmt = ps2val();
2050 break;
2051 default:
2052 return internal_error;
2053 }
2054
2055 /*
2056 * Format prompt string.
2057 */
2058 for (i = 0; (i < PROMPTLEN - 1) && (*fmt != '\0'); i++, fmt++)
2059 if (*fmt == '\\')
2060 switch (*++fmt) {
2061
2062 /*
2063 * Hostname.
2064 *
2065 * \h specifies just the local hostname,
2066 * \H specifies fully-qualified hostname.
2067 */
2068 case 'h':
2069 case 'H':
2070 ps[i] = '\0';
2071 gethostname(&ps[i], PROMPTLEN - i - 1);
2072 ps[PROMPTLEN - 1] = '\0';
2073 /* Skip to end of hostname. */
2074 trim = (*fmt == 'h') ? '.' : '\0';
2075 while ((ps[i] != '\0') && (ps[i] != trim))
2076 i++;
2077 --i;
2078 break;
2079
2080 /*
2081 * User name.
2082 */
2083 case 'u':
2084 ps[i] = '\0';
2085 getusername(&ps[i], PROMPTLEN - i);
2086 /* Skip to end of username. */
2087 while (ps[i + 1] != '\0')
2088 i++;
2089 break;
2090
2091 /*
2092 * Working directory.
2093 *
2094 * \W specifies just the final component,
2095 * \w specifies the entire path.
2096 */
2097 case 'W':
2098 case 'w':
2099 pwd = lookupvar("PWD");
2100 if (pwd == NULL || *pwd == '\0')
2101 pwd = "?";
2102 if (*fmt == 'W' &&
2103 *pwd == '/' && pwd[1] != '\0')
2104 strlcpy(&ps[i], strrchr(pwd, '/') + 1,
2105 PROMPTLEN - i);
2106 else {
2107 home = lookupvar("HOME");
2108 if (home != NULL)
2109 homelen = strlen(home);
2110 if (home != NULL &&
2111 strcmp(home, "/") != 0 &&
2112 strncmp(pwd, home, homelen) == 0 &&
2113 (pwd[homelen] == '/' ||
2114 pwd[homelen] == '\0')) {
2115 strlcpy(&ps[i], "~",
2116 PROMPTLEN - i);
2117 strlcpy(&ps[i + 1],
2118 pwd + homelen,
2119 PROMPTLEN - i - 1);
2120 } else {
2121 strlcpy(&ps[i], pwd, PROMPTLEN - i);
2122 }
2123 }
2124 /* Skip to end of path. */
2125 while (ps[i + 1] != '\0')
2126 i++;
2127 break;
2128
2129 /*
2130 * Superuser status.
2131 *
2132 * '$' for normal users, '#' for root.
2133 */
2134 case '$':
2135 ps[i] = (geteuid() != 0) ? '$' : '#';
2136 break;
2137
2138 /*
2139 * A literal \.
2140 */
2141 case '\\':
2142 ps[i] = '\\';
2143 break;
2144
2145 /*
2146 * Emit unrecognized formats verbatim.
2147 */
2148 default:
2149 ps[i] = '\\';
2150 if (i < PROMPTLEN - 2)
2151 ps[++i] = *fmt;
2152 break;
2153 }
2154 else
2155 ps[i] = *fmt;
2156 ps[i] = '\0';
2157 return (ps);
2158 }
2159
2160
2161 const char *
expandstr(const char * ps)2162 expandstr(const char *ps)
2163 {
2164 union node n;
2165 struct jmploc jmploc;
2166 struct jmploc *const savehandler = handler;
2167 const int saveprompt = doprompt;
2168 struct parsefile *const savetopfile = getcurrentfile();
2169 struct parser_temp *const saveparser_temp = parser_temp;
2170 const char *result = NULL;
2171
2172 if (!setjmp(jmploc.loc)) {
2173 handler = &jmploc;
2174 parser_temp = NULL;
2175 setinputstring(ps, 1);
2176 doprompt = 0;
2177 readtoken1(pgetc(), DQSYNTAX, NOEOFMARK, 0);
2178 if (backquotelist != NULL)
2179 error("Command substitution not allowed here");
2180
2181 n.narg.type = NARG;
2182 n.narg.next = NULL;
2183 n.narg.text = wordtext;
2184 n.narg.backquote = backquotelist;
2185
2186 expandarg(&n, NULL, 0);
2187 result = stackblock();
2188 INTOFF;
2189 }
2190 handler = savehandler;
2191 doprompt = saveprompt;
2192 popfilesupto(savetopfile);
2193 if (parser_temp != saveparser_temp) {
2194 parser_temp_free_all();
2195 parser_temp = saveparser_temp;
2196 }
2197 if (result != NULL) {
2198 INTON;
2199 } else if (exception == EXINT)
2200 raise(SIGINT);
2201 return result;
2202 }
2203