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#include <sys/param.h>
36#include <pwd.h>
37#include <stdlib.h>
38#include <unistd.h>
39#include <stdio.h>
40#include <time.h>
41
42#include "shell.h"
43
44#undef strlcpy
45#define strlcpy xstrlcpy
46size_t xstrlcpy(char *, const char *, size_t);
47
48#include "parser.h"
49#include "nodes.h"
50#include "expand.h" /* defines rmescapes() */
51#include "syntax.h"
52#include "options.h"
53#include "input.h"
54#include "output.h"
55#include "var.h"
56#include "error.h"
57#include "memalloc.h"
58#include "mystring.h"
59#include "alias.h"
60#include "show.h"
61#include "eval.h"
62#include "exec.h" /* to check for special builtins */
63#include "main.h"
64#include "jobs.h"
65#ifndef NO_HISTORY
66#include "lineedit.h"
67#endif
68
69/*
70 * Shell command parser.
71 */
72
73#define PROMPTLEN 192
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
85struct 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
92struct parser_temp {
93 struct parser_temp *next;
94 void *data;
95};
96
97
98static struct heredoc *heredoclist; /* list of here documents to read */
99static int doprompt; /* if set, prompt the user */
100static int needprompt; /* true if interactive and at start of line */
101static int lasttoken; /* last token read */
102static int tokpushback; /* last token pushed back */
103static char *wordtext; /* text of last word returned by readtoken */
104static int checkkwd;
105static struct nodelist *backquotelist;
106static union node *redirnode;
107static struct heredoc *heredoc;
108static int quoteflag; /* set if (part of) last token was quoted */
109static int startlinno; /* line # where last token started */
110static int funclinno; /* line # where the current function started */
111static struct parser_temp *parser_temp;
112
113#define NOEOFMARK ((const char *)&heredoclist)
114
115
116static union node *list(int);
117static union node *andor(void);
118static union node *pipeline(void);
119static union node *command(void);
120static union node *simplecmd(union node **, union node *);
121static union node *makename(void);
122static union node *makebinary(int type, union node *n1, union node *n2);
123static void parsefname(void);
124static void parseheredoc(void);
125static int peektoken(void);
126static int readtoken(void);
127static int xxreadtoken(void);
128static int readtoken1(int, const char *, const char *, int);
129static int noexpand(char *);
130static void consumetoken(int);
131static void synexpect(int) __dead2;
132static void synerror(const char *) __dead2;
133static void setprompt(int);
134static int pgetc_linecont(void);
135static void getusername(char *, size_t);
136
137
138static void *
139parser_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
154static void *
155parser_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
169static void
170parser_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
189static void
190parser_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
210union node *
211parsecmd(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 */
243union node *
244parsewordexp(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
272static union node *
273list(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
346static union node *
347andor(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
368static union node *
369pipeline(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
416static union node *
417command(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 checkkwd = CHKNL;
484 if (readtoken() == TWORD && !quoteflag &&
485 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)
495 tokpushback++;
496 else if (lasttoken != TSEMI)
497 synexpect(-1);
498 } else {
499 static char argvars[5] = {
500 CTLVAR, (char)(VSNORMAL|VSQUOTE), '@', '=', '\0'
501 };
502 n2 = (union node *)stalloc(sizeof (struct narg));
503 n2->type = NARG;
504 n2->narg.text = argvars;
505 n2->narg.backquote = NULL;
506 n2->narg.next = NULL;
507 n1->nfor.args = n2;
508 /*
509 * Newline or semicolon here is optional (but note
510 * that the original Bourne shell only allowed NL).
511 */
512 if (lasttoken != TSEMI)
513 tokpushback++;
514 }
515 checkkwd = CHKNL | CHKKWD | CHKALIAS;
516 if ((t = readtoken()) == TDO)
517 t = TDONE;
518 else if (t == TBEGIN)
519 t = TEND;
520 else
521 synexpect(-1);
522 n1->nfor.body = list(0);
523 consumetoken(t);
524 checkkwd = CHKKWD | CHKALIAS;
525 break;
526 case TCASE:
527 n1 = (union node *)stalloc(sizeof (struct ncase));
528 n1->type = NCASE;
529 consumetoken(TWORD);
530 n1->ncase.expr = makename();
531 checkkwd = CHKNL;
532 if (readtoken() != TWORD || ! equal(wordtext, "in"))
533 synerror("expecting \"in\"");
534 cpp = &n1->ncase.cases;
535 checkkwd = CHKNL | CHKKWD, readtoken();
536 while (lasttoken != TESAC) {
537 *cpp = cp = (union node *)stalloc(sizeof (struct nclist));
538 cp->type = NCLIST;
539 app = &cp->nclist.pattern;
540 if (lasttoken == TLP)
541 readtoken();
542 for (;;) {
543 *app = ap = makename();
544 checkkwd = CHKNL | CHKKWD;
545 if (readtoken() != TPIPE)
546 break;
547 app = &ap->narg.next;
548 readtoken();
549 }
550 ap->narg.next = NULL;
551 if (lasttoken != TRP)
552 synexpect(TRP);
553 cp->nclist.body = list(0);
554
555 checkkwd = CHKNL | CHKKWD | CHKALIAS;
556 if ((t = readtoken()) != TESAC) {
557 if (t == TENDCASE)
558 ;
559 else if (t == TFALLTHRU)
560 cp->type = NCLISTFALLTHRU;
561 else
562 synexpect(TENDCASE);
563 checkkwd = CHKNL | CHKKWD, readtoken();
564 }
565 cpp = &cp->nclist.next;
566 }
567 *cpp = NULL;
568 checkkwd = CHKKWD | CHKALIAS;
569 break;
570 case TLP:
571 n1 = (union node *)stalloc(sizeof (struct nredir));
572 n1->type = NSUBSHELL;
573 n1->nredir.n = list(0);
574 n1->nredir.redirect = NULL;
575 consumetoken(TRP);
576 checkkwd = CHKKWD | CHKALIAS;
577 is_subshell = 1;
578 break;
579 case TBEGIN:
580 n1 = list(0);
581 consumetoken(TEND);
582 checkkwd = CHKKWD | CHKALIAS;
583 break;
584 /* A simple command must have at least one redirection or word. */
585 case TBACKGND:
586 case TSEMI:
587 case TAND:
588 case TOR:
589 case TPIPE:
590 case TENDCASE:
591 case TFALLTHRU:
592 case TEOF:
593 case TNL:
594 case TRP:
595 if (!redir)
596 synexpect(-1);
597 /* fallthrough */
598 case TWORD:
599 tokpushback++;
600 n1 = simplecmd(rpp, redir);
601 return n1;
602 default:
603 synexpect(-1);
604 }
605
606 /* Now check for redirection which may follow command */
607 while (readtoken() == TREDIR) {
608 *rpp = n2 = redirnode;
609 rpp = &n2->nfile.next;
610 parsefname();
611 }
612 tokpushback++;
613 *rpp = NULL;
614 if (redir) {
615 if (!is_subshell) {
616 n2 = (union node *)stalloc(sizeof (struct nredir));
617 n2->type = NREDIR;
618 n2->nredir.n = n1;
619 n1 = n2;
620 }
621 n1->nredir.redirect = redir;
622 }
623
624 return n1;
625}
626
627
628static union node *
629simplecmd(union node **rpp, union node *redir)
630{
631 union node *args, **app;
632 union node **orig_rpp = rpp;
633 union node *n = NULL;
634 int special;
635 int savecheckkwd;
636
637 /* If we don't have any redirections already, then we must reset */
638 /* rpp to be the address of the local redir variable. */
639 if (redir == NULL)
640 rpp = &redir;
641
642 args = NULL;
643 app = &args;
644 /*
645 * We save the incoming value, because we need this for shell
646 * functions. There can not be a redirect or an argument between
647 * the function name and the open parenthesis.
648 */
649 orig_rpp = rpp;
650
651 savecheckkwd = CHKALIAS;
652
653 for (;;) {
654 checkkwd = savecheckkwd;
655 if (readtoken() == TWORD) {
656 n = makename();
657 *app = n;
658 app = &n->narg.next;
659 if (savecheckkwd != 0 && !isassignment(wordtext))
660 savecheckkwd = 0;
661 } else if (lasttoken == TREDIR) {
662 *rpp = n = redirnode;
663 rpp = &n->nfile.next;
664 parsefname(); /* read name of redirection file */
665 } else if (lasttoken == TLP && app == &args->narg.next
666 && rpp == orig_rpp) {
667 /* We have a function */
668 consumetoken(TRP);
669 funclinno = plinno;
670 /*
671 * - Require plain text.
672 * - Functions with '/' cannot be called.
673 * - Reject name=().
674 * - Reject ksh extended glob patterns.
675 */
676 if (!noexpand(n->narg.text) || quoteflag ||
677 strchr(n->narg.text, '/') ||
678 strchr("!%*+-=?@}~",
679 n->narg.text[strlen(n->narg.text) - 1]))
680 synerror("Bad function name");
681 rmescapes(n->narg.text);
682 if (find_builtin(n->narg.text, &special) >= 0 &&
683 special)
684 synerror("Cannot override a special builtin with a function");
685 n->type = NDEFUN;
686 n->narg.next = command();
687 funclinno = 0;
688 return n;
689 } else {
690 tokpushback++;
691 break;
692 }
693 }
694 *app = NULL;
695 *rpp = NULL;
696 n = (union node *)stalloc(sizeof (struct ncmd));
697 n->type = NCMD;
698 n->ncmd.args = args;
699 n->ncmd.redirect = redir;
700 return n;
701}
702
703static union node *
704makename(void)
705{
706 union node *n;
707
708 n = (union node *)stalloc(sizeof (struct narg));
709 n->type = NARG;
710 n->narg.next = NULL;
711 n->narg.text = wordtext;
712 n->narg.backquote = backquotelist;
713 return n;
714}
715
716static union node *
717makebinary(int type, union node *n1, union node *n2)
718{
719 union node *n;
720
721 n = (union node *)stalloc(sizeof (struct nbinary));
722 n->type = type;
723 n->nbinary.ch1 = n1;
724 n->nbinary.ch2 = n2;
725 return (n);
726}
727
728void
729forcealias(void)
730{
731 checkkwd |= CHKALIAS;
732}
733
734void
735fixredir(union node *n, const char *text, int err)
736{
737 TRACE(("Fix redir %s %d\n", text, err));
738 if (!err)
739 n->ndup.vname = NULL;
740
741 if (is_digit(text[0]) && text[1] == '\0')
742 n->ndup.dupfd = digit_val(text[0]);
743 else if (text[0] == '-' && text[1] == '\0')
744 n->ndup.dupfd = -1;
745 else {
746
747 if (err)
748 synerror("Bad fd number");
749 else
750 n->ndup.vname = makename();
751 }
752}
753
754
755static void
756parsefname(void)
757{
758 union node *n = redirnode;
759
760 consumetoken(TWORD);
761 if (n->type == NHERE) {
762 struct heredoc *here = heredoc;
763 struct heredoc *p;
764
765 if (quoteflag == 0)
766 n->type = NXHERE;
767 TRACE(("Here document %d\n", n->type));
768 if (here->striptabs) {
769 while (*wordtext == '\t')
770 wordtext++;
771 }
772 if (! noexpand(wordtext))
773 synerror("Illegal eof marker for << redirection");
774 rmescapes(wordtext);
775 here->eofmark = wordtext;
776 here->next = NULL;
777 if (heredoclist == NULL)
778 heredoclist = here;
779 else {
780 for (p = heredoclist ; p->next ; p = p->next);
781 p->next = here;
782 }
783 } else if (n->type == NTOFD || n->type == NFROMFD) {
784 fixredir(n, wordtext, 0);
785 } else {
786 n->nfile.fname = makename();
787 }
788}
789
790
791/*
792 * Input any here documents.
793 */
794
795static void
796parseheredoc(void)
797{
798 struct heredoc *here;
799 union node *n;
800
801 while (heredoclist) {
802 here = heredoclist;
803 heredoclist = here->next;
804 if (needprompt) {
805 setprompt(2);
806 needprompt = 0;
807 }
808 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX,
809 here->eofmark, here->striptabs);
810 n = makename();
811 here->here->nhere.doc = n;
812 }
813}
814
815static int
816peektoken(void)
817{
818 int t;
819
820 t = readtoken();
821 tokpushback++;
822 return (t);
823}
824
825static int
826readtoken(void)
827{
828 int t;
829 struct alias *ap;
830#ifdef DEBUG
831 int alreadyseen = tokpushback;
832#endif
833
834 top:
835 t = xxreadtoken();
836
837 /*
838 * eat newlines
839 */
840 if (checkkwd & CHKNL) {
841 while (t == TNL) {
842 parseheredoc();
843 t = xxreadtoken();
844 }
845 }
846
847 /*
848 * check for keywords and aliases
849 */
850 if (t == TWORD && !quoteflag)
851 {
852 const char * const *pp;
853
854 if (checkkwd & CHKKWD)
855 for (pp = parsekwd; *pp; pp++) {
856 if (**pp == *wordtext && equal(*pp, wordtext))
857 {
858 lasttoken = t = pp - parsekwd + KWDOFFSET;
859 TRACE(("keyword %s recognized\n", tokname[t]));
860 goto out;
861 }
862 }
863 if (checkkwd & CHKALIAS &&
864 (ap = lookupalias(wordtext, 1)) != NULL) {
865 pushstring(ap->val, strlen(ap->val), ap);
866 goto top;
867 }
868 }
869out:
870 if (t != TNOT)
871 checkkwd = 0;
872
873#ifdef DEBUG
874 if (!alreadyseen)
875 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
876 else
877 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
878#endif
879 return (t);
880}
881
882
883/*
884 * Read the next input token.
885 * If the token is a word, we set backquotelist to the list of cmds in
886 * backquotes. We set quoteflag to true if any part of the word was
887 * quoted.
888 * If the token is TREDIR, then we set redirnode to a structure containing
889 * the redirection.
890 * In all cases, the variable startlinno is set to the number of the line
891 * on which the token starts.
892 *
893 * [Change comment: here documents and internal procedures]
894 * [Readtoken shouldn't have any arguments. Perhaps we should make the
895 * word parsing code into a separate routine. In this case, readtoken
896 * doesn't need to have any internal procedures, but parseword does.
897 * We could also make parseoperator in essence the main routine, and
898 * have parseword (readtoken1?) handle both words and redirection.]
899 */
900
901#define RETURN(token) return lasttoken = token
902
903static int
904xxreadtoken(void)
905{
906 int c;
907
908 if (tokpushback) {
909 tokpushback = 0;
910 return lasttoken;
911 }
912 if (needprompt) {
913 setprompt(2);
914 needprompt = 0;
915 }
916 startlinno = plinno;
917 for (;;) { /* until token or start of word found */
918 c = pgetc_macro();
919 switch (c) {
920 case ' ': case '\t':
921 continue;
922 case '#':
923 while ((c = pgetc()) != '\n' && c != PEOF);
924 pungetc();
925 continue;
926 case '\\':
927 if (pgetc() == '\n') {
928 startlinno = ++plinno;
929 if (doprompt)
930 setprompt(2);
931 else
932 setprompt(0);
933 continue;
934 }
935 pungetc();
936 /* FALLTHROUGH */
937 default:
938 return readtoken1(c, BASESYNTAX, (char *)NULL, 0);
939 case '\n':
940 plinno++;
941 needprompt = doprompt;
942 RETURN(TNL);
943 case PEOF:
944 RETURN(TEOF);
945 case '&':
946 if (pgetc_linecont() == '&')
947 RETURN(TAND);
948 pungetc();
949 RETURN(TBACKGND);
950 case '|':
951 if (pgetc_linecont() == '|')
952 RETURN(TOR);
953 pungetc();
954 RETURN(TPIPE);
955 case ';':
956 c = pgetc_linecont();
957 if (c == ';')
958 RETURN(TENDCASE);
959 else if (c == '&')
960 RETURN(TFALLTHRU);
961 pungetc();
962 RETURN(TSEMI);
963 case '(':
964 RETURN(TLP);
965 case ')':
966 RETURN(TRP);
967 }
968 }
969#undef RETURN
970}
971
972
973#define MAXNEST_static 8
974struct tokenstate
975{
976 const char *syntax; /* *SYNTAX */
977 int parenlevel; /* levels of parentheses in arithmetic */
978 enum tokenstate_category
979 {
980 TSTATE_TOP,
981 TSTATE_VAR_OLD, /* ${var+-=?}, inherits dquotes */
982 TSTATE_VAR_NEW, /* other ${var...}, own dquote state */
983 TSTATE_ARITH
984 } category;
985};
986
987
988/*
989 * Check to see whether we are at the end of the here document. When this
990 * is called, c is set to the first character of the next input line. If
991 * we are at the end of the here document, this routine sets the c to PEOF.
992 * The new value of c is returned.
993 */
994
995static int
996checkend(int c, const char *eofmark, int striptabs)
997{
998 if (striptabs) {
999 while (c == '\t')
1000 c = pgetc();
1001 }
1002 if (c == *eofmark) {
1003 int c2;
1004 const char *q;
1005
1006 for (q = eofmark + 1; c2 = pgetc(), *q != '\0' && c2 == *q; q++)
1007 ;
1008 if ((c2 == PEOF || c2 == '\n') && *q == '\0') {
1009 c = PEOF;
1010 if (c2 == '\n') {
1011 plinno++;
1012 needprompt = doprompt;
1013 }
1014 } else {
1015 pungetc();
1016 pushstring(eofmark + 1, q - (eofmark + 1), NULL);
1017 }
1018 } else if (c == '\n' && *eofmark == '\0') {
1019 c = PEOF;
1020 plinno++;
1021 needprompt = doprompt;
1022 }
1023 return (c);
1024}
1025
1026
1027/*
1028 * Parse a redirection operator. The variable "out" points to a string
1029 * specifying the fd to be redirected. The variable "c" contains the
1030 * first character of the redirection operator.
1031 */
1032
1033static void
1034parseredir(char *out, int c)
1035{
1036 char fd = *out;
1037 union node *np;
1038
1039 np = (union node *)stalloc(sizeof (struct nfile));
1040 if (c == '>') {
1041 np->nfile.fd = 1;
1042 c = pgetc_linecont();
1043 if (c == '>')
1044 np->type = NAPPEND;
1045 else if (c == '&')
1046 np->type = NTOFD;
1047 else if (c == '|')
1048 np->type = NCLOBBER;
1049 else {
1050 np->type = NTO;
1051 pungetc();
1052 }
1053 } else { /* c == '<' */
1054 np->nfile.fd = 0;
1055 c = pgetc_linecont();
1056 if (c == '<') {
1057 if (sizeof (struct nfile) != sizeof (struct nhere)) {
1058 np = (union node *)stalloc(sizeof (struct nhere));
1059 np->nfile.fd = 0;
1060 }
1061 np->type = NHERE;
1062 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc));
1063 heredoc->here = np;
1064 if ((c = pgetc_linecont()) == '-') {
1065 heredoc->striptabs = 1;
1066 } else {
1067 heredoc->striptabs = 0;
1068 pungetc();
1069 }
1070 } else if (c == '&')
1071 np->type = NFROMFD;
1072 else if (c == '>')
1073 np->type = NFROMTO;
1074 else {
1075 np->type = NFROM;
1076 pungetc();
1077 }
1078 }
1079 if (fd != '\0')
1080 np->nfile.fd = digit_val(fd);
1081 redirnode = np;
1082}
1083
1084/*
1085 * Called to parse command substitutions.
1086 */
1087
1088static char *
1089parsebackq(char *out, struct nodelist **pbqlist,
1090 int oldstyle, int dblquote, int quoted)
1091{
1092 struct nodelist **nlpp;
1093 union node *n;
1094 char *volatile str;
1095 struct jmploc jmploc;
1096 struct jmploc *const savehandler = handler;
1097 size_t savelen;
1098 int saveprompt;
1099 const int bq_startlinno = plinno;
1100 char *volatile ostr = NULL;
1101 struct parsefile *const savetopfile = getcurrentfile();
1102 struct heredoc *const saveheredoclist = heredoclist;
1103 struct heredoc *here;
1104
1105 str = NULL;
1106 if (setjmp(jmploc.loc)) {
1107 popfilesupto(savetopfile);
1108 if (str)
1109 ckfree(str);
1110 if (ostr)
1111 ckfree(ostr);
1112 heredoclist = saveheredoclist;
1113 handler = savehandler;
1114 if (exception == EXERROR) {
1115 startlinno = bq_startlinno;
1116 synerror("Error in command substitution");
1117 }
1118 longjmp(handler->loc, 1);
1119 }
1120 INTOFF;
1121 savelen = out - stackblock();
1122 if (savelen > 0) {
1123 str = ckmalloc(savelen);
1124 memcpy(str, stackblock(), savelen);
1125 }
1126 handler = &jmploc;
1127 heredoclist = NULL;
1128 INTON;
1129 if (oldstyle) {
1130 /* We must read until the closing backquote, giving special
1131 treatment to some slashes, and then push the string and
1132 reread it as input, interpreting it normally. */
1133 char *oout;
1134 int c;
1135 int olen;
1136
1137
1138 STARTSTACKSTR(oout);
1139 for (;;) {
1140 if (needprompt) {
1141 setprompt(2);
1142 needprompt = 0;
1143 }
1144 CHECKSTRSPACE(2, oout);
1145 c = pgetc_linecont();
1146 if (c == '`')
1147 break;
1148 switch (c) {
1149 case '\\':
1150 c = pgetc();
1151 if (c != '\\' && c != '`' && c != '$'
1152 && (!dblquote || c != '"'))
1153 USTPUTC('\\', oout);
1154 break;
1155
1156 case '\n':
1157 plinno++;
1158 needprompt = doprompt;
1159 break;
1160
1161 case PEOF:
1162 startlinno = plinno;
1163 synerror("EOF in backquote substitution");
1164 break;
1165
1166 default:
1167 break;
1168 }
1169 USTPUTC(c, oout);
1170 }
1171 USTPUTC('\0', oout);
1172 olen = oout - stackblock();
1173 INTOFF;
1174 ostr = ckmalloc(olen);
1175 memcpy(ostr, stackblock(), olen);
1176 setinputstring(ostr);
1177 INTON;
1178 }
1179 nlpp = pbqlist;
1180 while (*nlpp)
1181 nlpp = &(*nlpp)->next;
1182 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist));
1183 (*nlpp)->next = NULL;
1184
1185 if (oldstyle) {
1186 saveprompt = doprompt;
1187 doprompt = 0;
1188 }
1189
1190 n = list(0);
1191
1192 if (oldstyle) {
1193 if (peektoken() != TEOF)
1194 synexpect(-1);
1195 doprompt = saveprompt;
1196 } else
1197 consumetoken(TRP);
1198
1199 (*nlpp)->n = n;
1200 if (oldstyle) {
1201 /*
1202 * Start reading from old file again, ignoring any pushed back
1203 * tokens left from the backquote parsing
1204 */
1205 popfile();
1206 tokpushback = 0;
1207 }
1208 STARTSTACKSTR(out);
1209 CHECKSTRSPACE(savelen + 1, out);
1210 INTOFF;
1211 if (str) {
1212 memcpy(out, str, savelen);
1213 STADJUST(savelen, out);
1214 ckfree(str);
1215 str = NULL;
1216 }
1217 if (ostr) {
1218 ckfree(ostr);
1219 ostr = NULL;
1220 }
1221 here = saveheredoclist;
1222 if (here != NULL) {
1223 while (here->next != NULL)
1224 here = here->next;
1225 here->next = heredoclist;
1226 heredoclist = saveheredoclist;
1227 }
1228 handler = savehandler;
1229 INTON;
1230 if (quoted)
1231 USTPUTC(CTLBACKQ | CTLQUOTE, out);
1232 else
1233 USTPUTC(CTLBACKQ, out);
1234 return out;
1235}
1236
1237
1238/*
1239 * Called to parse a backslash escape sequence inside $'...'.
1240 * The backslash has already been read.
1241 */
1242static char *
1243readcstyleesc(char *out)
1244{
1245 int c, vc, i, n;
1246 unsigned int v;
1247
1248 c = pgetc();
1249 switch (c) {
1250 case '\0':
1251 synerror("Unterminated quoted string");
1252 case '\n':
1253 plinno++;
1254 if (doprompt)
1255 setprompt(2);
1256 else
1257 setprompt(0);
1258 return out;
1259 case '\\':
1260 case '\'':
1261 case '"':
1262 v = c;
1263 break;
1264 case 'a': v = '\a'; break;
1265 case 'b': v = '\b'; break;
1266 case 'e': v = '\033'; break;
1267 case 'f': v = '\f'; break;
1268 case 'n': v = '\n'; break;
1269 case 'r': v = '\r'; break;
1270 case 't': v = '\t'; break;
1271 case 'v': v = '\v'; break;
1272 case 'x':
1273 v = 0;
1274 for (;;) {
1275 c = pgetc();
1276 if (c >= '0' && c <= '9')
1277 v = (v << 4) + c - '0';
1278 else if (c >= 'A' && c <= 'F')
1279 v = (v << 4) + c - 'A' + 10;
1280 else if (c >= 'a' && c <= 'f')
1281 v = (v << 4) + c - 'a' + 10;
1282 else
1283 break;
1284 }
1285 pungetc();
1286 break;
1287 case '0': case '1': case '2': case '3':
1288 case '4': case '5': case '6': case '7':
1289 v = c - '0';
1290 c = pgetc();
1291 if (c >= '0' && c <= '7') {
1292 v <<= 3;
1293 v += c - '0';
1294 c = pgetc();
1295 if (c >= '0' && c <= '7') {
1296 v <<= 3;
1297 v += c - '0';
1298 } else
1299 pungetc();
1300 } else
1301 pungetc();
1302 break;
1303 case 'c':
1304 c = pgetc();
1305 if (c < 0x3f || c > 0x7a || c == 0x60)
1306 synerror("Bad escape sequence");
1307 if (c == '\\' && pgetc() != '\\')
1308 synerror("Bad escape sequence");
1309 if (c == '?')
1310 v = 127;
1311 else
1312 v = c & 0x1f;
1313 break;
1314 case 'u':
1315 case 'U':
1316 n = c == 'U' ? 8 : 4;
1317 v = 0;
1318 for (i = 0; i < n; i++) {
1319 c = pgetc();
1320 if (c >= '0' && c <= '9')
1321 v = (v << 4) + c - '0';
1322 else if (c >= 'A' && c <= 'F')
1323 v = (v << 4) + c - 'A' + 10;
1324 else if (c >= 'a' && c <= 'f')
1325 v = (v << 4) + c - 'a' + 10;
1326 else
1327 synerror("Bad escape sequence");
1328 }
1329 if (v == 0 || (v >= 0xd800 && v <= 0xdfff))
1330 synerror("Bad escape sequence");
1331 /* We really need iconv here. */
1332 if (initial_localeisutf8 && v > 127) {
1333 CHECKSTRSPACE(4, out);
1334 /*
1335 * We cannot use wctomb() as the locale may have
1336 * changed.
1337 */
1338 if (v <= 0x7ff) {
1339 USTPUTC(0xc0 | v >> 6, out);
1340 USTPUTC(0x80 | (v & 0x3f), out);
1341 return out;
1342 } else if (v <= 0xffff) {
1343 USTPUTC(0xe0 | v >> 12, out);
1344 USTPUTC(0x80 | ((v >> 6) & 0x3f), out);
1345 USTPUTC(0x80 | (v & 0x3f), out);
1346 return out;
1347 } else if (v <= 0x10ffff) {
1348 USTPUTC(0xf0 | v >> 18, out);
1349 USTPUTC(0x80 | ((v >> 12) & 0x3f), out);
1350 USTPUTC(0x80 | ((v >> 6) & 0x3f), out);
1351 USTPUTC(0x80 | (v & 0x3f), out);
1352 return out;
1353 }
1354 }
1355 if (v > 127)
1356 v = '?';
1357 break;
1358 default:
1359 synerror("Bad escape sequence");
1360 }
1361 vc = (char)v;
1362 /*
1363 * We can't handle NUL bytes.
1364 * POSIX says we should skip till the closing quote.
1365 */
1366 if (vc == '\0') {
1367 while ((c = pgetc()) != '\'') {
1368 if (c == '\\')
1369 c = pgetc();
1370 if (c == PEOF)
1371 synerror("Unterminated quoted string");
1372 if (c == '\n') {
1373 plinno++;
1374 if (doprompt)
1375 setprompt(2);
1376 else
1377 setprompt(0);
1378 }
1379 }
1380 pungetc();
1381 return out;
1382 }
1383 if (SQSYNTAX[vc] == CCTL)
1384 USTPUTC(CTLESC, out);
1385 USTPUTC(vc, out);
1386 return out;
1387}
1388
1389
1390/*
1391 * If eofmark is NULL, read a word or a redirection symbol. If eofmark
1392 * is not NULL, read a here document. In the latter case, eofmark is the
1393 * word which marks the end of the document and striptabs is true if
1394 * leading tabs should be stripped from the document. The argument firstc
1395 * is the first character of the input token or document.
1396 *
1397 * Because C does not have internal subroutines, I have simulated them
1398 * using goto's to implement the subroutine linkage. The following macros
1399 * will run code that appears at the end of readtoken1.
1400 */
1401
1402#define PARSESUB() {goto parsesub; parsesub_return:;}
1403#define PARSEARITH() {goto parsearith; parsearith_return:;}
1404
1405static int
1406readtoken1(int firstc, char const *initialsyntax, const char *eofmark,
1407 int striptabs)
1408{
1409 int c = firstc;
1410 char *out;
1411 int len;
1412 struct nodelist *bqlist;
1413 int quotef;
1414 int newvarnest;
1415 int level;
1416 int synentry;
1417 struct tokenstate state_static[MAXNEST_static];
1418 int maxnest = MAXNEST_static;
1419 struct tokenstate *state = state_static;
1420 int sqiscstyle = 0;
1421
1422 startlinno = plinno;
1423 quotef = 0;
1424 bqlist = NULL;
1425 newvarnest = 0;
1426 level = 0;
1427 state[level].syntax = initialsyntax;
1428 state[level].parenlevel = 0;
1429 state[level].category = TSTATE_TOP;
1430
1431 STARTSTACKSTR(out);
1432 loop: { /* for each line, until end of word */
1433 if (eofmark && eofmark != NOEOFMARK)
1434 /* set c to PEOF if at end of here document */
1435 c = checkend(c, eofmark, striptabs);
1436 for (;;) { /* until end of line or end of word */
1437 CHECKSTRSPACE(4, out); /* permit 4 calls to USTPUTC */
1438
1439 synentry = state[level].syntax[c];
1440
1441 switch(synentry) {
1442 case CNL: /* '\n' */
1443 if (level == 0)
1444 goto endword; /* exit outer loop */
1445 /* FALLTHROUGH */
1446 case CQNL:
1447 USTPUTC(c, out);
1448 plinno++;
1449 if (doprompt)
1450 setprompt(2);
1451 else
1452 setprompt(0);
1453 c = pgetc();
1454 goto loop; /* continue outer loop */
1455 case CSBACK:
1456 if (sqiscstyle) {
1457 out = readcstyleesc(out);
1458 break;
1459 }
1460 /* FALLTHROUGH */
1461 case CWORD:
1462 USTPUTC(c, out);
1463 break;
1464 case CCTL:
1465 if (eofmark == NULL || initialsyntax != SQSYNTAX)
1466 USTPUTC(CTLESC, out);
1467 USTPUTC(c, out);
1468 break;
1469 case CBACK: /* backslash */
1470 c = pgetc();
1471 if (c == PEOF) {
1472 USTPUTC('\\', out);
1473 pungetc();
1474 } else if (c == '\n') {
1475 plinno++;
1476 if (doprompt)
1477 setprompt(2);
1478 else
1479 setprompt(0);
1480 } else {
1481 if (state[level].syntax == DQSYNTAX &&
1482 c != '\\' && c != '`' && c != '$' &&
1483 (c != '"' || (eofmark != NULL &&
1484 newvarnest == 0)) &&
1485 (c != '}' || state[level].category != TSTATE_VAR_OLD))
1486 USTPUTC('\\', out);
1487 if ((eofmark == NULL ||
1488 newvarnest > 0) &&
1489 state[level].syntax == BASESYNTAX)
1490 USTPUTC(CTLQUOTEMARK, out);
1491 if (SQSYNTAX[c] == CCTL)
1492 USTPUTC(CTLESC, out);
1493 USTPUTC(c, out);
1494 if ((eofmark == NULL ||
1495 newvarnest > 0) &&
1496 state[level].syntax == BASESYNTAX &&
1497 state[level].category == TSTATE_VAR_OLD)
1498 USTPUTC(CTLQUOTEEND, out);
1499 quotef++;
1500 }
1501 break;
1502 case CSQUOTE:
1503 USTPUTC(CTLQUOTEMARK, out);
1504 state[level].syntax = SQSYNTAX;
1505 sqiscstyle = 0;
1506 break;
1507 case CDQUOTE:
1508 USTPUTC(CTLQUOTEMARK, out);
1509 state[level].syntax = DQSYNTAX;
1510 break;
1511 case CENDQUOTE:
1512 if (eofmark != NULL && newvarnest == 0)
1513 USTPUTC(c, out);
1514 else {
1515 if (state[level].category == TSTATE_VAR_OLD)
1516 USTPUTC(CTLQUOTEEND, out);
1517 state[level].syntax = BASESYNTAX;
1518 quotef++;
1519 }
1520 break;
1521 case CVAR: /* '$' */
1522 PARSESUB(); /* parse substitution */
1523 break;
1524 case CENDVAR: /* '}' */
1525 if (level > 0 &&
1526 ((state[level].category == TSTATE_VAR_OLD &&
1527 state[level].syntax ==
1528 state[level - 1].syntax) ||
1529 (state[level].category == TSTATE_VAR_NEW &&
1530 state[level].syntax == BASESYNTAX))) {
1531 if (state[level].category == TSTATE_VAR_NEW)
1532 newvarnest--;
1533 level--;
1534 USTPUTC(CTLENDVAR, out);
1535 } else {
1536 USTPUTC(c, out);
1537 }
1538 break;
1539 case CLP: /* '(' in arithmetic */
1540 state[level].parenlevel++;
1541 USTPUTC(c, out);
1542 break;
1543 case CRP: /* ')' in arithmetic */
1544 if (state[level].parenlevel > 0) {
1545 USTPUTC(c, out);
1546 --state[level].parenlevel;
1547 } else {
1548 if (pgetc_linecont() == ')') {
1549 if (level > 0 &&
1550 state[level].category == TSTATE_ARITH) {
1551 level--;
1552 USTPUTC(CTLENDARI, out);
1553 } else
1554 USTPUTC(')', out);
1555 } else {
1556 /*
1557 * unbalanced parens
1558 * (don't 2nd guess - no error)
1559 */
1560 pungetc();
1561 USTPUTC(')', out);
1562 }
1563 }
1564 break;
1565 case CBQUOTE: /* '`' */
1566 out = parsebackq(out, &bqlist, 1,
1567 state[level].syntax == DQSYNTAX &&
1568 (eofmark == NULL || newvarnest > 0),
1569 state[level].syntax == DQSYNTAX || state[level].syntax == ARISYNTAX);
1570 break;
1571 case CEOF:
1572 goto endword; /* exit outer loop */
1573 case CIGN:
1574 break;
1575 default:
1576 if (level == 0)
1577 goto endword; /* exit outer loop */
1578 USTPUTC(c, out);
1579 }
1580 c = pgetc_macro();
1581 }
1582 }
1583endword:
1584 if (state[level].syntax == ARISYNTAX)
1585 synerror("Missing '))'");
1586 if (state[level].syntax != BASESYNTAX && eofmark == NULL)
1587 synerror("Unterminated quoted string");
1588 if (state[level].category == TSTATE_VAR_OLD ||
1589 state[level].category == TSTATE_VAR_NEW) {
1590 startlinno = plinno;
1591 synerror("Missing '}'");
1592 }
1593 if (state != state_static)
1594 parser_temp_free_upto(state);
1595 USTPUTC('\0', out);
1596 len = out - stackblock();
1597 out = stackblock();
1598 if (eofmark == NULL) {
1599 if ((c == '>' || c == '<')
1600 && quotef == 0
1601 && len <= 2
1602 && (*out == '\0' || is_digit(*out))) {
1603 parseredir(out, c);
1604 return lasttoken = TREDIR;
1605 } else {
1606 pungetc();
1607 }
1608 }
1609 quoteflag = quotef;
1610 backquotelist = bqlist;
1611 grabstackblock(len);
1612 wordtext = out;
1613 return lasttoken = TWORD;
1614/* end of readtoken routine */
1615
1616
1617/*
1618 * Parse a substitution. At this point, we have read the dollar sign
1619 * and nothing else.
1620 */
1621
1622parsesub: {
1623 int subtype;
1624 int typeloc;
1625 int flags;
1626 char *p;
1627 static const char types[] = "}-+?=";
1628 int linno;
1629 int length;
1630 int c1;
1631
1632 c = pgetc_linecont();
1633 if (c == '(') { /* $(command) or $((arith)) */
1634 if (pgetc_linecont() == '(') {
1635 PARSEARITH();
1636 } else {
1637 pungetc();
1638 out = parsebackq(out, &bqlist, 0,
1639 state[level].syntax == DQSYNTAX &&
1640 (eofmark == NULL || newvarnest > 0),
1641 state[level].syntax == DQSYNTAX ||
1642 state[level].syntax == ARISYNTAX);
1643 }
1644 } else if (c == '{' || is_name(c) || is_special(c)) {
1645 USTPUTC(CTLVAR, out);
1646 typeloc = out - stackblock();
1647 USTPUTC(VSNORMAL, out);
1648 subtype = VSNORMAL;
1649 flags = 0;
1650 if (c == '{') {
1651 c = pgetc_linecont();
1652 subtype = 0;
1653 }
1654varname:
1655 if (!is_eof(c) && is_name(c)) {
1656 length = 0;
1657 do {
1658 STPUTC(c, out);
1659 c = pgetc_linecont();
1660 length++;
1661 } while (!is_eof(c) && is_in_name(c));
1662 if (length == 6 &&
1663 strncmp(out - length, "LINENO", length) == 0) {
1664 /* Replace the variable name with the
1665 * current line number. */
1666 STADJUST(-6, out);
1667 CHECKSTRSPACE(11, out);
1668 linno = plinno;
1669 if (funclinno != 0)
1670 linno -= funclinno - 1;
1671 length = snprintf(out, 11, "%d", linno);
1672 if (length > 10)
1673 length = 10;
1674 out += length;
1675 flags |= VSLINENO;
1676 }
1677 } else if (is_digit(c)) {
1678 if (subtype != VSNORMAL) {
1679 do {
1680 STPUTC(c, out);
1681 c = pgetc_linecont();
1682 } while (is_digit(c));
1683 } else {
1684 USTPUTC(c, out);
1685 c = pgetc_linecont();
1686 }
1687 } else if (is_special(c)) {
1688 c1 = c;
1689 c = pgetc_linecont();
1690 if (subtype == 0 && c1 == '#') {
1691 subtype = VSLENGTH;
1692 if (strchr(types, c) == NULL && c != ':' &&
1693 c != '#' && c != '%')
1694 goto varname;
1695 c1 = c;
1696 c = pgetc_linecont();
1697 if (c1 != '}' && c == '}') {
1698 pungetc();
1699 c = c1;
1700 goto varname;
1701 }
1702 pungetc();
1703 c = c1;
1704 c1 = '#';
1705 subtype = 0;
1706 }
1707 USTPUTC(c1, out);
1708 } else {
1709 subtype = VSERROR;
1710 if (c == '}')
1711 pungetc();
1712 else if (c == '\n' || c == PEOF)
1713 synerror("Unexpected end of line in substitution");
1714 else if (BASESYNTAX[c] != CCTL)
1715 USTPUTC(c, out);
1716 }
1717 if (subtype == 0) {
1718 switch (c) {
1719 case ':':
1720 flags |= VSNUL;
1721 c = pgetc_linecont();
1722 /*FALLTHROUGH*/
1723 default:
1724 p = strchr(types, c);
1725 if (p == NULL) {
1726 if (c == '\n' || c == PEOF)
1727 synerror("Unexpected end of line in substitution");
1728 if (flags == VSNUL)
1729 STPUTC(':', out);
1730 if (BASESYNTAX[c] != CCTL)
1731 STPUTC(c, out);
1732 subtype = VSERROR;
1733 } else
1734 subtype = p - types + VSNORMAL;
1735 break;
1736 case '%':
1737 case '#':
1738 {
1739 int cc = c;
1740 subtype = c == '#' ? VSTRIMLEFT :
1741 VSTRIMRIGHT;
1742 c = pgetc_linecont();
1743 if (c == cc)
1744 subtype++;
1745 else
1746 pungetc();
1747 break;
1748 }
1749 }
1750 } else if (subtype != VSERROR) {
1751 if (subtype == VSLENGTH && c != '}')
1752 subtype = VSERROR;
1753 pungetc();
1754 }
1755 STPUTC('=', out);
1756 if (state[level].syntax == DQSYNTAX ||
1757 state[level].syntax == ARISYNTAX)
1758 flags |= VSQUOTE;
1759 *(stackblock() + typeloc) = subtype | flags;
1760 if (subtype != VSNORMAL) {
1761 if (level + 1 >= maxnest) {
1762 maxnest *= 2;
1763 if (state == state_static) {
1764 state = parser_temp_alloc(
1765 maxnest * sizeof(*state));
1766 memcpy(state, state_static,
1767 MAXNEST_static * sizeof(*state));
1768 } else
1769 state = parser_temp_realloc(state,
1770 maxnest * sizeof(*state));
1771 }
1772 level++;
1773 state[level].parenlevel = 0;
1774 if (subtype == VSMINUS || subtype == VSPLUS ||
1775 subtype == VSQUESTION || subtype == VSASSIGN) {
1776 /*
1777 * For operators that were in the Bourne shell,
1778 * inherit the double-quote state.
1779 */
1780 state[level].syntax = state[level - 1].syntax;
1781 state[level].category = TSTATE_VAR_OLD;
1782 } else {
1783 /*
1784 * The other operators take a pattern,
1785 * so go to BASESYNTAX.
1786 * Also, ' and " are now special, even
1787 * in here documents.
1788 */
1789 state[level].syntax = BASESYNTAX;
1790 state[level].category = TSTATE_VAR_NEW;
1791 newvarnest++;
1792 }
1793 }
1794 } else if (c == '\'' && state[level].syntax == BASESYNTAX) {
1795 /* $'cstylequotes' */
1796 USTPUTC(CTLQUOTEMARK, out);
1797 state[level].syntax = SQSYNTAX;
1798 sqiscstyle = 1;
1799 } else {
1800 USTPUTC('$', out);
1801 pungetc();
1802 }
1803 goto parsesub_return;
1804}
1805
1806
1807/*
1808 * Parse an arithmetic expansion (indicate start of one and set state)
1809 */
1810parsearith: {
1811
1812 if (level + 1 >= maxnest) {
1813 maxnest *= 2;
1814 if (state == state_static) {
1815 state = parser_temp_alloc(
1816 maxnest * sizeof(*state));
1817 memcpy(state, state_static,
1818 MAXNEST_static * sizeof(*state));
1819 } else
1820 state = parser_temp_realloc(state,
1821 maxnest * sizeof(*state));
1822 }
1823 level++;
1824 state[level].syntax = ARISYNTAX;
1825 state[level].parenlevel = 0;
1826 state[level].category = TSTATE_ARITH;
1827 USTPUTC(CTLARI, out);
1828 if (state[level - 1].syntax == DQSYNTAX)
1829 USTPUTC('"',out);
1830 else
1831 USTPUTC(' ',out);
1832 goto parsearith_return;
1833}
1834
1835} /* end of readtoken */
1836
1837
1838/*
1839 * Returns true if the text contains nothing to expand (no dollar signs
1840 * or backquotes).
1841 */
1842
1843static int
1844noexpand(char *text)
1845{
1846 char *p;
1847 char c;
1848
1849 p = text;
1850 while ((c = *p++) != '\0') {
1851 if ( c == CTLQUOTEMARK)
1852 continue;
1853 if (c == CTLESC)
1854 p++;
1855 else if (BASESYNTAX[(int)c] == CCTL)
1856 return 0;
1857 }
1858 return 1;
1859}
1860
1861
1862/*
1863 * Return true if the argument is a legal variable name (a letter or
1864 * underscore followed by zero or more letters, underscores, and digits).
1865 */
1866
1867int
1868goodname(const char *name)
1869{
1870 const char *p;
1871
1872 p = name;
1873 if (! is_name(*p))
1874 return 0;
1875 while (*++p) {
1876 if (! is_in_name(*p))
1877 return 0;
1878 }
1879 return 1;
1880}
1881
1882
1883int
1884isassignment(const char *p)
1885{
1886 if (!is_name(*p))
1887 return 0;
1888 p++;
1889 for (;;) {
1890 if (*p == '=')
1891 return 1;
1892 else if (!is_in_name(*p))
1893 return 0;
1894 p++;
1895 }
1896}
1897
1898
1899static void
1900consumetoken(int token)
1901{
1902 if (readtoken() != token)
1903 synexpect(token);
1904}
1905
1906
1907/*
1908 * Called when an unexpected token is read during the parse. The argument
1909 * is the token that is expected, or -1 if more than one type of token can
1910 * occur at this point.
1911 */
1912
1913static void
1914synexpect(int token)
1915{
1916 char msg[64];
1917
1918 if (token >= 0) {
1919 fmtstr(msg, 64, "%s unexpected (expecting %s)",
1920 tokname[lasttoken], tokname[token]);
1921 } else {
1922 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]);
1923 }
1924 synerror(msg);
1925}
1926
1927
1928static void
1929synerror(const char *msg)
1930{
1931 if (commandname)
1932 outfmt(out2, "%s: %d: ", commandname, startlinno);
1933 else if (arg0)
1934 outfmt(out2, "%s: ", arg0);
1935 outfmt(out2, "Syntax error: %s\n", msg);
1936 error((char *)NULL);
1937}
1938
1939static void
1940setprompt(int which)
1941{
1942 whichprompt = which;
1943 if (which == 0)
1944 return;
1945
1946#ifndef NO_HISTORY
1947 if (!sh_history_enabled)
1948#endif
1949 {
1950 out2str(getprompt(NULL));
1951 flushout(out2);
1952 }
1953}
1954
1955static int
1956pgetc_linecont(void)
1957{
1958 int c;
1959
1960 while ((c = pgetc_macro()) == '\\') {
1961 c = pgetc();
1962 if (c == '\n') {
1963 plinno++;
1964 if (doprompt)
1965 setprompt(2);
1966 else
1967 setprompt(0);
1968 } else {
1969 pungetc();
1970 /* Allow the backslash to be pushed back. */
1971 pushstring("\\", 1, NULL);
1972 return (pgetc());
1973 }
1974 }
1975 return (c);
1976}
1977
1978
1979static struct passwd *
1980getpwlogin(void)
1981{
1982 const char *login;
1983
1984 login = getlogin();
1985 if (login == NULL)
1986 return (NULL);
1987
1988 return (getpwnam(login));
1989}
1990
1991
1992static void
1993getusername(char *name, size_t namelen)
1994{
1995 static char cached_name[MAXLOGNAME];
1996 struct passwd *pw;
1997 uid_t euid;
1998
1999 if (cached_name[0] == '\0') {
2000 euid = geteuid();
2001
2002 /*
2003 * Handle the case when there is more than one
2004 * login with the same UID, or when the login
2005 * returned by getlogin(2) does no longer match
2006 * the current UID.
2007 */
2008 pw = getpwlogin();
2009 if (pw == NULL || pw->pw_uid != euid)
2010 pw = getpwuid(euid);
2011
2012 if (pw != NULL) {
2013 strlcpy(cached_name, pw->pw_name,
2014 sizeof(cached_name));
2015 } else {
2016 snprintf(cached_name, sizeof(cached_name),
2017 "%u", euid);
2018 }
2019 }
2020
2021 strlcpy(name, cached_name, namelen);
2022}
2023
2024
2025/*
2026 * called by editline -- any expansions to the prompt
2027 * should be added here.
2028 */
2029char *
2030getprompt(void *unused __unused)
2031{
2032 static char ps[PROMPTLEN];
2033 const char *fmt;
2034 const char *home;
2035 const char *pwd;
2036 size_t homelen;
2037 int i, trim;
2038 static char internal_error[] = "??";
2039
2040 /*
2041 * Select prompt format.
2042 */
2043 switch (whichprompt) {
2044 case 0:
2045 fmt = "";
2046 break;
2047 case 1:
2048 fmt = expandstr(ps1val());
2049 if (fmt == NULL)
2050 fmt = ps1val();
2051 break;
2052 case 2:
2053 fmt = ps2val();
2054 break;
2055 default:
2056 return internal_error;
2057 }
2058
2059 /*
2060 * Format prompt string.
2061 */
2062 for (i = 0; (i < PROMPTLEN - 1) && (*fmt != '\0'); i++, fmt++) {
2063 if (*fmt == '$') {
2064 const char *varname_start, *varname_end, *value;
2065 char varname[256];
2066 int namelen, braced = 0;
2067
2068 fmt++; /* Skip the '$' */
2069
2070 /* Check for ${VAR} syntax */
2071 if (*fmt == '{') {
2072 braced = 1;
2073 fmt++;
2074 }
2075
2076 varname_start = fmt;
2077
2078 /* Extract variable name */
2079 if (is_digit(*fmt)) {
2080 /* Positional parameter: $0, $1, etc. */
2081 fmt++;
2082 varname_end = fmt;
2083 } else if (is_special(*fmt)) {
2084 /* Special parameter: $?, $!, $$, etc. */
2085 fmt++;
2086 varname_end = fmt;
2087 } else if (is_name(*fmt)) {
2088 /* Regular variable name */
2089 do
2090 fmt++;
2091 while (is_in_name(*fmt));
2092 varname_end = fmt;
2093 } else {
2094 /*
2095 * Not a valid variable reference.
2096 * Output literal '$'.
2097 */
2098 ps[i] = '$';
2099 if (braced && i < PROMPTLEN - 2)
2100 ps[++i] = '{';
2101 fmt = varname_start - 1;
2102 continue;
2103 }
2104
2105 namelen = varname_end - varname_start;
2106 if (namelen == 0 || namelen >= (int)sizeof(varname)) {
2107 /* Invalid or too long, output literal */
2108 ps[i] = '$';
2109 fmt = varname_start - 1;
2110 continue;
2111 }
2112
2113 /* Copy variable name */
2114 memcpy(varname, varname_start, namelen);
2115 varname[namelen] = '\0';
2116
2117 /* Handle closing brace for ${VAR} */
2118 if (braced) {
2119 if (*fmt == '}') {
2120 fmt++;
2121 } else {
2122 /* Missing closing brace, treat as literal */
2123 ps[i] = '$';
2124 if (i < PROMPTLEN - 2)
2125 ps[++i] = '{';
2126 fmt = varname_start - 1;
2127 continue;
2128 }
2129 }
2130
2131 /* Look up the variable */
2132 if (namelen == 1 && is_digit(*varname)) {
2133 /* Positional parameters - check digits FIRST */
2134 int num = *varname - '0';
2135 if (num == 0)
2136 value = arg0 ? arg0 : "";
2137 else if (num > 0 && num <= shellparam.nparam)
2138 value = shellparam.p[num - 1];
2139 else
2140 value = "";
2141 } else if (namelen == 1 && is_special(*varname)) {
2142 /* Special parameters */
2143 char valbuf[20];
2144 int num;
2145
2146 switch (*varname) {
2147 case '$':
2148 num = rootpid;
2149 break;
2150 case '?':
2151 num = exitstatus;
2152 break;
2153 case '#':
2154 num = shellparam.nparam;
2155 break;
2156 case '!':
2157 num = backgndpidval();
2158 break;
2159 default:
2160 num = 0;
2161 break;
2162 }
2163 snprintf(valbuf, sizeof(valbuf), "%d", num);
2164 value = valbuf;
2165 } else {
2166 /* Regular variables */
2167 value = lookupvar(varname);
2168 if (value == NULL)
2169 value = "";
2170 }
2171
2172 /* Copy value to output, respecting buffer size */
2173 while (*value != '\0' && i < PROMPTLEN - 1) {
2174 ps[i++] = *value++;
2175 }
2176
2177 /*
2178 * Adjust fmt and i for the loop increment.
2179 * fmt will be incremented by the for loop,
2180 * so position it one before where we want.
2181 */
2182 fmt--;
2183 i--;
2184 continue;
2185 } else if (*fmt != '\\') {
2186 ps[i] = *fmt;
2187 continue;
2188 }
2189
2190 switch (*++fmt) {
2191
2192 /*
2193 * Non-printing sequence begin and end.
2194 */
2195 case '[':
2196 case ']':
2197 ps[i] = '\001';
2198 break;
2199
2200 /*
2201 * Literal \ and some ASCII characters:
2202 * \a BEL
2203 * \e ESC
2204 * \r CR
2205 */
2206 case '\\':
2207 case 'a':
2208 case 'e':
2209 case 'r':
2210 if (*fmt == 'a')
2211 ps[i] = '\007';
2212 else if (*fmt == 'e')
2213 ps[i] = '\033';
2214 else if (*fmt == 'r')
2215 ps[i] = '\r';
2216 else
2217 ps[i] = '\\';
2218 break;
2219
2220 /*
2221 * CRLF sequence
2222 */
2223 case 'n':
2224 if (i < PROMPTLEN - 3) {
2225 ps[i++] = '\r';
2226 ps[i] = '\n';
2227 }
2228 break;
2229
2230 /*
2231 * Print the current time as per provided strftime format.
2232 */
2233 case 'D': {
2234 char tfmt[128] = "%X"; /* \D{} means %X. */
2235 struct tm *now;
2236
2237 if (fmt[1] != '{') {
2238 /*
2239 * "\D" but not "\D{", so treat the '\'
2240 * literally and rewind fmt to treat 'D'
2241 * literally next iteration.
2242 */
2243 ps[i] = '\\';
2244 fmt--;
2245 break;
2246 }
2247 fmt += 2; /* Consume "D{". */
2248 if (fmt[0] != '}') {
2249 char *end;
2250
2251 end = memccpy(tfmt, fmt, '}', sizeof(tfmt));
2252 if (end == NULL) {
2253 /*
2254 * Format too long or no '}', so
2255 * ignore "\D{" altogether.
2256 * The loop will do i++, but nothing
2257 * was written to ps, so do i-- here.
2258 * Rewind fmt for similar reason.
2259 */
2260 i--;
2261 fmt--;
2262 break;
2263 }
2264 *--end = '\0'; /* Ignore the copy of '}'. */
2265 fmt += end - tfmt;
2266 }
2267 now = localtime(&(time_t){time(NULL)});
2268 i += strftime(&ps[i], PROMPTLEN - i - 1, tfmt, now);
2269 i--; /* The loop will do i++. */
2270 break;
2271 }
2272
2273 /*
2274 * Hostname.
2275 *
2276 * \h specifies just the local hostname,
2277 * \H specifies fully-qualified hostname.
2278 */
2279 case 'h':
2280 case 'H':
2281 ps[i] = '\0';
2282 gethostname(&ps[i], PROMPTLEN - i - 1);
2283 ps[PROMPTLEN - 1] = '\0';
2284 /* Skip to end of hostname. */
2285 trim = (*fmt == 'h') ? '.' : '\0';
2286 while ((ps[i] != '\0') && (ps[i] != trim))
2287 i++;
2288 --i;
2289 break;
2290
2291 /*
2292 * User name.
2293 */
2294 case 'u':
2295 ps[i] = '\0';
2296 getusername(&ps[i], PROMPTLEN - i);
2297 /* Skip to end of username. */
2298 while (ps[i + 1] != '\0')
2299 i++;
2300 break;
2301
2302 /*
2303 * Working directory.
2304 *
2305 * \W specifies just the final component,
2306 * \w specifies the entire path.
2307 */
2308 case 'W':
2309 case 'w':
2310 pwd = lookupvar("PWD");
2311 if (pwd == NULL || *pwd == '\0')
2312 pwd = "?";
2313 if (*fmt == 'W' &&
2314 *pwd == '/' && pwd[1] != '\0')
2315 strlcpy(&ps[i], strrchr(pwd, '/') + 1,
2316 PROMPTLEN - i);
2317 else {
2318 home = lookupvar("HOME");
2319 if (home != NULL)
2320 homelen = strlen(home);
2321 if (home != NULL &&
2322 strcmp(home, "/") != 0 &&
2323 strncmp(pwd, home, homelen) == 0 &&
2324 (pwd[homelen] == '/' ||
2325 pwd[homelen] == '\0')) {
2326 strlcpy(&ps[i], "~",
2327 PROMPTLEN - i);
2328 strlcpy(&ps[i + 1],
2329 pwd + homelen,
2330 PROMPTLEN - i - 1);
2331 } else {
2332 strlcpy(&ps[i], pwd, PROMPTLEN - i);
2333 }
2334 }
2335 /* Skip to end of path. */
2336 while (ps[i + 1] != '\0')
2337 i++;
2338 break;
2339
2340 /*
2341 * Superuser status.
2342 *
2343 * '$' for normal users, '#' for root.
2344 */
2345 case '$':
2346 ps[i] = (geteuid() != 0) ? '$' : '#';
2347 break;
2348
2349 /*
2350 * Emit unrecognized formats verbatim.
2351 */
2352 default:
2353 ps[i] = '\\';
2354 if (i < PROMPTLEN - 2)
2355 ps[++i] = *fmt;
2356 break;
2357 }
2358
2359 }
2360 ps[i] = '\0';
2361 return (ps);
2362}
2363
2364
2365const char *
2366expandstr(const char *ps)
2367{
2368 union node n;
2369 struct jmploc jmploc;
2370 struct jmploc *const savehandler = handler;
2371 const int saveprompt = doprompt;
2372 struct parsefile *const savetopfile = getcurrentfile();
2373 struct parser_temp *const saveparser_temp = parser_temp;
2374 const char *result = NULL;
2375
2376 if (!setjmp(jmploc.loc)) {
2377 handler = &jmploc;
2378 parser_temp = NULL;
2379 setinputstring(ps);
2380 doprompt = 0;
2381 readtoken1(pgetc(), DQSYNTAX, NOEOFMARK, 0);
2382 if (backquotelist != NULL)
2383 error("Command substitution not allowed here");
2384
2385 n.narg.type = NARG;
2386 n.narg.next = NULL;
2387 n.narg.text = wordtext;
2388 n.narg.backquote = backquotelist;
2389
2390 expandarg(&n, NULL, 0);
2391 result = stackblock();
2392 INTOFF;
2393 }
2394 handler = savehandler;
2395 doprompt = saveprompt;
2396 popfilesupto(savetopfile);
2397 if (parser_temp != saveparser_temp) {
2398 parser_temp_free_all();
2399 parser_temp = saveparser_temp;
2400 }
2401 if (result != NULL) {
2402 INTON;
2403 } else if (exception == EXINT)
2404 raise(SIGINT);
2405 return result;
2406}
