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 #include "parser.h"
44 #include "nodes.h"
45 #include "expand.h" /* defines rmescapes() */
46 #include "syntax.h"
47 #include "options.h"
48 #include "input.h"
49 #include "output.h"
50 #include "var.h"
51 #include "error.h"
52 #include "memalloc.h"
53 #include "mystring.h"
54 #include "alias.h"
55 #include "show.h"
56 #include "eval.h"
57 #include "exec.h" /* to check for special builtins */
58 #ifndef NO_HISTORY
59 #include "myhistedit.h"
60 #endif
61
62 /*
63 * Shell command parser.
64 */
65
66 #define PROMPTLEN 192
67
68 /* values of checkkwd variable */
69 #define CHKALIAS 0x1
70 #define CHKKWD 0x2
71 #define CHKNL 0x4
72
73 /* values returned by readtoken */
74 #include "token.h"
75
76
77
78 struct heredoc {
79 struct heredoc *next; /* next here document in list */
80 union node *here; /* redirection node */
81 char *eofmark; /* string indicating end of input */
82 int striptabs; /* if set, strip leading tabs */
83 };
84
85 struct parser_temp {
86 struct parser_temp *next;
87 void *data;
88 };
89
90
91 static struct heredoc *heredoclist; /* list of here documents to read */
92 static int doprompt; /* if set, prompt the user */
93 static int needprompt; /* true if interactive and at start of line */
94 static int lasttoken; /* last token read */
95 static int tokpushback; /* last token pushed back */
96 static char *wordtext; /* text of last word returned by readtoken */
97 static int checkkwd;
98 static struct nodelist *backquotelist;
99 static union node *redirnode;
100 static struct heredoc *heredoc;
101 static int quoteflag; /* set if (part of) last token was quoted */
102 static int startlinno; /* line # where last token started */
103 static int funclinno; /* line # where the current function started */
104 static struct parser_temp *parser_temp;
105
106 #define NOEOFMARK ((const char *)&heredoclist)
107
108
109 static union node *list(int);
110 static union node *andor(void);
111 static union node *pipeline(void);
112 static union node *command(void);
113 static union node *simplecmd(union node **, union node *);
114 static union node *makename(void);
115 static union node *makebinary(int type, union node *n1, union node *n2);
116 static void parsefname(void);
117 static void parseheredoc(void);
118 static int peektoken(void);
119 static int readtoken(void);
120 static int xxreadtoken(void);
121 static int readtoken1(int, const char *, const char *, int);
122 static int noexpand(char *);
123 static void consumetoken(int);
124 static void synexpect(int) __dead2;
125 static void synerror(const char *) __dead2;
126 static void setprompt(int);
127 static int pgetc_linecont(void);
128 static void getusername(char *, size_t);
129
130
131 static void *
parser_temp_alloc(size_t len)132 parser_temp_alloc(size_t len)
133 {
134 struct parser_temp *t;
135
136 INTOFF;
137 t = ckmalloc(sizeof(*t));
138 t->data = NULL;
139 t->next = parser_temp;
140 parser_temp = t;
141 t->data = ckmalloc(len);
142 INTON;
143 return t->data;
144 }
145
146
147 static void *
parser_temp_realloc(void * ptr,size_t len)148 parser_temp_realloc(void *ptr, size_t len)
149 {
150 struct parser_temp *t;
151
152 INTOFF;
153 t = parser_temp;
154 if (ptr != t->data)
155 error("bug: parser_temp_realloc misused");
156 t->data = ckrealloc(t->data, len);
157 INTON;
158 return t->data;
159 }
160
161
162 static void
parser_temp_free_upto(void * ptr)163 parser_temp_free_upto(void *ptr)
164 {
165 struct parser_temp *t;
166 int done = 0;
167
168 INTOFF;
169 while (parser_temp != NULL && !done) {
170 t = parser_temp;
171 parser_temp = t->next;
172 done = t->data == ptr;
173 ckfree(t->data);
174 ckfree(t);
175 }
176 INTON;
177 if (!done)
178 error("bug: parser_temp_free_upto misused");
179 }
180
181
182 static void
parser_temp_free_all(void)183 parser_temp_free_all(void)
184 {
185 struct parser_temp *t;
186
187 INTOFF;
188 while (parser_temp != NULL) {
189 t = parser_temp;
190 parser_temp = t->next;
191 ckfree(t->data);
192 ckfree(t);
193 }
194 INTON;
195 }
196
197
198 /*
199 * Read and parse a command. Returns NEOF on end of file. (NULL is a
200 * valid parse tree indicating a blank line.)
201 */
202
203 union node *
parsecmd(int interact)204 parsecmd(int interact)
205 {
206 int t;
207
208 /* This assumes the parser is not re-entered,
209 * which could happen if we add command substitution on PS1/PS2.
210 */
211 parser_temp_free_all();
212 heredoclist = NULL;
213
214 tokpushback = 0;
215 checkkwd = 0;
216 doprompt = interact;
217 if (doprompt)
218 setprompt(1);
219 else
220 setprompt(0);
221 needprompt = 0;
222 t = readtoken();
223 if (t == TEOF)
224 return NEOF;
225 if (t == TNL)
226 return NULL;
227 tokpushback++;
228 return list(1);
229 }
230
231
232 /*
233 * Read and parse words for wordexp.
234 * Returns a list of NARG nodes; NULL if there are no words.
235 */
236 union node *
parsewordexp(void)237 parsewordexp(void)
238 {
239 union node *n, *first = NULL, **pnext;
240 int t;
241
242 /* This assumes the parser is not re-entered,
243 * which could happen if we add command substitution on PS1/PS2.
244 */
245 parser_temp_free_all();
246 heredoclist = NULL;
247
248 tokpushback = 0;
249 checkkwd = 0;
250 doprompt = 0;
251 setprompt(0);
252 needprompt = 0;
253 pnext = &first;
254 while ((t = readtoken()) != TEOF) {
255 if (t != TWORD)
256 synexpect(TWORD);
257 n = makename();
258 *pnext = n;
259 pnext = &n->narg.next;
260 }
261 return first;
262 }
263
264
265 static union node *
list(int nlflag)266 list(int nlflag)
267 {
268 union node *ntop, *n1, *n2, *n3;
269 int tok;
270
271 checkkwd = CHKNL | CHKKWD | CHKALIAS;
272 if (!nlflag && tokendlist[peektoken()])
273 return NULL;
274 ntop = n1 = NULL;
275 for (;;) {
276 n2 = andor();
277 tok = readtoken();
278 if (tok == TBACKGND) {
279 if (n2 != NULL && n2->type == NPIPE) {
280 n2->npipe.backgnd = 1;
281 } else if (n2 != NULL && n2->type == NREDIR) {
282 n2->type = NBACKGND;
283 } else {
284 n3 = (union node *)stalloc(sizeof (struct nredir));
285 n3->type = NBACKGND;
286 n3->nredir.n = n2;
287 n3->nredir.redirect = NULL;
288 n2 = n3;
289 }
290 }
291 if (ntop == NULL)
292 ntop = n2;
293 else if (n1 == NULL) {
294 n1 = makebinary(NSEMI, ntop, n2);
295 ntop = n1;
296 }
297 else {
298 n3 = makebinary(NSEMI, n1->nbinary.ch2, n2);
299 n1->nbinary.ch2 = n3;
300 n1 = n3;
301 }
302 switch (tok) {
303 case TBACKGND:
304 case TSEMI:
305 tok = readtoken();
306 /* FALLTHROUGH */
307 case TNL:
308 if (tok == TNL) {
309 parseheredoc();
310 if (nlflag)
311 return ntop;
312 } else if (tok == TEOF && nlflag) {
313 parseheredoc();
314 return ntop;
315 } else {
316 tokpushback++;
317 }
318 checkkwd = CHKNL | CHKKWD | CHKALIAS;
319 if (!nlflag && tokendlist[peektoken()])
320 return ntop;
321 break;
322 case TEOF:
323 if (heredoclist)
324 parseheredoc();
325 else
326 pungetc(); /* push back EOF on input */
327 return ntop;
328 default:
329 if (nlflag)
330 synexpect(-1);
331 tokpushback++;
332 return ntop;
333 }
334 }
335 }
336
337
338
339 static union node *
andor(void)340 andor(void)
341 {
342 union node *n;
343 int t;
344
345 n = pipeline();
346 for (;;) {
347 if ((t = readtoken()) == TAND) {
348 t = NAND;
349 } else if (t == TOR) {
350 t = NOR;
351 } else {
352 tokpushback++;
353 return n;
354 }
355 n = makebinary(t, n, pipeline());
356 }
357 }
358
359
360
361 static union node *
pipeline(void)362 pipeline(void)
363 {
364 union node *n1, *n2, *pipenode;
365 struct nodelist *lp, *prev;
366 int negate, t;
367
368 negate = 0;
369 checkkwd = CHKNL | CHKKWD | CHKALIAS;
370 TRACE(("pipeline: entered\n"));
371 while (readtoken() == TNOT)
372 negate = !negate;
373 tokpushback++;
374 n1 = command();
375 if (readtoken() == TPIPE) {
376 pipenode = (union node *)stalloc(sizeof (struct npipe));
377 pipenode->type = NPIPE;
378 pipenode->npipe.backgnd = 0;
379 lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
380 pipenode->npipe.cmdlist = lp;
381 lp->n = n1;
382 do {
383 prev = lp;
384 lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
385 checkkwd = CHKNL | CHKKWD | CHKALIAS;
386 t = readtoken();
387 tokpushback++;
388 if (t == TNOT)
389 lp->n = pipeline();
390 else
391 lp->n = command();
392 prev->next = lp;
393 } while (readtoken() == TPIPE);
394 lp->next = NULL;
395 n1 = pipenode;
396 }
397 tokpushback++;
398 if (negate) {
399 n2 = (union node *)stalloc(sizeof (struct nnot));
400 n2->type = NNOT;
401 n2->nnot.com = n1;
402 return n2;
403 } else
404 return n1;
405 }
406
407
408
409 static union node *
command(void)410 command(void)
411 {
412 union node *n1, *n2;
413 union node *ap, **app;
414 union node *cp, **cpp;
415 union node *redir, **rpp;
416 int t;
417 int is_subshell;
418
419 checkkwd = CHKNL | CHKKWD | CHKALIAS;
420 is_subshell = 0;
421 redir = NULL;
422 n1 = NULL;
423 rpp = &redir;
424
425 /* Check for redirection which may precede command */
426 while (readtoken() == TREDIR) {
427 *rpp = n2 = redirnode;
428 rpp = &n2->nfile.next;
429 parsefname();
430 }
431 tokpushback++;
432
433 switch (readtoken()) {
434 case TIF:
435 n1 = (union node *)stalloc(sizeof (struct nif));
436 n1->type = NIF;
437 if ((n1->nif.test = list(0)) == NULL)
438 synexpect(-1);
439 consumetoken(TTHEN);
440 n1->nif.ifpart = list(0);
441 n2 = n1;
442 while (readtoken() == TELIF) {
443 n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif));
444 n2 = n2->nif.elsepart;
445 n2->type = NIF;
446 if ((n2->nif.test = list(0)) == NULL)
447 synexpect(-1);
448 consumetoken(TTHEN);
449 n2->nif.ifpart = list(0);
450 }
451 if (lasttoken == TELSE)
452 n2->nif.elsepart = list(0);
453 else {
454 n2->nif.elsepart = NULL;
455 tokpushback++;
456 }
457 consumetoken(TFI);
458 checkkwd = CHKKWD | CHKALIAS;
459 break;
460 case TWHILE:
461 case TUNTIL:
462 t = lasttoken;
463 if ((n1 = list(0)) == NULL)
464 synexpect(-1);
465 consumetoken(TDO);
466 n1 = makebinary((t == TWHILE)? NWHILE : NUNTIL, n1, list(0));
467 consumetoken(TDONE);
468 checkkwd = CHKKWD | CHKALIAS;
469 break;
470 case TFOR:
471 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext))
472 synerror("Bad for loop variable");
473 n1 = (union node *)stalloc(sizeof (struct nfor));
474 n1->type = NFOR;
475 n1->nfor.var = wordtext;
476 checkkwd = CHKNL;
477 if (readtoken() == TWORD && !quoteflag &&
478 equal(wordtext, "in")) {
479 app = ≈
480 while (readtoken() == TWORD) {
481 n2 = makename();
482 *app = n2;
483 app = &n2->narg.next;
484 }
485 *app = NULL;
486 n1->nfor.args = ap;
487 if (lasttoken == TNL)
488 tokpushback++;
489 else if (lasttoken != TSEMI)
490 synexpect(-1);
491 } else {
492 static char argvars[5] = {
493 CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0'
494 };
495 n2 = (union node *)stalloc(sizeof (struct narg));
496 n2->type = NARG;
497 n2->narg.text = argvars;
498 n2->narg.backquote = NULL;
499 n2->narg.next = NULL;
500 n1->nfor.args = n2;
501 /*
502 * Newline or semicolon here is optional (but note
503 * that the original Bourne shell only allowed NL).
504 */
505 if (lasttoken != TSEMI)
506 tokpushback++;
507 }
508 checkkwd = CHKNL | CHKKWD | CHKALIAS;
509 if ((t = readtoken()) == TDO)
510 t = TDONE;
511 else if (t == TBEGIN)
512 t = TEND;
513 else
514 synexpect(-1);
515 n1->nfor.body = list(0);
516 consumetoken(t);
517 checkkwd = CHKKWD | CHKALIAS;
518 break;
519 case TCASE:
520 n1 = (union node *)stalloc(sizeof (struct ncase));
521 n1->type = NCASE;
522 consumetoken(TWORD);
523 n1->ncase.expr = makename();
524 checkkwd = CHKNL;
525 if (readtoken() != TWORD || ! equal(wordtext, "in"))
526 synerror("expecting \"in\"");
527 cpp = &n1->ncase.cases;
528 checkkwd = CHKNL | CHKKWD, readtoken();
529 while (lasttoken != TESAC) {
530 *cpp = cp = (union node *)stalloc(sizeof (struct nclist));
531 cp->type = NCLIST;
532 app = &cp->nclist.pattern;
533 if (lasttoken == TLP)
534 readtoken();
535 for (;;) {
536 *app = ap = makename();
537 checkkwd = CHKNL | CHKKWD;
538 if (readtoken() != TPIPE)
539 break;
540 app = &ap->narg.next;
541 readtoken();
542 }
543 ap->narg.next = NULL;
544 if (lasttoken != TRP)
545 synexpect(TRP);
546 cp->nclist.body = list(0);
547
548 checkkwd = CHKNL | CHKKWD | CHKALIAS;
549 if ((t = readtoken()) != TESAC) {
550 if (t == TENDCASE)
551 ;
552 else if (t == TFALLTHRU)
553 cp->type = NCLISTFALLTHRU;
554 else
555 synexpect(TENDCASE);
556 checkkwd = CHKNL | CHKKWD, readtoken();
557 }
558 cpp = &cp->nclist.next;
559 }
560 *cpp = NULL;
561 checkkwd = CHKKWD | CHKALIAS;
562 break;
563 case TLP:
564 n1 = (union node *)stalloc(sizeof (struct nredir));
565 n1->type = NSUBSHELL;
566 n1->nredir.n = list(0);
567 n1->nredir.redirect = NULL;
568 consumetoken(TRP);
569 checkkwd = CHKKWD | CHKALIAS;
570 is_subshell = 1;
571 break;
572 case TBEGIN:
573 n1 = list(0);
574 consumetoken(TEND);
575 checkkwd = CHKKWD | CHKALIAS;
576 break;
577 /* A simple command must have at least one redirection or word. */
578 case TBACKGND:
579 case TSEMI:
580 case TAND:
581 case TOR:
582 case TPIPE:
583 case TENDCASE:
584 case TFALLTHRU:
585 case TEOF:
586 case TNL:
587 case TRP:
588 if (!redir)
589 synexpect(-1);
590 case TWORD:
591 tokpushback++;
592 n1 = simplecmd(rpp, redir);
593 return n1;
594 default:
595 synexpect(-1);
596 }
597
598 /* Now check for redirection which may follow command */
599 while (readtoken() == TREDIR) {
600 *rpp = n2 = redirnode;
601 rpp = &n2->nfile.next;
602 parsefname();
603 }
604 tokpushback++;
605 *rpp = NULL;
606 if (redir) {
607 if (!is_subshell) {
608 n2 = (union node *)stalloc(sizeof (struct nredir));
609 n2->type = NREDIR;
610 n2->nredir.n = n1;
611 n1 = n2;
612 }
613 n1->nredir.redirect = redir;
614 }
615
616 return n1;
617 }
618
619
620 static union node *
simplecmd(union node ** rpp,union node * redir)621 simplecmd(union node **rpp, union node *redir)
622 {
623 union node *args, **app;
624 union node **orig_rpp = rpp;
625 union node *n = NULL;
626 int special;
627 int savecheckkwd;
628
629 /* If we don't have any redirections already, then we must reset */
630 /* rpp to be the address of the local redir variable. */
631 if (redir == NULL)
632 rpp = &redir;
633
634 args = NULL;
635 app = &args;
636 /*
637 * We save the incoming value, because we need this for shell
638 * functions. There can not be a redirect or an argument between
639 * the function name and the open parenthesis.
640 */
641 orig_rpp = rpp;
642
643 savecheckkwd = CHKALIAS;
644
645 for (;;) {
646 checkkwd = savecheckkwd;
647 if (readtoken() == TWORD) {
648 n = makename();
649 *app = n;
650 app = &n->narg.next;
651 if (savecheckkwd != 0 && !isassignment(wordtext))
652 savecheckkwd = 0;
653 } else if (lasttoken == TREDIR) {
654 *rpp = n = redirnode;
655 rpp = &n->nfile.next;
656 parsefname(); /* read name of redirection file */
657 } else if (lasttoken == TLP && app == &args->narg.next
658 && rpp == orig_rpp) {
659 /* We have a function */
660 consumetoken(TRP);
661 funclinno = plinno;
662 /*
663 * - Require plain text.
664 * - Functions with '/' cannot be called.
665 * - Reject name=().
666 * - Reject ksh extended glob patterns.
667 */
668 if (!noexpand(n->narg.text) || quoteflag ||
669 strchr(n->narg.text, '/') ||
670 strchr("!%*+-=?@}~",
671 n->narg.text[strlen(n->narg.text) - 1]))
672 synerror("Bad function name");
673 rmescapes(n->narg.text);
674 if (find_builtin(n->narg.text, &special) >= 0 &&
675 special)
676 synerror("Cannot override a special builtin with a function");
677 n->type = NDEFUN;
678 n->narg.next = command();
679 funclinno = 0;
680 return n;
681 } else {
682 tokpushback++;
683 break;
684 }
685 }
686 *app = NULL;
687 *rpp = NULL;
688 n = (union node *)stalloc(sizeof (struct ncmd));
689 n->type = NCMD;
690 n->ncmd.args = args;
691 n->ncmd.redirect = redir;
692 return n;
693 }
694
695 static union node *
makename(void)696 makename(void)
697 {
698 union node *n;
699
700 n = (union node *)stalloc(sizeof (struct narg));
701 n->type = NARG;
702 n->narg.next = NULL;
703 n->narg.text = wordtext;
704 n->narg.backquote = backquotelist;
705 return n;
706 }
707
708 static union node *
makebinary(int type,union node * n1,union node * n2)709 makebinary(int type, union node *n1, union node *n2)
710 {
711 union node *n;
712
713 n = (union node *)stalloc(sizeof (struct nbinary));
714 n->type = type;
715 n->nbinary.ch1 = n1;
716 n->nbinary.ch2 = n2;
717 return (n);
718 }
719
720 void
forcealias(void)721 forcealias(void)
722 {
723 checkkwd |= CHKALIAS;
724 }
725
726 void
fixredir(union node * n,const char * text,int err)727 fixredir(union node *n, const char *text, int err)
728 {
729 TRACE(("Fix redir %s %d\n", text, err));
730 if (!err)
731 n->ndup.vname = NULL;
732
733 if (is_digit(text[0]) && text[1] == '\0')
734 n->ndup.dupfd = digit_val(text[0]);
735 else if (text[0] == '-' && text[1] == '\0')
736 n->ndup.dupfd = -1;
737 else {
738
739 if (err)
740 synerror("Bad fd number");
741 else
742 n->ndup.vname = makename();
743 }
744 }
745
746
747 static void
parsefname(void)748 parsefname(void)
749 {
750 union node *n = redirnode;
751
752 consumetoken(TWORD);
753 if (n->type == NHERE) {
754 struct heredoc *here = heredoc;
755 struct heredoc *p;
756
757 if (quoteflag == 0)
758 n->type = NXHERE;
759 TRACE(("Here document %d\n", n->type));
760 if (here->striptabs) {
761 while (*wordtext == '\t')
762 wordtext++;
763 }
764 if (! noexpand(wordtext))
765 synerror("Illegal eof marker for << redirection");
766 rmescapes(wordtext);
767 here->eofmark = wordtext;
768 here->next = NULL;
769 if (heredoclist == NULL)
770 heredoclist = here;
771 else {
772 for (p = heredoclist ; p->next ; p = p->next);
773 p->next = here;
774 }
775 } else if (n->type == NTOFD || n->type == NFROMFD) {
776 fixredir(n, wordtext, 0);
777 } else {
778 n->nfile.fname = makename();
779 }
780 }
781
782
783 /*
784 * Input any here documents.
785 */
786
787 static void
parseheredoc(void)788 parseheredoc(void)
789 {
790 struct heredoc *here;
791 union node *n;
792
793 while (heredoclist) {
794 here = heredoclist;
795 heredoclist = here->next;
796 if (needprompt) {
797 setprompt(2);
798 needprompt = 0;
799 }
800 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX,
801 here->eofmark, here->striptabs);
802 n = makename();
803 here->here->nhere.doc = n;
804 }
805 }
806
807 static int
peektoken(void)808 peektoken(void)
809 {
810 int t;
811
812 t = readtoken();
813 tokpushback++;
814 return (t);
815 }
816
817 static int
readtoken(void)818 readtoken(void)
819 {
820 int t;
821 struct alias *ap;
822 #ifdef DEBUG
823 int alreadyseen = tokpushback;
824 #endif
825
826 top:
827 t = xxreadtoken();
828
829 /*
830 * eat newlines
831 */
832 if (checkkwd & CHKNL) {
833 while (t == TNL) {
834 parseheredoc();
835 t = xxreadtoken();
836 }
837 }
838
839 /*
840 * check for keywords and aliases
841 */
842 if (t == TWORD && !quoteflag)
843 {
844 const char * const *pp;
845
846 if (checkkwd & CHKKWD)
847 for (pp = parsekwd; *pp; pp++) {
848 if (**pp == *wordtext && equal(*pp, wordtext))
849 {
850 lasttoken = t = pp - parsekwd + KWDOFFSET;
851 TRACE(("keyword %s recognized\n", tokname[t]));
852 goto out;
853 }
854 }
855 if (checkkwd & CHKALIAS &&
856 (ap = lookupalias(wordtext, 1)) != NULL) {
857 pushstring(ap->val, strlen(ap->val), ap);
858 goto top;
859 }
860 }
861 out:
862 if (t != TNOT)
863 checkkwd = 0;
864
865 #ifdef DEBUG
866 if (!alreadyseen)
867 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
868 else
869 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
870 #endif
871 return (t);
872 }
873
874
875 /*
876 * Read the next input token.
877 * If the token is a word, we set backquotelist to the list of cmds in
878 * backquotes. We set quoteflag to true if any part of the word was
879 * quoted.
880 * If the token is TREDIR, then we set redirnode to a structure containing
881 * the redirection.
882 * In all cases, the variable startlinno is set to the number of the line
883 * on which the token starts.
884 *
885 * [Change comment: here documents and internal procedures]
886 * [Readtoken shouldn't have any arguments. Perhaps we should make the
887 * word parsing code into a separate routine. In this case, readtoken
888 * doesn't need to have any internal procedures, but parseword does.
889 * We could also make parseoperator in essence the main routine, and
890 * have parseword (readtoken1?) handle both words and redirection.]
891 */
892
893 #define RETURN(token) return lasttoken = token
894
895 static int
xxreadtoken(void)896 xxreadtoken(void)
897 {
898 int c;
899
900 if (tokpushback) {
901 tokpushback = 0;
902 return lasttoken;
903 }
904 if (needprompt) {
905 setprompt(2);
906 needprompt = 0;
907 }
908 startlinno = plinno;
909 for (;;) { /* until token or start of word found */
910 c = pgetc_macro();
911 switch (c) {
912 case ' ': case '\t':
913 continue;
914 case '#':
915 while ((c = pgetc()) != '\n' && c != PEOF);
916 pungetc();
917 continue;
918 case '\\':
919 if (pgetc() == '\n') {
920 startlinno = ++plinno;
921 if (doprompt)
922 setprompt(2);
923 else
924 setprompt(0);
925 continue;
926 }
927 pungetc();
928 /* FALLTHROUGH */
929 default:
930 return readtoken1(c, BASESYNTAX, (char *)NULL, 0);
931 case '\n':
932 plinno++;
933 needprompt = doprompt;
934 RETURN(TNL);
935 case PEOF:
936 RETURN(TEOF);
937 case '&':
938 if (pgetc_linecont() == '&')
939 RETURN(TAND);
940 pungetc();
941 RETURN(TBACKGND);
942 case '|':
943 if (pgetc_linecont() == '|')
944 RETURN(TOR);
945 pungetc();
946 RETURN(TPIPE);
947 case ';':
948 c = pgetc_linecont();
949 if (c == ';')
950 RETURN(TENDCASE);
951 else if (c == '&')
952 RETURN(TFALLTHRU);
953 pungetc();
954 RETURN(TSEMI);
955 case '(':
956 RETURN(TLP);
957 case ')':
958 RETURN(TRP);
959 }
960 }
961 #undef RETURN
962 }
963
964
965 #define MAXNEST_static 8
966 struct tokenstate
967 {
968 const char *syntax; /* *SYNTAX */
969 int parenlevel; /* levels of parentheses in arithmetic */
970 enum tokenstate_category
971 {
972 TSTATE_TOP,
973 TSTATE_VAR_OLD, /* ${var+-=?}, inherits dquotes */
974 TSTATE_VAR_NEW, /* other ${var...}, own dquote state */
975 TSTATE_ARITH
976 } category;
977 };
978
979
980 /*
981 * Check to see whether we are at the end of the here document. When this
982 * is called, c is set to the first character of the next input line. If
983 * we are at the end of the here document, this routine sets the c to PEOF.
984 * The new value of c is returned.
985 */
986
987 static int
checkend(int c,const char * eofmark,int striptabs)988 checkend(int c, const char *eofmark, int striptabs)
989 {
990 if (striptabs) {
991 while (c == '\t')
992 c = pgetc();
993 }
994 if (c == *eofmark) {
995 int c2;
996 const char *q;
997
998 for (q = eofmark + 1; c2 = pgetc(), *q != '\0' && c2 == *q; q++)
999 ;
1000 if ((c2 == PEOF || c2 == '\n') && *q == '\0') {
1001 c = PEOF;
1002 if (c2 == '\n') {
1003 plinno++;
1004 needprompt = doprompt;
1005 }
1006 } else {
1007 pungetc();
1008 pushstring(eofmark + 1, q - (eofmark + 1), NULL);
1009 }
1010 } else if (c == '\n' && *eofmark == '\0') {
1011 c = PEOF;
1012 plinno++;
1013 needprompt = doprompt;
1014 }
1015 return (c);
1016 }
1017
1018
1019 /*
1020 * Parse a redirection operator. The variable "out" points to a string
1021 * specifying the fd to be redirected. The variable "c" contains the
1022 * first character of the redirection operator.
1023 */
1024
1025 static void
parseredir(char * out,int c)1026 parseredir(char *out, int c)
1027 {
1028 char fd = *out;
1029 union node *np;
1030
1031 np = (union node *)stalloc(sizeof (struct nfile));
1032 if (c == '>') {
1033 np->nfile.fd = 1;
1034 c = pgetc_linecont();
1035 if (c == '>')
1036 np->type = NAPPEND;
1037 else if (c == '&')
1038 np->type = NTOFD;
1039 else if (c == '|')
1040 np->type = NCLOBBER;
1041 else {
1042 np->type = NTO;
1043 pungetc();
1044 }
1045 } else { /* c == '<' */
1046 np->nfile.fd = 0;
1047 c = pgetc_linecont();
1048 if (c == '<') {
1049 if (sizeof (struct nfile) != sizeof (struct nhere)) {
1050 np = (union node *)stalloc(sizeof (struct nhere));
1051 np->nfile.fd = 0;
1052 }
1053 np->type = NHERE;
1054 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc));
1055 heredoc->here = np;
1056 if ((c = pgetc_linecont()) == '-') {
1057 heredoc->striptabs = 1;
1058 } else {
1059 heredoc->striptabs = 0;
1060 pungetc();
1061 }
1062 } else if (c == '&')
1063 np->type = NFROMFD;
1064 else if (c == '>')
1065 np->type = NFROMTO;
1066 else {
1067 np->type = NFROM;
1068 pungetc();
1069 }
1070 }
1071 if (fd != '\0')
1072 np->nfile.fd = digit_val(fd);
1073 redirnode = np;
1074 }
1075
1076 /*
1077 * Called to parse command substitutions.
1078 */
1079
1080 static char *
parsebackq(char * out,struct nodelist ** pbqlist,int oldstyle,int dblquote,int quoted)1081 parsebackq(char *out, struct nodelist **pbqlist,
1082 int oldstyle, int dblquote, int quoted)
1083 {
1084 struct nodelist **nlpp;
1085 union node *n;
1086 char *volatile str;
1087 struct jmploc jmploc;
1088 struct jmploc *const savehandler = handler;
1089 size_t savelen;
1090 int saveprompt;
1091 const int bq_startlinno = plinno;
1092 char *volatile ostr = NULL;
1093 struct parsefile *const savetopfile = getcurrentfile();
1094 struct heredoc *const saveheredoclist = heredoclist;
1095 struct heredoc *here;
1096
1097 str = NULL;
1098 if (setjmp(jmploc.loc)) {
1099 popfilesupto(savetopfile);
1100 if (str)
1101 ckfree(str);
1102 if (ostr)
1103 ckfree(ostr);
1104 heredoclist = saveheredoclist;
1105 handler = savehandler;
1106 if (exception == EXERROR) {
1107 startlinno = bq_startlinno;
1108 synerror("Error in command substitution");
1109 }
1110 longjmp(handler->loc, 1);
1111 }
1112 INTOFF;
1113 savelen = out - stackblock();
1114 if (savelen > 0) {
1115 str = ckmalloc(savelen);
1116 memcpy(str, stackblock(), savelen);
1117 }
1118 handler = &jmploc;
1119 heredoclist = NULL;
1120 INTON;
1121 if (oldstyle) {
1122 /* We must read until the closing backquote, giving special
1123 treatment to some slashes, and then push the string and
1124 reread it as input, interpreting it normally. */
1125 char *oout;
1126 int c;
1127 int olen;
1128
1129
1130 STARTSTACKSTR(oout);
1131 for (;;) {
1132 if (needprompt) {
1133 setprompt(2);
1134 needprompt = 0;
1135 }
1136 CHECKSTRSPACE(2, oout);
1137 c = pgetc_linecont();
1138 if (c == '`')
1139 break;
1140 switch (c) {
1141 case '\\':
1142 c = pgetc();
1143 if (c != '\\' && c != '`' && c != '$'
1144 && (!dblquote || c != '"'))
1145 USTPUTC('\\', oout);
1146 break;
1147
1148 case '\n':
1149 plinno++;
1150 needprompt = doprompt;
1151 break;
1152
1153 case PEOF:
1154 startlinno = plinno;
1155 synerror("EOF in backquote substitution");
1156 break;
1157
1158 default:
1159 break;
1160 }
1161 USTPUTC(c, oout);
1162 }
1163 USTPUTC('\0', oout);
1164 olen = oout - stackblock();
1165 INTOFF;
1166 ostr = ckmalloc(olen);
1167 memcpy(ostr, stackblock(), olen);
1168 setinputstring(ostr, 1);
1169 INTON;
1170 }
1171 nlpp = pbqlist;
1172 while (*nlpp)
1173 nlpp = &(*nlpp)->next;
1174 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist));
1175 (*nlpp)->next = NULL;
1176
1177 if (oldstyle) {
1178 saveprompt = doprompt;
1179 doprompt = 0;
1180 }
1181
1182 n = list(0);
1183
1184 if (oldstyle) {
1185 if (peektoken() != TEOF)
1186 synexpect(-1);
1187 doprompt = saveprompt;
1188 } else
1189 consumetoken(TRP);
1190
1191 (*nlpp)->n = n;
1192 if (oldstyle) {
1193 /*
1194 * Start reading from old file again, ignoring any pushed back
1195 * tokens left from the backquote parsing
1196 */
1197 popfile();
1198 tokpushback = 0;
1199 }
1200 STARTSTACKSTR(out);
1201 CHECKSTRSPACE(savelen + 1, out);
1202 INTOFF;
1203 if (str) {
1204 memcpy(out, str, savelen);
1205 STADJUST(savelen, out);
1206 ckfree(str);
1207 str = NULL;
1208 }
1209 if (ostr) {
1210 ckfree(ostr);
1211 ostr = NULL;
1212 }
1213 here = saveheredoclist;
1214 if (here != NULL) {
1215 while (here->next != NULL)
1216 here = here->next;
1217 here->next = heredoclist;
1218 heredoclist = saveheredoclist;
1219 }
1220 handler = savehandler;
1221 INTON;
1222 if (quoted)
1223 USTPUTC(CTLBACKQ | CTLQUOTE, out);
1224 else
1225 USTPUTC(CTLBACKQ, out);
1226 return out;
1227 }
1228
1229
1230 /*
1231 * Called to parse a backslash escape sequence inside $'...'.
1232 * The backslash has already been read.
1233 */
1234 static char *
readcstyleesc(char * out)1235 readcstyleesc(char *out)
1236 {
1237 int c, vc, i, n;
1238 unsigned int v;
1239
1240 c = pgetc();
1241 switch (c) {
1242 case '\0':
1243 synerror("Unterminated quoted string");
1244 case '\n':
1245 plinno++;
1246 if (doprompt)
1247 setprompt(2);
1248 else
1249 setprompt(0);
1250 return out;
1251 case '\\':
1252 case '\'':
1253 case '"':
1254 v = c;
1255 break;
1256 case 'a': v = '\a'; break;
1257 case 'b': v = '\b'; break;
1258 case 'e': v = '\033'; break;
1259 case 'f': v = '\f'; break;
1260 case 'n': v = '\n'; break;
1261 case 'r': v = '\r'; break;
1262 case 't': v = '\t'; break;
1263 case 'v': v = '\v'; break;
1264 case 'x':
1265 v = 0;
1266 for (;;) {
1267 c = pgetc();
1268 if (c >= '0' && c <= '9')
1269 v = (v << 4) + c - '0';
1270 else if (c >= 'A' && c <= 'F')
1271 v = (v << 4) + c - 'A' + 10;
1272 else if (c >= 'a' && c <= 'f')
1273 v = (v << 4) + c - 'a' + 10;
1274 else
1275 break;
1276 }
1277 pungetc();
1278 break;
1279 case '0': case '1': case '2': case '3':
1280 case '4': case '5': case '6': case '7':
1281 v = c - '0';
1282 c = pgetc();
1283 if (c >= '0' && c <= '7') {
1284 v <<= 3;
1285 v += c - '0';
1286 c = pgetc();
1287 if (c >= '0' && c <= '7') {
1288 v <<= 3;
1289 v += c - '0';
1290 } else
1291 pungetc();
1292 } else
1293 pungetc();
1294 break;
1295 case 'c':
1296 c = pgetc();
1297 if (c < 0x3f || c > 0x7a || c == 0x60)
1298 synerror("Bad escape sequence");
1299 if (c == '\\' && pgetc() != '\\')
1300 synerror("Bad escape sequence");
1301 if (c == '?')
1302 v = 127;
1303 else
1304 v = c & 0x1f;
1305 break;
1306 case 'u':
1307 case 'U':
1308 n = c == 'U' ? 8 : 4;
1309 v = 0;
1310 for (i = 0; i < n; i++) {
1311 c = pgetc();
1312 if (c >= '0' && c <= '9')
1313 v = (v << 4) + c - '0';
1314 else if (c >= 'A' && c <= 'F')
1315 v = (v << 4) + c - 'A' + 10;
1316 else if (c >= 'a' && c <= 'f')
1317 v = (v << 4) + c - 'a' + 10;
1318 else
1319 synerror("Bad escape sequence");
1320 }
1321 if (v == 0 || (v >= 0xd800 && v <= 0xdfff))
1322 synerror("Bad escape sequence");
1323 /* We really need iconv here. */
1324 if (initial_localeisutf8 && v > 127) {
1325 CHECKSTRSPACE(4, out);
1326 /*
1327 * We cannot use wctomb() as the locale may have
1328 * changed.
1329 */
1330 if (v <= 0x7ff) {
1331 USTPUTC(0xc0 | v >> 6, out);
1332 USTPUTC(0x80 | (v & 0x3f), out);
1333 return out;
1334 } else if (v <= 0xffff) {
1335 USTPUTC(0xe0 | v >> 12, out);
1336 USTPUTC(0x80 | ((v >> 6) & 0x3f), out);
1337 USTPUTC(0x80 | (v & 0x3f), out);
1338 return out;
1339 } else if (v <= 0x10ffff) {
1340 USTPUTC(0xf0 | v >> 18, out);
1341 USTPUTC(0x80 | ((v >> 12) & 0x3f), out);
1342 USTPUTC(0x80 | ((v >> 6) & 0x3f), out);
1343 USTPUTC(0x80 | (v & 0x3f), out);
1344 return out;
1345 }
1346 }
1347 if (v > 127)
1348 v = '?';
1349 break;
1350 default:
1351 synerror("Bad escape sequence");
1352 }
1353 vc = (char)v;
1354 /*
1355 * We can't handle NUL bytes.
1356 * POSIX says we should skip till the closing quote.
1357 */
1358 if (vc == '\0') {
1359 while ((c = pgetc()) != '\'') {
1360 if (c == '\\')
1361 c = pgetc();
1362 if (c == PEOF)
1363 synerror("Unterminated quoted string");
1364 if (c == '\n') {
1365 plinno++;
1366 if (doprompt)
1367 setprompt(2);
1368 else
1369 setprompt(0);
1370 }
1371 }
1372 pungetc();
1373 return out;
1374 }
1375 if (SQSYNTAX[vc] == CCTL)
1376 USTPUTC(CTLESC, out);
1377 USTPUTC(vc, out);
1378 return out;
1379 }
1380
1381
1382 /*
1383 * If eofmark is NULL, read a word or a redirection symbol. If eofmark
1384 * is not NULL, read a here document. In the latter case, eofmark is the
1385 * word which marks the end of the document and striptabs is true if
1386 * leading tabs should be stripped from the document. The argument firstc
1387 * is the first character of the input token or document.
1388 *
1389 * Because C does not have internal subroutines, I have simulated them
1390 * using goto's to implement the subroutine linkage. The following macros
1391 * will run code that appears at the end of readtoken1.
1392 */
1393
1394 #define PARSESUB() {goto parsesub; parsesub_return:;}
1395 #define PARSEARITH() {goto parsearith; parsearith_return:;}
1396
1397 static int
readtoken1(int firstc,char const * initialsyntax,const char * eofmark,int striptabs)1398 readtoken1(int firstc, char const *initialsyntax, const char *eofmark,
1399 int striptabs)
1400 {
1401 int c = firstc;
1402 char *out;
1403 int len;
1404 struct nodelist *bqlist;
1405 int quotef;
1406 int newvarnest;
1407 int level;
1408 int synentry;
1409 struct tokenstate state_static[MAXNEST_static];
1410 int maxnest = MAXNEST_static;
1411 struct tokenstate *state = state_static;
1412 int sqiscstyle = 0;
1413
1414 startlinno = plinno;
1415 quotef = 0;
1416 bqlist = NULL;
1417 newvarnest = 0;
1418 level = 0;
1419 state[level].syntax = initialsyntax;
1420 state[level].parenlevel = 0;
1421 state[level].category = TSTATE_TOP;
1422
1423 STARTSTACKSTR(out);
1424 loop: { /* for each line, until end of word */
1425 if (eofmark && eofmark != NOEOFMARK)
1426 /* set c to PEOF if at end of here document */
1427 c = checkend(c, eofmark, striptabs);
1428 for (;;) { /* until end of line or end of word */
1429 CHECKSTRSPACE(4, out); /* permit 4 calls to USTPUTC */
1430
1431 synentry = state[level].syntax[c];
1432
1433 switch(synentry) {
1434 case CNL: /* '\n' */
1435 if (level == 0)
1436 goto endword; /* exit outer loop */
1437 /* FALLTHROUGH */
1438 case CQNL:
1439 USTPUTC(c, out);
1440 plinno++;
1441 if (doprompt)
1442 setprompt(2);
1443 else
1444 setprompt(0);
1445 c = pgetc();
1446 goto loop; /* continue outer loop */
1447 case CSBACK:
1448 if (sqiscstyle) {
1449 out = readcstyleesc(out);
1450 break;
1451 }
1452 /* FALLTHROUGH */
1453 case CWORD:
1454 USTPUTC(c, out);
1455 break;
1456 case CCTL:
1457 if (eofmark == NULL || initialsyntax != SQSYNTAX)
1458 USTPUTC(CTLESC, out);
1459 USTPUTC(c, out);
1460 break;
1461 case CBACK: /* backslash */
1462 c = pgetc();
1463 if (c == PEOF) {
1464 USTPUTC('\\', out);
1465 pungetc();
1466 } else if (c == '\n') {
1467 plinno++;
1468 if (doprompt)
1469 setprompt(2);
1470 else
1471 setprompt(0);
1472 } else {
1473 if (state[level].syntax == DQSYNTAX &&
1474 c != '\\' && c != '`' && c != '$' &&
1475 (c != '"' || (eofmark != NULL &&
1476 newvarnest == 0)) &&
1477 (c != '}' || state[level].category != TSTATE_VAR_OLD))
1478 USTPUTC('\\', out);
1479 if ((eofmark == NULL ||
1480 newvarnest > 0) &&
1481 state[level].syntax == BASESYNTAX)
1482 USTPUTC(CTLQUOTEMARK, out);
1483 if (SQSYNTAX[c] == CCTL)
1484 USTPUTC(CTLESC, out);
1485 USTPUTC(c, out);
1486 if ((eofmark == NULL ||
1487 newvarnest > 0) &&
1488 state[level].syntax == BASESYNTAX &&
1489 state[level].category == TSTATE_VAR_OLD)
1490 USTPUTC(CTLQUOTEEND, out);
1491 quotef++;
1492 }
1493 break;
1494 case CSQUOTE:
1495 USTPUTC(CTLQUOTEMARK, out);
1496 state[level].syntax = SQSYNTAX;
1497 sqiscstyle = 0;
1498 break;
1499 case CDQUOTE:
1500 USTPUTC(CTLQUOTEMARK, out);
1501 state[level].syntax = DQSYNTAX;
1502 break;
1503 case CENDQUOTE:
1504 if (eofmark != NULL && newvarnest == 0)
1505 USTPUTC(c, out);
1506 else {
1507 if (state[level].category == TSTATE_VAR_OLD)
1508 USTPUTC(CTLQUOTEEND, out);
1509 state[level].syntax = BASESYNTAX;
1510 quotef++;
1511 }
1512 break;
1513 case CVAR: /* '$' */
1514 PARSESUB(); /* parse substitution */
1515 break;
1516 case CENDVAR: /* '}' */
1517 if (level > 0 &&
1518 ((state[level].category == TSTATE_VAR_OLD &&
1519 state[level].syntax ==
1520 state[level - 1].syntax) ||
1521 (state[level].category == TSTATE_VAR_NEW &&
1522 state[level].syntax == BASESYNTAX))) {
1523 if (state[level].category == TSTATE_VAR_NEW)
1524 newvarnest--;
1525 level--;
1526 USTPUTC(CTLENDVAR, out);
1527 } else {
1528 USTPUTC(c, out);
1529 }
1530 break;
1531 case CLP: /* '(' in arithmetic */
1532 state[level].parenlevel++;
1533 USTPUTC(c, out);
1534 break;
1535 case CRP: /* ')' in arithmetic */
1536 if (state[level].parenlevel > 0) {
1537 USTPUTC(c, out);
1538 --state[level].parenlevel;
1539 } else {
1540 if (pgetc_linecont() == ')') {
1541 if (level > 0 &&
1542 state[level].category == TSTATE_ARITH) {
1543 level--;
1544 USTPUTC(CTLENDARI, out);
1545 } else
1546 USTPUTC(')', out);
1547 } else {
1548 /*
1549 * unbalanced parens
1550 * (don't 2nd guess - no error)
1551 */
1552 pungetc();
1553 USTPUTC(')', out);
1554 }
1555 }
1556 break;
1557 case CBQUOTE: /* '`' */
1558 out = parsebackq(out, &bqlist, 1,
1559 state[level].syntax == DQSYNTAX &&
1560 (eofmark == NULL || newvarnest > 0),
1561 state[level].syntax == DQSYNTAX || state[level].syntax == ARISYNTAX);
1562 break;
1563 case CEOF:
1564 goto endword; /* exit outer loop */
1565 case CIGN:
1566 break;
1567 default:
1568 if (level == 0)
1569 goto endword; /* exit outer loop */
1570 USTPUTC(c, out);
1571 }
1572 c = pgetc_macro();
1573 }
1574 }
1575 endword:
1576 if (state[level].syntax == ARISYNTAX)
1577 synerror("Missing '))'");
1578 if (state[level].syntax != BASESYNTAX && eofmark == NULL)
1579 synerror("Unterminated quoted string");
1580 if (state[level].category == TSTATE_VAR_OLD ||
1581 state[level].category == TSTATE_VAR_NEW) {
1582 startlinno = plinno;
1583 synerror("Missing '}'");
1584 }
1585 if (state != state_static)
1586 parser_temp_free_upto(state);
1587 USTPUTC('\0', out);
1588 len = out - stackblock();
1589 out = stackblock();
1590 if (eofmark == NULL) {
1591 if ((c == '>' || c == '<')
1592 && quotef == 0
1593 && len <= 2
1594 && (*out == '\0' || is_digit(*out))) {
1595 parseredir(out, c);
1596 return lasttoken = TREDIR;
1597 } else {
1598 pungetc();
1599 }
1600 }
1601 quoteflag = quotef;
1602 backquotelist = bqlist;
1603 grabstackblock(len);
1604 wordtext = out;
1605 return lasttoken = TWORD;
1606 /* end of readtoken routine */
1607
1608
1609 /*
1610 * Parse a substitution. At this point, we have read the dollar sign
1611 * and nothing else.
1612 */
1613
1614 parsesub: {
1615 int subtype;
1616 int typeloc;
1617 int flags;
1618 char *p;
1619 static const char types[] = "}-+?=";
1620 int linno;
1621 int length;
1622 int c1;
1623
1624 c = pgetc_linecont();
1625 if (c == '(') { /* $(command) or $((arith)) */
1626 if (pgetc_linecont() == '(') {
1627 PARSEARITH();
1628 } else {
1629 pungetc();
1630 out = parsebackq(out, &bqlist, 0,
1631 state[level].syntax == DQSYNTAX &&
1632 (eofmark == NULL || newvarnest > 0),
1633 state[level].syntax == DQSYNTAX ||
1634 state[level].syntax == ARISYNTAX);
1635 }
1636 } else if (c == '{' || is_name(c) || is_special(c)) {
1637 USTPUTC(CTLVAR, out);
1638 typeloc = out - stackblock();
1639 USTPUTC(VSNORMAL, out);
1640 subtype = VSNORMAL;
1641 flags = 0;
1642 if (c == '{') {
1643 c = pgetc_linecont();
1644 subtype = 0;
1645 }
1646 varname:
1647 if (!is_eof(c) && is_name(c)) {
1648 length = 0;
1649 do {
1650 STPUTC(c, out);
1651 c = pgetc_linecont();
1652 length++;
1653 } while (!is_eof(c) && is_in_name(c));
1654 if (length == 6 &&
1655 strncmp(out - length, "LINENO", length) == 0) {
1656 /* Replace the variable name with the
1657 * current line number. */
1658 STADJUST(-6, out);
1659 CHECKSTRSPACE(11, out);
1660 linno = plinno;
1661 if (funclinno != 0)
1662 linno -= funclinno - 1;
1663 length = snprintf(out, 11, "%d", linno);
1664 if (length > 10)
1665 length = 10;
1666 out += length;
1667 flags |= VSLINENO;
1668 }
1669 } else if (is_digit(c)) {
1670 if (subtype != VSNORMAL) {
1671 do {
1672 STPUTC(c, out);
1673 c = pgetc_linecont();
1674 } while (is_digit(c));
1675 } else {
1676 USTPUTC(c, out);
1677 c = pgetc_linecont();
1678 }
1679 } else if (is_special(c)) {
1680 c1 = c;
1681 c = pgetc_linecont();
1682 if (subtype == 0 && c1 == '#') {
1683 subtype = VSLENGTH;
1684 if (strchr(types, c) == NULL && c != ':' &&
1685 c != '#' && c != '%')
1686 goto varname;
1687 c1 = c;
1688 c = pgetc_linecont();
1689 if (c1 != '}' && c == '}') {
1690 pungetc();
1691 c = c1;
1692 goto varname;
1693 }
1694 pungetc();
1695 c = c1;
1696 c1 = '#';
1697 subtype = 0;
1698 }
1699 USTPUTC(c1, out);
1700 } else {
1701 subtype = VSERROR;
1702 if (c == '}')
1703 pungetc();
1704 else if (c == '\n' || c == PEOF)
1705 synerror("Unexpected end of line in substitution");
1706 else if (BASESYNTAX[c] != CCTL)
1707 USTPUTC(c, out);
1708 }
1709 if (subtype == 0) {
1710 switch (c) {
1711 case ':':
1712 flags |= VSNUL;
1713 c = pgetc_linecont();
1714 /*FALLTHROUGH*/
1715 default:
1716 p = strchr(types, c);
1717 if (p == NULL) {
1718 if (c == '\n' || c == PEOF)
1719 synerror("Unexpected end of line in substitution");
1720 if (flags == VSNUL)
1721 STPUTC(':', out);
1722 if (BASESYNTAX[c] != CCTL)
1723 STPUTC(c, out);
1724 subtype = VSERROR;
1725 } else
1726 subtype = p - types + VSNORMAL;
1727 break;
1728 case '%':
1729 case '#':
1730 {
1731 int cc = c;
1732 subtype = c == '#' ? VSTRIMLEFT :
1733 VSTRIMRIGHT;
1734 c = pgetc_linecont();
1735 if (c == cc)
1736 subtype++;
1737 else
1738 pungetc();
1739 break;
1740 }
1741 }
1742 } else if (subtype != VSERROR) {
1743 if (subtype == VSLENGTH && c != '}')
1744 subtype = VSERROR;
1745 pungetc();
1746 }
1747 STPUTC('=', out);
1748 if (state[level].syntax == DQSYNTAX ||
1749 state[level].syntax == ARISYNTAX)
1750 flags |= VSQUOTE;
1751 *(stackblock() + typeloc) = subtype | flags;
1752 if (subtype != VSNORMAL) {
1753 if (level + 1 >= maxnest) {
1754 maxnest *= 2;
1755 if (state == state_static) {
1756 state = parser_temp_alloc(
1757 maxnest * sizeof(*state));
1758 memcpy(state, state_static,
1759 MAXNEST_static * sizeof(*state));
1760 } else
1761 state = parser_temp_realloc(state,
1762 maxnest * sizeof(*state));
1763 }
1764 level++;
1765 state[level].parenlevel = 0;
1766 if (subtype == VSMINUS || subtype == VSPLUS ||
1767 subtype == VSQUESTION || subtype == VSASSIGN) {
1768 /*
1769 * For operators that were in the Bourne shell,
1770 * inherit the double-quote state.
1771 */
1772 state[level].syntax = state[level - 1].syntax;
1773 state[level].category = TSTATE_VAR_OLD;
1774 } else {
1775 /*
1776 * The other operators take a pattern,
1777 * so go to BASESYNTAX.
1778 * Also, ' and " are now special, even
1779 * in here documents.
1780 */
1781 state[level].syntax = BASESYNTAX;
1782 state[level].category = TSTATE_VAR_NEW;
1783 newvarnest++;
1784 }
1785 }
1786 } else if (c == '\'' && state[level].syntax == BASESYNTAX) {
1787 /* $'cstylequotes' */
1788 USTPUTC(CTLQUOTEMARK, out);
1789 state[level].syntax = SQSYNTAX;
1790 sqiscstyle = 1;
1791 } else {
1792 USTPUTC('$', out);
1793 pungetc();
1794 }
1795 goto parsesub_return;
1796 }
1797
1798
1799 /*
1800 * Parse an arithmetic expansion (indicate start of one and set state)
1801 */
1802 parsearith: {
1803
1804 if (level + 1 >= maxnest) {
1805 maxnest *= 2;
1806 if (state == state_static) {
1807 state = parser_temp_alloc(
1808 maxnest * sizeof(*state));
1809 memcpy(state, state_static,
1810 MAXNEST_static * sizeof(*state));
1811 } else
1812 state = parser_temp_realloc(state,
1813 maxnest * sizeof(*state));
1814 }
1815 level++;
1816 state[level].syntax = ARISYNTAX;
1817 state[level].parenlevel = 0;
1818 state[level].category = TSTATE_ARITH;
1819 USTPUTC(CTLARI, out);
1820 if (state[level - 1].syntax == DQSYNTAX)
1821 USTPUTC('"',out);
1822 else
1823 USTPUTC(' ',out);
1824 goto parsearith_return;
1825 }
1826
1827 } /* end of readtoken */
1828
1829
1830 /*
1831 * Returns true if the text contains nothing to expand (no dollar signs
1832 * or backquotes).
1833 */
1834
1835 static int
noexpand(char * text)1836 noexpand(char *text)
1837 {
1838 char *p;
1839 char c;
1840
1841 p = text;
1842 while ((c = *p++) != '\0') {
1843 if ( c == CTLQUOTEMARK)
1844 continue;
1845 if (c == CTLESC)
1846 p++;
1847 else if (BASESYNTAX[(int)c] == CCTL)
1848 return 0;
1849 }
1850 return 1;
1851 }
1852
1853
1854 /*
1855 * Return true if the argument is a legal variable name (a letter or
1856 * underscore followed by zero or more letters, underscores, and digits).
1857 */
1858
1859 int
goodname(const char * name)1860 goodname(const char *name)
1861 {
1862 const char *p;
1863
1864 p = name;
1865 if (! is_name(*p))
1866 return 0;
1867 while (*++p) {
1868 if (! is_in_name(*p))
1869 return 0;
1870 }
1871 return 1;
1872 }
1873
1874
1875 int
isassignment(const char * p)1876 isassignment(const char *p)
1877 {
1878 if (!is_name(*p))
1879 return 0;
1880 p++;
1881 for (;;) {
1882 if (*p == '=')
1883 return 1;
1884 else if (!is_in_name(*p))
1885 return 0;
1886 p++;
1887 }
1888 }
1889
1890
1891 static void
consumetoken(int token)1892 consumetoken(int token)
1893 {
1894 if (readtoken() != token)
1895 synexpect(token);
1896 }
1897
1898
1899 /*
1900 * Called when an unexpected token is read during the parse. The argument
1901 * is the token that is expected, or -1 if more than one type of token can
1902 * occur at this point.
1903 */
1904
1905 static void
synexpect(int token)1906 synexpect(int token)
1907 {
1908 char msg[64];
1909
1910 if (token >= 0) {
1911 fmtstr(msg, 64, "%s unexpected (expecting %s)",
1912 tokname[lasttoken], tokname[token]);
1913 } else {
1914 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]);
1915 }
1916 synerror(msg);
1917 }
1918
1919
1920 static void
synerror(const char * msg)1921 synerror(const char *msg)
1922 {
1923 if (commandname)
1924 outfmt(out2, "%s: %d: ", commandname, startlinno);
1925 else if (arg0)
1926 outfmt(out2, "%s: ", arg0);
1927 outfmt(out2, "Syntax error: %s\n", msg);
1928 error((char *)NULL);
1929 }
1930
1931 static void
setprompt(int which)1932 setprompt(int which)
1933 {
1934 whichprompt = which;
1935 if (which == 0)
1936 return;
1937
1938 #ifndef NO_HISTORY
1939 if (!el)
1940 #endif
1941 {
1942 out2str(getprompt(NULL));
1943 flushout(out2);
1944 }
1945 }
1946
1947 static int
pgetc_linecont(void)1948 pgetc_linecont(void)
1949 {
1950 int c;
1951
1952 while ((c = pgetc_macro()) == '\\') {
1953 c = pgetc();
1954 if (c == '\n') {
1955 plinno++;
1956 if (doprompt)
1957 setprompt(2);
1958 else
1959 setprompt(0);
1960 } else {
1961 pungetc();
1962 /* Allow the backslash to be pushed back. */
1963 pushstring("\\", 1, NULL);
1964 return (pgetc());
1965 }
1966 }
1967 return (c);
1968 }
1969
1970
1971 static struct passwd *
getpwlogin(void)1972 getpwlogin(void)
1973 {
1974 const char *login;
1975
1976 login = getlogin();
1977 if (login == NULL)
1978 return (NULL);
1979
1980 return (getpwnam(login));
1981 }
1982
1983
1984 static void
getusername(char * name,size_t namelen)1985 getusername(char *name, size_t namelen)
1986 {
1987 static char cached_name[MAXLOGNAME];
1988 struct passwd *pw;
1989 uid_t euid;
1990
1991 if (cached_name[0] == '\0') {
1992 euid = geteuid();
1993
1994 /*
1995 * Handle the case when there is more than one
1996 * login with the same UID, or when the login
1997 * returned by getlogin(2) does no longer match
1998 * the current UID.
1999 */
2000 pw = getpwlogin();
2001 if (pw == NULL || pw->pw_uid != euid)
2002 pw = getpwuid(euid);
2003
2004 if (pw != NULL) {
2005 strlcpy(cached_name, pw->pw_name,
2006 sizeof(cached_name));
2007 } else {
2008 snprintf(cached_name, sizeof(cached_name),
2009 "%u", euid);
2010 }
2011 }
2012
2013 strlcpy(name, cached_name, namelen);
2014 }
2015
2016
2017 /*
2018 * called by editline -- any expansions to the prompt
2019 * should be added here.
2020 */
2021 char *
getprompt(void * unused __unused)2022 getprompt(void *unused __unused)
2023 {
2024 static char ps[PROMPTLEN];
2025 const char *fmt;
2026 const char *home;
2027 const char *pwd;
2028 size_t homelen;
2029 int i, trim;
2030 static char internal_error[] = "??";
2031
2032 /*
2033 * Select prompt format.
2034 */
2035 switch (whichprompt) {
2036 case 0:
2037 fmt = "";
2038 break;
2039 case 1:
2040 fmt = ps1val();
2041 break;
2042 case 2:
2043 fmt = ps2val();
2044 break;
2045 default:
2046 return internal_error;
2047 }
2048
2049 /*
2050 * Format prompt string.
2051 */
2052 for (i = 0; (i < PROMPTLEN - 1) && (*fmt != '\0'); i++, fmt++) {
2053 if (*fmt != '\\') {
2054 ps[i] = *fmt;
2055 continue;
2056 }
2057
2058 switch (*++fmt) {
2059
2060 /*
2061 * Non-printing sequence begin and end.
2062 */
2063 case '[':
2064 case ']':
2065 ps[i] = '\001';
2066 break;
2067
2068 /*
2069 * Literal \ and some ASCII characters:
2070 * \a BEL
2071 * \e ESC
2072 * \r CR
2073 */
2074 case '\\':
2075 case 'a':
2076 case 'e':
2077 case 'r':
2078 if (*fmt == 'a')
2079 ps[i] = '\007';
2080 else if (*fmt == 'e')
2081 ps[i] = '\033';
2082 else if (*fmt == 'r')
2083 ps[i] = '\r';
2084 else
2085 ps[i] = '\\';
2086 break;
2087
2088 /*
2089 * CRLF sequence
2090 */
2091 case 'n':
2092 if (i < PROMPTLEN - 3) {
2093 ps[i++] = '\r';
2094 ps[i] = '\n';
2095 }
2096 break;
2097
2098 /*
2099 * Print the current time as per provided strftime format.
2100 */
2101 case 'D': {
2102 char tfmt[128] = "%X"; /* \D{} means %X. */
2103 struct tm *now;
2104
2105 if (fmt[1] != '{') {
2106 /*
2107 * "\D" but not "\D{", so treat the '\'
2108 * literally and rewind fmt to treat 'D'
2109 * literally next iteration.
2110 */
2111 ps[i] = '\\';
2112 fmt--;
2113 break;
2114 }
2115 fmt += 2; /* Consume "D{". */
2116 if (fmt[0] != '}') {
2117 char *end;
2118
2119 end = memccpy(tfmt, fmt, '}', sizeof(tfmt));
2120 if (end == NULL) {
2121 /*
2122 * Format too long or no '}', so
2123 * ignore "\D{" altogether.
2124 * The loop will do i++, but nothing
2125 * was written to ps, so do i-- here.
2126 * Rewind fmt for similar reason.
2127 */
2128 i--;
2129 fmt--;
2130 break;
2131 }
2132 *--end = '\0'; /* Ignore the copy of '}'. */
2133 fmt += end - tfmt;
2134 }
2135 now = localtime(&(time_t){time(NULL)});
2136 i += strftime(&ps[i], PROMPTLEN - i - 1, tfmt, now);
2137 i--; /* The loop will do i++. */
2138 break;
2139 }
2140
2141 /*
2142 * Hostname.
2143 *
2144 * \h specifies just the local hostname,
2145 * \H specifies fully-qualified hostname.
2146 */
2147 case 'h':
2148 case 'H':
2149 ps[i] = '\0';
2150 gethostname(&ps[i], PROMPTLEN - i - 1);
2151 ps[PROMPTLEN - 1] = '\0';
2152 /* Skip to end of hostname. */
2153 trim = (*fmt == 'h') ? '.' : '\0';
2154 while ((ps[i] != '\0') && (ps[i] != trim))
2155 i++;
2156 --i;
2157 break;
2158
2159 /*
2160 * User name.
2161 */
2162 case 'u':
2163 ps[i] = '\0';
2164 getusername(&ps[i], PROMPTLEN - i);
2165 /* Skip to end of username. */
2166 while (ps[i + 1] != '\0')
2167 i++;
2168 break;
2169
2170 /*
2171 * Working directory.
2172 *
2173 * \W specifies just the final component,
2174 * \w specifies the entire path.
2175 */
2176 case 'W':
2177 case 'w':
2178 pwd = lookupvar("PWD");
2179 if (pwd == NULL || *pwd == '\0')
2180 pwd = "?";
2181 if (*fmt == 'W' &&
2182 *pwd == '/' && pwd[1] != '\0')
2183 strlcpy(&ps[i], strrchr(pwd, '/') + 1,
2184 PROMPTLEN - i);
2185 else {
2186 home = lookupvar("HOME");
2187 if (home != NULL)
2188 homelen = strlen(home);
2189 if (home != NULL &&
2190 strcmp(home, "/") != 0 &&
2191 strncmp(pwd, home, homelen) == 0 &&
2192 (pwd[homelen] == '/' ||
2193 pwd[homelen] == '\0')) {
2194 strlcpy(&ps[i], "~",
2195 PROMPTLEN - i);
2196 strlcpy(&ps[i + 1],
2197 pwd + homelen,
2198 PROMPTLEN - i - 1);
2199 } else {
2200 strlcpy(&ps[i], pwd, PROMPTLEN - i);
2201 }
2202 }
2203 /* Skip to end of path. */
2204 while (ps[i + 1] != '\0')
2205 i++;
2206 break;
2207
2208 /*
2209 * Superuser status.
2210 *
2211 * '$' for normal users, '#' for root.
2212 */
2213 case '$':
2214 ps[i] = (geteuid() != 0) ? '$' : '#';
2215 break;
2216
2217 /*
2218 * Emit unrecognized formats verbatim.
2219 */
2220 default:
2221 ps[i] = '\\';
2222 if (i < PROMPTLEN - 2)
2223 ps[++i] = *fmt;
2224 break;
2225 }
2226
2227 }
2228 ps[i] = '\0';
2229 return (ps);
2230 }
2231
2232
2233 const char *
expandstr(const char * ps)2234 expandstr(const char *ps)
2235 {
2236 union node n;
2237 struct jmploc jmploc;
2238 struct jmploc *const savehandler = handler;
2239 const int saveprompt = doprompt;
2240 struct parsefile *const savetopfile = getcurrentfile();
2241 struct parser_temp *const saveparser_temp = parser_temp;
2242 const char *result = NULL;
2243
2244 if (!setjmp(jmploc.loc)) {
2245 handler = &jmploc;
2246 parser_temp = NULL;
2247 setinputstring(ps, 1);
2248 doprompt = 0;
2249 readtoken1(pgetc(), DQSYNTAX, NOEOFMARK, 0);
2250 if (backquotelist != NULL)
2251 error("Command substitution not allowed here");
2252
2253 n.narg.type = NARG;
2254 n.narg.next = NULL;
2255 n.narg.text = wordtext;
2256 n.narg.backquote = backquotelist;
2257
2258 expandarg(&n, NULL, 0);
2259 result = stackblock();
2260 INTOFF;
2261 }
2262 handler = savehandler;
2263 doprompt = saveprompt;
2264 popfilesupto(savetopfile);
2265 if (parser_temp != saveparser_temp) {
2266 parser_temp_free_all();
2267 parser_temp = saveparser_temp;
2268 }
2269 if (result != NULL) {
2270 INTON;
2271 } else if (exception == EXINT)
2272 raise(SIGINT);
2273 return result;
2274 }
2275