7c7a2bfc7778f7d182dfc851c38924e0f7fe6a3c
[dragonfly.git] / bin / sh / parser.c
1 /*-
2  * Copyright (c) 1991, 1993
3  *      The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Kenneth Almquist.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *      This product includes software developed by the University of
19  *      California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  * @(#)parser.c 8.7 (Berkeley) 5/16/95
37  * $FreeBSD: src/bin/sh/parser.c,v 1.108 2011/05/04 21:49:34 jilles Exp $
38  */
39
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <unistd.h>
43
44 #include "shell.h"
45 #include "parser.h"
46 #include "nodes.h"
47 #include "expand.h"     /* defines rmescapes() */
48 #include "syntax.h"
49 #include "options.h"
50 #include "input.h"
51 #include "output.h"
52 #include "var.h"
53 #include "error.h"
54 #include "memalloc.h"
55 #include "mystring.h"
56 #include "alias.h"
57 #include "show.h"
58 #include "eval.h"
59 #include "exec.h"       /* to check for special builtins */
60 #ifndef NO_HISTORY
61 #include "myhistedit.h"
62 #endif
63
64 /*
65  * Shell command parser.
66  */
67
68 #define EOFMARKLEN      79
69 #define PROMPTLEN       128
70
71 /* values of checkkwd variable */
72 #define CHKALIAS        0x1
73 #define CHKKWD          0x2
74 #define CHKNL           0x4
75
76 /* values returned by readtoken */
77 #include "token.h"
78
79
80
81 struct heredoc {
82         struct heredoc *next;   /* next here document in list */
83         union node *here;               /* redirection node */
84         char *eofmark;          /* string indicating end of input */
85         int striptabs;          /* if set, strip leading tabs */
86 };
87
88 struct parser_temp {
89         struct parser_temp *next;
90         void *data;
91 };
92
93
94 static struct heredoc *heredoclist;     /* list of here documents to read */
95 static int doprompt;            /* if set, prompt the user */
96 static int needprompt;          /* true if interactive and at start of line */
97 static int lasttoken;           /* last token read */
98 MKINIT int tokpushback;         /* last token pushed back */
99 static char *wordtext;          /* text of last word returned by readtoken */
100 MKINIT int checkkwd;            /* 1 == check for kwds, 2 == also eat newlines */
101 static struct nodelist *backquotelist;
102 static union node *redirnode;
103 static struct heredoc *heredoc;
104 static int quoteflag;           /* set if (part of) last token was quoted */
105 static int startlinno;          /* line # where last token started */
106 static int funclinno;           /* line # where the current function started */
107 static struct parser_temp *parser_temp;
108
109
110 static union node *list(int, int);
111 static union node *andor(void);
112 static union node *pipeline(void);
113 static union node *command(void);
114 static union node *simplecmd(union node **, union node *);
115 static union node *makename(void);
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, char const *, char *, int);
122 static int noexpand(char *);
123 static void synexpect(int) __dead2;
124 static void synerror(const char *) __dead2;
125 static void setprompt(int);
126
127
128 static void *
129 parser_temp_alloc(size_t len)
130 {
131         struct parser_temp *t;
132
133         INTOFF;
134         t = ckmalloc(sizeof(*t));
135         t->data = NULL;
136         t->next = parser_temp;
137         parser_temp = t;
138         t->data = ckmalloc(len);
139         INTON;
140         return t->data;
141 }
142
143
144 static void *
145 parser_temp_realloc(void *ptr, size_t len)
146 {
147         struct parser_temp *t;
148
149         INTOFF;
150         t = parser_temp;
151         if (ptr != t->data)
152                 error("bug: parser_temp_realloc misused");
153         t->data = ckrealloc(t->data, len);
154         INTON;
155         return t->data;
156 }
157
158
159 static void
160 parser_temp_free_upto(void *ptr)
161 {
162         struct parser_temp *t;
163         int done = 0;
164
165         INTOFF;
166         while (parser_temp != NULL && !done) {
167                 t = parser_temp;
168                 parser_temp = t->next;
169                 done = t->data == ptr;
170                 ckfree(t->data);
171                 ckfree(t);
172         }
173         INTON;
174         if (!done)
175                 error("bug: parser_temp_free_upto misused");
176 }
177
178
179 static void
180 parser_temp_free_all(void)
181 {
182         struct parser_temp *t;
183
184         INTOFF;
185         while (parser_temp != NULL) {
186                 t = parser_temp;
187                 parser_temp = t->next;
188                 ckfree(t->data);
189                 ckfree(t);
190         }
191         INTON;
192 }
193
194
195 /*
196  * Read and parse a command.  Returns NEOF on end of file.  (NULL is a
197  * valid parse tree indicating a blank line.)
198  */
199
200 union node *
201 parsecmd(int interact)
202 {
203         int t;
204
205         /* This assumes the parser is not re-entered,
206          * which could happen if we add command substitution on PS1/PS2.
207          */
208         parser_temp_free_all();
209         heredoclist = NULL;
210
211         tokpushback = 0;
212         doprompt = interact;
213         if (doprompt)
214                 setprompt(1);
215         else
216                 setprompt(0);
217         needprompt = 0;
218         t = readtoken();
219         if (t == TEOF)
220                 return NEOF;
221         if (t == TNL)
222                 return NULL;
223         tokpushback++;
224         return list(1, 1);
225 }
226
227
228 static union node *
229 list(int nlflag, int erflag)
230 {
231         union node *ntop, *n1, *n2, *n3;
232         int tok;
233
234         checkkwd = CHKNL | CHKKWD | CHKALIAS;
235         if (!nlflag && !erflag && tokendlist[peektoken()])
236                 return NULL;
237         ntop = n1 = NULL;
238         for (;;) {
239                 n2 = andor();
240                 tok = readtoken();
241                 if (tok == TBACKGND) {
242                         if (n2->type == NCMD || n2->type == NPIPE) {
243                                 n2->ncmd.backgnd = 1;
244                         } else if (n2->type == NREDIR) {
245                                 n2->type = NBACKGND;
246                         } else {
247                                 n3 = (union node *)stalloc(sizeof (struct nredir));
248                                 n3->type = NBACKGND;
249                                 n3->nredir.n = n2;
250                                 n3->nredir.redirect = NULL;
251                                 n2 = n3;
252                         }
253                 }
254                 if (ntop == NULL)
255                         ntop = n2;
256                 else if (n1 == NULL) {
257                         n1 = (union node *)stalloc(sizeof (struct nbinary));
258                         n1->type = NSEMI;
259                         n1->nbinary.ch1 = ntop;
260                         n1->nbinary.ch2 = n2;
261                         ntop = n1;
262                 }
263                 else {
264                         n3 = (union node *)stalloc(sizeof (struct nbinary));
265                         n3->type = NSEMI;
266                         n3->nbinary.ch1 = n1->nbinary.ch2;
267                         n3->nbinary.ch2 = n2;
268                         n1->nbinary.ch2 = n3;
269                         n1 = n3;
270                 }
271                 switch (tok) {
272                 case TBACKGND:
273                 case TSEMI:
274                         tok = readtoken();
275                         /* FALLTHROUGH */
276                 case TNL:
277                         if (tok == TNL) {
278                                 parseheredoc();
279                                 if (nlflag)
280                                         return ntop;
281                         } else if (tok == TEOF && nlflag) {
282                                 parseheredoc();
283                                 return ntop;
284                         } else {
285                                 tokpushback++;
286                         }
287                         checkkwd = CHKNL | CHKKWD | CHKALIAS;
288                         if (!nlflag && !erflag && tokendlist[peektoken()])
289                                 return ntop;
290                         break;
291                 case TEOF:
292                         if (heredoclist)
293                                 parseheredoc();
294                         else
295                                 pungetc();              /* push back EOF on input */
296                         return ntop;
297                 default:
298                         if (nlflag || erflag)
299                                 synexpect(-1);
300                         tokpushback++;
301                         return ntop;
302                 }
303         }
304 }
305
306
307
308 static union node *
309 andor(void)
310 {
311         union node *n1, *n2, *n3;
312         int t;
313
314         n1 = pipeline();
315         for (;;) {
316                 if ((t = readtoken()) == TAND) {
317                         t = NAND;
318                 } else if (t == TOR) {
319                         t = NOR;
320                 } else {
321                         tokpushback++;
322                         return n1;
323                 }
324                 n2 = pipeline();
325                 n3 = (union node *)stalloc(sizeof (struct nbinary));
326                 n3->type = t;
327                 n3->nbinary.ch1 = n1;
328                 n3->nbinary.ch2 = n2;
329                 n1 = n3;
330         }
331 }
332
333
334
335 static union node *
336 pipeline(void)
337 {
338         union node *n1, *n2, *pipenode;
339         struct nodelist *lp, *prev;
340         int negate, t;
341
342         negate = 0;
343         checkkwd = CHKNL | CHKKWD | CHKALIAS;
344         TRACE(("pipeline: entered\n"));
345         while (readtoken() == TNOT)
346                 negate = !negate;
347         tokpushback++;
348         n1 = command();
349         if (readtoken() == TPIPE) {
350                 pipenode = (union node *)stalloc(sizeof (struct npipe));
351                 pipenode->type = NPIPE;
352                 pipenode->npipe.backgnd = 0;
353                 lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
354                 pipenode->npipe.cmdlist = lp;
355                 lp->n = n1;
356                 do {
357                         prev = lp;
358                         lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
359                         checkkwd = CHKNL | CHKKWD | CHKALIAS;
360                         t = readtoken();
361                         tokpushback++;
362                         if (t == TNOT)
363                                 lp->n = pipeline();
364                         else
365                                 lp->n = command();
366                         prev->next = lp;
367                 } while (readtoken() == TPIPE);
368                 lp->next = NULL;
369                 n1 = pipenode;
370         }
371         tokpushback++;
372         if (negate) {
373                 n2 = (union node *)stalloc(sizeof (struct nnot));
374                 n2->type = NNOT;
375                 n2->nnot.com = n1;
376                 return n2;
377         } else
378                 return n1;
379 }
380
381
382
383 static union node *
384 command(void)
385 {
386         union node *n1, *n2;
387         union node *ap, **app;
388         union node *cp, **cpp;
389         union node *redir, **rpp;
390         int t;
391         int is_subshell;
392
393         checkkwd = CHKNL | CHKKWD | CHKALIAS;
394         is_subshell = 0;
395         redir = NULL;
396         n1 = NULL;
397         rpp = &redir;
398
399         /* Check for redirection which may precede command */
400         while (readtoken() == TREDIR) {
401                 *rpp = n2 = redirnode;
402                 rpp = &n2->nfile.next;
403                 parsefname();
404         }
405         tokpushback++;
406
407         switch (readtoken()) {
408         case TIF:
409                 n1 = (union node *)stalloc(sizeof (struct nif));
410                 n1->type = NIF;
411                 if ((n1->nif.test = list(0, 0)) == NULL)
412                         synexpect(-1);
413                 if (readtoken() != TTHEN)
414                         synexpect(TTHEN);
415                 n1->nif.ifpart = list(0, 0);
416                 n2 = n1;
417                 while (readtoken() == TELIF) {
418                         n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif));
419                         n2 = n2->nif.elsepart;
420                         n2->type = NIF;
421                         if ((n2->nif.test = list(0, 0)) == NULL)
422                                 synexpect(-1);
423                         if (readtoken() != TTHEN)
424                                 synexpect(TTHEN);
425                         n2->nif.ifpart = list(0, 0);
426                 }
427                 if (lasttoken == TELSE)
428                         n2->nif.elsepart = list(0, 0);
429                 else {
430                         n2->nif.elsepart = NULL;
431                         tokpushback++;
432                 }
433                 if (readtoken() != TFI)
434                         synexpect(TFI);
435                 checkkwd = CHKKWD | CHKALIAS;
436                 break;
437         case TWHILE:
438         case TUNTIL: {
439                 int got;
440                 n1 = (union node *)stalloc(sizeof (struct nbinary));
441                 n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL;
442                 if ((n1->nbinary.ch1 = list(0, 0)) == NULL)
443                         synexpect(-1);
444                 if ((got=readtoken()) != TDO) {
445 TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : ""));
446                         synexpect(TDO);
447                 }
448                 n1->nbinary.ch2 = list(0, 0);
449                 if (readtoken() != TDONE)
450                         synexpect(TDONE);
451                 checkkwd = CHKKWD | CHKALIAS;
452                 break;
453         }
454         case TFOR:
455                 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext))
456                         synerror("Bad for loop variable");
457                 n1 = (union node *)stalloc(sizeof (struct nfor));
458                 n1->type = NFOR;
459                 n1->nfor.var = wordtext;
460                 while (readtoken() == TNL)
461                         ;
462                 if (lasttoken == TWORD && ! quoteflag && equal(wordtext, "in")) {
463                         app = &ap;
464                         while (readtoken() == TWORD) {
465                                 n2 = (union node *)stalloc(sizeof (struct narg));
466                                 n2->type = NARG;
467                                 n2->narg.text = wordtext;
468                                 n2->narg.backquote = backquotelist;
469                                 *app = n2;
470                                 app = &n2->narg.next;
471                         }
472                         *app = NULL;
473                         n1->nfor.args = ap;
474                         if (lasttoken != TNL && lasttoken != TSEMI)
475                                 synexpect(-1);
476                 } else {
477                         static char argvars[5] = {
478                                 CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0'
479                         };
480                         n2 = (union node *)stalloc(sizeof (struct narg));
481                         n2->type = NARG;
482                         n2->narg.text = argvars;
483                         n2->narg.backquote = NULL;
484                         n2->narg.next = NULL;
485                         n1->nfor.args = n2;
486                         /*
487                          * Newline or semicolon here is optional (but note
488                          * that the original Bourne shell only allowed NL).
489                          */
490                         if (lasttoken != TNL && lasttoken != TSEMI)
491                                 tokpushback++;
492                 }
493                 checkkwd = CHKNL | CHKKWD | CHKALIAS;
494                 if ((t = readtoken()) == TDO)
495                         t = TDONE;
496                 else if (t == TBEGIN)
497                         t = TEND;
498                 else
499                         synexpect(-1);
500                 n1->nfor.body = list(0, 0);
501                 if (readtoken() != t)
502                         synexpect(t);
503                 checkkwd = CHKKWD | CHKALIAS;
504                 break;
505         case TCASE:
506                 n1 = (union node *)stalloc(sizeof (struct ncase));
507                 n1->type = NCASE;
508                 if (readtoken() != TWORD)
509                         synexpect(TWORD);
510                 n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg));
511                 n2->type = NARG;
512                 n2->narg.text = wordtext;
513                 n2->narg.backquote = backquotelist;
514                 n2->narg.next = NULL;
515                 while (readtoken() == TNL);
516                 if (lasttoken != TWORD || ! equal(wordtext, "in"))
517                         synerror("expecting \"in\"");
518                 cpp = &n1->ncase.cases;
519                 checkkwd = CHKNL | CHKKWD, readtoken();
520                 while (lasttoken != TESAC) {
521                         *cpp = cp = (union node *)stalloc(sizeof (struct nclist));
522                         cp->type = NCLIST;
523                         app = &cp->nclist.pattern;
524                         if (lasttoken == TLP)
525                                 readtoken();
526                         for (;;) {
527                                 *app = ap = (union node *)stalloc(sizeof (struct narg));
528                                 ap->type = NARG;
529                                 ap->narg.text = wordtext;
530                                 ap->narg.backquote = backquotelist;
531                                 checkkwd = CHKNL | CHKKWD;
532                                 if (readtoken() != TPIPE)
533                                         break;
534                                 app = &ap->narg.next;
535                                 readtoken();
536                         }
537                         ap->narg.next = NULL;
538                         if (lasttoken != TRP)
539                                 synexpect(TRP);
540                         cp->nclist.body = list(0, 0);
541
542                         checkkwd = CHKNL | CHKKWD | CHKALIAS;
543                         if ((t = readtoken()) != TESAC) {
544                                 if (t != TENDCASE)
545                                         synexpect(TENDCASE);
546                                 else
547                                         checkkwd = CHKNL | CHKKWD, readtoken();
548                         }
549                         cpp = &cp->nclist.next;
550                 }
551                 *cpp = NULL;
552                 checkkwd = CHKKWD | CHKALIAS;
553                 break;
554         case TLP:
555                 n1 = (union node *)stalloc(sizeof (struct nredir));
556                 n1->type = NSUBSHELL;
557                 n1->nredir.n = list(0, 0);
558                 n1->nredir.redirect = NULL;
559                 if (readtoken() != TRP)
560                         synexpect(TRP);
561                 checkkwd = CHKKWD | CHKALIAS;
562                 is_subshell = 1;
563                 break;
564         case TBEGIN:
565                 n1 = list(0, 0);
566                 if (readtoken() != TEND)
567                         synexpect(TEND);
568                 checkkwd = CHKKWD | CHKALIAS;
569                 break;
570         /* Handle an empty command like other simple commands.  */
571         case TBACKGND:
572         case TSEMI:
573         case TAND:
574         case TOR:
575                 /*
576                  * An empty command before a ; doesn't make much sense, and
577                  * should certainly be disallowed in the case of `if ;'.
578                  */
579                 if (!redir)
580                         synexpect(-1);
581         case TNL:
582         case TEOF:
583         case TWORD:
584         case TRP:
585                 tokpushback++;
586                 n1 = simplecmd(rpp, redir);
587                 return n1;
588         default:
589                 synexpect(-1);
590         }
591
592         /* Now check for redirection which may follow command */
593         while (readtoken() == TREDIR) {
594                 *rpp = n2 = redirnode;
595                 rpp = &n2->nfile.next;
596                 parsefname();
597         }
598         tokpushback++;
599         *rpp = NULL;
600         if (redir) {
601                 if (!is_subshell) {
602                         n2 = (union node *)stalloc(sizeof (struct nredir));
603                         n2->type = NREDIR;
604                         n2->nredir.n = n1;
605                         n1 = n2;
606                 }
607                 n1->nredir.redirect = redir;
608         }
609
610         return n1;
611 }
612
613
614 static union node *
615 simplecmd(union node **rpp, union node *redir)
616 {
617         union node *args, **app;
618         union node **orig_rpp = rpp;
619         union node *n = NULL;
620         int special;
621
622         /* If we don't have any redirections already, then we must reset */
623         /* rpp to be the address of the local redir variable.  */
624         if (redir == 0)
625                 rpp = &redir;
626
627         args = NULL;
628         app = &args;
629         /*
630          * We save the incoming value, because we need this for shell
631          * functions.  There can not be a redirect or an argument between
632          * the function name and the open parenthesis.
633          */
634         orig_rpp = rpp;
635
636         for (;;) {
637                 if (readtoken() == TWORD) {
638                         n = (union node *)stalloc(sizeof (struct narg));
639                         n->type = NARG;
640                         n->narg.text = wordtext;
641                         n->narg.backquote = backquotelist;
642                         *app = n;
643                         app = &n->narg.next;
644                 } else if (lasttoken == TREDIR) {
645                         *rpp = n = redirnode;
646                         rpp = &n->nfile.next;
647                         parsefname();   /* read name of redirection file */
648                 } else if (lasttoken == TLP && app == &args->narg.next
649                                             && rpp == orig_rpp) {
650                         /* We have a function */
651                         if (readtoken() != TRP)
652                                 synexpect(TRP);
653                         funclinno = plinno;
654                         /*
655                          * - Require plain text.
656                          * - Functions with '/' cannot be called.
657                          * - Reject name=().
658                          * - Reject ksh extended glob patterns.
659                          */
660                         if (!noexpand(n->narg.text) || quoteflag ||
661                             strchr(n->narg.text, '/') ||
662                             strchr("!%*+-=?@}~",
663                                 n->narg.text[strlen(n->narg.text) - 1]))
664                                 synerror("Bad function name");
665                         rmescapes(n->narg.text);
666                         if (find_builtin(n->narg.text, &special) >= 0 &&
667                             special)
668                                 synerror("Cannot override a special builtin with a function");
669                         n->type = NDEFUN;
670                         n->narg.next = command();
671                         funclinno = 0;
672                         return n;
673                 } else {
674                         tokpushback++;
675                         break;
676                 }
677         }
678         *app = NULL;
679         *rpp = NULL;
680         n = (union node *)stalloc(sizeof (struct ncmd));
681         n->type = NCMD;
682         n->ncmd.backgnd = 0;
683         n->ncmd.args = args;
684         n->ncmd.redirect = redir;
685         return n;
686 }
687
688 static union node *
689 makename(void)
690 {
691         union node *n;
692
693         n = (union node *)stalloc(sizeof (struct narg));
694         n->type = NARG;
695         n->narg.next = NULL;
696         n->narg.text = wordtext;
697         n->narg.backquote = backquotelist;
698         return n;
699 }
700
701 void
702 fixredir(union node *n, const char *text, int err)
703 {
704         TRACE(("Fix redir %s %d\n", text, err));
705         if (!err)
706                 n->ndup.vname = NULL;
707
708         if (is_digit(text[0]) && text[1] == '\0')
709                 n->ndup.dupfd = digit_val(text[0]);
710         else if (text[0] == '-' && text[1] == '\0')
711                 n->ndup.dupfd = -1;
712         else {
713
714                 if (err)
715                         synerror("Bad fd number");
716                 else
717                         n->ndup.vname = makename();
718         }
719 }
720
721
722 static void
723 parsefname(void)
724 {
725         union node *n = redirnode;
726
727         if (readtoken() != TWORD)
728                 synexpect(-1);
729         if (n->type == NHERE) {
730                 struct heredoc *here = heredoc;
731                 struct heredoc *p;
732                 int i;
733
734                 if (quoteflag == 0)
735                         n->type = NXHERE;
736                 TRACE(("Here document %d\n", n->type));
737                 if (here->striptabs) {
738                         while (*wordtext == '\t')
739                                 wordtext++;
740                 }
741                 if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN)
742                         synerror("Illegal eof marker for << redirection");
743                 rmescapes(wordtext);
744                 here->eofmark = wordtext;
745                 here->next = NULL;
746                 if (heredoclist == NULL)
747                         heredoclist = here;
748                 else {
749                         for (p = heredoclist ; p->next ; p = p->next);
750                         p->next = here;
751                 }
752         } else if (n->type == NTOFD || n->type == NFROMFD) {
753                 fixredir(n, wordtext, 0);
754         } else {
755                 n->nfile.fname = makename();
756         }
757 }
758
759
760 /*
761  * Input any here documents.
762  */
763
764 static void
765 parseheredoc(void)
766 {
767         struct heredoc *here;
768         union node *n;
769
770         while (heredoclist) {
771                 here = heredoclist;
772                 heredoclist = here->next;
773                 if (needprompt) {
774                         setprompt(2);
775                         needprompt = 0;
776                 }
777                 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX,
778                                 here->eofmark, here->striptabs);
779                 n = (union node *)stalloc(sizeof (struct narg));
780                 n->narg.type = NARG;
781                 n->narg.next = NULL;
782                 n->narg.text = wordtext;
783                 n->narg.backquote = backquotelist;
784                 here->here->nhere.doc = n;
785         }
786 }
787
788 static int
789 peektoken(void)
790 {
791         int t;
792
793         t = readtoken();
794         tokpushback++;
795         return (t);
796 }
797
798 static int
799 readtoken(void)
800 {
801         int t;
802         struct alias *ap;
803 #ifdef DEBUG
804         int alreadyseen = tokpushback;
805 #endif
806
807         top:
808         t = xxreadtoken();
809
810         /*
811          * eat newlines
812          */
813         if (checkkwd & CHKNL) {
814                 while (t == TNL) {
815                         parseheredoc();
816                         t = xxreadtoken();
817                 }
818         }
819
820         /*
821          * check for keywords and aliases
822          */
823         if (t == TWORD && !quoteflag)
824         {
825                 const char * const *pp;
826
827                 if (checkkwd & CHKKWD)
828                         for (pp = parsekwd; *pp; pp++) {
829                                 if (**pp == *wordtext && equal(*pp, wordtext))
830                                 {
831                                         lasttoken = t = pp - parsekwd + KWDOFFSET;
832                                         TRACE(("keyword %s recognized\n", tokname[t]));
833                                         goto out;
834                                 }
835                         }
836                 if (checkkwd & CHKALIAS &&
837                     (ap = lookupalias(wordtext, 1)) != NULL) {
838                         pushstring(ap->val, strlen(ap->val), ap);
839                         goto top;
840                 }
841         }
842 out:
843         if (t != TNOT)
844                 checkkwd = 0;
845
846 #ifdef DEBUG
847         if (!alreadyseen)
848             TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
849         else
850             TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
851 #endif
852         return (t);
853 }
854
855
856 /*
857  * Read the next input token.
858  * If the token is a word, we set backquotelist to the list of cmds in
859  *      backquotes.  We set quoteflag to true if any part of the word was
860  *      quoted.
861  * If the token is TREDIR, then we set redirnode to a structure containing
862  *      the redirection.
863  * In all cases, the variable startlinno is set to the number of the line
864  *      on which the token starts.
865  *
866  * [Change comment:  here documents and internal procedures]
867  * [Readtoken shouldn't have any arguments.  Perhaps we should make the
868  *  word parsing code into a separate routine.  In this case, readtoken
869  *  doesn't need to have any internal procedures, but parseword does.
870  *  We could also make parseoperator in essence the main routine, and
871  *  have parseword (readtoken1?) handle both words and redirection.]
872  */
873
874 #define RETURN(token)   return lasttoken = token
875
876 static int
877 xxreadtoken(void)
878 {
879         int c;
880
881         if (tokpushback) {
882                 tokpushback = 0;
883                 return lasttoken;
884         }
885         if (needprompt) {
886                 setprompt(2);
887                 needprompt = 0;
888         }
889         startlinno = plinno;
890         for (;;) {      /* until token or start of word found */
891                 c = pgetc_macro();
892                 switch (c) {
893                 case ' ': case '\t':
894                         continue;
895                 case '#':
896                         while ((c = pgetc()) != '\n' && c != PEOF);
897                         pungetc();
898                         continue;
899                 case '\\':
900                         if (pgetc() == '\n') {
901                                 startlinno = ++plinno;
902                                 if (doprompt)
903                                         setprompt(2);
904                                 else
905                                         setprompt(0);
906                                 continue;
907                         }
908                         pungetc();
909                         goto breakloop;
910                 case '\n':
911                         plinno++;
912                         needprompt = doprompt;
913                         RETURN(TNL);
914                 case PEOF:
915                         RETURN(TEOF);
916                 case '&':
917                         if (pgetc() == '&')
918                                 RETURN(TAND);
919                         pungetc();
920                         RETURN(TBACKGND);
921                 case '|':
922                         if (pgetc() == '|')
923                                 RETURN(TOR);
924                         pungetc();
925                         RETURN(TPIPE);
926                 case ';':
927                         if (pgetc() == ';')
928                                 RETURN(TENDCASE);
929                         pungetc();
930                         RETURN(TSEMI);
931                 case '(':
932                         RETURN(TLP);
933                 case ')':
934                         RETURN(TRP);
935                 default:
936                         goto breakloop;
937                 }
938         }
939 breakloop:
940         return readtoken1(c, BASESYNTAX, NULL, 0);
941 #undef RETURN
942 }
943
944
945 #define MAXNEST_STATIC 8
946 struct tokenstate
947 {
948         const char *syntax; /* *SYNTAX */
949         int parenlevel; /* levels of parentheses in arithmetic */
950         enum tokenstate_category
951         {
952                 TSTATE_TOP,
953                 TSTATE_VAR_OLD, /* ${var+-=?}, inherits dquotes */
954                 TSTATE_VAR_NEW, /* other ${var...}, own dquote state */
955                 TSTATE_ARITH
956         } category;
957 };
958
959
960 /*
961  * Called to parse command substitutions.
962  */
963
964 static char *
965 parsebackq(char *out, struct nodelist **pbqlist,
966     int oldstyle, int dblquote, int quoted)
967 {
968         struct nodelist **nlpp;
969         union node *n;
970         char *volatile str;
971         struct jmploc jmploc;
972         struct jmploc *const savehandler = handler;
973         int savelen;
974         int saveprompt;
975         const int bq_startlinno = plinno;
976         char *volatile ostr = NULL;
977         struct parsefile *const savetopfile = getcurrentfile();
978         struct heredoc *const saveheredoclist = heredoclist;
979         struct heredoc *here;
980
981         str = NULL;
982         if (setjmp(jmploc.loc)) {
983                 popfilesupto(savetopfile);
984                 if (str)
985                         ckfree(str);
986                 if (ostr)
987                         ckfree(ostr);
988                 heredoclist = saveheredoclist;
989                 handler = savehandler;
990                 if (exception == EXERROR) {
991                         startlinno = bq_startlinno;
992                         synerror("Error in command substitution");
993                 }
994                 longjmp(handler->loc, 1);
995         }
996         INTOFF;
997         savelen = out - stackblock();
998         if (savelen > 0) {
999                 str = ckmalloc(savelen);
1000                 memcpy(str, stackblock(), savelen);
1001         }
1002         handler = &jmploc;
1003         heredoclist = NULL;
1004         INTON;
1005         if (oldstyle) {
1006                 /*
1007                  * We must read until the closing backquote, giving special
1008                  * treatment to some slashes, and then push the string and
1009                  * reread it as input, interpreting it normally.
1010                  */
1011                 char *oout;
1012                 int c, olen;
1013
1014                 STARTSTACKSTR(oout);
1015                 for (;;) {
1016                         if (needprompt) {
1017                                 setprompt(2);
1018                                 needprompt = 0;
1019                         }
1020                         CHECKSTRSPACE(2, oout);
1021                         switch (c = pgetc()) {
1022                         case '`':
1023                                 goto done;
1024
1025                         case '\\':
1026                                 if ((c = pgetc()) == '\n') {
1027                                         plinno++;
1028                                         if (doprompt)
1029                                                 setprompt(2);
1030                                         else
1031                                                 setprompt(0);
1032                                         /*
1033                                          * If eating a newline, avoid putting
1034                                          * the newline into the new character
1035                                          * stream (via the USTPUTC after the
1036                                          * switch).
1037                                          */
1038                                         continue;
1039                                 }
1040                                 if (c != '\\' && c != '`' && c != '$'
1041                                     && (!dblquote || c != '"'))
1042                                         USTPUTC('\\', oout);
1043                                 break;
1044
1045                         case '\n':
1046                                 plinno++;
1047                                 needprompt = doprompt;
1048                                 break;
1049
1050                         case PEOF:
1051                                 startlinno = plinno;
1052                                 synerror("EOF in backquote substitution");
1053                                 break;
1054
1055                         default:
1056                                 break;
1057                         }
1058                         USTPUTC(c, oout);
1059                 }
1060 done:
1061                 USTPUTC('\0', oout);
1062                 olen = oout - stackblock();
1063                 INTOFF;
1064                 ostr = ckmalloc(olen);
1065                 memcpy(ostr, stackblock(), olen);
1066                 setinputstring(ostr, 1);
1067                 INTON;
1068         }
1069         nlpp = pbqlist;
1070         while (*nlpp)
1071                 nlpp = &(*nlpp)->next;
1072         *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist));
1073         (*nlpp)->next = NULL;
1074
1075         if (oldstyle) {
1076                 saveprompt = doprompt;
1077                 doprompt = 0;
1078         }
1079
1080         n = list(0, oldstyle);
1081
1082         if (oldstyle)
1083                 doprompt = saveprompt;
1084         else {
1085                 if (readtoken() != TRP)
1086                         synexpect(TRP);
1087         }
1088
1089         (*nlpp)->n = n;
1090         if (oldstyle) {
1091                 /*
1092                  * Start reading from old file again, ignoring any pushed back
1093                  * tokens left from the backquote parsing
1094                  */
1095                 popfile();
1096                 tokpushback = 0;
1097         }
1098         STARTSTACKSTR(out);
1099         CHECKSTRSPACE(savelen + 1, out);
1100         INTOFF;
1101         if (str) {
1102                 memcpy(out, str, savelen);
1103                 STADJUST(savelen, out);
1104                 ckfree(str);
1105                 str = NULL;
1106         }
1107         if (ostr) {
1108                 ckfree(ostr);
1109                 ostr = NULL;
1110         }
1111         here = saveheredoclist;
1112         if (here != NULL) {
1113                 while (here->next != NULL)
1114                         here = here->next;
1115                 here->next = heredoclist;
1116                 heredoclist = saveheredoclist;
1117         }
1118         handler = savehandler;
1119         INTON;
1120         if (quoted)
1121                 USTPUTC(CTLBACKQ | CTLQUOTE, out);
1122         else
1123                 USTPUTC(CTLBACKQ, out);
1124         return out;
1125 }
1126
1127
1128 /*
1129  * If eofmark is NULL, read a word or a redirection symbol.  If eofmark
1130  * is not NULL, read a here document.  In the latter case, eofmark is the
1131  * word which marks the end of the document and striptabs is true if
1132  * leading tabs should be stripped from the document.  The argument firstc
1133  * is the first character of the input token or document.
1134  *
1135  * Because C does not have internal subroutines, I have simulated them
1136  * using goto's to implement the subroutine linkage.  The following macros
1137  * will run code that appears at the end of readtoken1.
1138  */
1139
1140 #define CHECKEND()      {goto checkend; checkend_return:;}
1141 #define PARSEREDIR()    {goto parseredir; parseredir_return:;}
1142 #define PARSESUB()      {goto parsesub; parsesub_return:;}
1143 #define PARSEARITH()    {goto parsearith; parsearith_return:;}
1144
1145 static int
1146 readtoken1(int firstc, char const *initialsyntax, char *eofmark, int striptabs)
1147 {
1148         int c = firstc;
1149         char * volatile out;
1150         int len;
1151         char line[EOFMARKLEN + 1];
1152         struct nodelist *bqlist;
1153         volatile int quotef;
1154         int newvarnest;
1155         int level;
1156         int synentry;
1157         struct tokenstate state_static[MAXNEST_STATIC];
1158         int maxnest = MAXNEST_STATIC;
1159         struct tokenstate *state = state_static;
1160
1161         startlinno = plinno;
1162         quotef = 0;
1163         bqlist = NULL;
1164         newvarnest = 0;
1165         level = 0;
1166         state[level].syntax = initialsyntax;
1167         state[level].parenlevel = 0;
1168         state[level].category = TSTATE_TOP;
1169
1170         STARTSTACKSTR(out);
1171         loop: { /* for each line, until end of word */
1172                 CHECKEND();     /* set c to PEOF if at end of here document */
1173                 for (;;) {      /* until end of line or end of word */
1174                         CHECKSTRSPACE(4, out);  /* permit 4 calls to USTPUTC */
1175
1176                         synentry = state[level].syntax[c];
1177
1178                         switch(synentry) {
1179                         case CNL:       /* '\n' */
1180                                 if (state[level].syntax == BASESYNTAX)
1181                                         goto endword;   /* exit outer loop */
1182                                 USTPUTC(c, out);
1183                                 plinno++;
1184                                 if (doprompt)
1185                                         setprompt(2);
1186                                 else
1187                                         setprompt(0);
1188                                 c = pgetc();
1189                                 goto loop;              /* continue outer loop */
1190                         case CWORD:
1191                                 USTPUTC(c, out);
1192                                 break;
1193                         case CCTL:
1194                                 if (eofmark == NULL || initialsyntax != SQSYNTAX)
1195                                         USTPUTC(CTLESC, out);
1196                                 USTPUTC(c, out);
1197                                 break;
1198                         case CBACK:     /* backslash */
1199                                 c = pgetc();
1200                                 if (c == PEOF) {
1201                                         USTPUTC('\\', out);
1202                                         pungetc();
1203                                 } else if (c == '\n') {
1204                                         plinno++;
1205                                         if (doprompt)
1206                                                 setprompt(2);
1207                                         else
1208                                                 setprompt(0);
1209                                 } else {
1210                                         if (state[level].syntax == DQSYNTAX &&
1211                                             c != '\\' && c != '`' && c != '$' &&
1212                                             (c != '"' || (eofmark != NULL &&
1213                                                 newvarnest == 0)) &&
1214                                             (c != '}' || state[level].category != TSTATE_VAR_OLD))
1215                                                 USTPUTC('\\', out);
1216                                         if ((eofmark == NULL ||
1217                                             newvarnest > 0) &&
1218                                             state[level].syntax == BASESYNTAX)
1219                                                 USTPUTC(CTLQUOTEMARK, out);
1220                                         if (SQSYNTAX[c] == CCTL)
1221                                                 USTPUTC(CTLESC, out);
1222                                         USTPUTC(c, out);
1223                                         if ((eofmark == NULL ||
1224                                             newvarnest > 0) &&
1225                                             state[level].syntax == BASESYNTAX &&
1226                                             state[level].category == TSTATE_VAR_OLD)
1227                                                 USTPUTC(CTLQUOTEEND, out);
1228                                         quotef++;
1229                                 }
1230                                 break;
1231                         case CSQUOTE:
1232                                 USTPUTC(CTLQUOTEMARK, out);
1233                                 state[level].syntax = SQSYNTAX;
1234                                 break;
1235                         case CDQUOTE:
1236                                 USTPUTC(CTLQUOTEMARK, out);
1237                                 state[level].syntax = DQSYNTAX;
1238                                 break;
1239                         case CENDQUOTE:
1240                                 if (eofmark != NULL && newvarnest == 0)
1241                                         USTPUTC(c, out);
1242                                 else {
1243                                         if (state[level].category == TSTATE_VAR_OLD)
1244                                                 USTPUTC(CTLQUOTEEND, out);
1245                                         state[level].syntax = BASESYNTAX;
1246                                         quotef++;
1247                                 }
1248                                 break;
1249                         case CVAR:      /* '$' */
1250                                 PARSESUB();             /* parse substitution */
1251                                 break;
1252                         case CENDVAR:   /* '}' */
1253                                 if (level > 0 &&
1254                                     ((state[level].category == TSTATE_VAR_OLD &&
1255                                       state[level].syntax ==
1256                                       state[level - 1].syntax) ||
1257                                     (state[level].category == TSTATE_VAR_NEW &&
1258                                      state[level].syntax == BASESYNTAX))) {
1259                                         if (state[level].category == TSTATE_VAR_NEW)
1260                                                 newvarnest--;
1261                                         level--;
1262                                         USTPUTC(CTLENDVAR, out);
1263                                 } else {
1264                                         USTPUTC(c, out);
1265                                 }
1266                                 break;
1267                         case CLP:       /* '(' in arithmetic */
1268                                 state[level].parenlevel++;
1269                                 USTPUTC(c, out);
1270                                 break;
1271                         case CRP:       /* ')' in arithmetic */
1272                                 if (state[level].parenlevel > 0) {
1273                                         USTPUTC(c, out);
1274                                         --state[level].parenlevel;
1275                                 } else {
1276                                         if (pgetc() == ')') {
1277                                                 if (level > 0 &&
1278                                                     state[level].category == TSTATE_ARITH) {
1279                                                         level--;
1280                                                         USTPUTC(CTLENDARI, out);
1281                                                 } else
1282                                                         USTPUTC(')', out);
1283                                         } else {
1284                                                 /*
1285                                                  * unbalanced parens
1286                                                  *  (don't 2nd guess - no error)
1287                                                  */
1288                                                 pungetc();
1289                                                 USTPUTC(')', out);
1290                                         }
1291                                 }
1292                                 break;
1293                         case CBQUOTE:   /* '`' */
1294                                 out = parsebackq(out, &bqlist, 1,
1295                                     state[level].syntax == DQSYNTAX &&
1296                                     (eofmark == NULL || newvarnest > 0),
1297                                     state[level].syntax == DQSYNTAX || state[level].syntax == ARISYNTAX);
1298                                 break;
1299                         case CEOF:
1300                                 goto endword;           /* exit outer loop */
1301                         case CIGN:
1302                                 break;
1303                         default:
1304                                 if (level == 0)
1305                                         goto endword;   /* exit outer loop */
1306                                 USTPUTC(c, out);
1307                         }
1308                         c = pgetc_macro();
1309                 }
1310         }
1311 endword:
1312         if (state[level].syntax == ARISYNTAX)
1313                 synerror("Missing '))'");
1314         if (state[level].syntax != BASESYNTAX && eofmark == NULL)
1315                 synerror("Unterminated quoted string");
1316         if (state[level].category == TSTATE_VAR_OLD ||
1317             state[level].category == TSTATE_VAR_NEW) {
1318                 startlinno = plinno;
1319                 synerror("Missing '}'");
1320         }
1321         if (state != state_static)
1322                 parser_temp_free_upto(state);
1323         USTPUTC('\0', out);
1324         len = out - stackblock();
1325         out = stackblock();
1326         if (eofmark == NULL) {
1327                 if ((c == '>' || c == '<')
1328                  && quotef == 0
1329                  && len <= 2
1330                  && (*out == '\0' || is_digit(*out))) {
1331                         PARSEREDIR();
1332                         return lasttoken = TREDIR;
1333                 } else {
1334                         pungetc();
1335                 }
1336         }
1337         quoteflag = quotef;
1338         backquotelist = bqlist;
1339         grabstackblock(len);
1340         wordtext = out;
1341         return lasttoken = TWORD;
1342 /* end of readtoken routine */
1343
1344
1345 /*
1346  * Check to see whether we are at the end of the here document.  When this
1347  * is called, c is set to the first character of the next input line.  If
1348  * we are at the end of the here document, this routine sets the c to PEOF.
1349  */
1350
1351 checkend: {
1352         if (eofmark) {
1353                 if (striptabs) {
1354                         while (c == '\t')
1355                                 c = pgetc();
1356                 }
1357                 if (c == *eofmark) {
1358                         if (pfgets(line, sizeof line) != NULL) {
1359                                 char *p, *q;
1360
1361                                 p = line;
1362                                 for (q = eofmark + 1 ; *q && *p == *q ; p++, q++);
1363                                 if (*p == '\n' && *q == '\0') {
1364                                         c = PEOF;
1365                                         plinno++;
1366                                         needprompt = doprompt;
1367                                 } else {
1368                                         pushstring(line, strlen(line), NULL);
1369                                 }
1370                         }
1371                 }
1372         }
1373         goto checkend_return;
1374 }
1375
1376
1377 /*
1378  * Parse a redirection operator.  The variable "out" points to a string
1379  * specifying the fd to be redirected.  The variable "c" contains the
1380  * first character of the redirection operator.
1381  */
1382
1383 parseredir: {
1384         char fd = *out;
1385         union node *np;
1386
1387         np = (union node *)stalloc(sizeof (struct nfile));
1388         if (c == '>') {
1389                 np->nfile.fd = 1;
1390                 c = pgetc();
1391                 if (c == '>')
1392                         np->type = NAPPEND;
1393                 else if (c == '&')
1394                         np->type = NTOFD;
1395                 else if (c == '|')
1396                         np->type = NCLOBBER;
1397                 else {
1398                         np->type = NTO;
1399                         pungetc();
1400                 }
1401         } else {        /* c == '<' */
1402                 np->nfile.fd = 0;
1403                 c = pgetc();
1404                 if (c == '<') {
1405                         if (sizeof (struct nfile) != sizeof (struct nhere)) {
1406                                 np = (union node *)stalloc(sizeof (struct nhere));
1407                                 np->nfile.fd = 0;
1408                         }
1409                         np->type = NHERE;
1410                         heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc));
1411                         heredoc->here = np;
1412                         if ((c = pgetc()) == '-') {
1413                                 heredoc->striptabs = 1;
1414                         } else {
1415                                 heredoc->striptabs = 0;
1416                                 pungetc();
1417                         }
1418                 } else if (c == '&')
1419                         np->type = NFROMFD;
1420                 else if (c == '>')
1421                         np->type = NFROMTO;
1422                 else {
1423                         np->type = NFROM;
1424                         pungetc();
1425                 }
1426         }
1427         if (fd != '\0')
1428                 np->nfile.fd = digit_val(fd);
1429         redirnode = np;
1430         goto parseredir_return;
1431 }
1432
1433
1434 /*
1435  * Parse a substitution.  At this point, we have read the dollar sign
1436  * and nothing else.
1437  */
1438
1439 parsesub: {
1440         char buf[10];
1441         int subtype;
1442         int typeloc;
1443         int flags;
1444         char *p;
1445         static const char types[] = "}-+?=";
1446         int bracketed_name = 0; /* used to handle ${[0-9]*} variables */
1447         int linno;
1448         int length;
1449         int c1;
1450
1451         c = pgetc();
1452         if (c != '(' && c != '{' && (is_eof(c) || !is_name(c)) &&
1453             !is_special(c)) {
1454                 USTPUTC('$', out);
1455                 pungetc();
1456         } else if (c == '(') {  /* $(command) or $((arith)) */
1457                 if (pgetc() == '(') {
1458                         PARSEARITH();
1459                 } else {
1460                         pungetc();
1461                         out = parsebackq(out, &bqlist, 0,
1462                             state[level].syntax == DQSYNTAX &&
1463                             (eofmark == NULL || newvarnest > 0),
1464                             state[level].syntax == DQSYNTAX ||
1465                             state[level].syntax == ARISYNTAX);
1466                 }
1467         } else {
1468                 USTPUTC(CTLVAR, out);
1469                 typeloc = out - stackblock();
1470                 USTPUTC(VSNORMAL, out);
1471                 subtype = VSNORMAL;
1472                 flags = 0;
1473                 if (c == '{') {
1474                         bracketed_name = 1;
1475                         c = pgetc();
1476                         subtype = 0;
1477                 }
1478 varname:
1479                 if (!is_eof(c) && is_name(c)) {
1480                         length = 0;
1481                         do {
1482                                 STPUTC(c, out);
1483                                 c = pgetc();
1484                                 length++;
1485                         } while (!is_eof(c) && is_in_name(c));
1486                         if (length == 6 &&
1487                             strncmp(out - length, "LINENO", length) == 0) {
1488                                 /* Replace the variable name with the
1489                                  * current line number. */
1490                                 linno = plinno;
1491                                 if (funclinno != 0)
1492                                         linno -= funclinno - 1;
1493                                 snprintf(buf, sizeof(buf), "%d", linno);
1494                                 STADJUST(-6, out);
1495                                 STPUTS(buf, out);
1496                                 flags |= VSLINENO;
1497                         }
1498                 } else if (is_digit(c)) {
1499                         if (bracketed_name) {
1500                                 do {
1501                                         STPUTC(c, out);
1502                                         c = pgetc();
1503                                 } while (is_digit(c));
1504                         } else {
1505                                 STPUTC(c, out);
1506                                 c = pgetc();
1507                         }
1508                 } else if (is_special(c)) {
1509                         c1 = c;
1510                         c = pgetc();
1511                         if (subtype == 0 && c1 == '#') {
1512                                 subtype = VSLENGTH;
1513                                 if (strchr(types, c) == NULL && c != ':' &&
1514                                     c != '#' && c != '%')
1515                                         goto varname;
1516                                 c1 = c;
1517                                 c = pgetc();
1518                                 if (c1 != '}' && c == '}') {
1519                                         pungetc();
1520                                         c = c1;
1521                                         goto varname;
1522                                 }
1523                                 pungetc();
1524                                 c = c1;
1525                                 c1 = '#';
1526                                 subtype = 0;
1527                         }
1528                         USTPUTC(c1, out);
1529                 } else {
1530                         subtype = VSERROR;
1531                         if (c == '}')
1532                                 pungetc();
1533                         else if (c == '\n' || c == PEOF)
1534                                 synerror("Unexpected end of line in substitution");
1535                         else
1536                                 USTPUTC(c, out);
1537                 }
1538                 if (subtype == 0) {
1539                         switch (c) {
1540                         case ':':
1541                                 flags |= VSNUL;
1542                                 c = pgetc();
1543                                 /*FALLTHROUGH*/
1544                         default:
1545                                 p = strchr(types, c);
1546                                 if (p == NULL) {
1547                                         if (c == '\n' || c == PEOF)
1548                                                 synerror("Unexpected end of line in substitution");
1549                                         if (flags == VSNUL)
1550                                                 STPUTC(':', out);
1551                                         STPUTC(c, out);
1552                                         subtype = VSERROR;
1553                                 } else
1554                                         subtype = p - types + VSNORMAL;
1555                                 break;
1556                         case '%':
1557                         case '#':
1558                                 {
1559                                         int cc = c;
1560                                         subtype = c == '#' ? VSTRIMLEFT :
1561                                                              VSTRIMRIGHT;
1562                                         c = pgetc();
1563                                         if (c == cc)
1564                                                 subtype++;
1565                                         else
1566                                                 pungetc();
1567                                         break;
1568                                 }
1569                         }
1570                 } else if (subtype != VSERROR) {
1571                         if (subtype == VSLENGTH && c != '}')
1572                                 subtype = VSERROR;
1573                         pungetc();
1574                 }
1575                 STPUTC('=', out);
1576                 if (state[level].syntax == DQSYNTAX ||
1577                     state[level].syntax == ARISYNTAX)
1578                         flags |= VSQUOTE;
1579                 *(stackblock() + typeloc) = subtype | flags;
1580                 if (subtype != VSNORMAL) {
1581                         if (level + 1 >= maxnest) {
1582                                 maxnest *= 2;
1583                                 if (state == state_static) {
1584                                         state = parser_temp_alloc(
1585                                             maxnest * sizeof(*state));
1586                                         memcpy(state, state_static,
1587                                             MAXNEST_STATIC * sizeof(*state));
1588                                 } else
1589                                         state = parser_temp_realloc(state,
1590                                             maxnest * sizeof(*state));
1591                         }
1592                         level++;
1593                         state[level].parenlevel = 0;
1594                         if (subtype == VSMINUS || subtype == VSPLUS ||
1595                             subtype == VSQUESTION || subtype == VSASSIGN) {
1596                                 /*
1597                                  * For operators that were in the Bourne shell,
1598                                  * inherit the double-quote state.
1599                                  */
1600                                 state[level].syntax = state[level - 1].syntax;
1601                                 state[level].category = TSTATE_VAR_OLD;
1602                         } else {
1603                                 /*
1604                                  * The other operators take a pattern,
1605                                  * so go to BASESYNTAX.
1606                                  * Also, ' and " are now special, even
1607                                  * in here documents.
1608                                  */
1609                                 state[level].syntax = BASESYNTAX;
1610                                 state[level].category = TSTATE_VAR_NEW;
1611                                 newvarnest++;
1612                         }
1613                 }
1614         }
1615         goto parsesub_return;
1616 }
1617
1618
1619 /*
1620  * Parse an arithmetic expansion (indicate start of one and set state)
1621  */
1622 parsearith: {
1623
1624         if (level + 1 >= maxnest) {
1625                 maxnest *= 2;
1626                 if (state == state_static) {
1627                         state = parser_temp_alloc(
1628                             maxnest * sizeof(*state));
1629                         memcpy(state, state_static,
1630                             MAXNEST_STATIC * sizeof(*state));
1631                 } else
1632                         state = parser_temp_realloc(state,
1633                             maxnest * sizeof(*state));
1634         }
1635         level++;
1636         state[level].syntax = ARISYNTAX;
1637         state[level].parenlevel = 0;
1638         state[level].category = TSTATE_ARITH;
1639         USTPUTC(CTLARI, out);
1640         if (state[level - 1].syntax == DQSYNTAX)
1641                 USTPUTC('"',out);
1642         else
1643                 USTPUTC(' ',out);
1644         goto parsearith_return;
1645 }
1646
1647 } /* end of readtoken */
1648
1649
1650
1651 #ifdef mkinit
1652 RESET {
1653         tokpushback = 0;
1654         checkkwd = 0;
1655 }
1656 #endif
1657
1658 /*
1659  * Returns true if the text contains nothing to expand (no dollar signs
1660  * or backquotes).
1661  */
1662
1663 static int
1664 noexpand(char *text)
1665 {
1666         char *p;
1667         char c;
1668
1669         p = text;
1670         while ((c = *p++) != '\0') {
1671                 if ( c == CTLQUOTEMARK)
1672                         continue;
1673                 if (c == CTLESC)
1674                         p++;
1675                 else if (BASESYNTAX[(int)c] == CCTL)
1676                         return 0;
1677         }
1678         return 1;
1679 }
1680
1681
1682 /*
1683  * Return true if the argument is a legal variable name (a letter or
1684  * underscore followed by zero or more letters, underscores, and digits).
1685  */
1686
1687 int
1688 goodname(const char *name)
1689 {
1690         const char *p;
1691
1692         p = name;
1693         if (! is_name(*p))
1694                 return 0;
1695         while (*++p) {
1696                 if (! is_in_name(*p))
1697                         return 0;
1698         }
1699         return 1;
1700 }
1701
1702
1703 /*
1704  * Called when an unexpected token is read during the parse.  The argument
1705  * is the token that is expected, or -1 if more than one type of token can
1706  * occur at this point.
1707  */
1708
1709 static void
1710 synexpect(int token)
1711 {
1712         char msg[64];
1713
1714         if (token >= 0) {
1715                 fmtstr(msg, 64, "%s unexpected (expecting %s)",
1716                         tokname[lasttoken], tokname[token]);
1717         } else {
1718                 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]);
1719         }
1720         synerror(msg);
1721 }
1722
1723
1724 static void
1725 synerror(const char *msg)
1726 {
1727         if (commandname)
1728                 outfmt(out2, "%s: %d: ", commandname, startlinno);
1729         outfmt(out2, "Syntax error: %s\n", msg);
1730         error(NULL);
1731 }
1732
1733 static void
1734 setprompt(int which)
1735 {
1736         whichprompt = which;
1737
1738 #ifndef NO_HISTORY
1739         if (!el)
1740 #endif
1741         {
1742                 out2str(getprompt(NULL));
1743                 flushout(out2);
1744         }
1745 }
1746
1747 /*
1748  * called by editline -- any expansions to the prompt
1749  *    should be added here.
1750  */
1751 const char *
1752 getprompt(void *unused __unused)
1753 {
1754         static char ps[PROMPTLEN];
1755         const char *fmt;
1756         const char *pwd;
1757         int i, trim;
1758
1759         /*
1760          * Select prompt format.
1761          */
1762         switch (whichprompt) {
1763         case 0:
1764                 fmt = "";
1765                 break;
1766         case 1:
1767                 fmt = ps1val();
1768                 break;
1769         case 2:
1770                 fmt = ps2val();
1771                 break;
1772         default:
1773                 return "??";
1774         }
1775
1776         /*
1777          * Format prompt string.
1778          */
1779         for (i = 0; (i < 127) && (*fmt != '\0'); i++, fmt++)
1780                 if (*fmt == '\\')
1781                         switch (*++fmt) {
1782
1783                                 /*
1784                                  * Hostname.
1785                                  *
1786                                  * \h specifies just the local hostname,
1787                                  * \H specifies fully-qualified hostname.
1788                                  */
1789                         case 'h':
1790                         case 'H':
1791                                 ps[i] = '\0';
1792                                 gethostname(&ps[i], PROMPTLEN - i);
1793                                 /* Skip to end of hostname. */
1794                                 trim = (*fmt == 'h') ? '.' : '\0';
1795                                 while ((ps[i+1] != '\0') && (ps[i+1] != trim))
1796                                         i++;
1797                                 break;
1798
1799                                 /*
1800                                  * Working directory.
1801                                  *
1802                                  * \W specifies just the final component,
1803                                  * \w specifies the entire path.
1804                                  */
1805                         case 'W':
1806                         case 'w':
1807                                 pwd = lookupvar("PWD");
1808                                 if (pwd == NULL)
1809                                         pwd = "?";
1810                                 if (*fmt == 'W' &&
1811                                     *pwd == '/' && pwd[1] != '\0')
1812                                         strlcpy(&ps[i], strrchr(pwd, '/') + 1,
1813                                             PROMPTLEN - i);
1814                                 else
1815                                         strlcpy(&ps[i], pwd, PROMPTLEN - i);
1816                                 /* Skip to end of path. */
1817                                 while (ps[i + 1] != '\0')
1818                                         i++;
1819                                 break;
1820
1821                                 /*
1822                                  * Superuser status.
1823                                  *
1824                                  * '$' for normal users, '#' for root.
1825                                  */
1826                         case '$':
1827                                 ps[i] = (geteuid() != 0) ? '$' : '#';
1828                                 break;
1829
1830                                 /*
1831                                  * A literal \.
1832                                  */
1833                         case '\\':
1834                                 ps[i] = '\\';
1835                                 break;
1836
1837                                 /*
1838                                  * Emit unrecognized formats verbatim.
1839                                  */
1840                         default:
1841                                 ps[i++] = '\\';
1842                                 ps[i] = *fmt;
1843                                 break;
1844                         }
1845                 else
1846                         ps[i] = *fmt;
1847         ps[i] = '\0';
1848         return (ps);
1849 }