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
  37 #ifndef lint
  38 #if 0
  39 static char sccsid[] = "@(#)parser.c    8.7 (Berkeley) 5/16/95";
  40 #endif
  41 #endif /* not lint */
  42 #include <sys/cdefs.h>
  43 __FBSDID("$FreeBSD: src/bin/sh/parser.c,v 1.29.2.9 2002/10/18 11:24:04 tjr Exp $");
  44
  45 #include <stdlib.h>
  46
  47 #include "shell.h"
  48 #include "parser.h"
  49 #include "nodes.h"
  50 #include "expand.h"     /* defines rmescapes() */
  51 #include "redir.h"      /* defines copyfd() */
  52 #include "syntax.h"
  53 #include "options.h"
  54 #include "input.h"
  55 #include "output.h"
  56 #include "var.h"
  57 #include "error.h"
  58 #include "memalloc.h"
  59 #include "mystring.h"
  60 #include "alias.h"
  61 #include "show.h"
  62 #include "eval.h"
  63 #ifndef NO_HISTORY
  64 #include "myhistedit.h"
  65 #endif
  66
  67 /*
  68  * Shell command parser.
  69  */
  70
  71 #define EOFMARKLEN 79
  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
  86
  87 struct heredoc *heredoclist;    /* list of here documents to read */
  88 int parsebackquote;             /* nonzero if we are inside backquotes */
  89 int doprompt;                   /* if set, prompt the user */
  90 int needprompt;                 /* true if interactive and at start of line */
  91 int lasttoken;                  /* last token read */
  92 MKINIT int tokpushback;         /* last token pushed back */
  93 char *wordtext;                 /* text of last word returned by readtoken */
  94 MKINIT int checkkwd;            /* 1 == check for kwds, 2 == also eat newlines */
  95 struct nodelist *backquotelist;
  96 union node *redirnode;
  97 struct heredoc *heredoc;
  98 int quoteflag;                  /* set if (part of) last token was quoted */
  99 int startlinno;                 /* line # where last token started */
 100
 101 /* XXX When 'noaliases' is set to one, no alias expansion takes place. */
 102 static int noaliases = 0;
 103
 104 #define GDB_HACK 1 /* avoid local declarations which gdb can't handle */
 105 #ifdef GDB_HACK
 106 static const char argvars[5] = {CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0'};
 107 static const char types[] = "}-+?=";
 108 #endif
 109
 110
 111 STATIC union node *list(int);
 112 STATIC union node *andor(void);
 113 STATIC union node *pipeline(void);
 114 STATIC union node *command(void);
 115 STATIC union node *simplecmd(union node **, union node *);
 116 STATIC union node *makename(void);
 117 STATIC void parsefname(void);
 118 STATIC void parseheredoc(void);
 119 STATIC int peektoken(void);
 120 STATIC int readtoken(void);
 121 STATIC int xxreadtoken(void);
 122 STATIC int readtoken1(int, char const *, char *, int);
 123 STATIC int noexpand(char *);
 124 STATIC void synexpect(int);
 125 STATIC void synerror(char *);
 126 STATIC void setprompt(int);
 127
 128
 129 /*
 130  * Read and parse a command.  Returns NEOF on end of file.  (NULL is a
 131  * valid parse tree indicating a blank line.)
 132  */
 133
 134 union node *
 135 parsecmd(int interact)
 136 {
 137         int t;
 138
 139         tokpushback = 0;
 140         doprompt = interact;
 141         if (doprompt)
 142                 setprompt(1);
 143         else
 144                 setprompt(0);
 145         needprompt = 0;
 146         t = readtoken();
 147         if (t == TEOF)
 148                 return NEOF;
 149         if (t == TNL)
 150                 return NULL;
 151         tokpushback++;
 152         return list(1);
 153 }
 154
 155
 156 STATIC union node *
 157 list(int nlflag)
 158 {
 159         union node *n1, *n2, *n3;
 160         int tok;
 161
 162         checkkwd = 2;
 163         if (nlflag == 0 && tokendlist[peektoken()])
 164                 return NULL;
 165         n1 = NULL;
 166         for (;;) {
 167                 n2 = andor();
 168                 tok = readtoken();
 169                 if (tok == TBACKGND) {
 170                         if (n2->type == NCMD || n2->type == NPIPE) {
 171                                 n2->ncmd.backgnd = 1;
 172                         } else if (n2->type == NREDIR) {
 173                                 n2->type = NBACKGND;
 174                         } else {
 175                                 n3 = (union node *)stalloc(sizeof (struct nredir));
 176                                 n3->type = NBACKGND;
 177                                 n3->nredir.n = n2;
 178                                 n3->nredir.redirect = NULL;
 179                                 n2 = n3;
 180                         }
 181                 }
 182                 if (n1 == NULL) {
 183                         n1 = n2;
 184                 }
 185                 else {
 186                         n3 = (union node *)stalloc(sizeof (struct nbinary));
 187                         n3->type = NSEMI;
 188                         n3->nbinary.ch1 = n1;
 189                         n3->nbinary.ch2 = n2;
 190                         n1 = n3;
 191                 }
 192                 switch (tok) {
 193                 case TBACKGND:
 194                 case TSEMI:
 195                         tok = readtoken();
 196                         /* fall through */
 197                 case TNL:
 198                         if (tok == TNL) {
 199                                 parseheredoc();
 200                                 if (nlflag)
 201                                         return n1;
 202                         } else {
 203                                 tokpushback++;
 204                         }
 205                         checkkwd = 2;
 206                         if (tokendlist[peektoken()])
 207                                 return n1;
 208                         break;
 209                 case TEOF:
 210                         if (heredoclist)
 211                                 parseheredoc();
 212                         else
 213                                 pungetc();              /* push back EOF on input */
 214                         return n1;
 215                 default:
 216                         if (nlflag)
 217                                 synexpect(-1);
 218                         tokpushback++;
 219                         return n1;
 220                 }
 221         }
 222 }
 223
 224
 225
 226 STATIC union node *
 227 andor(void)
 228 {
 229         union node *n1, *n2, *n3;
 230         int t;
 231
 232         n1 = pipeline();
 233         for (;;) {
 234                 if ((t = readtoken()) == TAND) {
 235                         t = NAND;
 236                 } else if (t == TOR) {
 237                         t = NOR;
 238                 } else {
 239                         tokpushback++;
 240                         return n1;
 241                 }
 242                 n2 = pipeline();
 243                 n3 = (union node *)stalloc(sizeof (struct nbinary));
 244                 n3->type = t;
 245                 n3->nbinary.ch1 = n1;
 246                 n3->nbinary.ch2 = n2;
 247                 n1 = n3;
 248         }
 249 }
 250
 251
 252
 253 STATIC union node *
 254 pipeline(void)
 255 {
 256         union node *n1, *n2, *pipenode;
 257         struct nodelist *lp, *prev;
 258         int negate;
 259
 260         negate = 0;
 261         TRACE(("pipeline: entered\n"));
 262         while (readtoken() == TNOT)
 263                 negate = !negate;
 264         tokpushback++;
 265         n1 = command();
 266         if (readtoken() == TPIPE) {
 267                 pipenode = (union node *)stalloc(sizeof (struct npipe));
 268                 pipenode->type = NPIPE;
 269                 pipenode->npipe.backgnd = 0;
 270                 lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
 271                 pipenode->npipe.cmdlist = lp;
 272                 lp->n = n1;
 273                 do {
 274                         prev = lp;
 275                         lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
 276                         lp->n = command();
 277                         prev->next = lp;
 278                 } while (readtoken() == TPIPE);
 279                 lp->next = NULL;
 280                 n1 = pipenode;
 281         }
 282         tokpushback++;
 283         if (negate) {
 284                 n2 = (union node *)stalloc(sizeof (struct nnot));
 285                 n2->type = NNOT;
 286                 n2->nnot.com = n1;
 287                 return n2;
 288         } else
 289                 return n1;
 290 }
 291
 292
 293
 294 STATIC union node *
 295 command(void)
 296 {
 297         union node *n1, *n2;
 298         union node *ap, **app;
 299         union node *cp, **cpp;
 300         union node *redir, **rpp;
 301         int t, negate = 0;
 302
 303         checkkwd = 2;
 304         redir = NULL;
 305         n1 = NULL;
 306         rpp = &redir;
 307
 308         /* Check for redirection which may precede command */
 309         while (readtoken() == TREDIR) {
 310                 *rpp = n2 = redirnode;
 311                 rpp = &n2->nfile.next;
 312                 parsefname();
 313         }
 314         tokpushback++;
 315
 316         while (readtoken() == TNOT) {
 317                 TRACE(("command: TNOT recognized\n"));
 318                 negate = !negate;
 319         }
 320         tokpushback++;
 321
 322         switch (readtoken()) {
 323         case TIF:
 324                 n1 = (union node *)stalloc(sizeof (struct nif));
 325                 n1->type = NIF;
 326                 n1->nif.test = list(0);
 327                 if (readtoken() != TTHEN)
 328                         synexpect(TTHEN);
 329                 n1->nif.ifpart = list(0);
 330                 n2 = n1;
 331                 while (readtoken() == TELIF) {
 332                         n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif));
 333                         n2 = n2->nif.elsepart;
 334                         n2->type = NIF;
 335                         n2->nif.test = list(0);
 336                         if (readtoken() != TTHEN)
 337                                 synexpect(TTHEN);
 338                         n2->nif.ifpart = list(0);
 339                 }
 340                 if (lasttoken == TELSE)
 341                         n2->nif.elsepart = list(0);
 342                 else {
 343                         n2->nif.elsepart = NULL;
 344                         tokpushback++;
 345                 }
 346                 if (readtoken() != TFI)
 347                         synexpect(TFI);
 348                 checkkwd = 1;
 349                 break;
 350         case TWHILE:
 351         case TUNTIL: {
 352                 int got;
 353                 n1 = (union node *)stalloc(sizeof (struct nbinary));
 354                 n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL;
 355                 n1->nbinary.ch1 = list(0);
 356                 if ((got=readtoken()) != TDO) {
 357 TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : ""));
 358                         synexpect(TDO);
 359                 }
 360                 n1->nbinary.ch2 = list(0);
 361                 if (readtoken() != TDONE)
 362                         synexpect(TDONE);
 363                 checkkwd = 1;
 364                 break;
 365         }
 366         case TFOR:
 367                 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext))
 368                         synerror("Bad for loop variable");
 369                 n1 = (union node *)stalloc(sizeof (struct nfor));
 370                 n1->type = NFOR;
 371                 n1->nfor.var = wordtext;
 372                 if (readtoken() == TWORD && ! quoteflag && equal(wordtext, "in")) {
 373                         app = &ap;
 374                         while (readtoken() == TWORD) {
 375                                 n2 = (union node *)stalloc(sizeof (struct narg));
 376                                 n2->type = NARG;
 377                                 n2->narg.text = wordtext;
 378                                 n2->narg.backquote = backquotelist;
 379                                 *app = n2;
 380                                 app = &n2->narg.next;
 381                         }
 382                         *app = NULL;
 383                         n1->nfor.args = ap;
 384                         if (lasttoken != TNL && lasttoken != TSEMI)
 385                                 synexpect(-1);
 386                 } else {
 387 #ifndef GDB_HACK
 388                         static const char argvars[5] = {CTLVAR, VSNORMAL|VSQUOTE,
 389                                                                    '@', '=', '\0'};
 390 #endif
 391                         n2 = (union node *)stalloc(sizeof (struct narg));
 392                         n2->type = NARG;
 393                         n2->narg.text = (char *)argvars;
 394                         n2->narg.backquote = NULL;
 395                         n2->narg.next = NULL;
 396                         n1->nfor.args = n2;
 397                         /*
 398                          * Newline or semicolon here is optional (but note
 399                          * that the original Bourne shell only allowed NL).
 400                          */
 401                         if (lasttoken != TNL && lasttoken != TSEMI)
 402                                 tokpushback++;
 403                 }
 404                 checkkwd = 2;
 405                 if ((t = readtoken()) == TDO)
 406                         t = TDONE;
 407                 else if (t == TBEGIN)
 408                         t = TEND;
 409                 else
 410                         synexpect(-1);
 411                 n1->nfor.body = list(0);
 412                 if (readtoken() != t)
 413                         synexpect(t);
 414                 checkkwd = 1;
 415                 break;
 416         case TCASE:
 417                 n1 = (union node *)stalloc(sizeof (struct ncase));
 418                 n1->type = NCASE;
 419                 if (readtoken() != TWORD)
 420                         synexpect(TWORD);
 421                 n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg));
 422                 n2->type = NARG;
 423                 n2->narg.text = wordtext;
 424                 n2->narg.backquote = backquotelist;
 425                 n2->narg.next = NULL;
 426                 while (readtoken() == TNL);
 427                 if (lasttoken != TWORD || ! equal(wordtext, "in"))
 428                         synerror("expecting \"in\"");
 429                 cpp = &n1->ncase.cases;
 430                 noaliases = 1;  /* turn off alias expansion */
 431                 checkkwd = 2, readtoken();
 432                 while (lasttoken != TESAC) {
 433                         *cpp = cp = (union node *)stalloc(sizeof (struct nclist));
 434                         cp->type = NCLIST;
 435                         app = &cp->nclist.pattern;
 436                         if (lasttoken == TLP)
 437                                 readtoken();
 438                         for (;;) {
 439                                 *app = ap = (union node *)stalloc(sizeof (struct narg));
 440                                 ap->type = NARG;
 441                                 ap->narg.text = wordtext;
 442                                 ap->narg.backquote = backquotelist;
 443                                 if (checkkwd = 2, readtoken() != TPIPE)
 444                                         break;
 445                                 app = &ap->narg.next;
 446                                 readtoken();
 447                         }
 448                         ap->narg.next = NULL;
 449                         if (lasttoken != TRP)
 450                                 noaliases = 0, synexpect(TRP);
 451                         cp->nclist.body = list(0);
 452
 453                         checkkwd = 2;
 454                         if ((t = readtoken()) != TESAC) {
 455                                 if (t != TENDCASE)
 456                                         noaliases = 0, synexpect(TENDCASE);
 457                                 else
 458                                         checkkwd = 2, readtoken();
 459                         }
 460                         cpp = &cp->nclist.next;
 461                 }
 462                 noaliases = 0;  /* reset alias expansion */
 463                 *cpp = NULL;
 464                 checkkwd = 1;
 465                 break;
 466         case TLP:
 467                 n1 = (union node *)stalloc(sizeof (struct nredir));
 468                 n1->type = NSUBSHELL;
 469                 n1->nredir.n = list(0);
 470                 n1->nredir.redirect = NULL;
 471                 if (readtoken() != TRP)
 472                         synexpect(TRP);
 473                 checkkwd = 1;
 474                 break;
 475         case TBEGIN:
 476                 n1 = list(0);
 477                 if (readtoken() != TEND)
 478                         synexpect(TEND);
 479                 checkkwd = 1;
 480                 break;
 481         /* Handle an empty command like other simple commands.  */
 482         case TSEMI:
 483         case TAND:
 484         case TOR:
 485                 /*
 486                  * An empty command before a ; doesn't make much sense, and
 487                  * should certainly be disallowed in the case of `if ;'.
 488                  */
 489                 if (!redir)
 490                         synexpect(-1);
 491         case TNL:
 492         case TEOF:
 493         case TWORD:
 494         case TRP:
 495                 tokpushback++;
 496                 n1 = simplecmd(rpp, redir);
 497                 goto checkneg;
 498         default:
 499                 synexpect(-1);
 500         }
 501
 502         /* Now check for redirection which may follow command */
 503         while (readtoken() == TREDIR) {
 504                 *rpp = n2 = redirnode;
 505                 rpp = &n2->nfile.next;
 506                 parsefname();
 507         }
 508         tokpushback++;
 509         *rpp = NULL;
 510         if (redir) {
 511                 if (n1->type != NSUBSHELL) {
 512                         n2 = (union node *)stalloc(sizeof (struct nredir));
 513                         n2->type = NREDIR;
 514                         n2->nredir.n = n1;
 515                         n1 = n2;
 516                 }
 517                 n1->nredir.redirect = redir;
 518         }
 519
 520 checkneg:
 521         if (negate) {
 522                 n2 = (union node *)stalloc(sizeof (struct nnot));
 523                 n2->type = NNOT;
 524                 n2->nnot.com = n1;
 525                 return n2;
 526         }
 527         else
 528                 return n1;
 529 }
 530
 531
 532 STATIC union node *
 533 simplecmd(union node **rpp, union node *redir)
 534 {
 535         union node *args, **app;
 536         union node **orig_rpp = rpp;
 537         union node *n = NULL, *n2;
 538         int negate = 0;
 539
 540         /* If we don't have any redirections already, then we must reset */
 541         /* rpp to be the address of the local redir variable.  */
 542         if (redir == 0)
 543                 rpp = &redir;
 544
 545         args = NULL;
 546         app = &args;
 547         /*
 548          * We save the incoming value, because we need this for shell
 549          * functions.  There can not be a redirect or an argument between
 550          * the function name and the open parenthesis.
 551          */
 552         orig_rpp = rpp;
 553
 554         while (readtoken() == TNOT) {
 555                 TRACE(("command: TNOT recognized\n"));
 556                 negate = !negate;
 557         }
 558         tokpushback++;
 559
 560         for (;;) {
 561                 if (readtoken() == TWORD) {
 562                         n = (union node *)stalloc(sizeof (struct narg));
 563                         n->type = NARG;
 564                         n->narg.text = wordtext;
 565                         n->narg.backquote = backquotelist;
 566                         *app = n;
 567                         app = &n->narg.next;
 568                 } else if (lasttoken == TREDIR) {
 569                         *rpp = n = redirnode;
 570                         rpp = &n->nfile.next;
 571                         parsefname();   /* read name of redirection file */
 572                 } else if (lasttoken == TLP && app == &args->narg.next
 573                                             && rpp == orig_rpp) {
 574                         /* We have a function */
 575                         if (readtoken() != TRP)
 576                                 synexpect(TRP);
 577 #ifdef notdef
 578                         if (! goodname(n->narg.text))
 579                                 synerror("Bad function name");
 580 #endif
 581                         n->type = NDEFUN;
 582                         n->narg.next = command();
 583                         goto checkneg;
 584                 } else {
 585                         tokpushback++;
 586                         break;
 587                 }
 588         }
 589         *app = NULL;
 590         *rpp = NULL;
 591         n = (union node *)stalloc(sizeof (struct ncmd));
 592         n->type = NCMD;
 593         n->ncmd.backgnd = 0;
 594         n->ncmd.args = args;
 595         n->ncmd.redirect = redir;
 596
 597 checkneg:
 598         if (negate) {
 599                 n2 = (union node *)stalloc(sizeof (struct nnot));
 600                 n2->type = NNOT;
 601                 n2->nnot.com = n;
 602                 return n2;
 603         }
 604         else
 605                 return n;
 606 }
 607
 608 STATIC union node *
 609 makename(void)
 610 {
 611         union node *n;
 612
 613         n = (union node *)stalloc(sizeof (struct narg));
 614         n->type = NARG;
 615         n->narg.next = NULL;
 616         n->narg.text = wordtext;
 617         n->narg.backquote = backquotelist;
 618         return n;
 619 }
 620
 621 void fixredir(union node *n, const char *text, int err)
 622 {
 623         TRACE(("Fix redir %s %d\n", text, err));
 624         if (!err)
 625                 n->ndup.vname = NULL;
 626
 627         if (is_digit(text[0]) && text[1] == '\0')
 628                 n->ndup.dupfd = digit_val(text[0]);
 629         else if (text[0] == '-' && text[1] == '\0')
 630                 n->ndup.dupfd = -1;
 631         else {
 632
 633                 if (err)
 634                         synerror("Bad fd number");
 635                 else
 636                         n->ndup.vname = makename();
 637         }
 638 }
 639
 640
 641 STATIC void
 642 parsefname(void)
 643 {
 644         union node *n = redirnode;
 645
 646         if (readtoken() != TWORD)
 647                 synexpect(-1);
 648         if (n->type == NHERE) {
 649                 struct heredoc *here = heredoc;
 650                 struct heredoc *p;
 651                 int i;
 652
 653                 if (quoteflag == 0)
 654                         n->type = NXHERE;
 655                 TRACE(("Here document %d\n", n->type));
 656                 if (here->striptabs) {
 657                         while (*wordtext == '\t')
 658                                 wordtext++;
 659                 }
 660                 if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN)
 661                         synerror("Illegal eof marker for << redirection");
 662                 rmescapes(wordtext);
 663                 here->eofmark = wordtext;
 664                 here->next = NULL;
 665                 if (heredoclist == NULL)
 666                         heredoclist = here;
 667                 else {
 668                         for (p = heredoclist ; p->next ; p = p->next);
 669                         p->next = here;
 670                 }
 671         } else if (n->type == NTOFD || n->type == NFROMFD) {
 672                 fixredir(n, wordtext, 0);
 673         } else {
 674                 n->nfile.fname = makename();
 675         }
 676 }
 677
 678
 679 /*
 680  * Input any here documents.
 681  */
 682
 683 STATIC void
 684 parseheredoc(void)
 685 {
 686         struct heredoc *here;
 687         union node *n;
 688
 689         while (heredoclist) {
 690                 here = heredoclist;
 691                 heredoclist = here->next;
 692                 if (needprompt) {
 693                         setprompt(2);
 694                         needprompt = 0;
 695                 }
 696                 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX,
 697                                 here->eofmark, here->striptabs);
 698                 n = (union node *)stalloc(sizeof (struct narg));
 699                 n->narg.type = NARG;
 700                 n->narg.next = NULL;
 701                 n->narg.text = wordtext;
 702                 n->narg.backquote = backquotelist;
 703                 here->here->nhere.doc = n;
 704         }
 705 }
 706
 707 STATIC int
 708 peektoken(void)
 709 {
 710         int t;
 711
 712         t = readtoken();
 713         tokpushback++;
 714         return (t);
 715 }
 716
 717 STATIC int
 718 readtoken(void)
 719 {
 720         int t;
 721         int savecheckkwd = checkkwd;
 722         struct alias *ap;
 723 #ifdef DEBUG
 724         int alreadyseen = tokpushback;
 725 #endif
 726
 727         top:
 728         t = xxreadtoken();
 729
 730         if (checkkwd) {
 731                 /*
 732                  * eat newlines
 733                  */
 734                 if (checkkwd == 2) {
 735                         checkkwd = 0;
 736                         while (t == TNL) {
 737                                 parseheredoc();
 738                                 t = xxreadtoken();
 739                         }
 740                 } else
 741                         checkkwd = 0;
 742                 /*
 743                  * check for keywords and aliases
 744                  */
 745                 if (t == TWORD && !quoteflag)
 746                 {
 747                         const char * const *pp;
 748
 749                         for (pp = parsekwd; *pp; pp++) {
 750                                 if (**pp == *wordtext && equal(*pp, wordtext))
 751                                 {
 752                                         lasttoken = t = pp - parsekwd + KWDOFFSET;
 753                                         TRACE(("keyword %s recognized\n", tokname[t]));
 754                                         goto out;
 755                                 }
 756                         }
 757                         if (noaliases == 0 &&
 758                             (ap = lookupalias(wordtext, 1)) != NULL) {
 759                                 pushstring(ap->val, strlen(ap->val), ap);
 760                                 checkkwd = savecheckkwd;
 761                                 goto top;
 762                         }
 763                 }
 764 out:
 765                 checkkwd = (t == TNOT) ? savecheckkwd : 0;
 766         }
 767 #ifdef DEBUG
 768         if (!alreadyseen)
 769             TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
 770         else
 771             TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
 772 #endif
 773         return (t);
 774 }
 775
 776
 777 /*
 778  * Read the next input token.
 779  * If the token is a word, we set backquotelist to the list of cmds in
 780  *      backquotes.  We set quoteflag to true if any part of the word was
 781  *      quoted.
 782  * If the token is TREDIR, then we set redirnode to a structure containing
 783  *      the redirection.
 784  * In all cases, the variable startlinno is set to the number of the line
 785  *      on which the token starts.
 786  *
 787  * [Change comment:  here documents and internal procedures]
 788  * [Readtoken shouldn't have any arguments.  Perhaps we should make the
 789  *  word parsing code into a separate routine.  In this case, readtoken
 790  *  doesn't need to have any internal procedures, but parseword does.
 791  *  We could also make parseoperator in essence the main routine, and
 792  *  have parseword (readtoken1?) handle both words and redirection.]
 793  */
 794
 795 #define RETURN(token)   return lasttoken = token
 796
 797 STATIC int
 798 xxreadtoken(void)
 799 {
 800         int c;
 801
 802         if (tokpushback) {
 803                 tokpushback = 0;
 804                 return lasttoken;
 805         }
 806         if (needprompt) {
 807                 setprompt(2);
 808                 needprompt = 0;
 809         }
 810         startlinno = plinno;
 811         for (;;) {      /* until token or start of word found */
 812                 c = pgetc_macro();
 813                 if (c == ' ' || c == '\t')
 814                         continue;               /* quick check for white space first */
 815                 switch (c) {
 816                 case ' ': case '\t':
 817                         continue;
 818                 case '#':
 819                         while ((c = pgetc()) != '\n' && c != PEOF);
 820                         pungetc();
 821                         continue;
 822                 case '\\':
 823                         if (pgetc() == '\n') {
 824                                 startlinno = ++plinno;
 825                                 if (doprompt)
 826                                         setprompt(2);
 827                                 else
 828                                         setprompt(0);
 829                                 continue;
 830                         }
 831                         pungetc();
 832                         goto breakloop;
 833                 case '\n':
 834                         plinno++;
 835                         needprompt = doprompt;
 836                         RETURN(TNL);
 837                 case PEOF:
 838                         RETURN(TEOF);
 839                 case '&':
 840                         if (pgetc() == '&')
 841                                 RETURN(TAND);
 842                         pungetc();
 843                         RETURN(TBACKGND);
 844                 case '|':
 845                         if (pgetc() == '|')
 846                                 RETURN(TOR);
 847                         pungetc();
 848                         RETURN(TPIPE);
 849                 case ';':
 850                         if (pgetc() == ';')
 851                                 RETURN(TENDCASE);
 852                         pungetc();
 853                         RETURN(TSEMI);
 854                 case '(':
 855                         RETURN(TLP);
 856                 case ')':
 857                         RETURN(TRP);
 858                 default:
 859                         goto breakloop;
 860                 }
 861         }
 862 breakloop:
 863         return readtoken1(c, BASESYNTAX, (char *)NULL, 0);
 864 #undef RETURN
 865 }
 866
 867
 868
 869 /*
 870  * If eofmark is NULL, read a word or a redirection symbol.  If eofmark
 871  * is not NULL, read a here document.  In the latter case, eofmark is the
 872  * word which marks the end of the document and striptabs is true if
 873  * leading tabs should be stripped from the document.  The argument firstc
 874  * is the first character of the input token or document.
 875  *
 876  * Because C does not have internal subroutines, I have simulated them
 877  * using goto's to implement the subroutine linkage.  The following macros
 878  * will run code that appears at the end of readtoken1.
 879  */
 880
 881 #define CHECKEND()      {goto checkend; checkend_return:;}
 882 #define PARSEREDIR()    {goto parseredir; parseredir_return:;}
 883 #define PARSESUB()      {goto parsesub; parsesub_return:;}
 884 #define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;}
 885 #define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;}
 886 #define PARSEARITH()    {goto parsearith; parsearith_return:;}
 887
 888 STATIC int
 889 readtoken1(int firstc, char const *syntax, char *eofmark, int striptabs)
 890 {
 891         int c = firstc;
 892         char *out;
 893         int len;
 894         char line[EOFMARKLEN + 1];
 895         struct nodelist *bqlist;
 896         int quotef;
 897         int dblquote;
 898         int varnest;    /* levels of variables expansion */
 899         int arinest;    /* levels of arithmetic expansion */
 900         int parenlevel; /* levels of parens in arithmetic */
 901         int oldstyle;
 902         char const *prevsyntax; /* syntax before arithmetic */
 903         int synentry;
 904 #if __GNUC__
 905         /* Avoid longjmp clobbering */
 906         (void) &out;
 907         (void) &quotef;
 908         (void) &dblquote;
 909         (void) &varnest;
 910         (void) &arinest;
 911         (void) &parenlevel;
 912         (void) &oldstyle;
 913         (void) &prevsyntax;
 914         (void) &syntax;
 915         (void) &synentry;
 916 #endif
 917
 918         startlinno = plinno;
 919         dblquote = 0;
 920         if (syntax == DQSYNTAX)
 921                 dblquote = 1;
 922         quotef = 0;
 923         bqlist = NULL;
 924         varnest = 0;
 925         arinest = 0;
 926         parenlevel = 0;
 927
 928         STARTSTACKSTR(out);
 929         loop: { /* for each line, until end of word */
 930 #if ATTY
 931                 if (c == '\034' && doprompt
 932                  && attyset() && ! equal(termval(), "emacs")) {
 933                         attyline();
 934                         if (syntax == BASESYNTAX)
 935                                 return readtoken();
 936                         c = pgetc();
 937                         goto loop;
 938                 }
 939 #endif
 940                 CHECKEND();     /* set c to PEOF if at end of here document */
 941                 for (;;) {      /* until end of line or end of word */
 942                         CHECKSTRSPACE(3, out);  /* permit 3 calls to USTPUTC */
 943
 944                         synentry = syntax[c];
 945
 946                         switch(synentry) {
 947                         case CNL:       /* '\n' */
 948                                 if (syntax == BASESYNTAX)
 949                                         goto endword;   /* exit outer loop */
 950                                 USTPUTC(c, out);
 951                                 plinno++;
 952                                 if (doprompt)
 953                                         setprompt(2);
 954                                 else
 955                                         setprompt(0);
 956                                 c = pgetc();
 957                                 goto loop;              /* continue outer loop */
 958                         case CWORD:
 959                                 USTPUTC(c, out);
 960                                 break;
 961                         case CCTL:
 962                                 if (eofmark == NULL || dblquote)
 963                                         USTPUTC(CTLESC, out);
 964                                 USTPUTC(c, out);
 965                                 break;
 966                         case CBACK:     /* backslash */
 967                                 c = pgetc();
 968                                 if (c == PEOF) {
 969                                         USTPUTC('\\', out);
 970                                         pungetc();
 971                                 } else if (c == '\n') {
 972                                         if (doprompt)
 973                                                 setprompt(2);
 974                                         else
 975                                                 setprompt(0);
 976                                 } else {
 977                                         if (dblquote && c != '\\' &&
 978                                             c != '`' && c != '$' &&
 979                                             (c != '"' || eofmark != NULL))
 980                                                 USTPUTC('\\', out);
 981                                         if (SQSYNTAX[c] == CCTL)
 982                                                 USTPUTC(CTLESC, out);
 983                                         else if (eofmark == NULL)
 984                                                 USTPUTC(CTLQUOTEMARK, out);
 985                                         USTPUTC(c, out);
 986                                         quotef++;
 987                                 }
 988                                 break;
 989                         case CSQUOTE:
 990                                 if (eofmark == NULL)
 991                                         USTPUTC(CTLQUOTEMARK, out);
 992                                 syntax = SQSYNTAX;
 993                                 break;
 994                         case CDQUOTE:
 995                                 if (eofmark == NULL)
 996                                         USTPUTC(CTLQUOTEMARK, out);
 997                                 syntax = DQSYNTAX;
 998                                 dblquote = 1;
 999                                 break;
1000                         case CENDQUOTE:
1001                                 if (eofmark != NULL && arinest == 0 &&
1002                                     varnest == 0) {
1003                                         USTPUTC(c, out);
1004                                 } else {
1005                                         if (arinest) {
1006                                                 syntax = ARISYNTAX;
1007                                                 dblquote = 0;
1008                                         } else if (eofmark == NULL) {
1009                                                 syntax = BASESYNTAX;
1010                                                 dblquote = 0;
1011                                         }
1012                                         quotef++;
1013                                 }
1014                                 break;
1015                         case CVAR:      /* '$' */
1016                                 PARSESUB();             /* parse substitution */
1017                                 break;
1018                         case CENDVAR:   /* '}' */
1019                                 if (varnest > 0) {
1020                                         varnest--;
1021                                         USTPUTC(CTLENDVAR, out);
1022                                 } else {
1023                                         USTPUTC(c, out);
1024                                 }
1025                                 break;
1026                         case CLP:       /* '(' in arithmetic */
1027                                 parenlevel++;
1028                                 USTPUTC(c, out);
1029                                 break;
1030                         case CRP:       /* ')' in arithmetic */
1031                                 if (parenlevel > 0) {
1032                                         USTPUTC(c, out);
1033                                         --parenlevel;
1034                                 } else {
1035                                         if (pgetc() == ')') {
1036                                                 if (--arinest == 0) {
1037                                                         USTPUTC(CTLENDARI, out);
1038                                                         syntax = prevsyntax;
1039                                                         if (syntax == DQSYNTAX)
1040                                                                 dblquote = 1;
1041                                                         else
1042                                                                 dblquote = 0;
1043                                                 } else
1044                                                         USTPUTC(')', out);
1045                                         } else {
1046                                                 /*
1047                                                  * unbalanced parens
1048                                                  *  (don't 2nd guess - no error)
1049                                                  */
1050                                                 pungetc();
1051                                                 USTPUTC(')', out);
1052                                         }
1053                                 }
1054                                 break;
1055                         case CBQUOTE:   /* '`' */
1056                                 PARSEBACKQOLD();
1057                                 break;
1058                         case CEOF:
1059                                 goto endword;           /* exit outer loop */
1060                         default:
1061                                 if (varnest == 0)
1062                                         goto endword;   /* exit outer loop */
1063                                 USTPUTC(c, out);
1064                         }
1065                         c = pgetc_macro();
1066                 }
1067         }
1068 endword:
1069         if (syntax == ARISYNTAX)
1070                 synerror("Missing '))'");
1071         if (syntax != BASESYNTAX && ! parsebackquote && eofmark == NULL)
1072                 synerror("Unterminated quoted string");
1073         if (varnest != 0) {
1074                 startlinno = plinno;
1075                 synerror("Missing '}'");
1076         }
1077         USTPUTC('\0', out);
1078         len = out - stackblock();
1079         out = stackblock();
1080         if (eofmark == NULL) {
1081                 if ((c == '>' || c == '<')
1082                  && quotef == 0
1083                  && len <= 2
1084                  && (*out == '\0' || is_digit(*out))) {
1085                         PARSEREDIR();
1086                         return lasttoken = TREDIR;
1087                 } else {
1088                         pungetc();
1089                 }
1090         }
1091         quoteflag = quotef;
1092         backquotelist = bqlist;
1093         grabstackblock(len);
1094         wordtext = out;
1095         return lasttoken = TWORD;
1096 /* end of readtoken routine */
1097
1098
1099
1100 /*
1101  * Check to see whether we are at the end of the here document.  When this
1102  * is called, c is set to the first character of the next input line.  If
1103  * we are at the end of the here document, this routine sets the c to PEOF.
1104  */
1105
1106 checkend: {
1107         if (eofmark) {
1108                 if (striptabs) {
1109                         while (c == '\t')
1110                                 c = pgetc();
1111                 }
1112                 if (c == *eofmark) {
1113                         if (pfgets(line, sizeof line) != NULL) {
1114                                 char *p, *q;
1115
1116                                 p = line;
1117                                 for (q = eofmark + 1 ; *q && *p == *q ; p++, q++);
1118                                 if (*p == '\n' && *q == '\0') {
1119                                         c = PEOF;
1120                                         plinno++;
1121                                         needprompt = doprompt;
1122                                 } else {
1123                                         pushstring(line, strlen(line), NULL);
1124                                 }
1125                         }
1126                 }
1127         }
1128         goto checkend_return;
1129 }
1130
1131
1132 /*
1133  * Parse a redirection operator.  The variable "out" points to a string
1134  * specifying the fd to be redirected.  The variable "c" contains the
1135  * first character of the redirection operator.
1136  */
1137
1138 parseredir: {
1139         char fd = *out;
1140         union node *np;
1141
1142         np = (union node *)stalloc(sizeof (struct nfile));
1143         if (c == '>') {
1144                 np->nfile.fd = 1;
1145                 c = pgetc();
1146                 if (c == '>')
1147                         np->type = NAPPEND;
1148                 else if (c == '&')
1149                         np->type = NTOFD;
1150                 else if (c == '|')
1151                         np->type = NCLOBBER;
1152                 else {
1153                         np->type = NTO;
1154                         pungetc();
1155                 }
1156         } else {        /* c == '<' */
1157                 np->nfile.fd = 0;
1158                 c = pgetc();
1159                 if (c == '<') {
1160                         if (sizeof (struct nfile) != sizeof (struct nhere)) {
1161                                 np = (union node *)stalloc(sizeof (struct nhere));
1162                                 np->nfile.fd = 0;
1163                         }
1164                         np->type = NHERE;
1165                         heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc));
1166                         heredoc->here = np;
1167                         if ((c = pgetc()) == '-') {
1168                                 heredoc->striptabs = 1;
1169                         } else {
1170                                 heredoc->striptabs = 0;
1171                                 pungetc();
1172                         }
1173                 } else if (c == '&')
1174                         np->type = NFROMFD;
1175                 else if (c == '>')
1176                         np->type = NFROMTO;
1177                 else {
1178                         np->type = NFROM;
1179                         pungetc();
1180                 }
1181         }
1182         if (fd != '\0')
1183                 np->nfile.fd = digit_val(fd);
1184         redirnode = np;
1185         goto parseredir_return;
1186 }
1187
1188
1189 /*
1190  * Parse a substitution.  At this point, we have read the dollar sign
1191  * and nothing else.
1192  */
1193
1194 parsesub: {
1195         int subtype;
1196         int typeloc;
1197         int flags;
1198         char *p;
1199 #ifndef GDB_HACK
1200         static const char types[] = "}-+?=";
1201 #endif
1202        int bracketed_name = 0; /* used to handle ${[0-9]*} variables */
1203
1204         c = pgetc();
1205         if (c != '(' && c != '{' && !is_name(c) && !is_special(c)) {
1206                 USTPUTC('$', out);
1207                 pungetc();
1208         } else if (c == '(') {  /* $(command) or $((arith)) */
1209                 if (pgetc() == '(') {
1210                         PARSEARITH();
1211                 } else {
1212                         pungetc();
1213                         PARSEBACKQNEW();
1214                 }
1215         } else {
1216                 USTPUTC(CTLVAR, out);
1217                 typeloc = out - stackblock();
1218                 USTPUTC(VSNORMAL, out);
1219                 subtype = VSNORMAL;
1220                 if (c == '{') {
1221                         bracketed_name = 1;
1222                         c = pgetc();
1223                         if (c == '#') {
1224                                 if ((c = pgetc()) == '}')
1225                                         c = '#';
1226                                 else
1227                                         subtype = VSLENGTH;
1228                         }
1229                         else
1230                                 subtype = 0;
1231                 }
1232                 if (is_name(c)) {
1233                         do {
1234                                 STPUTC(c, out);
1235                                 c = pgetc();
1236                         } while (is_in_name(c));
1237                 } else if (is_digit(c)) {
1238                         if (bracketed_name) {
1239                                 do {
1240                                         STPUTC(c, out);
1241                                         c = pgetc();
1242                                 } while (is_digit(c));
1243                         } else {
1244                                 STPUTC(c, out);
1245                                 c = pgetc();
1246                         }
1247                 } else {
1248                         if (! is_special(c))
1249 badsub:                         synerror("Bad substitution");
1250                         USTPUTC(c, out);
1251                         c = pgetc();
1252                 }
1253                 STPUTC('=', out);
1254                 flags = 0;
1255                 if (subtype == 0) {
1256                         switch (c) {
1257                         case ':':
1258                                 flags = VSNUL;
1259                                 c = pgetc();
1260                                 /*FALLTHROUGH*/
1261                         default:
1262                                 p = strchr(types, c);
1263                                 if (p == NULL)
1264                                         goto badsub;
1265                                 subtype = p - types + VSNORMAL;
1266                                 break;
1267                         case '%':
1268                         case '#':
1269                                 {
1270                                         int cc = c;
1271                                         subtype = c == '#' ? VSTRIMLEFT :
1272                                                              VSTRIMRIGHT;
1273                                         c = pgetc();
1274                                         if (c == cc)
1275                                                 subtype++;
1276                                         else
1277                                                 pungetc();
1278                                         break;
1279                                 }
1280                         }
1281                 } else {
1282                         pungetc();
1283                 }
1284                 if (subtype != VSLENGTH && (dblquote || arinest))
1285                         flags |= VSQUOTE;
1286                 *(stackblock() + typeloc) = subtype | flags;
1287                 if (subtype != VSNORMAL)
1288                         varnest++;
1289         }
1290         goto parsesub_return;
1291 }
1292
1293
1294 /*
1295  * Called to parse command substitutions.  Newstyle is set if the command
1296  * is enclosed inside $(...); nlpp is a pointer to the head of the linked
1297  * list of commands (passed by reference), and savelen is the number of
1298  * characters on the top of the stack which must be preserved.
1299  */
1300
1301 parsebackq: {
1302         struct nodelist **nlpp;
1303         int savepbq;
1304         union node *n;
1305         char *volatile str;
1306         struct jmploc jmploc;
1307         struct jmploc *volatile savehandler;
1308         int savelen;
1309         int saveprompt;
1310 #if __GNUC__
1311         /* Avoid longjmp clobbering */
1312         (void) &saveprompt;
1313 #endif
1314
1315         savepbq = parsebackquote;
1316         if (setjmp(jmploc.loc)) {
1317                 if (str)
1318                         ckfree(str);
1319                 parsebackquote = 0;
1320                 handler = savehandler;
1321                 longjmp(handler->loc, 1);
1322         }
1323         INTOFF;
1324         str = NULL;
1325         savelen = out - stackblock();
1326         if (savelen > 0) {
1327                 str = ckmalloc(savelen);
1328                 memcpy(str, stackblock(), savelen);
1329         }
1330         savehandler = handler;
1331         handler = &jmploc;
1332         INTON;
1333         if (oldstyle) {
1334                 /* We must read until the closing backquote, giving special
1335                    treatment to some slashes, and then push the string and
1336                    reread it as input, interpreting it normally.  */
1337                 char *out;
1338                 int c;
1339                 int savelen;
1340                 char *str;
1341
1342
1343                 STARTSTACKSTR(out);
1344                 for (;;) {
1345                         if (needprompt) {
1346                                 setprompt(2);
1347                                 needprompt = 0;
1348                         }
1349                         switch (c = pgetc()) {
1350                         case '`':
1351                                 goto done;
1352
1353                         case '\\':
1354                                 if ((c = pgetc()) == '\n') {
1355                                         plinno++;
1356                                         if (doprompt)
1357                                                 setprompt(2);
1358                                         else
1359                                                 setprompt(0);
1360                                         /*
1361                                          * If eating a newline, avoid putting
1362                                          * the newline into the new character
1363                                          * stream (via the STPUTC after the
1364                                          * switch).
1365                                          */
1366                                         continue;
1367                                 }
1368                                 if (c != '\\' && c != '`' && c != '$'
1369                                     && (!dblquote || c != '"'))
1370                                         STPUTC('\\', out);
1371                                 break;
1372
1373                         case '\n':
1374                                 plinno++;
1375                                 needprompt = doprompt;
1376                                 break;
1377
1378                         case PEOF:
1379                                 startlinno = plinno;
1380                                 synerror("EOF in backquote substitution");
1381                                 break;
1382
1383                         default:
1384                                 break;
1385                         }
1386                         STPUTC(c, out);
1387                 }
1388 done:
1389                 STPUTC('\0', out);
1390                 savelen = out - stackblock();
1391                 if (savelen > 0) {
1392                         str = ckmalloc(savelen);
1393                         memcpy(str, stackblock(), savelen);
1394                         setinputstring(str, 1);
1395                 }
1396         }
1397         nlpp = &bqlist;
1398         while (*nlpp)
1399                 nlpp = &(*nlpp)->next;
1400         *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist));
1401         (*nlpp)->next = NULL;
1402         parsebackquote = oldstyle;
1403
1404         if (oldstyle) {
1405                 saveprompt = doprompt;
1406                 doprompt = 0;
1407         }
1408
1409         n = list(0);
1410
1411         if (oldstyle)
1412                 doprompt = saveprompt;
1413         else {
1414                 if (readtoken() != TRP)
1415                         synexpect(TRP);
1416         }
1417
1418         (*nlpp)->n = n;
1419         if (oldstyle) {
1420                 /*
1421                  * Start reading from old file again, ignoring any pushed back
1422                  * tokens left from the backquote parsing
1423                  */
1424                 popfile();
1425                 tokpushback = 0;
1426         }
1427         while (stackblocksize() <= savelen)
1428                 growstackblock();
1429         STARTSTACKSTR(out);
1430         if (str) {
1431                 memcpy(out, str, savelen);
1432                 STADJUST(savelen, out);
1433                 INTOFF;
1434                 ckfree(str);
1435                 str = NULL;
1436                 INTON;
1437         }
1438         parsebackquote = savepbq;
1439         handler = savehandler;
1440         if (arinest || dblquote)
1441                 USTPUTC(CTLBACKQ | CTLQUOTE, out);
1442         else
1443                 USTPUTC(CTLBACKQ, out);
1444         if (oldstyle)
1445                 goto parsebackq_oldreturn;
1446         else
1447                 goto parsebackq_newreturn;
1448 }
1449
1450 /*
1451  * Parse an arithmetic expansion (indicate start of one and set state)
1452  */
1453 parsearith: {
1454
1455         if (++arinest == 1) {
1456                 prevsyntax = syntax;
1457                 syntax = ARISYNTAX;
1458                 USTPUTC(CTLARI, out);
1459                 if (dblquote)
1460                         USTPUTC('"',out);
1461                 else
1462                         USTPUTC(' ',out);
1463         } else {
1464                 /*
1465                  * we collapse embedded arithmetic expansion to
1466                  * parenthesis, which should be equivalent
1467                  */
1468                 USTPUTC('(', out);
1469         }
1470         goto parsearith_return;
1471 }
1472
1473 } /* end of readtoken */
1474
1475
1476
1477 #ifdef mkinit
1478 RESET {
1479         tokpushback = 0;
1480         checkkwd = 0;
1481 }
1482 #endif
1483
1484 /*
1485  * Returns true if the text contains nothing to expand (no dollar signs
1486  * or backquotes).
1487  */
1488
1489 STATIC int
1490 noexpand(char *text)
1491 {
1492         char *p;
1493         char c;
1494
1495         p = text;
1496         while ((c = *p++) != '\0') {
1497                 if ( c == CTLQUOTEMARK)
1498                         continue;
1499                 if (c == CTLESC)
1500                         p++;
1501                 else if (BASESYNTAX[(int)c] == CCTL)
1502                         return 0;
1503         }
1504         return 1;
1505 }
1506
1507
1508 /*
1509  * Return true if the argument is a legal variable name (a letter or
1510  * underscore followed by zero or more letters, underscores, and digits).
1511  */
1512
1513 int
1514 goodname(char *name)
1515 {
1516         char *p;
1517
1518         p = name;
1519         if (! is_name(*p))
1520                 return 0;
1521         while (*++p) {
1522                 if (! is_in_name(*p))
1523                         return 0;
1524         }
1525         return 1;
1526 }
1527
1528
1529 /*
1530  * Called when an unexpected token is read during the parse.  The argument
1531  * is the token that is expected, or -1 if more than one type of token can
1532  * occur at this point.
1533  */
1534
1535 STATIC void
1536 synexpect(int token)
1537 {
1538         char msg[64];
1539
1540         if (token >= 0) {
1541                 fmtstr(msg, 64, "%s unexpected (expecting %s)",
1542                         tokname[lasttoken], tokname[token]);
1543         } else {
1544                 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]);
1545         }
1546         synerror(msg);
1547 }
1548
1549
1550 STATIC void
1551 synerror(char *msg)
1552 {
1553         if (commandname)
1554                 outfmt(&errout, "%s: %d: ", commandname, startlinno);
1555         outfmt(&errout, "Syntax error: %s\n", msg);
1556         error((char *)NULL);
1557 }
1558
1559 STATIC void
1560 setprompt(int which)
1561 {
1562         whichprompt = which;
1563
1564 #ifndef NO_HISTORY
1565         if (!el)
1566 #endif
1567                 out2str(getprompt(NULL));
1568 }
1569
1570 /*
1571  * called by editline -- any expansions to the prompt
1572  *    should be added here.
1573  */
1574 char *
1575 getprompt(void *unused __unused)
1576 {
1577         switch (whichprompt) {
1578         case 0:
1579                 return "";
1580         case 1:
1581                 return ps1val();
1582         case 2:
1583                 return ps2val();
1584         default:
1585                 return "<internal prompt error>";
1586         }
1587 }