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 1.29.2.9 2002/10/18 11:24:04 tjr Exp $
  38  * $DragonFly: src/bin/sh/parser.c,v 1.8 2006/09/28 22:29:44 pavalos Exp $
  39  */
  40
  41 #include <stdlib.h>
  42
  43 #include "shell.h"
  44 #include "parser.h"
  45 #include "nodes.h"
  46 #include "expand.h"     /* defines rmescapes() */
  47 #include "redir.h"      /* defines copyfd() */
  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 #ifndef NO_HISTORY
  60 #include "myhistedit.h"
  61 #endif
  62
  63 /*
  64  * Shell command parser.
  65  */
  66
  67 #define EOFMARKLEN 79
  68
  69 /* values returned by readtoken */
  70 #include "token.h"
  71
  72
  73
  74 struct heredoc {
  75         struct heredoc *next;   /* next here document in list */
  76         union node *here;               /* redirection node */
  77         char *eofmark;          /* string indicating end of input */
  78         int striptabs;          /* if set, strip leading tabs */
  79 };
  80
  81
  82
  83 STATIC struct heredoc *heredoclist;     /* list of here documents to read */
  84 STATIC int parsebackquote;      /* nonzero if we are inside backquotes */
  85 STATIC int doprompt;            /* if set, prompt the user */
  86 STATIC int needprompt;          /* true if interactive and at start of line */
  87 STATIC int lasttoken;           /* last token read */
  88 MKINIT int tokpushback;         /* last token pushed back */
  89 STATIC char *wordtext;          /* text of last word returned by readtoken */
  90 MKINIT int checkkwd;            /* 1 == check for kwds, 2 == also eat newlines */
  91 STATIC struct nodelist *backquotelist;
  92 STATIC union node *redirnode;
  93 STATIC struct heredoc *heredoc;
  94 STATIC int quoteflag;           /* set if (part of) last token was quoted */
  95 STATIC int startlinno;          /* line # where last token started */
  96
  97 /* XXX When 'noaliases' is set to one, no alias expansion takes place. */
  98 static int noaliases = 0;
  99
 100 STATIC union node *list(int);
 101 STATIC union node *andor(void);
 102 STATIC union node *pipeline(void);
 103 STATIC union node *command(void);
 104 STATIC union node *simplecmd(union node **, union node *);
 105 STATIC union node *makename(void);
 106 STATIC void parsefname(void);
 107 STATIC void parseheredoc(void);
 108 STATIC int peektoken(void);
 109 STATIC int readtoken(void);
 110 STATIC int xxreadtoken(void);
 111 STATIC int readtoken1(int, char const *, char *, int);
 112 STATIC int noexpand(char *);
 113 STATIC void synexpect(int);
 114 STATIC void synerror(const char *);
 115 STATIC void setprompt(int);
 116
 117
 118 /*
 119  * Read and parse a command.  Returns NEOF on end of file.  (NULL is a
 120  * valid parse tree indicating a blank line.)
 121  */
 122
 123 union node *
 124 parsecmd(int interact)
 125 {
 126         int t;
 127
 128         tokpushback = 0;
 129         doprompt = interact;
 130         if (doprompt)
 131                 setprompt(1);
 132         else
 133                 setprompt(0);
 134         needprompt = 0;
 135         t = readtoken();
 136         if (t == TEOF)
 137                 return NEOF;
 138         if (t == TNL)
 139                 return NULL;
 140         tokpushback++;
 141         return list(1);
 142 }
 143
 144
 145 STATIC union node *
 146 list(int nlflag)
 147 {
 148         union node *n1, *n2, *n3;
 149         int tok;
 150
 151         checkkwd = 2;
 152         if (nlflag == 0 && tokendlist[peektoken()])
 153                 return NULL;
 154         n1 = NULL;
 155         for (;;) {
 156                 n2 = andor();
 157                 tok = readtoken();
 158                 if (tok == TBACKGND) {
 159                         if (n2->type == NCMD || n2->type == NPIPE) {
 160                                 n2->ncmd.backgnd = 1;
 161                         } else if (n2->type == NREDIR) {
 162                                 n2->type = NBACKGND;
 163                         } else {
 164                                 n3 = (union node *)stalloc(sizeof (struct nredir));
 165                                 n3->type = NBACKGND;
 166                                 n3->nredir.n = n2;
 167                                 n3->nredir.redirect = NULL;
 168                                 n2 = n3;
 169                         }
 170                 }
 171                 if (n1 == NULL) {
 172                         n1 = n2;
 173                 }
 174                 else {
 175                         n3 = (union node *)stalloc(sizeof (struct nbinary));
 176                         n3->type = NSEMI;
 177                         n3->nbinary.ch1 = n1;
 178                         n3->nbinary.ch2 = n2;
 179                         n1 = n3;
 180                 }
 181                 switch (tok) {
 182                 case TBACKGND:
 183                 case TSEMI:
 184                         tok = readtoken();
 185                         /* fall through */
 186                 case TNL:
 187                         if (tok == TNL) {
 188                                 parseheredoc();
 189                                 if (nlflag)
 190                                         return n1;
 191                         } else {
 192                                 tokpushback++;
 193                         }
 194                         checkkwd = 2;
 195                         if (tokendlist[peektoken()])
 196                                 return n1;
 197                         break;
 198                 case TEOF:
 199                         if (heredoclist)
 200                                 parseheredoc();
 201                         else
 202                                 pungetc();              /* push back EOF on input */
 203                         return n1;
 204                 default:
 205                         if (nlflag)
 206                                 synexpect(-1);
 207                         tokpushback++;
 208                         return n1;
 209                 }
 210         }
 211 }
 212
 213
 214
 215 STATIC union node *
 216 andor(void)
 217 {
 218         union node *n1, *n2, *n3;
 219         int t;
 220
 221         n1 = pipeline();
 222         for (;;) {
 223                 if ((t = readtoken()) == TAND) {
 224                         t = NAND;
 225                 } else if (t == TOR) {
 226                         t = NOR;
 227                 } else {
 228                         tokpushback++;
 229                         return n1;
 230                 }
 231                 n2 = pipeline();
 232                 n3 = (union node *)stalloc(sizeof (struct nbinary));
 233                 n3->type = t;
 234                 n3->nbinary.ch1 = n1;
 235                 n3->nbinary.ch2 = n2;
 236                 n1 = n3;
 237         }
 238 }
 239
 240
 241
 242 STATIC union node *
 243 pipeline(void)
 244 {
 245         union node *n1, *n2, *pipenode;
 246         struct nodelist *lp, *prev;
 247         int negate;
 248
 249         negate = 0;
 250         TRACE(("pipeline: entered\n"));
 251         while (readtoken() == TNOT)
 252                 negate = !negate;
 253         tokpushback++;
 254         n1 = command();
 255         if (readtoken() == TPIPE) {
 256                 pipenode = (union node *)stalloc(sizeof (struct npipe));
 257                 pipenode->type = NPIPE;
 258                 pipenode->npipe.backgnd = 0;
 259                 lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
 260                 pipenode->npipe.cmdlist = lp;
 261                 lp->n = n1;
 262                 do {
 263                         prev = lp;
 264                         lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
 265                         lp->n = command();
 266                         prev->next = lp;
 267                 } while (readtoken() == TPIPE);
 268                 lp->next = NULL;
 269                 n1 = pipenode;
 270         }
 271         tokpushback++;
 272         if (negate) {
 273                 n2 = (union node *)stalloc(sizeof (struct nnot));
 274                 n2->type = NNOT;
 275                 n2->nnot.com = n1;
 276                 return n2;
 277         } else
 278                 return n1;
 279 }
 280
 281
 282
 283 STATIC union node *
 284 command(void)
 285 {
 286         union node *n1, *n2;
 287         union node *ap, **app;
 288         union node *cp, **cpp;
 289         union node *redir, **rpp;
 290         int t, negate = 0;
 291
 292         checkkwd = 2;
 293         redir = NULL;
 294         n1 = NULL;
 295         rpp = &redir;
 296
 297         /* Check for redirection which may precede command */
 298         while (readtoken() == TREDIR) {
 299                 *rpp = n2 = redirnode;
 300                 rpp = &n2->nfile.next;
 301                 parsefname();
 302         }
 303         tokpushback++;
 304
 305         while (readtoken() == TNOT) {
 306                 TRACE(("command: TNOT recognized\n"));
 307                 negate = !negate;
 308         }
 309         tokpushback++;
 310
 311         switch (readtoken()) {
 312         case TIF:
 313                 n1 = (union node *)stalloc(sizeof (struct nif));
 314                 n1->type = NIF;
 315                 n1->nif.test = list(0);
 316                 if (readtoken() != TTHEN)
 317                         synexpect(TTHEN);
 318                 n1->nif.ifpart = list(0);
 319                 n2 = n1;
 320                 while (readtoken() == TELIF) {
 321                         n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif));
 322                         n2 = n2->nif.elsepart;
 323                         n2->type = NIF;
 324                         n2->nif.test = list(0);
 325                         if (readtoken() != TTHEN)
 326                                 synexpect(TTHEN);
 327                         n2->nif.ifpart = list(0);
 328                 }
 329                 if (lasttoken == TELSE)
 330                         n2->nif.elsepart = list(0);
 331                 else {
 332                         n2->nif.elsepart = NULL;
 333                         tokpushback++;
 334                 }
 335                 if (readtoken() != TFI)
 336                         synexpect(TFI);
 337                 checkkwd = 1;
 338                 break;
 339         case TWHILE:
 340         case TUNTIL: {
 341                 int got;
 342                 n1 = (union node *)stalloc(sizeof (struct nbinary));
 343                 n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL;
 344                 n1->nbinary.ch1 = list(0);
 345                 if ((got=readtoken()) != TDO) {
 346 TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : ""));
 347                         synexpect(TDO);
 348                 }
 349                 n1->nbinary.ch2 = list(0);
 350                 if (readtoken() != TDONE)
 351                         synexpect(TDONE);
 352                 checkkwd = 1;
 353                 break;
 354         }
 355         case TFOR:
 356                 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext))
 357                         synerror("Bad for loop variable");
 358                 n1 = (union node *)stalloc(sizeof (struct nfor));
 359                 n1->type = NFOR;
 360                 n1->nfor.var = wordtext;
 361                 if (readtoken() == TWORD && ! quoteflag && equal(wordtext, "in")) {
 362                         app = &ap;
 363                         while (readtoken() == TWORD) {
 364                                 n2 = (union node *)stalloc(sizeof (struct narg));
 365                                 n2->type = NARG;
 366                                 n2->narg.text = wordtext;
 367                                 n2->narg.backquote = backquotelist;
 368                                 *app = n2;
 369                                 app = &n2->narg.next;
 370                         }
 371                         *app = NULL;
 372                         n1->nfor.args = ap;
 373                         if (lasttoken != TNL && lasttoken != TSEMI)
 374                                 synexpect(-1);
 375                 } else {
 376                         static char argvars[5] = {CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0'};
 377                         n2 = (union node *)stalloc(sizeof (struct narg));
 378                         n2->type = NARG;
 379                         n2->narg.text = argvars;
 380                         n2->narg.backquote = NULL;
 381                         n2->narg.next = NULL;
 382                         n1->nfor.args = n2;
 383                         /*
 384                          * Newline or semicolon here is optional (but note
 385                          * that the original Bourne shell only allowed NL).
 386                          */
 387                         if (lasttoken != TNL && lasttoken != TSEMI)
 388                                 tokpushback++;
 389                 }
 390                 checkkwd = 2;
 391                 if ((t = readtoken()) == TDO)
 392                         t = TDONE;
 393                 else if (t == TBEGIN)
 394                         t = TEND;
 395                 else
 396                         synexpect(-1);
 397                 n1->nfor.body = list(0);
 398                 if (readtoken() != t)
 399                         synexpect(t);
 400                 checkkwd = 1;
 401                 break;
 402         case TCASE:
 403                 n1 = (union node *)stalloc(sizeof (struct ncase));
 404                 n1->type = NCASE;
 405                 if (readtoken() != TWORD)
 406                         synexpect(TWORD);
 407                 n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg));
 408                 n2->type = NARG;
 409                 n2->narg.text = wordtext;
 410                 n2->narg.backquote = backquotelist;
 411                 n2->narg.next = NULL;
 412                 while (readtoken() == TNL);
 413                 if (lasttoken != TWORD || ! equal(wordtext, "in"))
 414                         synerror("expecting \"in\"");
 415                 cpp = &n1->ncase.cases;
 416                 noaliases = 1;  /* turn off alias expansion */
 417                 checkkwd = 2, readtoken();
 418                 while (lasttoken != TESAC) {
 419                         *cpp = cp = (union node *)stalloc(sizeof (struct nclist));
 420                         cp->type = NCLIST;
 421                         app = &cp->nclist.pattern;
 422                         if (lasttoken == TLP)
 423                                 readtoken();
 424                         for (;;) {
 425                                 *app = ap = (union node *)stalloc(sizeof (struct narg));
 426                                 ap->type = NARG;
 427                                 ap->narg.text = wordtext;
 428                                 ap->narg.backquote = backquotelist;
 429                                 if (checkkwd = 2, readtoken() != TPIPE)
 430                                         break;
 431                                 app = &ap->narg.next;
 432                                 readtoken();
 433                         }
 434                         ap->narg.next = NULL;
 435                         if (lasttoken != TRP)
 436                                 noaliases = 0, synexpect(TRP);
 437                         cp->nclist.body = list(0);
 438
 439                         checkkwd = 2;
 440                         if ((t = readtoken()) != TESAC) {
 441                                 if (t != TENDCASE)
 442                                         noaliases = 0, synexpect(TENDCASE);
 443                                 else
 444                                         checkkwd = 2, readtoken();
 445                         }
 446                         cpp = &cp->nclist.next;
 447                 }
 448                 noaliases = 0;  /* reset alias expansion */
 449                 *cpp = NULL;
 450                 checkkwd = 1;
 451                 break;
 452         case TLP:
 453                 n1 = (union node *)stalloc(sizeof (struct nredir));
 454                 n1->type = NSUBSHELL;
 455                 n1->nredir.n = list(0);
 456                 n1->nredir.redirect = NULL;
 457                 if (readtoken() != TRP)
 458                         synexpect(TRP);
 459                 checkkwd = 1;
 460                 break;
 461         case TBEGIN:
 462                 n1 = list(0);
 463                 if (readtoken() != TEND)
 464                         synexpect(TEND);
 465                 checkkwd = 1;
 466                 break;
 467         /* Handle an empty command like other simple commands.  */
 468         case TSEMI:
 469         case TAND:
 470         case TOR:
 471                 /*
 472                  * An empty command before a ; doesn't make much sense, and
 473                  * should certainly be disallowed in the case of `if ;'.
 474                  */
 475                 if (!redir)
 476                         synexpect(-1);
 477         case TNL:
 478         case TEOF:
 479         case TWORD:
 480         case TRP:
 481                 tokpushback++;
 482                 n1 = simplecmd(rpp, redir);
 483                 goto checkneg;
 484         default:
 485                 synexpect(-1);
 486         }
 487
 488         /* Now check for redirection which may follow command */
 489         while (readtoken() == TREDIR) {
 490                 *rpp = n2 = redirnode;
 491                 rpp = &n2->nfile.next;
 492                 parsefname();
 493         }
 494         tokpushback++;
 495         *rpp = NULL;
 496         if (redir) {
 497                 if (n1->type != NSUBSHELL) {
 498                         n2 = (union node *)stalloc(sizeof (struct nredir));
 499                         n2->type = NREDIR;
 500                         n2->nredir.n = n1;
 501                         n1 = n2;
 502                 }
 503                 n1->nredir.redirect = redir;
 504         }
 505
 506 checkneg:
 507         if (negate) {
 508                 n2 = (union node *)stalloc(sizeof (struct nnot));
 509                 n2->type = NNOT;
 510                 n2->nnot.com = n1;
 511                 return n2;
 512         }
 513         else
 514                 return n1;
 515 }
 516
 517
 518 STATIC union node *
 519 simplecmd(union node **rpp, union node *redir)
 520 {
 521         union node *args, **app;
 522         union node **orig_rpp = rpp;
 523         union node *n = NULL, *n2;
 524         int negate = 0;
 525
 526         /* If we don't have any redirections already, then we must reset */
 527         /* rpp to be the address of the local redir variable.  */
 528         if (redir == 0)
 529                 rpp = &redir;
 530
 531         args = NULL;
 532         app = &args;
 533         /*
 534          * We save the incoming value, because we need this for shell
 535          * functions.  There can not be a redirect or an argument between
 536          * the function name and the open parenthesis.
 537          */
 538         orig_rpp = rpp;
 539
 540         while (readtoken() == TNOT) {
 541                 TRACE(("command: TNOT recognized\n"));
 542                 negate = !negate;
 543         }
 544         tokpushback++;
 545
 546         for (;;) {
 547                 if (readtoken() == TWORD) {
 548                         n = (union node *)stalloc(sizeof (struct narg));
 549                         n->type = NARG;
 550                         n->narg.text = wordtext;
 551                         n->narg.backquote = backquotelist;
 552                         *app = n;
 553                         app = &n->narg.next;
 554                 } else if (lasttoken == TREDIR) {
 555                         *rpp = n = redirnode;
 556                         rpp = &n->nfile.next;
 557                         parsefname();   /* read name of redirection file */
 558                 } else if (lasttoken == TLP && app == &args->narg.next
 559                                             && rpp == orig_rpp) {
 560                         /* We have a function */
 561                         if (readtoken() != TRP)
 562                                 synexpect(TRP);
 563 #ifdef notdef
 564                         if (! goodname(n->narg.text))
 565                                 synerror("Bad function name");
 566 #endif
 567                         n->type = NDEFUN;
 568                         n->narg.next = command();
 569                         goto checkneg;
 570                 } else {
 571                         tokpushback++;
 572                         break;
 573                 }
 574         }
 575         *app = NULL;
 576         *rpp = NULL;
 577         n = (union node *)stalloc(sizeof (struct ncmd));
 578         n->type = NCMD;
 579         n->ncmd.backgnd = 0;
 580         n->ncmd.args = args;
 581         n->ncmd.redirect = redir;
 582
 583 checkneg:
 584         if (negate) {
 585                 n2 = (union node *)stalloc(sizeof (struct nnot));
 586                 n2->type = NNOT;
 587                 n2->nnot.com = n;
 588                 return n2;
 589         }
 590         else
 591                 return n;
 592 }
 593
 594 STATIC union node *
 595 makename(void)
 596 {
 597         union node *n;
 598
 599         n = (union node *)stalloc(sizeof (struct narg));
 600         n->type = NARG;
 601         n->narg.next = NULL;
 602         n->narg.text = wordtext;
 603         n->narg.backquote = backquotelist;
 604         return n;
 605 }
 606
 607 void
 608 fixredir(union node *n, const char *text, int err)
 609 {
 610         TRACE(("Fix redir %s %d\n", text, err));
 611         if (!err)
 612                 n->ndup.vname = NULL;
 613
 614         if (is_digit(text[0]) && text[1] == '\0')
 615                 n->ndup.dupfd = digit_val(text[0]);
 616         else if (text[0] == '-' && text[1] == '\0')
 617                 n->ndup.dupfd = -1;
 618         else {
 619
 620                 if (err)
 621                         synerror("Bad fd number");
 622                 else
 623                         n->ndup.vname = makename();
 624         }
 625 }
 626
 627
 628 STATIC void
 629 parsefname(void)
 630 {
 631         union node *n = redirnode;
 632
 633         if (readtoken() != TWORD)
 634                 synexpect(-1);
 635         if (n->type == NHERE) {
 636                 struct heredoc *here = heredoc;
 637                 struct heredoc *p;
 638                 int i;
 639
 640                 if (quoteflag == 0)
 641                         n->type = NXHERE;
 642                 TRACE(("Here document %d\n", n->type));
 643                 if (here->striptabs) {
 644                         while (*wordtext == '\t')
 645                                 wordtext++;
 646                 }
 647                 if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN)
 648                         synerror("Illegal eof marker for << redirection");
 649                 rmescapes(wordtext);
 650                 here->eofmark = wordtext;
 651                 here->next = NULL;
 652                 if (heredoclist == NULL)
 653                         heredoclist = here;
 654                 else {
 655                         for (p = heredoclist ; p->next ; p = p->next);
 656                         p->next = here;
 657                 }
 658         } else if (n->type == NTOFD || n->type == NFROMFD) {
 659                 fixredir(n, wordtext, 0);
 660         } else {
 661                 n->nfile.fname = makename();
 662         }
 663 }
 664
 665
 666 /*
 667  * Input any here documents.
 668  */
 669
 670 STATIC void
 671 parseheredoc(void)
 672 {
 673         struct heredoc *here;
 674         union node *n;
 675
 676         while (heredoclist) {
 677                 here = heredoclist;
 678                 heredoclist = here->next;
 679                 if (needprompt) {
 680                         setprompt(2);
 681                         needprompt = 0;
 682                 }
 683                 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX,
 684                                 here->eofmark, here->striptabs);
 685                 n = (union node *)stalloc(sizeof (struct narg));
 686                 n->narg.type = NARG;
 687                 n->narg.next = NULL;
 688                 n->narg.text = wordtext;
 689                 n->narg.backquote = backquotelist;
 690                 here->here->nhere.doc = n;
 691         }
 692 }
 693
 694 STATIC int
 695 peektoken(void)
 696 {
 697         int t;
 698
 699         t = readtoken();
 700         tokpushback++;
 701         return (t);
 702 }
 703
 704 STATIC int
 705 readtoken(void)
 706 {
 707         int t;
 708         int savecheckkwd = checkkwd;
 709         struct alias *ap;
 710 #ifdef DEBUG
 711         int alreadyseen = tokpushback;
 712 #endif
 713
 714         top:
 715         t = xxreadtoken();
 716
 717         if (checkkwd) {
 718                 /*
 719                  * eat newlines
 720                  */
 721                 if (checkkwd == 2) {
 722                         checkkwd = 0;
 723                         while (t == TNL) {
 724                                 parseheredoc();
 725                                 t = xxreadtoken();
 726                         }
 727                 } else
 728                         checkkwd = 0;
 729                 /*
 730                  * check for keywords and aliases
 731                  */
 732                 if (t == TWORD && !quoteflag)
 733                 {
 734                         const char * const *pp;
 735
 736                         for (pp = parsekwd; *pp; pp++) {
 737                                 if (**pp == *wordtext && equal(*pp, wordtext))
 738                                 {
 739                                         lasttoken = t = pp - parsekwd + KWDOFFSET;
 740                                         TRACE(("keyword %s recognized\n", tokname[t]));
 741                                         goto out;
 742                                 }
 743                         }
 744                         if (noaliases == 0 &&
 745                             (ap = lookupalias(wordtext, 1)) != NULL) {
 746                                 pushstring(ap->val, strlen(ap->val), ap);
 747                                 checkkwd = savecheckkwd;
 748                                 goto top;
 749                         }
 750                 }
 751 out:
 752                 checkkwd = (t == TNOT) ? savecheckkwd : 0;
 753         }
 754 #ifdef DEBUG
 755         if (!alreadyseen)
 756             TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
 757         else
 758             TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
 759 #endif
 760         return (t);
 761 }
 762
 763
 764 /*
 765  * Read the next input token.
 766  * If the token is a word, we set backquotelist to the list of cmds in
 767  *      backquotes.  We set quoteflag to true if any part of the word was
 768  *      quoted.
 769  * If the token is TREDIR, then we set redirnode to a structure containing
 770  *      the redirection.
 771  * In all cases, the variable startlinno is set to the number of the line
 772  *      on which the token starts.
 773  *
 774  * [Change comment:  here documents and internal procedures]
 775  * [Readtoken shouldn't have any arguments.  Perhaps we should make the
 776  *  word parsing code into a separate routine.  In this case, readtoken
 777  *  doesn't need to have any internal procedures, but parseword does.
 778  *  We could also make parseoperator in essence the main routine, and
 779  *  have parseword (readtoken1?) handle both words and redirection.]
 780  */
 781
 782 #define RETURN(token)   return lasttoken = token
 783
 784 STATIC int
 785 xxreadtoken(void)
 786 {
 787         int c;
 788
 789         if (tokpushback) {
 790                 tokpushback = 0;
 791                 return lasttoken;
 792         }
 793         if (needprompt) {
 794                 setprompt(2);
 795                 needprompt = 0;
 796         }
 797         startlinno = plinno;
 798         for (;;) {      /* until token or start of word found */
 799                 c = pgetc_macro();
 800                 if (c == ' ' || c == '\t')
 801                         continue;               /* quick check for white space first */
 802                 switch (c) {
 803                 case ' ': case '\t':
 804                         continue;
 805                 case '#':
 806                         while ((c = pgetc()) != '\n' && c != PEOF);
 807                         pungetc();
 808                         continue;
 809                 case '\\':
 810                         if (pgetc() == '\n') {
 811                                 startlinno = ++plinno;
 812                                 if (doprompt)
 813                                         setprompt(2);
 814                                 else
 815                                         setprompt(0);
 816                                 continue;
 817                         }
 818                         pungetc();
 819                         goto breakloop;
 820                 case '\n':
 821                         plinno++;
 822                         needprompt = doprompt;
 823                         RETURN(TNL);
 824                 case PEOF:
 825                         RETURN(TEOF);
 826                 case '&':
 827                         if (pgetc() == '&')
 828                                 RETURN(TAND);
 829                         pungetc();
 830                         RETURN(TBACKGND);
 831                 case '|':
 832                         if (pgetc() == '|')
 833                                 RETURN(TOR);
 834                         pungetc();
 835                         RETURN(TPIPE);
 836                 case ';':
 837                         if (pgetc() == ';')
 838                                 RETURN(TENDCASE);
 839                         pungetc();
 840                         RETURN(TSEMI);
 841                 case '(':
 842                         RETURN(TLP);
 843                 case ')':
 844                         RETURN(TRP);
 845                 default:
 846                         goto breakloop;
 847                 }
 848         }
 849 breakloop:
 850         return readtoken1(c, BASESYNTAX, (char *)NULL, 0);
 851 #undef RETURN
 852 }
 853
 854
 855
 856 /*
 857  * If eofmark is NULL, read a word or a redirection symbol.  If eofmark
 858  * is not NULL, read a here document.  In the latter case, eofmark is the
 859  * word which marks the end of the document and striptabs is true if
 860  * leading tabs should be stripped from the document.  The argument firstc
 861  * is the first character of the input token or document.
 862  *
 863  * Because C does not have internal subroutines, I have simulated them
 864  * using goto's to implement the subroutine linkage.  The following macros
 865  * will run code that appears at the end of readtoken1.
 866  */
 867
 868 #define CHECKEND()      {goto checkend; checkend_return:;}
 869 #define PARSEREDIR()    {goto parseredir; parseredir_return:;}
 870 #define PARSESUB()      {goto parsesub; parsesub_return:;}
 871 #define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;}
 872 #define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;}
 873 #define PARSEARITH()    {goto parsearith; parsearith_return:;}
 874
 875 STATIC int
 876 readtoken1(int firstc, char const *syntax, char *eofmark, int striptabs)
 877 {
 878         int c = firstc;
 879         char *out;
 880         int len;
 881         char line[EOFMARKLEN + 1];
 882         struct nodelist *bqlist;
 883         int quotef;
 884         int dblquote;
 885         int varnest;    /* levels of variables expansion */
 886         int arinest;    /* levels of arithmetic expansion */
 887         int parenlevel; /* levels of parens in arithmetic */
 888         int oldstyle;
 889         char const *prevsyntax; /* syntax before arithmetic */
 890         int synentry;
 891 #if __GNUC__
 892         /* Avoid longjmp clobbering */
 893         (void) &out;
 894         (void) &quotef;
 895         (void) &dblquote;
 896         (void) &varnest;
 897         (void) &arinest;
 898         (void) &parenlevel;
 899         (void) &oldstyle;
 900         (void) &prevsyntax;
 901         (void) &syntax;
 902         (void) &synentry;
 903 #endif
 904
 905         startlinno = plinno;
 906         dblquote = 0;
 907         if (syntax == DQSYNTAX)
 908                 dblquote = 1;
 909         quotef = 0;
 910         bqlist = NULL;
 911         varnest = 0;
 912         arinest = 0;
 913         parenlevel = 0;
 914
 915         STARTSTACKSTR(out);
 916         loop: { /* for each line, until end of word */
 917                 CHECKEND();     /* set c to PEOF if at end of here document */
 918                 for (;;) {      /* until end of line or end of word */
 919                         CHECKSTRSPACE(3, out);  /* permit 3 calls to USTPUTC */
 920
 921                         synentry = syntax[c];
 922
 923                         switch(synentry) {
 924                         case CNL:       /* '\n' */
 925                                 if (syntax == BASESYNTAX)
 926                                         goto endword;   /* exit outer loop */
 927                                 USTPUTC(c, out);
 928                                 plinno++;
 929                                 if (doprompt)
 930                                         setprompt(2);
 931                                 else
 932                                         setprompt(0);
 933                                 c = pgetc();
 934                                 goto loop;              /* continue outer loop */
 935                         case CWORD:
 936                                 USTPUTC(c, out);
 937                                 break;
 938                         case CCTL:
 939                                 if (eofmark == NULL || dblquote)
 940                                         USTPUTC(CTLESC, out);
 941                                 USTPUTC(c, out);
 942                                 break;
 943                         case CBACK:     /* backslash */
 944                                 c = pgetc();
 945                                 if (c == PEOF) {
 946                                         USTPUTC('\\', out);
 947                                         pungetc();
 948                                 } else if (c == '\n') {
 949                                         if (doprompt)
 950                                                 setprompt(2);
 951                                         else
 952                                                 setprompt(0);
 953                                 } else {
 954                                         if (dblquote && c != '\\' &&
 955                                             c != '`' && c != '$' &&
 956                                             (c != '"' || eofmark != NULL))
 957                                                 USTPUTC('\\', out);
 958                                         if (SQSYNTAX[c] == CCTL)
 959                                                 USTPUTC(CTLESC, out);
 960                                         else if (eofmark == NULL)
 961                                                 USTPUTC(CTLQUOTEMARK, out);
 962                                         USTPUTC(c, out);
 963                                         quotef++;
 964                                 }
 965                                 break;
 966                         case CSQUOTE:
 967                                 if (eofmark == NULL)
 968                                         USTPUTC(CTLQUOTEMARK, out);
 969                                 syntax = SQSYNTAX;
 970                                 break;
 971                         case CDQUOTE:
 972                                 if (eofmark == NULL)
 973                                         USTPUTC(CTLQUOTEMARK, out);
 974                                 syntax = DQSYNTAX;
 975                                 dblquote = 1;
 976                                 break;
 977                         case CENDQUOTE:
 978                                 if (eofmark != NULL && arinest == 0 &&
 979                                     varnest == 0) {
 980                                         USTPUTC(c, out);
 981                                 } else {
 982                                         if (arinest) {
 983                                                 syntax = ARISYNTAX;
 984                                                 dblquote = 0;
 985                                         } else if (eofmark == NULL) {
 986                                                 syntax = BASESYNTAX;
 987                                                 dblquote = 0;
 988                                         }
 989                                         quotef++;
 990                                 }
 991                                 break;
 992                         case CVAR:      /* '$' */
 993                                 PARSESUB();             /* parse substitution */
 994                                 break;
 995                         case CENDVAR:   /* '}' */
 996                                 if (varnest > 0) {
 997                                         varnest--;
 998                                         USTPUTC(CTLENDVAR, out);
 999                                 } else {
1000                                         USTPUTC(c, out);
1001                                 }
1002                                 break;
1003                         case CLP:       /* '(' in arithmetic */
1004                                 parenlevel++;
1005                                 USTPUTC(c, out);
1006                                 break;
1007                         case CRP:       /* ')' in arithmetic */
1008                                 if (parenlevel > 0) {
1009                                         USTPUTC(c, out);
1010                                         --parenlevel;
1011                                 } else {
1012                                         if (pgetc() == ')') {
1013                                                 if (--arinest == 0) {
1014                                                         USTPUTC(CTLENDARI, out);
1015                                                         syntax = prevsyntax;
1016                                                         if (syntax == DQSYNTAX)
1017                                                                 dblquote = 1;
1018                                                         else
1019                                                                 dblquote = 0;
1020                                                 } else
1021                                                         USTPUTC(')', out);
1022                                         } else {
1023                                                 /*
1024                                                  * unbalanced parens
1025                                                  *  (don't 2nd guess - no error)
1026                                                  */
1027                                                 pungetc();
1028                                                 USTPUTC(')', out);
1029                                         }
1030                                 }
1031                                 break;
1032                         case CBQUOTE:   /* '`' */
1033                                 PARSEBACKQOLD();
1034                                 break;
1035                         case CEOF:
1036                                 goto endword;           /* exit outer loop */
1037                         default:
1038                                 if (varnest == 0)
1039                                         goto endword;   /* exit outer loop */
1040                                 USTPUTC(c, out);
1041                         }
1042                         c = pgetc_macro();
1043                 }
1044         }
1045 endword:
1046         if (syntax == ARISYNTAX)
1047                 synerror("Missing '))'");
1048         if (syntax != BASESYNTAX && ! parsebackquote && eofmark == NULL)
1049                 synerror("Unterminated quoted string");
1050         if (varnest != 0) {
1051                 startlinno = plinno;
1052                 synerror("Missing '}'");
1053         }
1054         USTPUTC('\0', out);
1055         len = out - stackblock();
1056         out = stackblock();
1057         if (eofmark == NULL) {
1058                 if ((c == '>' || c == '<')
1059                  && quotef == 0
1060                  && len <= 2
1061                  && (*out == '\0' || is_digit(*out))) {
1062                         PARSEREDIR();
1063                         return lasttoken = TREDIR;
1064                 } else {
1065                         pungetc();
1066                 }
1067         }
1068         quoteflag = quotef;
1069         backquotelist = bqlist;
1070         grabstackblock(len);
1071         wordtext = out;
1072         return lasttoken = TWORD;
1073 /* end of readtoken routine */
1074
1075
1076
1077 /*
1078  * Check to see whether we are at the end of the here document.  When this
1079  * is called, c is set to the first character of the next input line.  If
1080  * we are at the end of the here document, this routine sets the c to PEOF.
1081  */
1082
1083 checkend: {
1084         if (eofmark) {
1085                 if (striptabs) {
1086                         while (c == '\t')
1087                                 c = pgetc();
1088                 }
1089                 if (c == *eofmark) {
1090                         if (pfgets(line, sizeof line) != NULL) {
1091                                 char *p, *q;
1092
1093                                 p = line;
1094                                 for (q = eofmark + 1 ; *q && *p == *q ; p++, q++);
1095                                 if (*p == '\n' && *q == '\0') {
1096                                         c = PEOF;
1097                                         plinno++;
1098                                         needprompt = doprompt;
1099                                 } else {
1100                                         pushstring(line, strlen(line), NULL);
1101                                 }
1102                         }
1103                 }
1104         }
1105         goto checkend_return;
1106 }
1107
1108
1109 /*
1110  * Parse a redirection operator.  The variable "out" points to a string
1111  * specifying the fd to be redirected.  The variable "c" contains the
1112  * first character of the redirection operator.
1113  */
1114
1115 parseredir: {
1116         char fd = *out;
1117         union node *np;
1118
1119         np = (union node *)stalloc(sizeof (struct nfile));
1120         if (c == '>') {
1121                 np->nfile.fd = 1;
1122                 c = pgetc();
1123                 if (c == '>')
1124                         np->type = NAPPEND;
1125                 else if (c == '&')
1126                         np->type = NTOFD;
1127                 else if (c == '|')
1128                         np->type = NCLOBBER;
1129                 else {
1130                         np->type = NTO;
1131                         pungetc();
1132                 }
1133         } else {        /* c == '<' */
1134                 np->nfile.fd = 0;
1135                 c = pgetc();
1136                 if (c == '<') {
1137                         if (sizeof (struct nfile) != sizeof (struct nhere)) {
1138                                 np = (union node *)stalloc(sizeof (struct nhere));
1139                                 np->nfile.fd = 0;
1140                         }
1141                         np->type = NHERE;
1142                         heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc));
1143                         heredoc->here = np;
1144                         if ((c = pgetc()) == '-') {
1145                                 heredoc->striptabs = 1;
1146                         } else {
1147                                 heredoc->striptabs = 0;
1148                                 pungetc();
1149                         }
1150                 } else if (c == '&')
1151                         np->type = NFROMFD;
1152                 else if (c == '>')
1153                         np->type = NFROMTO;
1154                 else {
1155                         np->type = NFROM;
1156                         pungetc();
1157                 }
1158         }
1159         if (fd != '\0')
1160                 np->nfile.fd = digit_val(fd);
1161         redirnode = np;
1162         goto parseredir_return;
1163 }
1164
1165
1166 /*
1167  * Parse a substitution.  At this point, we have read the dollar sign
1168  * and nothing else.
1169  */
1170
1171 parsesub: {
1172         int subtype;
1173         int typeloc;
1174         int flags;
1175         char *p;
1176         static const char types[] = "}-+?=";
1177        int bracketed_name = 0; /* used to handle ${[0-9]*} variables */
1178
1179         c = pgetc();
1180         if (c != '(' && c != '{' && (is_eof(c) || !is_name(c)) &&
1181             !is_special(c)) {
1182                 USTPUTC('$', out);
1183                 pungetc();
1184         } else if (c == '(') {  /* $(command) or $((arith)) */
1185                 if (pgetc() == '(') {
1186                         PARSEARITH();
1187                 } else {
1188                         pungetc();
1189                         PARSEBACKQNEW();
1190                 }
1191         } else {
1192                 USTPUTC(CTLVAR, out);
1193                 typeloc = out - stackblock();
1194                 USTPUTC(VSNORMAL, out);
1195                 subtype = VSNORMAL;
1196                 if (c == '{') {
1197                         bracketed_name = 1;
1198                         c = pgetc();
1199                         if (c == '#') {
1200                                 if ((c = pgetc()) == '}')
1201                                         c = '#';
1202                                 else
1203                                         subtype = VSLENGTH;
1204                         }
1205                         else
1206                                 subtype = 0;
1207                 }
1208                 if (!is_eof(c) && is_name(c)) {
1209                         do {
1210                                 STPUTC(c, out);
1211                                 c = pgetc();
1212                         } while (!is_eof(c) && is_in_name(c));
1213                 } else if (is_digit(c)) {
1214                         if (bracketed_name) {
1215                                 do {
1216                                         STPUTC(c, out);
1217                                         c = pgetc();
1218                                 } while (is_digit(c));
1219                         } else {
1220                                 STPUTC(c, out);
1221                                 c = pgetc();
1222                         }
1223                 } else {
1224                         if (! is_special(c))
1225 badsub:                         synerror("Bad substitution");
1226                         USTPUTC(c, out);
1227                         c = pgetc();
1228                 }
1229                 STPUTC('=', out);
1230                 flags = 0;
1231                 if (subtype == 0) {
1232                         switch (c) {
1233                         case ':':
1234                                 flags = VSNUL;
1235                                 c = pgetc();
1236                                 /*FALLTHROUGH*/
1237                         default:
1238                                 p = strchr(types, c);
1239                                 if (p == NULL)
1240                                         goto badsub;
1241                                 subtype = p - types + VSNORMAL;
1242                                 break;
1243                         case '%':
1244                         case '#':
1245                                 {
1246                                         int cc = c;
1247                                         subtype = c == '#' ? VSTRIMLEFT :
1248                                                              VSTRIMRIGHT;
1249                                         c = pgetc();
1250                                         if (c == cc)
1251                                                 subtype++;
1252                                         else
1253                                                 pungetc();
1254                                         break;
1255                                 }
1256                         }
1257                 } else {
1258                         pungetc();
1259                 }
1260                 if (subtype != VSLENGTH && (dblquote || arinest))
1261                         flags |= VSQUOTE;
1262                 *(stackblock() + typeloc) = subtype | flags;
1263                 if (subtype != VSNORMAL)
1264                         varnest++;
1265         }
1266         goto parsesub_return;
1267 }
1268
1269
1270 /*
1271  * Called to parse command substitutions.  Newstyle is set if the command
1272  * is enclosed inside $(...); nlpp is a pointer to the head of the linked
1273  * list of commands (passed by reference), and savelen is the number of
1274  * characters on the top of the stack which must be preserved.
1275  */
1276
1277 parsebackq: {
1278         struct nodelist **nlpp;
1279         int savepbq;
1280         union node *n;
1281         char *volatile str;
1282         struct jmploc jmploc;
1283         struct jmploc *volatile savehandler;
1284         int savelen;
1285         int saveprompt;
1286 #if __GNUC__
1287         /* Avoid longjmp clobbering */
1288         (void) &saveprompt;
1289 #endif
1290
1291         savepbq = parsebackquote;
1292         if (setjmp(jmploc.loc)) {
1293                 if (str)
1294                         ckfree(str);
1295                 parsebackquote = 0;
1296                 handler = savehandler;
1297                 longjmp(handler->loc, 1);
1298         }
1299         INTOFF;
1300         str = NULL;
1301         savelen = out - stackblock();
1302         if (savelen > 0) {
1303                 str = ckmalloc(savelen);
1304                 memcpy(str, stackblock(), savelen);
1305         }
1306         savehandler = handler;
1307         handler = &jmploc;
1308         INTON;
1309         if (oldstyle) {
1310                 /* We must read until the closing backquote, giving special
1311                    treatment to some slashes, and then push the string and
1312                    reread it as input, interpreting it normally.  */
1313                 char *pout;
1314                 int pc;
1315                 int psavelen;
1316                 char *pstr;
1317
1318
1319                 STARTSTACKSTR(pout);
1320                 for (;;) {
1321                         if (needprompt) {
1322                                 setprompt(2);
1323                                 needprompt = 0;
1324                         }
1325                         switch (pc = pgetc()) {
1326                         case '`':
1327                                 goto done;
1328
1329                         case '\\':
1330                                 if ((pc = pgetc()) == '\n') {
1331                                         plinno++;
1332                                         if (doprompt)
1333                                                 setprompt(2);
1334                                         else
1335                                                 setprompt(0);
1336                                         /*
1337                                          * If eating a newline, avoid putting
1338                                          * the newline into the new character
1339                                          * stream (via the STPUTC after the
1340                                          * switch).
1341                                          */
1342                                         continue;
1343                                 }
1344                                 if (pc != '\\' && pc != '`' && pc != '$'
1345                                     && (!dblquote || pc != '"'))
1346                                         STPUTC('\\', pout);
1347                                 break;
1348
1349                         case '\n':
1350                                 plinno++;
1351                                 needprompt = doprompt;
1352                                 break;
1353
1354                         case PEOF:
1355                                 startlinno = plinno;
1356                                 synerror("EOF in backquote substitution");
1357                                 break;
1358
1359                         default:
1360                                 break;
1361                         }
1362                         STPUTC(pc, pout);
1363                 }
1364 done:
1365                 STPUTC('\0', pout);
1366                 psavelen = pout - stackblock();
1367                 if (psavelen > 0) {
1368                         pstr = ckmalloc(psavelen);
1369                         memcpy(pstr, stackblock(), psavelen);
1370                         setinputstring(pstr, 1);
1371                 }
1372         }
1373         nlpp = &bqlist;
1374         while (*nlpp)
1375                 nlpp = &(*nlpp)->next;
1376         *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist));
1377         (*nlpp)->next = NULL;
1378         parsebackquote = oldstyle;
1379
1380         if (oldstyle) {
1381                 saveprompt = doprompt;
1382                 doprompt = 0;
1383         }
1384
1385         n = list(0);
1386
1387         if (oldstyle)
1388                 doprompt = saveprompt;
1389         else {
1390                 if (readtoken() != TRP)
1391                         synexpect(TRP);
1392         }
1393
1394         (*nlpp)->n = n;
1395         if (oldstyle) {
1396                 /*
1397                  * Start reading from old file again, ignoring any pushed back
1398                  * tokens left from the backquote parsing
1399                  */
1400                 popfile();
1401                 tokpushback = 0;
1402         }
1403         while (stackblocksize() <= savelen)
1404                 growstackblock();
1405         STARTSTACKSTR(out);
1406         if (str) {
1407                 memcpy(out, str, savelen);
1408                 STADJUST(savelen, out);
1409                 INTOFF;
1410                 ckfree(str);
1411                 str = NULL;
1412                 INTON;
1413         }
1414         parsebackquote = savepbq;
1415         handler = savehandler;
1416         if (arinest || dblquote)
1417                 USTPUTC(CTLBACKQ | CTLQUOTE, out);
1418         else
1419                 USTPUTC(CTLBACKQ, out);
1420         if (oldstyle)
1421                 goto parsebackq_oldreturn;
1422         else
1423                 goto parsebackq_newreturn;
1424 }
1425
1426 /*
1427  * Parse an arithmetic expansion (indicate start of one and set state)
1428  */
1429 parsearith: {
1430
1431         if (++arinest == 1) {
1432                 prevsyntax = syntax;
1433                 syntax = ARISYNTAX;
1434                 USTPUTC(CTLARI, out);
1435                 if (dblquote)
1436                         USTPUTC('"',out);
1437                 else
1438                         USTPUTC(' ',out);
1439         } else {
1440                 /*
1441                  * we collapse embedded arithmetic expansion to
1442                  * parenthesis, which should be equivalent
1443                  */
1444                 USTPUTC('(', out);
1445         }
1446         goto parsearith_return;
1447 }
1448
1449 } /* end of readtoken */
1450
1451
1452
1453 #ifdef mkinit
1454 RESET {
1455         tokpushback = 0;
1456         checkkwd = 0;
1457 }
1458 #endif
1459
1460 /*
1461  * Returns true if the text contains nothing to expand (no dollar signs
1462  * or backquotes).
1463  */
1464
1465 STATIC int
1466 noexpand(char *text)
1467 {
1468         char *p;
1469         char c;
1470
1471         p = text;
1472         while ((c = *p++) != '\0') {
1473                 if ( c == CTLQUOTEMARK)
1474                         continue;
1475                 if (c == CTLESC)
1476                         p++;
1477                 else if (BASESYNTAX[(int)c] == CCTL)
1478                         return 0;
1479         }
1480         return 1;
1481 }
1482
1483
1484 /*
1485  * Return true if the argument is a legal variable name (a letter or
1486  * underscore followed by zero or more letters, underscores, and digits).
1487  */
1488
1489 int
1490 goodname(char *name)
1491 {
1492         char *p;
1493
1494         p = name;
1495         if (! is_name(*p))
1496                 return 0;
1497         while (*++p) {
1498                 if (! is_in_name(*p))
1499                         return 0;
1500         }
1501         return 1;
1502 }
1503
1504
1505 /*
1506  * Called when an unexpected token is read during the parse.  The argument
1507  * is the token that is expected, or -1 if more than one type of token can
1508  * occur at this point.
1509  */
1510
1511 STATIC void
1512 synexpect(int token)
1513 {
1514         char msg[64];
1515
1516         if (token >= 0) {
1517                 fmtstr(msg, 64, "%s unexpected (expecting %s)",
1518                         tokname[lasttoken], tokname[token]);
1519         } else {
1520                 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]);
1521         }
1522         synerror(msg);
1523 }
1524
1525
1526 STATIC void
1527 synerror(const char *msg)
1528 {
1529         if (commandname)
1530                 outfmt(&errout, "%s: %d: ", commandname, startlinno);
1531         outfmt(&errout, "Syntax error: %s\n", msg);
1532         error((char *)NULL);
1533 }
1534
1535 STATIC void
1536 setprompt(int which)
1537 {
1538         whichprompt = which;
1539
1540 #ifndef NO_HISTORY
1541         if (!el)
1542 #endif
1543                 out2str(getprompt(NULL));
1544 }
1545
1546 /*
1547  * called by editline -- any expansions to the prompt
1548  *    should be added here.
1549  */
1550 const char *
1551 getprompt(void *unused __unused)
1552 {
1553         switch (whichprompt) {
1554         case 0:
1555                 return "";
1556         case 1:
1557                 return ps1val();
1558         case 2:
1559                 return ps2val();
1560         default:
1561                 return "<internal prompt error>";
1562         }
1563 }