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 1.58 2006/11/05 18:36:05 stefanf Exp $
  38  * $DragonFly: src/bin/sh/parser.c,v 1.12 2007/01/18 17:03:18 corecode Exp $
  39  */
  40
  41 #include <stdlib.h>
  42 #include <unistd.h>
  43
  44 #include "shell.h"
  45 #include "parser.h"
  46 #include "nodes.h"
  47 #include "expand.h"     /* defines rmescapes() */
  48 #include "syntax.h"
  49 #include "options.h"
  50 #include "input.h"
  51 #include "output.h"
  52 #include "var.h"
  53 #include "error.h"
  54 #include "memalloc.h"
  55 #include "mystring.h"
  56 #include "alias.h"
  57 #include "show.h"
  58 #include "eval.h"
  59 #ifndef NO_HISTORY
  60 #include "myhistedit.h"
  61 #endif
  62
  63 /*
  64  * Shell command parser.
  65  */
  66
  67 #define EOFMARKLEN      79
  68 #define PROMPTLEN       128
  69
  70 /* values returned by readtoken */
  71 #include "token.h"
  72
  73
  74
  75 struct heredoc {
  76         struct heredoc *next;   /* next here document in list */
  77         union node *here;               /* redirection node */
  78         char *eofmark;          /* string indicating end of input */
  79         int striptabs;          /* if set, strip leading tabs */
  80 };
  81
  82
  83
  84 STATIC struct heredoc *heredoclist;     /* list of here documents to read */
  85 STATIC int parsebackquote;      /* nonzero if we are inside backquotes */
  86 STATIC int doprompt;            /* if set, prompt the user */
  87 STATIC int needprompt;          /* true if interactive and at start of line */
  88 STATIC int lasttoken;           /* last token read */
  89 MKINIT int tokpushback;         /* last token pushed back */
  90 STATIC char *wordtext;          /* text of last word returned by readtoken */
  91 /*
  92  * 1 == check for kwds
  93  * 2 == also eat newlines
  94  * 3 == check for TNOT
  95  */
  96 MKINIT int checkkwd;
  97 STATIC struct nodelist *backquotelist;
  98 STATIC union node *redirnode;
  99 STATIC struct heredoc *heredoc;
 100 STATIC int quoteflag;           /* set if (part of) last token was quoted */
 101 STATIC int startlinno;          /* line # where last token started */
 102
 103 /* XXX When 'noaliases' is set to one, no alias expansion takes place. */
 104 static int noaliases = 0;
 105
 106
 107 STATIC union node *list(int);
 108 STATIC union node *andor(void);
 109 STATIC union node *pipeline(void);
 110 STATIC union node *command(void);
 111 STATIC union node *simplecmd(union node **, union node *);
 112 STATIC union node *makename(void);
 113 STATIC void parsefname(void);
 114 STATIC void parseheredoc(void);
 115 STATIC int peektoken(void);
 116 STATIC int readtoken(void);
 117 STATIC int xxreadtoken(void);
 118 STATIC int readtoken1(int, char const *, char *, int);
 119 STATIC int noexpand(char *);
 120 STATIC void synexpect(int);
 121 STATIC void synerror(const char *);
 122 STATIC void setprompt(int);
 123
 124
 125 /*
 126  * Read and parse a command.  Returns NEOF on end of file.  (NULL is a
 127  * valid parse tree indicating a blank line.)
 128  */
 129
 130 union node *
 131 parsecmd(int interact)
 132 {
 133         int t;
 134
 135         tokpushback = 0;
 136         doprompt = interact;
 137         if (doprompt)
 138                 setprompt(1);
 139         else
 140                 setprompt(0);
 141         needprompt = 0;
 142         t = readtoken();
 143         if (t == TEOF)
 144                 return NEOF;
 145         if (t == TNL)
 146                 return NULL;
 147         tokpushback++;
 148         return list(1);
 149 }
 150
 151
 152 STATIC union node *
 153 list(int nlflag)
 154 {
 155         union node *n1, *n2, *n3;
 156         int tok;
 157
 158         checkkwd = 2;
 159         if (nlflag == 0 && tokendlist[peektoken()])
 160                 return NULL;
 161         n1 = NULL;
 162         for (;;) {
 163                 n2 = andor();
 164                 tok = readtoken();
 165                 if (tok == TBACKGND) {
 166                         if (n2->type == NCMD || n2->type == NPIPE) {
 167                                 n2->ncmd.backgnd = 1;
 168                         } else if (n2->type == NREDIR) {
 169                                 n2->type = NBACKGND;
 170                         } else {
 171                                 n3 = (union node *)stalloc(sizeof (struct nredir));
 172                                 n3->type = NBACKGND;
 173                                 n3->nredir.n = n2;
 174                                 n3->nredir.redirect = NULL;
 175                                 n2 = n3;
 176                         }
 177                 }
 178                 if (n1 == NULL) {
 179                         n1 = n2;
 180                 }
 181                 else {
 182                         n3 = (union node *)stalloc(sizeof (struct nbinary));
 183                         n3->type = NSEMI;
 184                         n3->nbinary.ch1 = n1;
 185                         n3->nbinary.ch2 = n2;
 186                         n1 = n3;
 187                 }
 188                 switch (tok) {
 189                 case TBACKGND:
 190                 case TSEMI:
 191                         tok = readtoken();
 192                         /* FALLTHROUGH */
 193                 case TNL:
 194                         if (tok == TNL) {
 195                                 parseheredoc();
 196                                 if (nlflag)
 197                                         return n1;
 198                         } else {
 199                                 tokpushback++;
 200                         }
 201                         checkkwd = 2;
 202                         if (tokendlist[peektoken()])
 203                                 return n1;
 204                         break;
 205                 case TEOF:
 206                         if (heredoclist)
 207                                 parseheredoc();
 208                         else
 209                                 pungetc();              /* push back EOF on input */
 210                         return n1;
 211                 default:
 212                         if (nlflag)
 213                                 synexpect(-1);
 214                         tokpushback++;
 215                         return n1;
 216                 }
 217         }
 218 }
 219
 220
 221
 222 STATIC union node *
 223 andor(void)
 224 {
 225         union node *n1, *n2, *n3;
 226         int t;
 227
 228         n1 = pipeline();
 229         for (;;) {
 230                 if ((t = readtoken()) == TAND) {
 231                         t = NAND;
 232                 } else if (t == TOR) {
 233                         t = NOR;
 234                 } else {
 235                         tokpushback++;
 236                         return n1;
 237                 }
 238                 n2 = pipeline();
 239                 n3 = (union node *)stalloc(sizeof (struct nbinary));
 240                 n3->type = t;
 241                 n3->nbinary.ch1 = n1;
 242                 n3->nbinary.ch2 = n2;
 243                 n1 = n3;
 244         }
 245 }
 246
 247
 248
 249 STATIC union node *
 250 pipeline(void)
 251 {
 252         union node *n1, *n2, *pipenode;
 253         struct nodelist *lp, *prev;
 254         int negate;
 255
 256         negate = 0;
 257         TRACE(("pipeline: entered\n"));
 258
 259         checkkwd = 3;
 260         while (readtoken() == TNOT)
 261                 negate = !negate;
 262         tokpushback++;
 263
 264         n1 = command();
 265         if (readtoken() == TPIPE) {
 266                 pipenode = (union node *)stalloc(sizeof (struct npipe));
 267                 pipenode->type = NPIPE;
 268                 pipenode->npipe.backgnd = 0;
 269                 lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
 270                 pipenode->npipe.cmdlist = lp;
 271                 lp->n = n1;
 272                 do {
 273                         int innernegate = 0;
 274
 275                         checkkwd = 3;
 276                         while (readtoken() == TNOT)
 277                                 innernegate = !innernegate;
 278                         tokpushback++;
 279
 280                         prev = lp;
 281                         lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
 282                         lp->n = command();
 283                         prev->next = lp;
 284
 285                         if (innernegate) {
 286                                 n2 = (union node *)stalloc(sizeof (struct nnot));
 287                                 n2->type = NNOT;
 288                                 n2->nnot.com = lp->n;
 289                                 lp->n = n2;
 290                         }
 291                 } while (readtoken() == TPIPE);
 292                 lp->next = NULL;
 293                 n1 = pipenode;
 294         }
 295         tokpushback++;
 296         if (negate) {
 297                 n2 = (union node *)stalloc(sizeof (struct nnot));
 298                 n2->type = NNOT;
 299                 n2->nnot.com = n1;
 300                 return n2;
 301         } else
 302                 return n1;
 303 }
 304
 305
 306
 307 STATIC union node *
 308 command(void)
 309 {
 310         union node *n1, *n2;
 311         union node *ap, **app;
 312         union node *cp, **cpp;
 313         union node *redir, **rpp;
 314         int t;
 315
 316         checkkwd = 2;
 317         redir = NULL;
 318         n1 = NULL;
 319         rpp = &redir;
 320
 321         /* Check for redirection which may precede command */
 322         while (readtoken() == TREDIR) {
 323                 *rpp = n2 = redirnode;
 324                 rpp = &n2->nfile.next;
 325                 parsefname();
 326         }
 327         tokpushback++;
 328
 329         switch (readtoken()) {
 330         case TIF:
 331                 n1 = (union node *)stalloc(sizeof (struct nif));
 332                 n1->type = NIF;
 333                 if ((n1->nif.test = list(0)) == NULL)
 334                         synexpect(-1);
 335                 if (readtoken() != TTHEN)
 336                         synexpect(TTHEN);
 337                 n1->nif.ifpart = list(0);
 338                 n2 = n1;
 339                 while (readtoken() == TELIF) {
 340                         n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif));
 341                         n2 = n2->nif.elsepart;
 342                         n2->type = NIF;
 343                         if ((n2->nif.test = list(0)) == NULL)
 344                                 synexpect(-1);
 345                         if (readtoken() != TTHEN)
 346                                 synexpect(TTHEN);
 347                         n2->nif.ifpart = list(0);
 348                 }
 349                 if (lasttoken == TELSE)
 350                         n2->nif.elsepart = list(0);
 351                 else {
 352                         n2->nif.elsepart = NULL;
 353                         tokpushback++;
 354                 }
 355                 if (readtoken() != TFI)
 356                         synexpect(TFI);
 357                 checkkwd = 1;
 358                 break;
 359         case TWHILE:
 360         case TUNTIL: {
 361                 int got;
 362                 n1 = (union node *)stalloc(sizeof (struct nbinary));
 363                 n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL;
 364                 if ((n1->nbinary.ch1 = list(0)) == NULL)
 365                         synexpect(-1);
 366                 if ((got=readtoken()) != TDO) {
 367 TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : ""));
 368                         synexpect(TDO);
 369                 }
 370                 n1->nbinary.ch2 = list(0);
 371                 if (readtoken() != TDONE)
 372                         synexpect(TDONE);
 373                 checkkwd = 1;
 374                 break;
 375         }
 376         case TFOR:
 377                 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext))
 378                         synerror("Bad for loop variable");
 379                 n1 = (union node *)stalloc(sizeof (struct nfor));
 380                 n1->type = NFOR;
 381                 n1->nfor.var = wordtext;
 382                 if (readtoken() == TWORD && ! quoteflag && equal(wordtext, "in")) {
 383                         app = &ap;
 384                         while (readtoken() == TWORD) {
 385                                 n2 = (union node *)stalloc(sizeof (struct narg));
 386                                 n2->type = NARG;
 387                                 n2->narg.text = wordtext;
 388                                 n2->narg.backquote = backquotelist;
 389                                 *app = n2;
 390                                 app = &n2->narg.next;
 391                         }
 392                         *app = NULL;
 393                         n1->nfor.args = ap;
 394                         if (lasttoken != TNL && lasttoken != TSEMI)
 395                                 synexpect(-1);
 396                 } else {
 397                         static char argvars[5] = {
 398                                 CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0'
 399                         };
 400                         n2 = (union node *)stalloc(sizeof (struct narg));
 401                         n2->type = NARG;
 402                         n2->narg.text = argvars;
 403                         n2->narg.backquote = NULL;
 404                         n2->narg.next = NULL;
 405                         n1->nfor.args = n2;
 406                         /*
 407                          * Newline or semicolon here is optional (but note
 408                          * that the original Bourne shell only allowed NL).
 409                          */
 410                         if (lasttoken != TNL && lasttoken != TSEMI)
 411                                 tokpushback++;
 412                 }
 413                 checkkwd = 2;
 414                 if ((t = readtoken()) == TDO)
 415                         t = TDONE;
 416                 else if (t == TBEGIN)
 417                         t = TEND;
 418                 else
 419                         synexpect(-1);
 420                 n1->nfor.body = list(0);
 421                 if (readtoken() != t)
 422                         synexpect(t);
 423                 checkkwd = 1;
 424                 break;
 425         case TCASE:
 426                 n1 = (union node *)stalloc(sizeof (struct ncase));
 427                 n1->type = NCASE;
 428                 if (readtoken() != TWORD)
 429                         synexpect(TWORD);
 430                 n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg));
 431                 n2->type = NARG;
 432                 n2->narg.text = wordtext;
 433                 n2->narg.backquote = backquotelist;
 434                 n2->narg.next = NULL;
 435                 while (readtoken() == TNL);
 436                 if (lasttoken != TWORD || ! equal(wordtext, "in"))
 437                         synerror("expecting \"in\"");
 438                 cpp = &n1->ncase.cases;
 439                 noaliases = 1;  /* turn off alias expansion */
 440                 checkkwd = 2, readtoken();
 441                 while (lasttoken != TESAC) {
 442                         *cpp = cp = (union node *)stalloc(sizeof (struct nclist));
 443                         cp->type = NCLIST;
 444                         app = &cp->nclist.pattern;
 445                         if (lasttoken == TLP)
 446                                 readtoken();
 447                         for (;;) {
 448                                 *app = ap = (union node *)stalloc(sizeof (struct narg));
 449                                 ap->type = NARG;
 450                                 ap->narg.text = wordtext;
 451                                 ap->narg.backquote = backquotelist;
 452                                 if (checkkwd = 2, readtoken() != TPIPE)
 453                                         break;
 454                                 app = &ap->narg.next;
 455                                 readtoken();
 456                         }
 457                         ap->narg.next = NULL;
 458                         if (lasttoken != TRP)
 459                                 noaliases = 0, synexpect(TRP);
 460                         cp->nclist.body = list(0);
 461
 462                         checkkwd = 2;
 463                         if ((t = readtoken()) != TESAC) {
 464                                 if (t != TENDCASE)
 465                                         noaliases = 0, synexpect(TENDCASE);
 466                                 else
 467                                         checkkwd = 2, readtoken();
 468                         }
 469                         cpp = &cp->nclist.next;
 470                 }
 471                 noaliases = 0;  /* reset alias expansion */
 472                 *cpp = NULL;
 473                 checkkwd = 1;
 474                 break;
 475         case TLP:
 476                 n1 = (union node *)stalloc(sizeof (struct nredir));
 477                 n1->type = NSUBSHELL;
 478                 n1->nredir.n = list(0);
 479                 n1->nredir.redirect = NULL;
 480                 if (readtoken() != TRP)
 481                         synexpect(TRP);
 482                 checkkwd = 1;
 483                 break;
 484         case TBEGIN:
 485                 n1 = list(0);
 486                 if (readtoken() != TEND)
 487                         synexpect(TEND);
 488                 checkkwd = 1;
 489                 break;
 490         /* Handle an empty command like other simple commands.  */
 491         case TSEMI:
 492         case TAND:
 493         case TOR:
 494                 /*
 495                  * An empty command before a ; doesn't make much sense, and
 496                  * should certainly be disallowed in the case of `if ;'.
 497                  */
 498                 if (!redir)
 499                         synexpect(-1);
 500         case TNL:
 501         case TEOF:
 502         case TWORD:
 503         case TRP:
 504                 tokpushback++;
 505                 return simplecmd(rpp, redir);
 506         default:
 507                 synexpect(-1);
 508         }
 509
 510         /* Now check for redirection which may follow command */
 511         while (readtoken() == TREDIR) {
 512                 *rpp = n2 = redirnode;
 513                 rpp = &n2->nfile.next;
 514                 parsefname();
 515         }
 516         tokpushback++;
 517         *rpp = NULL;
 518         if (redir) {
 519                 if (n1->type != NSUBSHELL) {
 520                         n2 = (union node *)stalloc(sizeof (struct nredir));
 521                         n2->type = NREDIR;
 522                         n2->nredir.n = n1;
 523                         n1 = n2;
 524                 }
 525                 n1->nredir.redirect = redir;
 526         }
 527         return n1;
 528 }
 529
 530
 531 STATIC union node *
 532 simplecmd(union node **rpp, union node *redir)
 533 {
 534         union node *args, **app;
 535         union node **orig_rpp = rpp;
 536         union node *n = NULL;
 537
 538         /* If we don't have any redirections already, then we must reset */
 539         /* rpp to be the address of the local redir variable.  */
 540         if (redir == 0)
 541                 rpp = &redir;
 542
 543         args = NULL;
 544         app = &args;
 545         /*
 546          * We save the incoming value, because we need this for shell
 547          * functions.  There can not be a redirect or an argument between
 548          * the function name and the open parenthesis.
 549          */
 550         orig_rpp = rpp;
 551
 552         for (;;) {
 553                 if (readtoken() == TWORD) {
 554                         n = (union node *)stalloc(sizeof (struct narg));
 555                         n->type = NARG;
 556                         n->narg.text = wordtext;
 557                         n->narg.backquote = backquotelist;
 558                         *app = n;
 559                         app = &n->narg.next;
 560                 } else if (lasttoken == TREDIR) {
 561                         *rpp = n = redirnode;
 562                         rpp = &n->nfile.next;
 563                         parsefname();   /* read name of redirection file */
 564                 } else if (lasttoken == TLP && app == &args->narg.next
 565                                             && rpp == orig_rpp) {
 566                         /* We have a function */
 567                         if (readtoken() != TRP)
 568                                 synexpect(TRP);
 569 #ifdef notdef
 570                         if (! goodname(n->narg.text))
 571                                 synerror("Bad function name");
 572 #endif
 573                         n->type = NDEFUN;
 574                         n->narg.next = command();
 575                         return n;
 576                 } else {
 577                         tokpushback++;
 578                         break;
 579                 }
 580         }
 581         *app = NULL;
 582         *rpp = NULL;
 583         n = (union node *)stalloc(sizeof (struct ncmd));
 584         n->type = NCMD;
 585         n->ncmd.backgnd = 0;
 586         n->ncmd.args = args;
 587         n->ncmd.redirect = redir;
 588         return n;
 589 }
 590
 591 STATIC union node *
 592 makename(void)
 593 {
 594         union node *n;
 595
 596         n = (union node *)stalloc(sizeof (struct narg));
 597         n->type = NARG;
 598         n->narg.next = NULL;
 599         n->narg.text = wordtext;
 600         n->narg.backquote = backquotelist;
 601         return n;
 602 }
 603
 604 void
 605 fixredir(union node *n, const char *text, int err)
 606 {
 607         TRACE(("Fix redir %s %d\n", text, err));
 608         if (!err)
 609                 n->ndup.vname = NULL;
 610
 611         if (is_digit(text[0]) && text[1] == '\0')
 612                 n->ndup.dupfd = digit_val(text[0]);
 613         else if (text[0] == '-' && text[1] == '\0')
 614                 n->ndup.dupfd = -1;
 615         else {
 616
 617                 if (err)
 618                         synerror("Bad fd number");
 619                 else
 620                         n->ndup.vname = makename();
 621         }
 622 }
 623
 624
 625 STATIC void
 626 parsefname(void)
 627 {
 628         union node *n = redirnode;
 629
 630         if (readtoken() != TWORD)
 631                 synexpect(-1);
 632         if (n->type == NHERE) {
 633                 struct heredoc *here = heredoc;
 634                 struct heredoc *p;
 635                 int i;
 636
 637                 if (quoteflag == 0)
 638                         n->type = NXHERE;
 639                 TRACE(("Here document %d\n", n->type));
 640                 if (here->striptabs) {
 641                         while (*wordtext == '\t')
 642                                 wordtext++;
 643                 }
 644                 if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN)
 645                         synerror("Illegal eof marker for << redirection");
 646                 rmescapes(wordtext);
 647                 here->eofmark = wordtext;
 648                 here->next = NULL;
 649                 if (heredoclist == NULL)
 650                         heredoclist = here;
 651                 else {
 652                         for (p = heredoclist ; p->next ; p = p->next);
 653                         p->next = here;
 654                 }
 655         } else if (n->type == NTOFD || n->type == NFROMFD) {
 656                 fixredir(n, wordtext, 0);
 657         } else {
 658                 n->nfile.fname = makename();
 659         }
 660 }
 661
 662
 663 /*
 664  * Input any here documents.
 665  */
 666
 667 STATIC void
 668 parseheredoc(void)
 669 {
 670         struct heredoc *here;
 671         union node *n;
 672
 673         while (heredoclist) {
 674                 here = heredoclist;
 675                 heredoclist = here->next;
 676                 if (needprompt) {
 677                         setprompt(2);
 678                         needprompt = 0;
 679                 }
 680                 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX,
 681                                 here->eofmark, here->striptabs);
 682                 n = (union node *)stalloc(sizeof (struct narg));
 683                 n->narg.type = NARG;
 684                 n->narg.next = NULL;
 685                 n->narg.text = wordtext;
 686                 n->narg.backquote = backquotelist;
 687                 here->here->nhere.doc = n;
 688         }
 689 }
 690
 691 STATIC int
 692 peektoken(void)
 693 {
 694         int t;
 695
 696         t = readtoken();
 697         tokpushback++;
 698         return (t);
 699 }
 700
 701 STATIC int
 702 readtoken(void)
 703 {
 704         int t;
 705         int savecheckkwd = checkkwd;
 706         struct alias *ap;
 707 #ifdef DEBUG
 708         int alreadyseen = tokpushback;
 709 #endif
 710
 711         top:
 712         t = xxreadtoken();
 713
 714         if (checkkwd) {
 715                 /*
 716                  * eat newlines
 717                  */
 718                 if (checkkwd > 1) {
 719                         checkkwd = 0;
 720                         while (t == TNL) {
 721                                 parseheredoc();
 722                                 t = xxreadtoken();
 723                         }
 724                 } else
 725                         checkkwd = 0;
 726                 /*
 727                  * check for keywords and aliases
 728                  */
 729                 if (t == TWORD && !quoteflag)
 730                 {
 731                         const char * const *pp;
 732
 733                         for (pp = parsekwd; *pp; pp++) {
 734                                 if (**pp == *wordtext && equal(*pp, wordtext))
 735                                 {
 736                                         lasttoken = t = pp - parsekwd + KWDOFFSET;
 737                                         TRACE(("keyword %s recognized\n", tokname[t]));
 738                                         goto out;
 739                                 }
 740                         }
 741                         if (noaliases == 0 &&
 742                             (ap = lookupalias(wordtext, 1)) != NULL) {
 743                                 pushstring(ap->val, strlen(ap->val), ap);
 744                                 checkkwd = savecheckkwd;
 745                                 goto top;
 746                         }
 747                 }
 748 out:
 749                 checkkwd = 0;
 750         }
 751 #ifdef DEBUG
 752         if (!alreadyseen)
 753             TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
 754         else
 755             TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
 756 #endif
 757         return (t);
 758 }
 759
 760
 761 /*
 762  * Read the next input token.
 763  * If the token is a word, we set backquotelist to the list of cmds in
 764  *      backquotes.  We set quoteflag to true if any part of the word was
 765  *      quoted.
 766  * If the token is TREDIR, then we set redirnode to a structure containing
 767  *      the redirection.
 768  * In all cases, the variable startlinno is set to the number of the line
 769  *      on which the token starts.
 770  *
 771  * [Change comment:  here documents and internal procedures]
 772  * [Readtoken shouldn't have any arguments.  Perhaps we should make the
 773  *  word parsing code into a separate routine.  In this case, readtoken
 774  *  doesn't need to have any internal procedures, but parseword does.
 775  *  We could also make parseoperator in essence the main routine, and
 776  *  have parseword (readtoken1?) handle both words and redirection.]
 777  */
 778
 779 #define RETURN(token)   return lasttoken = token
 780
 781 STATIC int
 782 xxreadtoken(void)
 783 {
 784         int c;
 785
 786         if (tokpushback) {
 787                 tokpushback = 0;
 788                 return lasttoken;
 789         }
 790         if (needprompt) {
 791                 setprompt(2);
 792                 needprompt = 0;
 793         }
 794         startlinno = plinno;
 795         for (;;) {      /* until token or start of word found */
 796                 c = pgetc_macro();
 797                 if (c == ' ' || c == '\t')
 798                         continue;               /* quick check for white space first */
 799                 switch (c) {
 800                 case ' ': case '\t':
 801                         continue;
 802                 case '#':
 803                         while ((c = pgetc()) != '\n' && c != PEOF);
 804                         pungetc();
 805                         continue;
 806                 case '\\':
 807                         if (pgetc() == '\n') {
 808                                 startlinno = ++plinno;
 809                                 if (doprompt)
 810                                         setprompt(2);
 811                                 else
 812                                         setprompt(0);
 813                                 continue;
 814                         }
 815                         pungetc();
 816                         goto breakloop;
 817                 case '\n':
 818                         plinno++;
 819                         needprompt = doprompt;
 820                         RETURN(TNL);
 821                 case PEOF:
 822                         RETURN(TEOF);
 823                 case '&':
 824                         if (pgetc() == '&')
 825                                 RETURN(TAND);
 826                         pungetc();
 827                         RETURN(TBACKGND);
 828                 case '|':
 829                         if (pgetc() == '|')
 830                                 RETURN(TOR);
 831                         pungetc();
 832                         RETURN(TPIPE);
 833                 case ';':
 834                         if (pgetc() == ';')
 835                                 RETURN(TENDCASE);
 836                         pungetc();
 837                         RETURN(TSEMI);
 838                 case '(':
 839                         RETURN(TLP);
 840                 case ')':
 841                         RETURN(TRP);
 842                 case '!':
 843                         if (checkkwd == 3)
 844                                 RETURN(TNOT);
 845                         /* else FALLTHROUGH */
 846                 default:
 847                         goto breakloop;
 848                 }
 849         }
 850 breakloop:
 851         return readtoken1(c, BASESYNTAX, NULL, 0);
 852 #undef RETURN
 853 }
 854
 855
 856
 857 /*
 858  * If eofmark is NULL, read a word or a redirection symbol.  If eofmark
 859  * is not NULL, read a here document.  In the latter case, eofmark is the
 860  * word which marks the end of the document and striptabs is true if
 861  * leading tabs should be stripped from the document.  The argument firstc
 862  * is the first character of the input token or document.
 863  *
 864  * Because C does not have internal subroutines, I have simulated them
 865  * using goto's to implement the subroutine linkage.  The following macros
 866  * will run code that appears at the end of readtoken1.
 867  */
 868
 869 #define CHECKEND()      {goto checkend; checkend_return:;}
 870 #define PARSEREDIR()    {goto parseredir; parseredir_return:;}
 871 #define PARSESUB()      {goto parsesub; parsesub_return:;}
 872 #define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;}
 873 #define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;}
 874 #define PARSEARITH()    {goto parsearith; parsearith_return:;}
 875
 876 STATIC int
 877 readtoken1(int firstc, char const *syn, char *eofmark, int striptabs)
 878 {
 879         int c = firstc;
 880         char const * volatile syntax = syn;
 881         char * volatile out;
 882         int len;
 883         char line[EOFMARKLEN + 1];
 884         struct nodelist *bqlist;
 885         volatile int quotef;
 886         volatile int dblquote;
 887         volatile int varnest;   /* levels of variables expansion */
 888         volatile int arinest;   /* levels of arithmetic expansion */
 889         volatile int parenlevel;        /* levels of parens in arithmetic */
 890         volatile int oldstyle;
 891         char const * volatile prevsyntax = NULL;        /* syntax before arithmetic */
 892         int synentry;
 893
 894         startlinno = plinno;
 895         dblquote = 0;
 896         if (syntax == DQSYNTAX)
 897                 dblquote = 1;
 898         quotef = 0;
 899         bqlist = NULL;
 900         varnest = 0;
 901         arinest = 0;
 902         parenlevel = 0;
 903
 904         STARTSTACKSTR(out);
 905         loop: { /* for each line, until end of word */
 906                 CHECKEND();     /* set c to PEOF if at end of here document */
 907                 for (;;) {      /* until end of line or end of word */
 908                         CHECKSTRSPACE(3, out);  /* permit 3 calls to USTPUTC */
 909
 910                         synentry = syntax[c];
 911
 912                         switch(synentry) {
 913                         case CNL:       /* '\n' */
 914                                 if (syntax == BASESYNTAX)
 915                                         goto endword;   /* exit outer loop */
 916                                 USTPUTC(c, out);
 917                                 plinno++;
 918                                 if (doprompt)
 919                                         setprompt(2);
 920                                 else
 921                                         setprompt(0);
 922                                 c = pgetc();
 923                                 goto loop;              /* continue outer loop */
 924                         case CWORD:
 925                                 USTPUTC(c, out);
 926                                 break;
 927                         case CCTL:
 928                                 if (eofmark == NULL || dblquote)
 929                                         USTPUTC(CTLESC, out);
 930                                 USTPUTC(c, out);
 931                                 break;
 932                         case CBACK:     /* backslash */
 933                                 c = pgetc();
 934                                 if (c == PEOF) {
 935                                         USTPUTC('\\', out);
 936                                         pungetc();
 937                                 } else if (c == '\n') {
 938                                         plinno++;
 939                                         if (doprompt)
 940                                                 setprompt(2);
 941                                         else
 942                                                 setprompt(0);
 943                                 } else {
 944                                         if (dblquote && c != '\\' &&
 945                                             c != '`' && c != '$' &&
 946                                             (c != '"' || eofmark != NULL))
 947                                                 USTPUTC('\\', out);
 948                                         if (SQSYNTAX[c] == CCTL)
 949                                                 USTPUTC(CTLESC, out);
 950                                         else if (eofmark == NULL)
 951                                                 USTPUTC(CTLQUOTEMARK, out);
 952                                         USTPUTC(c, out);
 953                                         quotef++;
 954                                 }
 955                                 break;
 956                         case CSQUOTE:
 957                                 if (eofmark == NULL)
 958                                         USTPUTC(CTLQUOTEMARK, out);
 959                                 syntax = SQSYNTAX;
 960                                 break;
 961                         case CDQUOTE:
 962                                 if (eofmark == NULL)
 963                                         USTPUTC(CTLQUOTEMARK, out);
 964                                 syntax = DQSYNTAX;
 965                                 dblquote = 1;
 966                                 break;
 967                         case CENDQUOTE:
 968                                 if (eofmark != NULL && arinest == 0 &&
 969                                     varnest == 0) {
 970                                         USTPUTC(c, out);
 971                                 } else {
 972                                         if (arinest) {
 973                                                 syntax = ARISYNTAX;
 974                                                 dblquote = 0;
 975                                         } else if (eofmark == NULL) {
 976                                                 syntax = BASESYNTAX;
 977                                                 dblquote = 0;
 978                                         }
 979                                         quotef++;
 980                                 }
 981                                 break;
 982                         case CVAR:      /* '$' */
 983                                 PARSESUB();             /* parse substitution */
 984                                 break;
 985                         case CENDVAR:   /* '}' */
 986                                 if (varnest > 0) {
 987                                         varnest--;
 988                                         USTPUTC(CTLENDVAR, out);
 989                                 } else {
 990                                         USTPUTC(c, out);
 991                                 }
 992                                 break;
 993                         case CLP:       /* '(' in arithmetic */
 994                                 parenlevel++;
 995                                 USTPUTC(c, out);
 996                                 break;
 997                         case CRP:       /* ')' in arithmetic */
 998                                 if (parenlevel > 0) {
 999                                         USTPUTC(c, out);
1000                                         --parenlevel;
1001                                 } else {
1002                                         if (pgetc() == ')') {
1003                                                 if (--arinest == 0) {
1004                                                         USTPUTC(CTLENDARI, out);
1005                                                         syntax = prevsyntax;
1006                                                         if (syntax == DQSYNTAX)
1007                                                                 dblquote = 1;
1008                                                         else
1009                                                                 dblquote = 0;
1010                                                 } else
1011                                                         USTPUTC(')', out);
1012                                         } else {
1013                                                 /*
1014                                                  * unbalanced parens
1015                                                  *  (don't 2nd guess - no error)
1016                                                  */
1017                                                 pungetc();
1018                                                 USTPUTC(')', out);
1019                                         }
1020                                 }
1021                                 break;
1022                         case CBQUOTE:   /* '`' */
1023                                 PARSEBACKQOLD();
1024                                 break;
1025                         case CEOF:
1026                                 goto endword;           /* exit outer loop */
1027                         default:
1028                                 if (varnest == 0)
1029                                         goto endword;   /* exit outer loop */
1030                                 USTPUTC(c, out);
1031                         }
1032                         c = pgetc_macro();
1033                 }
1034         }
1035 endword:
1036         if (syntax == ARISYNTAX)
1037                 synerror("Missing '))'");
1038         if (syntax != BASESYNTAX && ! parsebackquote && eofmark == NULL)
1039                 synerror("Unterminated quoted string");
1040         if (varnest != 0) {
1041                 startlinno = plinno;
1042                 synerror("Missing '}'");
1043         }
1044         USTPUTC('\0', out);
1045         len = out - stackblock();
1046         out = stackblock();
1047         if (eofmark == NULL) {
1048                 if ((c == '>' || c == '<')
1049                  && quotef == 0
1050                  && len <= 2
1051                  && (*out == '\0' || is_digit(*out))) {
1052                         PARSEREDIR();
1053                         return lasttoken = TREDIR;
1054                 } else {
1055                         pungetc();
1056                 }
1057         }
1058         quoteflag = quotef;
1059         backquotelist = bqlist;
1060         grabstackblock(len);
1061         wordtext = out;
1062         return lasttoken = TWORD;
1063 /* end of readtoken routine */
1064
1065
1066
1067 /*
1068  * Check to see whether we are at the end of the here document.  When this
1069  * is called, c is set to the first character of the next input line.  If
1070  * we are at the end of the here document, this routine sets the c to PEOF.
1071  */
1072
1073 checkend: {
1074         if (eofmark) {
1075                 if (striptabs) {
1076                         while (c == '\t')
1077                                 c = pgetc();
1078                 }
1079                 if (c == *eofmark) {
1080                         if (pfgets(line, sizeof line) != NULL) {
1081                                 char *p, *q;
1082
1083                                 p = line;
1084                                 for (q = eofmark + 1 ; *q && *p == *q ; p++, q++);
1085                                 if (*p == '\n' && *q == '\0') {
1086                                         c = PEOF;
1087                                         plinno++;
1088                                         needprompt = doprompt;
1089                                 } else {
1090                                         pushstring(line, strlen(line), NULL);
1091                                 }
1092                         }
1093                 }
1094         }
1095         goto checkend_return;
1096 }
1097
1098
1099 /*
1100  * Parse a redirection operator.  The variable "out" points to a string
1101  * specifying the fd to be redirected.  The variable "c" contains the
1102  * first character of the redirection operator.
1103  */
1104
1105 parseredir: {
1106         char fd = *out;
1107         union node *np;
1108
1109         np = (union node *)stalloc(sizeof (struct nfile));
1110         if (c == '>') {
1111                 np->nfile.fd = 1;
1112                 c = pgetc();
1113                 if (c == '>')
1114                         np->type = NAPPEND;
1115                 else if (c == '&')
1116                         np->type = NTOFD;
1117                 else if (c == '|')
1118                         np->type = NCLOBBER;
1119                 else {
1120                         np->type = NTO;
1121                         pungetc();
1122                 }
1123         } else {        /* c == '<' */
1124                 np->nfile.fd = 0;
1125                 c = pgetc();
1126                 if (c == '<') {
1127                         if (sizeof (struct nfile) != sizeof (struct nhere)) {
1128                                 np = (union node *)stalloc(sizeof (struct nhere));
1129                                 np->nfile.fd = 0;
1130                         }
1131                         np->type = NHERE;
1132                         heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc));
1133                         heredoc->here = np;
1134                         if ((c = pgetc()) == '-') {
1135                                 heredoc->striptabs = 1;
1136                         } else {
1137                                 heredoc->striptabs = 0;
1138                                 pungetc();
1139                         }
1140                 } else if (c == '&')
1141                         np->type = NFROMFD;
1142                 else if (c == '>')
1143                         np->type = NFROMTO;
1144                 else {
1145                         np->type = NFROM;
1146                         pungetc();
1147                 }
1148         }
1149         if (fd != '\0')
1150                 np->nfile.fd = digit_val(fd);
1151         redirnode = np;
1152         goto parseredir_return;
1153 }
1154
1155
1156 /*
1157  * Parse a substitution.  At this point, we have read the dollar sign
1158  * and nothing else.
1159  */
1160
1161 parsesub: {
1162         int subtype;
1163         int typeloc;
1164         int flags;
1165         char *p;
1166         static const char types[] = "}-+?=";
1167        int bracketed_name = 0; /* used to handle ${[0-9]*} variables */
1168
1169         c = pgetc();
1170         if (c != '(' && c != '{' && (is_eof(c) || !is_name(c)) &&
1171             !is_special(c)) {
1172                 USTPUTC('$', out);
1173                 pungetc();
1174         } else if (c == '(') {  /* $(command) or $((arith)) */
1175                 if (pgetc() == '(') {
1176                         PARSEARITH();
1177                 } else {
1178                         pungetc();
1179                         PARSEBACKQNEW();
1180                 }
1181         } else {
1182                 USTPUTC(CTLVAR, out);
1183                 typeloc = out - stackblock();
1184                 USTPUTC(VSNORMAL, out);
1185                 subtype = VSNORMAL;
1186                 if (c == '{') {
1187                         bracketed_name = 1;
1188                         c = pgetc();
1189                         if (c == '#') {
1190                                 if ((c = pgetc()) == '}')
1191                                         c = '#';
1192                                 else
1193                                         subtype = VSLENGTH;
1194                         }
1195                         else
1196                                 subtype = 0;
1197                 }
1198                 if (!is_eof(c) && is_name(c)) {
1199                         do {
1200                                 STPUTC(c, out);
1201                                 c = pgetc();
1202                         } while (!is_eof(c) && is_in_name(c));
1203                 } else if (is_digit(c)) {
1204                         if (bracketed_name) {
1205                                 do {
1206                                         STPUTC(c, out);
1207                                         c = pgetc();
1208                                 } while (is_digit(c));
1209                         } else {
1210                                 STPUTC(c, out);
1211                                 c = pgetc();
1212                         }
1213                 } else {
1214                         if (! is_special(c)) {
1215                                 subtype = VSERROR;
1216                                 if (c == '}')
1217                                         pungetc();
1218                                 else
1219                                         USTPUTC(c, out);
1220                         } else {
1221                                 USTPUTC(c, out);
1222                                 c = pgetc();
1223                         }
1224                 }
1225                 flags = 0;
1226                 if (subtype == 0) {
1227                         switch (c) {
1228                         case ':':
1229                                 flags = VSNUL;
1230                                 c = pgetc();
1231                                 /*FALLTHROUGH*/
1232                         default:
1233                                 p = strchr(types, c);
1234                                 if (p == NULL) {
1235                                         if (flags == VSNUL)
1236                                                 STPUTC(':', out);
1237                                         STPUTC(c, out);
1238                                         subtype = VSERROR;
1239                                 } else
1240                                         subtype = p - types + VSNORMAL;
1241                                 break;
1242                         case '%':
1243                         case '#':
1244                                 {
1245                                         int cc = c;
1246                                         subtype = c == '#' ? VSTRIMLEFT :
1247                                                              VSTRIMRIGHT;
1248                                         c = pgetc();
1249                                         if (c == cc)
1250                                                 subtype++;
1251                                         else
1252                                                 pungetc();
1253                                         break;
1254                                 }
1255                         }
1256                 } else if (subtype != VSERROR) {
1257                         pungetc();
1258                 }
1259                 STPUTC('=', out);
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         volatile int saveprompt;
1286
1287         savepbq = parsebackquote;
1288         if (setjmp(jmploc.loc)) {
1289                 if (str)
1290                         ckfree(str);
1291                 parsebackquote = 0;
1292                 handler = savehandler;
1293                 longjmp(handler->loc, 1);
1294         }
1295         INTOFF;
1296         str = NULL;
1297         savelen = out - stackblock();
1298         if (savelen > 0) {
1299                 str = ckmalloc(savelen);
1300                 memcpy(str, stackblock(), savelen);
1301         }
1302         savehandler = handler;
1303         handler = &jmploc;
1304         INTON;
1305         if (oldstyle) {
1306                 /* We must read until the closing backquote, giving special
1307                    treatment to some slashes, and then push the string and
1308                    reread it as input, interpreting it normally.  */
1309                 char *pout;
1310                 int pc;
1311                 int psavelen;
1312                 char *pstr;
1313
1314
1315                 STARTSTACKSTR(pout);
1316                 for (;;) {
1317                         if (needprompt) {
1318                                 setprompt(2);
1319                                 needprompt = 0;
1320                         }
1321                         switch (pc = pgetc()) {
1322                         case '`':
1323                                 goto done;
1324
1325                         case '\\':
1326                                 if ((pc = pgetc()) == '\n') {
1327                                         plinno++;
1328                                         if (doprompt)
1329                                                 setprompt(2);
1330                                         else
1331                                                 setprompt(0);
1332                                         /*
1333                                          * If eating a newline, avoid putting
1334                                          * the newline into the new character
1335                                          * stream (via the STPUTC after the
1336                                          * switch).
1337                                          */
1338                                         continue;
1339                                 }
1340                                 if (pc != '\\' && pc != '`' && pc != '$'
1341                                     && (!dblquote || pc != '"'))
1342                                         STPUTC('\\', pout);
1343                                 break;
1344
1345                         case '\n':
1346                                 plinno++;
1347                                 needprompt = doprompt;
1348                                 break;
1349
1350                         case PEOF:
1351                                 startlinno = plinno;
1352                                 synerror("EOF in backquote substitution");
1353                                 break;
1354
1355                         default:
1356                                 break;
1357                         }
1358                         STPUTC(pc, pout);
1359                 }
1360 done:
1361                 STPUTC('\0', pout);
1362                 psavelen = pout - stackblock();
1363                 if (psavelen > 0) {
1364                         pstr = ckmalloc(psavelen);
1365                         memcpy(pstr, stackblock(), psavelen);
1366                         setinputstring(pstr, 1);
1367                 }
1368         }
1369         nlpp = &bqlist;
1370         while (*nlpp)
1371                 nlpp = &(*nlpp)->next;
1372         *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist));
1373         (*nlpp)->next = NULL;
1374         parsebackquote = oldstyle;
1375
1376         if (oldstyle) {
1377                 saveprompt = doprompt;
1378                 doprompt = 0;
1379         }
1380
1381         n = list(0);
1382
1383         if (oldstyle)
1384                 doprompt = saveprompt;
1385         else {
1386                 if (readtoken() != TRP)
1387                         synexpect(TRP);
1388         }
1389
1390         (*nlpp)->n = n;
1391         if (oldstyle) {
1392                 /*
1393                  * Start reading from old file again, ignoring any pushed back
1394                  * tokens left from the backquote parsing
1395                  */
1396                 popfile();
1397                 tokpushback = 0;
1398         }
1399         while (stackblocksize() <= savelen)
1400                 growstackblock();
1401         STARTSTACKSTR(out);
1402         if (str) {
1403                 memcpy(out, str, savelen);
1404                 STADJUST(savelen, out);
1405                 INTOFF;
1406                 ckfree(str);
1407                 str = NULL;
1408                 INTON;
1409         }
1410         parsebackquote = savepbq;
1411         handler = savehandler;
1412         if (arinest || dblquote)
1413                 USTPUTC(CTLBACKQ | CTLQUOTE, out);
1414         else
1415                 USTPUTC(CTLBACKQ, out);
1416         if (oldstyle)
1417                 goto parsebackq_oldreturn;
1418         else
1419                 goto parsebackq_newreturn;
1420 }
1421
1422 /*
1423  * Parse an arithmetic expansion (indicate start of one and set state)
1424  */
1425 parsearith: {
1426
1427         if (++arinest == 1) {
1428                 prevsyntax = syntax;
1429                 syntax = ARISYNTAX;
1430                 USTPUTC(CTLARI, out);
1431                 if (dblquote)
1432                         USTPUTC('"',out);
1433                 else
1434                         USTPUTC(' ',out);
1435         } else {
1436                 /*
1437                  * we collapse embedded arithmetic expansion to
1438                  * parenthesis, which should be equivalent
1439                  */
1440                 USTPUTC('(', out);
1441         }
1442         goto parsearith_return;
1443 }
1444
1445 } /* end of readtoken */
1446
1447
1448
1449 #ifdef mkinit
1450 RESET {
1451         tokpushback = 0;
1452         checkkwd = 0;
1453 }
1454 #endif
1455
1456 /*
1457  * Returns true if the text contains nothing to expand (no dollar signs
1458  * or backquotes).
1459  */
1460
1461 STATIC int
1462 noexpand(char *text)
1463 {
1464         char *p;
1465         char c;
1466
1467         p = text;
1468         while ((c = *p++) != '\0') {
1469                 if ( c == CTLQUOTEMARK)
1470                         continue;
1471                 if (c == CTLESC)
1472                         p++;
1473                 else if (BASESYNTAX[(int)c] == CCTL)
1474                         return 0;
1475         }
1476         return 1;
1477 }
1478
1479
1480 /*
1481  * Return true if the argument is a legal variable name (a letter or
1482  * underscore followed by zero or more letters, underscores, and digits).
1483  */
1484
1485 int
1486 goodname(char *name)
1487 {
1488         char *p;
1489
1490         p = name;
1491         if (! is_name(*p))
1492                 return 0;
1493         while (*++p) {
1494                 if (! is_in_name(*p))
1495                         return 0;
1496         }
1497         return 1;
1498 }
1499
1500
1501 /*
1502  * Called when an unexpected token is read during the parse.  The argument
1503  * is the token that is expected, or -1 if more than one type of token can
1504  * occur at this point.
1505  */
1506
1507 STATIC void
1508 synexpect(int token)
1509 {
1510         char msg[64];
1511
1512         if (token >= 0) {
1513                 fmtstr(msg, 64, "%s unexpected (expecting %s)",
1514                         tokname[lasttoken], tokname[token]);
1515         } else {
1516                 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]);
1517         }
1518         synerror(msg);
1519 }
1520
1521
1522 STATIC void
1523 synerror(const char *msg)
1524 {
1525         if (commandname)
1526                 outfmt(&errout, "%s: %d: ", commandname, startlinno);
1527         outfmt(&errout, "Syntax error: %s\n", msg);
1528         error(NULL);
1529 }
1530
1531 STATIC void
1532 setprompt(int which)
1533 {
1534         whichprompt = which;
1535
1536 #ifndef NO_HISTORY
1537         if (!el)
1538 #endif
1539                 out2str(getprompt(NULL));
1540 }
1541
1542 /*
1543  * called by editline -- any expansions to the prompt
1544  *    should be added here.
1545  */
1546 const char *
1547 getprompt(void *unused __unused)
1548 {
1549         static char ps[PROMPTLEN];
1550         const char *fmt;
1551         int i, j, trim;
1552
1553         /*
1554          * Select prompt format.
1555          */
1556         switch (whichprompt) {
1557         case 0:
1558                 fmt = "";
1559                 break;
1560         case 1:
1561                 fmt = ps1val();
1562                 break;
1563         case 2:
1564                 fmt = ps2val();
1565                 break;
1566         default:
1567                 return "<internal prompt error>";
1568         }
1569
1570         /*
1571          * Format prompt string.
1572          */
1573         for (i = 0; (i < 127) && (*fmt != '\0'); i++, fmt++)
1574                 if (*fmt == '\\')
1575                         switch (*++fmt) {
1576
1577                                 /*
1578                                  * Hostname.
1579                                  *
1580                                  * \h specifies just the local hostname,
1581                                  * \H specifies fully-qualified hostname.
1582                                  */
1583                         case 'h':
1584                         case 'H':
1585                                 ps[i] = '\0';
1586                                 gethostname(&ps[i], PROMPTLEN - i);
1587                                 /* Skip to end of hostname. */
1588                                 trim = (*fmt == 'h') ? '.' : '\0';
1589                                 while ((ps[i+1] != '\0') && (ps[i+1] != trim))
1590                                         i++;
1591                                 break;
1592
1593                                 /*
1594                                  * Working directory.
1595                                  *
1596                                  * \W specifies just the final component,
1597                                  * \w specifies the entire path.
1598                                  */
1599                         case 'W':
1600                         case 'w':
1601                                 ps[i] = '\0';
1602                                 getcwd(&ps[i], PROMPTLEN - i);
1603                                 if (*fmt == 'W') {
1604                                         /* Final path component only. */
1605                                         trim = 1;
1606                                         for (j = i; ps[j] != '\0'; j++)
1607                                           if (ps[j] == '/')
1608                                                 trim = j + 1;
1609                                         memmove(&ps[i], &ps[trim],
1610                                             j - trim + 1);
1611                                 }
1612                                 /* Skip to end of path. */
1613                                 while (ps[i + 1] != '\0')
1614                                         i++;
1615                                 break;
1616
1617                                 /*
1618                                  * Superuser status.
1619                                  *
1620                                  * '$' for normal users, '#' for root.
1621                                  */
1622                         case '$':
1623                                 ps[i] = (geteuid() != 0) ? '$' : '#';
1624                                 break;
1625
1626                                 /*
1627                                  * A literal \.
1628                                  */
1629                         case '\\':
1630                                 ps[i] = '\\';
1631                                 break;
1632
1633                                 /*
1634                                  * Emit unrecognized formats verbatim.
1635                                  */
1636                         default:
1637                                 ps[i++] = '\\';
1638                                 ps[i] = *fmt;
1639                                 break;
1640                         }
1641                 else
1642                         ps[i] = *fmt;
1643         ps[i] = '\0';
1644         return (ps);
1645 }