1 /* $NetBSD: parser.c,v 1.53 2002/05/15 16:33:35 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Kenneth Almquist. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #ifndef lint 41 #if 0 42 static char sccsid[] = "@(#)parser.c 8.7 (Berkeley) 5/16/95"; 43 #else 44 __RCSID("$NetBSD: parser.c,v 1.53 2002/05/15 16:33:35 christos Exp $"); 45 #endif 46 #endif /* not lint */ 47 48 #include <stdlib.h> 49 50 #include "shell.h" 51 #include "parser.h" 52 #include "nodes.h" 53 #include "expand.h" /* defines rmescapes() */ 54 #include "eval.h" /* defines commandname */ 55 #include "redir.h" /* defines copyfd() */ 56 #include "syntax.h" 57 #include "options.h" 58 #include "input.h" 59 #include "output.h" 60 #include "var.h" 61 #include "error.h" 62 #include "memalloc.h" 63 #include "mystring.h" 64 #include "alias.h" 65 #include "show.h" 66 #ifndef SMALL 67 #include "myhistedit.h" 68 #endif 69 70 /* 71 * Shell command parser. 72 */ 73 74 #define EOFMARKLEN 79 75 76 /* values returned by readtoken */ 77 #include "token.h" 78 79 #define OPENBRACE '{' 80 #define CLOSEBRACE '}' 81 82 83 struct heredoc { 84 struct heredoc *next; /* next here document in list */ 85 union node *here; /* redirection node */ 86 char *eofmark; /* string indicating end of input */ 87 int striptabs; /* if set, strip leading tabs */ 88 }; 89 90 91 92 static int noalias = 0; /* when set, don't handle aliases */ 93 struct heredoc *heredoclist; /* list of here documents to read */ 94 int parsebackquote; /* nonzero if we are inside backquotes */ 95 int doprompt; /* if set, prompt the user */ 96 int needprompt; /* true if interactive and at start of line */ 97 int lasttoken; /* last token read */ 98 MKINIT int tokpushback; /* last token pushed back */ 99 char *wordtext; /* text of last word returned by readtoken */ 100 MKINIT int checkkwd; /* 1 == check for kwds, 2 == also eat newlines */ 101 struct nodelist *backquotelist; 102 union node *redirnode; 103 struct heredoc *heredoc; 104 int quoteflag; /* set if (part of) last token was quoted */ 105 int startlinno; /* line # where last token started */ 106 107 108 STATIC union node *list __P((int)); 109 STATIC union node *andor __P((void)); 110 STATIC union node *pipeline __P((void)); 111 STATIC union node *command __P((void)); 112 STATIC union node *simplecmd __P((union node **, union node *)); 113 STATIC union node *makename __P((void)); 114 STATIC void parsefname __P((void)); 115 STATIC void parseheredoc __P((void)); 116 STATIC int peektoken __P((void)); 117 STATIC int readtoken __P((void)); 118 STATIC int xxreadtoken __P((void)); 119 STATIC int readtoken1 __P((int, char const *, char *, int)); 120 STATIC int noexpand __P((char *)); 121 STATIC void synexpect __P((int)) __attribute__((noreturn)); 122 STATIC void synerror __P((const char *)) __attribute__((noreturn)); 123 STATIC void setprompt __P((int)); 124 125 126 /* 127 * Read and parse a command. Returns NEOF on end of file. (NULL is a 128 * valid parse tree indicating a blank line.) 129 */ 130 131 union node * 132 parsecmd(int interact) 133 { 134 int t; 135 136 tokpushback = 0; 137 doprompt = interact; 138 if (doprompt) 139 setprompt(1); 140 else 141 setprompt(0); 142 needprompt = 0; 143 t = readtoken(); 144 if (t == TEOF) 145 return NEOF; 146 if (t == TNL) 147 return NULL; 148 tokpushback++; 149 return list(1); 150 } 151 152 153 STATIC union node * 154 list(nlflag) 155 int nlflag; 156 { 157 union node *n1, *n2, *n3; 158 int tok; 159 160 checkkwd = 2; 161 if (nlflag == 0 && tokendlist[peektoken()]) 162 return NULL; 163 n1 = NULL; 164 for (;;) { 165 n2 = andor(); 166 tok = readtoken(); 167 if (tok == TBACKGND) { 168 if (n2->type == NCMD || n2->type == NPIPE) { 169 n2->ncmd.backgnd = 1; 170 } else if (n2->type == NREDIR) { 171 n2->type = NBACKGND; 172 } else { 173 n3 = (union node *)stalloc(sizeof (struct nredir)); 174 n3->type = NBACKGND; 175 n3->nredir.n = n2; 176 n3->nredir.redirect = NULL; 177 n2 = n3; 178 } 179 } 180 if (n1 == NULL) { 181 n1 = n2; 182 } 183 else { 184 n3 = (union node *)stalloc(sizeof (struct nbinary)); 185 n3->type = NSEMI; 186 n3->nbinary.ch1 = n1; 187 n3->nbinary.ch2 = n2; 188 n1 = n3; 189 } 190 switch (tok) { 191 case TBACKGND: 192 case TSEMI: 193 tok = readtoken(); 194 /* fall through */ 195 case TNL: 196 if (tok == TNL) { 197 parseheredoc(); 198 if (nlflag) 199 return n1; 200 } else { 201 tokpushback++; 202 } 203 checkkwd = 2; 204 if (tokendlist[peektoken()]) 205 return n1; 206 break; 207 case TEOF: 208 if (heredoclist) 209 parseheredoc(); 210 else 211 pungetc(); /* push back EOF on input */ 212 return n1; 213 default: 214 if (nlflag) 215 synexpect(-1); 216 tokpushback++; 217 return n1; 218 } 219 } 220 } 221 222 223 224 STATIC union node * 225 andor() { 226 union node *n1, *n2, *n3; 227 int t; 228 229 n1 = pipeline(); 230 for (;;) { 231 if ((t = readtoken()) == TAND) { 232 t = NAND; 233 } else if (t == TOR) { 234 t = NOR; 235 } else { 236 tokpushback++; 237 return n1; 238 } 239 n2 = pipeline(); 240 n3 = (union node *)stalloc(sizeof (struct nbinary)); 241 n3->type = t; 242 n3->nbinary.ch1 = n1; 243 n3->nbinary.ch2 = n2; 244 n1 = n3; 245 } 246 } 247 248 249 250 STATIC union node * 251 pipeline() { 252 union node *n1, *n2, *pipenode; 253 struct nodelist *lp, *prev; 254 int negate; 255 256 negate = 0; 257 TRACE(("pipeline: entered\n")); 258 while (readtoken() == TNOT) 259 negate = !negate; 260 tokpushback++; 261 n1 = command(); 262 if (readtoken() == TPIPE) { 263 pipenode = (union node *)stalloc(sizeof (struct npipe)); 264 pipenode->type = NPIPE; 265 pipenode->npipe.backgnd = 0; 266 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 267 pipenode->npipe.cmdlist = lp; 268 lp->n = n1; 269 do { 270 prev = lp; 271 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 272 lp->n = command(); 273 prev->next = lp; 274 } while (readtoken() == TPIPE); 275 lp->next = NULL; 276 n1 = pipenode; 277 } 278 tokpushback++; 279 if (negate) { 280 n2 = (union node *)stalloc(sizeof (struct nnot)); 281 n2->type = NNOT; 282 n2->nnot.com = n1; 283 return n2; 284 } else 285 return n1; 286 } 287 288 289 290 STATIC union node * 291 command() { 292 union node *n1, *n2; 293 union node *ap, **app; 294 union node *cp, **cpp; 295 union node *redir, **rpp; 296 int t, negate = 0; 297 298 checkkwd = 2; 299 redir = NULL; 300 n1 = NULL; 301 rpp = &redir; 302 303 /* Check for redirection which may precede command */ 304 while (readtoken() == TREDIR) { 305 *rpp = n2 = redirnode; 306 rpp = &n2->nfile.next; 307 parsefname(); 308 } 309 tokpushback++; 310 311 while (readtoken() == TNOT) { 312 TRACE(("command: TNOT recognized\n")); 313 negate = !negate; 314 } 315 tokpushback++; 316 317 switch (readtoken()) { 318 case TIF: 319 n1 = (union node *)stalloc(sizeof (struct nif)); 320 n1->type = NIF; 321 n1->nif.test = list(0); 322 if (readtoken() != TTHEN) 323 synexpect(TTHEN); 324 n1->nif.ifpart = list(0); 325 n2 = n1; 326 while (readtoken() == TELIF) { 327 n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif)); 328 n2 = n2->nif.elsepart; 329 n2->type = NIF; 330 n2->nif.test = list(0); 331 if (readtoken() != TTHEN) 332 synexpect(TTHEN); 333 n2->nif.ifpart = list(0); 334 } 335 if (lasttoken == TELSE) 336 n2->nif.elsepart = list(0); 337 else { 338 n2->nif.elsepart = NULL; 339 tokpushback++; 340 } 341 if (readtoken() != TFI) 342 synexpect(TFI); 343 checkkwd = 1; 344 break; 345 case TWHILE: 346 case TUNTIL: { 347 int got; 348 n1 = (union node *)stalloc(sizeof (struct nbinary)); 349 n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL; 350 n1->nbinary.ch1 = list(0); 351 if ((got=readtoken()) != TDO) { 352 TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : "")); 353 synexpect(TDO); 354 } 355 n1->nbinary.ch2 = list(0); 356 if (readtoken() != TDONE) 357 synexpect(TDONE); 358 checkkwd = 1; 359 break; 360 } 361 case TFOR: 362 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext)) 363 synerror("Bad for loop variable"); 364 n1 = (union node *)stalloc(sizeof (struct nfor)); 365 n1->type = NFOR; 366 n1->nfor.var = wordtext; 367 if (readtoken() == TWORD && ! quoteflag && equal(wordtext, "in")) { 368 app = ≈ 369 while (readtoken() == TWORD) { 370 n2 = (union node *)stalloc(sizeof (struct narg)); 371 n2->type = NARG; 372 n2->narg.text = wordtext; 373 n2->narg.backquote = backquotelist; 374 *app = n2; 375 app = &n2->narg.next; 376 } 377 *app = NULL; 378 n1->nfor.args = ap; 379 if (lasttoken != TNL && lasttoken != TSEMI) 380 synexpect(-1); 381 } else { 382 static char argvars[5] = {CTLVAR, VSNORMAL|VSQUOTE, 383 '@', '=', '\0'}; 384 n2 = (union node *)stalloc(sizeof (struct narg)); 385 n2->type = NARG; 386 n2->narg.text = argvars; 387 n2->narg.backquote = NULL; 388 n2->narg.next = NULL; 389 n1->nfor.args = n2; 390 /* 391 * Newline or semicolon here is optional (but note 392 * that the original Bourne shell only allowed NL). 393 */ 394 if (lasttoken != TNL && lasttoken != TSEMI) 395 tokpushback++; 396 } 397 checkkwd = 2; 398 if ((t = readtoken()) == TDO) 399 t = TDONE; 400 else if (t == TBEGIN) 401 t = TEND; 402 else 403 synexpect(-1); 404 n1->nfor.body = list(0); 405 if (readtoken() != t) 406 synexpect(t); 407 checkkwd = 1; 408 break; 409 case TCASE: 410 n1 = (union node *)stalloc(sizeof (struct ncase)); 411 n1->type = NCASE; 412 if (readtoken() != TWORD) 413 synexpect(TWORD); 414 n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg)); 415 n2->type = NARG; 416 n2->narg.text = wordtext; 417 n2->narg.backquote = backquotelist; 418 n2->narg.next = NULL; 419 while (readtoken() == TNL); 420 if (lasttoken != TWORD || ! equal(wordtext, "in")) 421 synerror("expecting \"in\""); 422 cpp = &n1->ncase.cases; 423 noalias = 1; 424 checkkwd = 2, readtoken(); 425 do { 426 *cpp = cp = (union node *)stalloc(sizeof (struct nclist)); 427 cp->type = NCLIST; 428 app = &cp->nclist.pattern; 429 for (;;) { 430 *app = ap = (union node *)stalloc(sizeof (struct narg)); 431 ap->type = NARG; 432 ap->narg.text = wordtext; 433 ap->narg.backquote = backquotelist; 434 if (checkkwd = 2, readtoken() != TPIPE) 435 break; 436 app = &ap->narg.next; 437 readtoken(); 438 } 439 ap->narg.next = NULL; 440 noalias = 0; 441 if (lasttoken != TRP) { 442 synexpect(TRP); 443 } 444 cp->nclist.body = list(0); 445 446 checkkwd = 2; 447 if ((t = readtoken()) != TESAC) { 448 if (t != TENDCASE) { 449 noalias = 0; 450 synexpect(TENDCASE); 451 } else { 452 noalias = 1; 453 checkkwd = 2; 454 readtoken(); 455 } 456 } 457 cpp = &cp->nclist.next; 458 } while(lasttoken != TESAC); 459 noalias = 0; 460 *cpp = NULL; 461 checkkwd = 1; 462 break; 463 case TLP: 464 n1 = (union node *)stalloc(sizeof (struct nredir)); 465 n1->type = NSUBSHELL; 466 n1->nredir.n = list(0); 467 n1->nredir.redirect = NULL; 468 if (readtoken() != TRP) 469 synexpect(TRP); 470 checkkwd = 1; 471 break; 472 case TBEGIN: 473 n1 = list(0); 474 if (readtoken() != TEND) 475 synexpect(TEND); 476 checkkwd = 1; 477 break; 478 /* Handle an empty command like other simple commands. */ 479 case TSEMI: 480 /* 481 * An empty command before a ; doesn't make much sense, and 482 * should certainly be disallowed in the case of `if ;'. 483 */ 484 if (!redir) 485 synexpect(-1); 486 case TAND: 487 case TOR: 488 case TNL: 489 case TEOF: 490 case TWORD: 491 case TRP: 492 tokpushback++; 493 n1 = simplecmd(rpp, redir); 494 goto checkneg; 495 default: 496 synexpect(-1); 497 /* NOTREACHED */ 498 } 499 500 /* Now check for redirection which may follow command */ 501 while (readtoken() == TREDIR) { 502 *rpp = n2 = redirnode; 503 rpp = &n2->nfile.next; 504 parsefname(); 505 } 506 tokpushback++; 507 *rpp = NULL; 508 if (redir) { 509 if (n1->type != NSUBSHELL) { 510 n2 = (union node *)stalloc(sizeof (struct nredir)); 511 n2->type = NREDIR; 512 n2->nredir.n = n1; 513 n1 = n2; 514 } 515 n1->nredir.redirect = redir; 516 } 517 518 checkneg: 519 if (negate) { 520 n2 = (union node *)stalloc(sizeof (struct nnot)); 521 n2->type = NNOT; 522 n2->nnot.com = n1; 523 return n2; 524 } 525 else 526 return n1; 527 } 528 529 530 STATIC union node * 531 simplecmd(rpp, redir) 532 union node **rpp, *redir; 533 { 534 union node *args, **app; 535 union node **orig_rpp = rpp; 536 union node *n = NULL, *n2; 537 int negate = 0; 538 539 /* If we don't have any redirections already, then we must reset */ 540 /* rpp to be the address of the local redir variable. */ 541 if (redir == 0) 542 rpp = &redir; 543 544 args = NULL; 545 app = &args; 546 /* 547 * We save the incoming value, because we need this for shell 548 * functions. There can not be a redirect or an argument between 549 * the function name and the open parenthesis. 550 */ 551 orig_rpp = rpp; 552 553 while (readtoken() == TNOT) { 554 TRACE(("command: TNOT recognized\n")); 555 negate = !negate; 556 } 557 tokpushback++; 558 559 for (;;) { 560 if (readtoken() == TWORD) { 561 n = (union node *)stalloc(sizeof (struct narg)); 562 n->type = NARG; 563 n->narg.text = wordtext; 564 n->narg.backquote = backquotelist; 565 *app = n; 566 app = &n->narg.next; 567 } else if (lasttoken == TREDIR) { 568 *rpp = n = redirnode; 569 rpp = &n->nfile.next; 570 parsefname(); /* read name of redirection file */ 571 } else if (lasttoken == TLP && app == &args->narg.next 572 && rpp == orig_rpp) { 573 /* We have a function */ 574 if (readtoken() != TRP) 575 synexpect(TRP); 576 #ifdef notdef 577 if (! goodname(n->narg.text)) 578 synerror("Bad function name"); 579 #endif 580 n->type = NDEFUN; 581 n->narg.next = command(); 582 goto checkneg; 583 } else { 584 tokpushback++; 585 break; 586 } 587 } 588 *app = NULL; 589 *rpp = NULL; 590 n = (union node *)stalloc(sizeof (struct ncmd)); 591 n->type = NCMD; 592 n->ncmd.backgnd = 0; 593 n->ncmd.args = args; 594 n->ncmd.redirect = redir; 595 596 checkneg: 597 if (negate) { 598 n2 = (union node *)stalloc(sizeof (struct nnot)); 599 n2->type = NNOT; 600 n2->nnot.com = n; 601 return n2; 602 } 603 else 604 return n; 605 } 606 607 STATIC union node * 608 makename() { 609 union node *n; 610 611 n = (union node *)stalloc(sizeof (struct narg)); 612 n->type = NARG; 613 n->narg.next = NULL; 614 n->narg.text = wordtext; 615 n->narg.backquote = backquotelist; 616 return n; 617 } 618 619 void fixredir(union node *n, const char *text, int err) 620 { 621 TRACE(("Fix redir %s %d\n", text, err)); 622 if (!err) 623 n->ndup.vname = NULL; 624 625 if (is_digit(text[0]) && text[1] == '\0') 626 n->ndup.dupfd = digit_val(text[0]); 627 else if (text[0] == '-' && text[1] == '\0') 628 n->ndup.dupfd = -1; 629 else { 630 631 if (err) 632 synerror("Bad fd number"); 633 else 634 n->ndup.vname = makename(); 635 } 636 } 637 638 639 STATIC void 640 parsefname() { 641 union node *n = redirnode; 642 643 if (readtoken() != TWORD) 644 synexpect(-1); 645 if (n->type == NHERE) { 646 struct heredoc *here = heredoc; 647 struct heredoc *p; 648 int i; 649 650 if (quoteflag == 0) 651 n->type = NXHERE; 652 TRACE(("Here document %d\n", n->type)); 653 if (here->striptabs) { 654 while (*wordtext == '\t') 655 wordtext++; 656 } 657 if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN) 658 synerror("Illegal eof marker for << redirection"); 659 rmescapes(wordtext); 660 here->eofmark = wordtext; 661 here->next = NULL; 662 if (heredoclist == NULL) 663 heredoclist = here; 664 else { 665 for (p = heredoclist ; p->next ; p = p->next); 666 p->next = here; 667 } 668 } else if (n->type == NTOFD || n->type == NFROMFD) { 669 fixredir(n, wordtext, 0); 670 } else { 671 n->nfile.fname = makename(); 672 } 673 } 674 675 676 /* 677 * Input any here documents. 678 */ 679 680 STATIC void 681 parseheredoc() { 682 struct heredoc *here; 683 union node *n; 684 685 while (heredoclist) { 686 here = heredoclist; 687 heredoclist = here->next; 688 if (needprompt) { 689 setprompt(2); 690 needprompt = 0; 691 } 692 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, 693 here->eofmark, here->striptabs); 694 n = (union node *)stalloc(sizeof (struct narg)); 695 n->narg.type = NARG; 696 n->narg.next = NULL; 697 n->narg.text = wordtext; 698 n->narg.backquote = backquotelist; 699 here->here->nhere.doc = n; 700 } 701 } 702 703 STATIC int 704 peektoken() { 705 int t; 706 707 t = readtoken(); 708 tokpushback++; 709 return (t); 710 } 711 712 STATIC int 713 readtoken() { 714 int t; 715 int savecheckkwd = checkkwd; 716 #ifdef DEBUG 717 int alreadyseen = tokpushback; 718 #endif 719 struct alias *ap; 720 721 top: 722 t = xxreadtoken(); 723 724 if (checkkwd) { 725 /* 726 * eat newlines 727 */ 728 if (checkkwd == 2) { 729 checkkwd = 0; 730 while (t == TNL) { 731 parseheredoc(); 732 t = xxreadtoken(); 733 } 734 } else 735 checkkwd = 0; 736 /* 737 * check for keywords and aliases 738 */ 739 if (t == TWORD && !quoteflag) 740 { 741 const char *const *pp; 742 743 for (pp = parsekwd; *pp; pp++) { 744 if (**pp == *wordtext && equal(*pp, wordtext)) 745 { 746 lasttoken = t = pp - 747 parsekwd + KWDOFFSET; 748 TRACE(("keyword %s recognized\n", tokname[t])); 749 goto out; 750 } 751 } 752 if(!noalias && 753 (ap = lookupalias(wordtext, 1)) != NULL) { 754 pushstring(ap->val, strlen(ap->val), ap); 755 checkkwd = savecheckkwd; 756 goto top; 757 } 758 } 759 out: 760 checkkwd = (t == TNOT) ? savecheckkwd : 0; 761 } 762 #ifdef DEBUG 763 if (!alreadyseen) 764 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 765 else 766 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 767 #endif 768 return (t); 769 } 770 771 772 /* 773 * Read the next input token. 774 * If the token is a word, we set backquotelist to the list of cmds in 775 * backquotes. We set quoteflag to true if any part of the word was 776 * quoted. 777 * If the token is TREDIR, then we set redirnode to a structure containing 778 * the redirection. 779 * In all cases, the variable startlinno is set to the number of the line 780 * on which the token starts. 781 * 782 * [Change comment: here documents and internal procedures] 783 * [Readtoken shouldn't have any arguments. Perhaps we should make the 784 * word parsing code into a separate routine. In this case, readtoken 785 * doesn't need to have any internal procedures, but parseword does. 786 * We could also make parseoperator in essence the main routine, and 787 * have parseword (readtoken1?) handle both words and redirection.] 788 */ 789 790 #define RETURN(token) return lasttoken = token 791 792 STATIC int 793 xxreadtoken() { 794 int c; 795 796 if (tokpushback) { 797 tokpushback = 0; 798 return lasttoken; 799 } 800 if (needprompt) { 801 setprompt(2); 802 needprompt = 0; 803 } 804 startlinno = plinno; 805 for (;;) { /* until token or start of word found */ 806 c = pgetc_macro(); 807 if (c == ' ' || c == '\t') 808 continue; /* quick check for white space first */ 809 switch (c) { 810 case ' ': case '\t': 811 continue; 812 case '#': 813 while ((c = pgetc()) != '\n' && c != PEOF); 814 pungetc(); 815 continue; 816 case '\\': 817 if (pgetc() == '\n') { 818 startlinno = ++plinno; 819 if (doprompt) 820 setprompt(2); 821 else 822 setprompt(0); 823 continue; 824 } 825 pungetc(); 826 goto breakloop; 827 case '\n': 828 plinno++; 829 needprompt = doprompt; 830 RETURN(TNL); 831 case PEOF: 832 RETURN(TEOF); 833 case '&': 834 if (pgetc() == '&') 835 RETURN(TAND); 836 pungetc(); 837 RETURN(TBACKGND); 838 case '|': 839 if (pgetc() == '|') 840 RETURN(TOR); 841 pungetc(); 842 RETURN(TPIPE); 843 case ';': 844 if (pgetc() == ';') 845 RETURN(TENDCASE); 846 pungetc(); 847 RETURN(TSEMI); 848 case '(': 849 RETURN(TLP); 850 case ')': 851 RETURN(TRP); 852 default: 853 goto breakloop; 854 } 855 } 856 breakloop: 857 return readtoken1(c, BASESYNTAX, (char *)NULL, 0); 858 #undef RETURN 859 } 860 861 862 863 /* 864 * If eofmark is NULL, read a word or a redirection symbol. If eofmark 865 * is not NULL, read a here document. In the latter case, eofmark is the 866 * word which marks the end of the document and striptabs is true if 867 * leading tabs should be stripped from the document. The argument firstc 868 * is the first character of the input token or document. 869 * 870 * Because C does not have internal subroutines, I have simulated them 871 * using goto's to implement the subroutine linkage. The following macros 872 * will run code that appears at the end of readtoken1. 873 */ 874 875 #define CHECKEND() {goto checkend; checkend_return:;} 876 #define PARSEREDIR() {goto parseredir; parseredir_return:;} 877 #define PARSESUB() {goto parsesub; parsesub_return:;} 878 #define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;} 879 #define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;} 880 #define PARSEARITH() {goto parsearith; parsearith_return:;} 881 882 /* 883 * Keep track of nested doublequotes in dblquote and doublequotep. 884 * We use dblquote for the first 32 levels, and we expand to a malloc'ed 885 * region for levels above that. Usually we never need to malloc. 886 * This code assumes that an int is 32 bits. We don't use uint32_t, 887 * because the rest of the code does not. 888 */ 889 #define ISDBLQUOTE() ((varnest < 32) ? (dblquote & (1 << varnest)) : \ 890 (dblquotep[(varnest / 32) - 1] & (1 << (varnest % 32)))) 891 892 #define SETDBLQUOTE() \ 893 if (varnest < 32) \ 894 dblquote |= (1 << varnest); \ 895 else \ 896 dblquotep[(varnest / 32) - 1] |= (1 << (varnest % 32)) 897 898 #define CLRDBLQUOTE() \ 899 if (varnest < 32) \ 900 dblquote &= ~(1 << varnest); \ 901 else \ 902 dblquotep[(varnest / 32) - 1] &= ~(1 << (varnest % 32)) 903 904 STATIC int 905 readtoken1(firstc, syntax, eofmark, striptabs) 906 int firstc; 907 char const *syntax; 908 char *eofmark; 909 int striptabs; 910 { 911 int c = firstc; 912 char *out; 913 int len; 914 char line[EOFMARKLEN + 1]; 915 struct nodelist *bqlist; 916 int quotef; 917 int *dblquotep = NULL; 918 size_t maxnest = 32; 919 int dblquote; 920 int varnest; /* levels of variables expansion */ 921 int arinest; /* levels of arithmetic expansion */ 922 int parenlevel; /* levels of parens in arithmetic */ 923 int oldstyle; 924 char const *prevsyntax; /* syntax before arithmetic */ 925 #if __GNUC__ 926 /* Avoid longjmp clobbering */ 927 (void) &maxnest; 928 (void) &dblquotep; 929 (void) &out; 930 (void) "ef; 931 (void) &dblquote; 932 (void) &varnest; 933 (void) &arinest; 934 (void) &parenlevel; 935 (void) &oldstyle; 936 (void) &prevsyntax; 937 (void) &syntax; 938 #endif 939 940 startlinno = plinno; 941 dblquote = 0; 942 varnest = 0; 943 if (syntax == DQSYNTAX) { 944 SETDBLQUOTE(); 945 } 946 quotef = 0; 947 bqlist = NULL; 948 arinest = 0; 949 parenlevel = 0; 950 951 STARTSTACKSTR(out); 952 loop: { /* for each line, until end of word */ 953 #if ATTY 954 if (c == '\034' && doprompt 955 && attyset() && ! equal(termval(), "emacs")) { 956 attyline(); 957 if (syntax == BASESYNTAX) 958 return readtoken(); 959 c = pgetc(); 960 goto loop; 961 } 962 #endif 963 CHECKEND(); /* set c to PEOF if at end of here document */ 964 for (;;) { /* until end of line or end of word */ 965 CHECKSTRSPACE(3, out); /* permit 3 calls to USTPUTC */ 966 switch(syntax[c]) { 967 case CNL: /* '\n' */ 968 if (syntax == BASESYNTAX) 969 goto endword; /* exit outer loop */ 970 USTPUTC(c, out); 971 plinno++; 972 if (doprompt) 973 setprompt(2); 974 else 975 setprompt(0); 976 c = pgetc(); 977 goto loop; /* continue outer loop */ 978 case CWORD: 979 USTPUTC(c, out); 980 break; 981 case CCTL: 982 if (eofmark == NULL || ISDBLQUOTE()) 983 USTPUTC(CTLESC, out); 984 USTPUTC(c, out); 985 break; 986 case CBACK: /* backslash */ 987 c = pgetc(); 988 if (c == PEOF) { 989 USTPUTC('\\', out); 990 pungetc(); 991 } else if (c == '\n') { 992 if (doprompt) 993 setprompt(2); 994 else 995 setprompt(0); 996 } else { 997 if (ISDBLQUOTE() && c != '\\' && 998 c != '`' && c != '$' && 999 (c != '"' || eofmark != NULL)) 1000 USTPUTC('\\', out); 1001 if (SQSYNTAX[c] == CCTL) 1002 USTPUTC(CTLESC, out); 1003 else if (eofmark == NULL) 1004 USTPUTC(CTLQUOTEMARK, out); 1005 USTPUTC(c, out); 1006 quotef++; 1007 } 1008 break; 1009 case CSQUOTE: 1010 if (syntax != SQSYNTAX) { 1011 if (eofmark == NULL) 1012 USTPUTC(CTLQUOTEMARK, out); 1013 syntax = SQSYNTAX; 1014 break; 1015 } 1016 /* FALLTHROUGH */ 1017 case CDQUOTE: 1018 if (eofmark != NULL && arinest == 0 && 1019 varnest == 0) { 1020 USTPUTC(c, out); 1021 } else { 1022 if (arinest) { 1023 if (c != '"' || ISDBLQUOTE()) { 1024 syntax = ARISYNTAX; 1025 CLRDBLQUOTE(); 1026 } else { 1027 syntax = DQSYNTAX; 1028 SETDBLQUOTE(); 1029 USTPUTC(CTLQUOTEMARK, out); 1030 } 1031 } else if (eofmark == NULL) { 1032 if (c != '"' || ISDBLQUOTE()) { 1033 syntax = BASESYNTAX; 1034 CLRDBLQUOTE(); 1035 } else { 1036 syntax = DQSYNTAX; 1037 SETDBLQUOTE(); 1038 USTPUTC(CTLQUOTEMARK, out); 1039 } 1040 } 1041 quotef++; 1042 } 1043 break; 1044 case CVAR: /* '$' */ 1045 PARSESUB(); /* parse substitution */ 1046 break; 1047 case CENDVAR: /* CLOSEBRACE */ 1048 if (varnest > 0 && !ISDBLQUOTE()) { 1049 varnest--; 1050 USTPUTC(CTLENDVAR, out); 1051 } else { 1052 USTPUTC(c, out); 1053 } 1054 break; 1055 case CLP: /* '(' in arithmetic */ 1056 parenlevel++; 1057 USTPUTC(c, out); 1058 break; 1059 case CRP: /* ')' in arithmetic */ 1060 if (parenlevel > 0) { 1061 USTPUTC(c, out); 1062 --parenlevel; 1063 } else { 1064 if (pgetc() == ')') { 1065 if (--arinest == 0) { 1066 USTPUTC(CTLENDARI, out); 1067 syntax = prevsyntax; 1068 if (syntax == DQSYNTAX) 1069 SETDBLQUOTE(); 1070 else 1071 CLRDBLQUOTE(); 1072 } else 1073 USTPUTC(')', out); 1074 } else { 1075 /* 1076 * unbalanced parens 1077 * (don't 2nd guess - no error) 1078 */ 1079 pungetc(); 1080 USTPUTC(')', out); 1081 } 1082 } 1083 break; 1084 case CBQUOTE: /* '`' */ 1085 PARSEBACKQOLD(); 1086 break; 1087 case CEOF: 1088 goto endword; /* exit outer loop */ 1089 default: 1090 if (varnest == 0) 1091 goto endword; /* exit outer loop */ 1092 USTPUTC(c, out); 1093 } 1094 c = pgetc_macro(); 1095 } 1096 } 1097 endword: 1098 if (syntax == ARISYNTAX) 1099 synerror("Missing '))'"); 1100 if (syntax != BASESYNTAX && ! parsebackquote && eofmark == NULL) 1101 synerror("Unterminated quoted string"); 1102 if (varnest != 0) { 1103 startlinno = plinno; 1104 /* { */ 1105 synerror("Missing '}'"); 1106 } 1107 USTPUTC('\0', out); 1108 len = out - stackblock(); 1109 out = stackblock(); 1110 if (eofmark == NULL) { 1111 if ((c == '>' || c == '<') 1112 && quotef == 0 1113 && len <= 2 1114 && (*out == '\0' || is_digit(*out))) { 1115 PARSEREDIR(); 1116 return lasttoken = TREDIR; 1117 } else { 1118 pungetc(); 1119 } 1120 } 1121 quoteflag = quotef; 1122 backquotelist = bqlist; 1123 grabstackblock(len); 1124 wordtext = out; 1125 if (dblquotep != NULL) 1126 ckfree(dblquotep); 1127 return lasttoken = TWORD; 1128 /* end of readtoken routine */ 1129 1130 1131 1132 /* 1133 * Check to see whether we are at the end of the here document. When this 1134 * is called, c is set to the first character of the next input line. If 1135 * we are at the end of the here document, this routine sets the c to PEOF. 1136 */ 1137 1138 checkend: { 1139 if (eofmark) { 1140 if (striptabs) { 1141 while (c == '\t') 1142 c = pgetc(); 1143 } 1144 if (c == *eofmark) { 1145 if (pfgets(line, sizeof line) != NULL) { 1146 char *p, *q; 1147 1148 p = line; 1149 for (q = eofmark + 1 ; *q && *p == *q ; p++, q++); 1150 if (*p == '\n' && *q == '\0') { 1151 c = PEOF; 1152 plinno++; 1153 needprompt = doprompt; 1154 } else { 1155 pushstring(line, strlen(line), NULL); 1156 } 1157 } 1158 } 1159 } 1160 goto checkend_return; 1161 } 1162 1163 1164 /* 1165 * Parse a redirection operator. The variable "out" points to a string 1166 * specifying the fd to be redirected. The variable "c" contains the 1167 * first character of the redirection operator. 1168 */ 1169 1170 parseredir: { 1171 char fd = *out; 1172 union node *np; 1173 1174 np = (union node *)stalloc(sizeof (struct nfile)); 1175 if (c == '>') { 1176 np->nfile.fd = 1; 1177 c = pgetc(); 1178 if (c == '>') 1179 np->type = NAPPEND; 1180 else if (c == '|') 1181 np->type = NCLOBBER; 1182 else if (c == '&') 1183 np->type = NTOFD; 1184 else { 1185 np->type = NTO; 1186 pungetc(); 1187 } 1188 } else { /* c == '<' */ 1189 np->nfile.fd = 0; 1190 switch (c = pgetc()) { 1191 case '<': 1192 if (sizeof (struct nfile) != sizeof (struct nhere)) { 1193 np = (union node *)stalloc(sizeof (struct nhere)); 1194 np->nfile.fd = 0; 1195 } 1196 np->type = NHERE; 1197 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); 1198 heredoc->here = np; 1199 if ((c = pgetc()) == '-') { 1200 heredoc->striptabs = 1; 1201 } else { 1202 heredoc->striptabs = 0; 1203 pungetc(); 1204 } 1205 break; 1206 1207 case '&': 1208 np->type = NFROMFD; 1209 break; 1210 1211 case '>': 1212 np->type = NFROMTO; 1213 break; 1214 1215 default: 1216 np->type = NFROM; 1217 pungetc(); 1218 break; 1219 } 1220 } 1221 if (fd != '\0') 1222 np->nfile.fd = digit_val(fd); 1223 redirnode = np; 1224 goto parseredir_return; 1225 } 1226 1227 1228 /* 1229 * Parse a substitution. At this point, we have read the dollar sign 1230 * and nothing else. 1231 */ 1232 1233 parsesub: { 1234 int subtype; 1235 int typeloc; 1236 int flags; 1237 char *p; 1238 static const char types[] = "}-+?="; 1239 1240 c = pgetc(); 1241 if (c != '(' && c != OPENBRACE && !is_name(c) && !is_special(c)) { 1242 USTPUTC('$', out); 1243 pungetc(); 1244 } else if (c == '(') { /* $(command) or $((arith)) */ 1245 if (pgetc() == '(') { 1246 PARSEARITH(); 1247 } else { 1248 pungetc(); 1249 PARSEBACKQNEW(); 1250 } 1251 } else { 1252 USTPUTC(CTLVAR, out); 1253 typeloc = out - stackblock(); 1254 USTPUTC(VSNORMAL, out); 1255 subtype = VSNORMAL; 1256 if (c == OPENBRACE) { 1257 c = pgetc(); 1258 if (c == '#') { 1259 if ((c = pgetc()) == CLOSEBRACE) 1260 c = '#'; 1261 else 1262 subtype = VSLENGTH; 1263 } 1264 else 1265 subtype = 0; 1266 } 1267 if (is_name(c)) { 1268 do { 1269 STPUTC(c, out); 1270 c = pgetc(); 1271 } while (is_in_name(c)); 1272 } else if (is_digit(c)) { 1273 do { 1274 USTPUTC(c, out); 1275 c = pgetc(); 1276 } while (is_digit(c)); 1277 } 1278 else if (is_special(c)) { 1279 USTPUTC(c, out); 1280 c = pgetc(); 1281 } 1282 else 1283 badsub: synerror("Bad substitution"); 1284 1285 STPUTC('=', out); 1286 flags = 0; 1287 if (subtype == 0) { 1288 switch (c) { 1289 case ':': 1290 flags = VSNUL; 1291 c = pgetc(); 1292 /*FALLTHROUGH*/ 1293 default: 1294 p = strchr(types, c); 1295 if (p == NULL) 1296 goto badsub; 1297 subtype = p - types + VSNORMAL; 1298 break; 1299 case '%': 1300 case '#': 1301 { 1302 int cc = c; 1303 subtype = c == '#' ? VSTRIMLEFT : 1304 VSTRIMRIGHT; 1305 c = pgetc(); 1306 if (c == cc) 1307 subtype++; 1308 else 1309 pungetc(); 1310 break; 1311 } 1312 } 1313 } else { 1314 pungetc(); 1315 } 1316 if (ISDBLQUOTE() || arinest) 1317 flags |= VSQUOTE; 1318 *(stackblock() + typeloc) = subtype | flags; 1319 if (subtype != VSNORMAL) { 1320 varnest++; 1321 if (varnest >= maxnest) { 1322 dblquotep = ckrealloc(dblquotep, maxnest / 8); 1323 dblquotep[(maxnest / 32) - 1] = 0; 1324 maxnest += 32; 1325 } 1326 } 1327 } 1328 goto parsesub_return; 1329 } 1330 1331 1332 /* 1333 * Called to parse command substitutions. Newstyle is set if the command 1334 * is enclosed inside $(...); nlpp is a pointer to the head of the linked 1335 * list of commands (passed by reference), and savelen is the number of 1336 * characters on the top of the stack which must be preserved. 1337 */ 1338 1339 parsebackq: { 1340 struct nodelist **nlpp; 1341 int savepbq; 1342 union node *n; 1343 char *volatile str; 1344 struct jmploc jmploc; 1345 struct jmploc *volatile savehandler; 1346 int savelen; 1347 int saveprompt; 1348 #ifdef __GNUC__ 1349 (void) &saveprompt; 1350 #endif 1351 1352 savepbq = parsebackquote; 1353 if (setjmp(jmploc.loc)) { 1354 if (str) 1355 ckfree(str); 1356 parsebackquote = 0; 1357 handler = savehandler; 1358 longjmp(handler->loc, 1); 1359 } 1360 INTOFF; 1361 str = NULL; 1362 savelen = out - stackblock(); 1363 if (savelen > 0) { 1364 str = ckmalloc(savelen); 1365 memcpy(str, stackblock(), savelen); 1366 } 1367 savehandler = handler; 1368 handler = &jmploc; 1369 INTON; 1370 if (oldstyle) { 1371 /* We must read until the closing backquote, giving special 1372 treatment to some slashes, and then push the string and 1373 reread it as input, interpreting it normally. */ 1374 char *pout; 1375 int pc; 1376 int psavelen; 1377 char *pstr; 1378 1379 1380 STARTSTACKSTR(pout); 1381 for (;;) { 1382 if (needprompt) { 1383 setprompt(2); 1384 needprompt = 0; 1385 } 1386 switch (pc = pgetc()) { 1387 case '`': 1388 goto done; 1389 1390 case '\\': 1391 if ((pc = pgetc()) == '\n') { 1392 plinno++; 1393 if (doprompt) 1394 setprompt(2); 1395 else 1396 setprompt(0); 1397 /* 1398 * If eating a newline, avoid putting 1399 * the newline into the new character 1400 * stream (via the STPUTC after the 1401 * switch). 1402 */ 1403 continue; 1404 } 1405 if (pc != '\\' && pc != '`' && pc != '$' 1406 && (!ISDBLQUOTE() || pc != '"')) 1407 STPUTC('\\', pout); 1408 break; 1409 1410 case '\n': 1411 plinno++; 1412 needprompt = doprompt; 1413 break; 1414 1415 case PEOF: 1416 startlinno = plinno; 1417 synerror("EOF in backquote substitution"); 1418 break; 1419 1420 default: 1421 break; 1422 } 1423 STPUTC(pc, pout); 1424 } 1425 done: 1426 STPUTC('\0', pout); 1427 psavelen = pout - stackblock(); 1428 if (psavelen > 0) { 1429 pstr = grabstackstr(pout); 1430 setinputstring(pstr, 1); 1431 } 1432 } 1433 nlpp = &bqlist; 1434 while (*nlpp) 1435 nlpp = &(*nlpp)->next; 1436 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 1437 (*nlpp)->next = NULL; 1438 parsebackquote = oldstyle; 1439 1440 if (oldstyle) { 1441 saveprompt = doprompt; 1442 doprompt = 0; 1443 } 1444 1445 n = list(0); 1446 1447 if (oldstyle) 1448 doprompt = saveprompt; 1449 else { 1450 if (readtoken() != TRP) 1451 synexpect(TRP); 1452 } 1453 1454 (*nlpp)->n = n; 1455 if (oldstyle) { 1456 /* 1457 * Start reading from old file again, ignoring any pushed back 1458 * tokens left from the backquote parsing 1459 */ 1460 popfile(); 1461 tokpushback = 0; 1462 } 1463 while (stackblocksize() <= savelen) 1464 growstackblock(); 1465 STARTSTACKSTR(out); 1466 if (str) { 1467 memcpy(out, str, savelen); 1468 STADJUST(savelen, out); 1469 INTOFF; 1470 ckfree(str); 1471 str = NULL; 1472 INTON; 1473 } 1474 parsebackquote = savepbq; 1475 handler = savehandler; 1476 if (arinest || ISDBLQUOTE()) 1477 USTPUTC(CTLBACKQ | CTLQUOTE, out); 1478 else 1479 USTPUTC(CTLBACKQ, out); 1480 if (oldstyle) 1481 goto parsebackq_oldreturn; 1482 else 1483 goto parsebackq_newreturn; 1484 } 1485 1486 /* 1487 * Parse an arithmetic expansion (indicate start of one and set state) 1488 */ 1489 parsearith: { 1490 1491 if (++arinest == 1) { 1492 prevsyntax = syntax; 1493 syntax = ARISYNTAX; 1494 USTPUTC(CTLARI, out); 1495 if (ISDBLQUOTE()) 1496 USTPUTC('"',out); 1497 else 1498 USTPUTC(' ',out); 1499 } else { 1500 /* 1501 * we collapse embedded arithmetic expansion to 1502 * parenthesis, which should be equivalent 1503 */ 1504 USTPUTC('(', out); 1505 } 1506 goto parsearith_return; 1507 } 1508 1509 } /* end of readtoken */ 1510 1511 1512 1513 #ifdef mkinit 1514 RESET { 1515 tokpushback = 0; 1516 checkkwd = 0; 1517 } 1518 #endif 1519 1520 /* 1521 * Returns true if the text contains nothing to expand (no dollar signs 1522 * or backquotes). 1523 */ 1524 1525 STATIC int 1526 noexpand(text) 1527 char *text; 1528 { 1529 char *p; 1530 char c; 1531 1532 p = text; 1533 while ((c = *p++) != '\0') { 1534 if (c == CTLQUOTEMARK) 1535 continue; 1536 if (c == CTLESC) 1537 p++; 1538 else if (BASESYNTAX[(int)c] == CCTL) 1539 return 0; 1540 } 1541 return 1; 1542 } 1543 1544 1545 /* 1546 * Return true if the argument is a legal variable name (a letter or 1547 * underscore followed by zero or more letters, underscores, and digits). 1548 */ 1549 1550 int 1551 goodname(char *name) 1552 { 1553 char *p; 1554 1555 p = name; 1556 if (! is_name(*p)) 1557 return 0; 1558 while (*++p) { 1559 if (! is_in_name(*p)) 1560 return 0; 1561 } 1562 return 1; 1563 } 1564 1565 1566 /* 1567 * Called when an unexpected token is read during the parse. The argument 1568 * is the token that is expected, or -1 if more than one type of token can 1569 * occur at this point. 1570 */ 1571 1572 STATIC void 1573 synexpect(token) 1574 int token; 1575 { 1576 char msg[64]; 1577 1578 if (token >= 0) { 1579 fmtstr(msg, 64, "%s unexpected (expecting %s)", 1580 tokname[lasttoken], tokname[token]); 1581 } else { 1582 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]); 1583 } 1584 synerror(msg); 1585 /* NOTREACHED */ 1586 } 1587 1588 1589 STATIC void 1590 synerror(msg) 1591 const char *msg; 1592 { 1593 if (commandname) 1594 outfmt(&errout, "%s: %d: ", commandname, startlinno); 1595 outfmt(&errout, "Syntax error: %s\n", msg); 1596 error((char *)NULL); 1597 /* NOTREACHED */ 1598 } 1599 1600 STATIC void 1601 setprompt(which) 1602 int which; 1603 { 1604 whichprompt = which; 1605 1606 #ifndef SMALL 1607 if (!el) 1608 #endif 1609 out2str(getprompt(NULL)); 1610 } 1611 1612 /* 1613 * called by editline -- any expansions to the prompt 1614 * should be added here. 1615 */ 1616 const char * 1617 getprompt(void *unused) 1618 { 1619 switch (whichprompt) { 1620 case 0: 1621 return ""; 1622 case 1: 1623 return ps1val(); 1624 case 2: 1625 return ps2val(); 1626 default: 1627 return "<internal prompt error>"; 1628 } 1629 } 1630