1 /* $NetBSD: parser.c,v 1.54 2002/11/24 22:35:42 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 1.54 2002/11/24 22:35:42 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(int); 109 STATIC union node *andor(void); 110 STATIC union node *pipeline(void); 111 STATIC union node *command(void); 112 STATIC union node *simplecmd(union node **, union node *); 113 STATIC union node *makename(void); 114 STATIC void parsefname(void); 115 STATIC void parseheredoc(void); 116 STATIC int peektoken(void); 117 STATIC int readtoken(void); 118 STATIC int xxreadtoken(void); 119 STATIC int readtoken1(int, char const *, char *, int); 120 STATIC int noexpand(char *); 121 STATIC void synexpect(int) __attribute__((__noreturn__)); 122 STATIC void synerror(const char *) __attribute__((__noreturn__)); 123 STATIC void setprompt(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(int nlflag) 155 { 156 union node *n1, *n2, *n3; 157 int tok; 158 159 checkkwd = 2; 160 if (nlflag == 0 && tokendlist[peektoken()]) 161 return NULL; 162 n1 = NULL; 163 for (;;) { 164 n2 = andor(); 165 tok = readtoken(); 166 if (tok == TBACKGND) { 167 if (n2->type == NCMD || n2->type == NPIPE) { 168 n2->ncmd.backgnd = 1; 169 } else if (n2->type == NREDIR) { 170 n2->type = NBACKGND; 171 } else { 172 n3 = (union node *)stalloc(sizeof (struct nredir)); 173 n3->type = NBACKGND; 174 n3->nredir.n = n2; 175 n3->nredir.redirect = NULL; 176 n2 = n3; 177 } 178 } 179 if (n1 == NULL) { 180 n1 = n2; 181 } 182 else { 183 n3 = (union node *)stalloc(sizeof (struct nbinary)); 184 n3->type = NSEMI; 185 n3->nbinary.ch1 = n1; 186 n3->nbinary.ch2 = n2; 187 n1 = n3; 188 } 189 switch (tok) { 190 case TBACKGND: 191 case TSEMI: 192 tok = readtoken(); 193 /* fall through */ 194 case TNL: 195 if (tok == TNL) { 196 parseheredoc(); 197 if (nlflag) 198 return n1; 199 } else { 200 tokpushback++; 201 } 202 checkkwd = 2; 203 if (tokendlist[peektoken()]) 204 return n1; 205 break; 206 case TEOF: 207 if (heredoclist) 208 parseheredoc(); 209 else 210 pungetc(); /* push back EOF on input */ 211 return n1; 212 default: 213 if (nlflag) 214 synexpect(-1); 215 tokpushback++; 216 return n1; 217 } 218 } 219 } 220 221 222 223 STATIC union node * 224 andor(void) 225 { 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(void) 252 { 253 union node *n1, *n2, *pipenode; 254 struct nodelist *lp, *prev; 255 int negate; 256 257 negate = 0; 258 TRACE(("pipeline: entered\n")); 259 while (readtoken() == TNOT) 260 negate = !negate; 261 tokpushback++; 262 n1 = command(); 263 if (readtoken() == TPIPE) { 264 pipenode = (union node *)stalloc(sizeof (struct npipe)); 265 pipenode->type = NPIPE; 266 pipenode->npipe.backgnd = 0; 267 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 268 pipenode->npipe.cmdlist = lp; 269 lp->n = n1; 270 do { 271 prev = lp; 272 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 273 lp->n = command(); 274 prev->next = lp; 275 } while (readtoken() == TPIPE); 276 lp->next = NULL; 277 n1 = pipenode; 278 } 279 tokpushback++; 280 if (negate) { 281 n2 = (union node *)stalloc(sizeof (struct nnot)); 282 n2->type = NNOT; 283 n2->nnot.com = n1; 284 return n2; 285 } else 286 return n1; 287 } 288 289 290 291 STATIC union node * 292 command(void) 293 { 294 union node *n1, *n2; 295 union node *ap, **app; 296 union node *cp, **cpp; 297 union node *redir, **rpp; 298 int t, negate = 0; 299 300 checkkwd = 2; 301 redir = NULL; 302 n1 = NULL; 303 rpp = &redir; 304 305 /* Check for redirection which may precede command */ 306 while (readtoken() == TREDIR) { 307 *rpp = n2 = redirnode; 308 rpp = &n2->nfile.next; 309 parsefname(); 310 } 311 tokpushback++; 312 313 while (readtoken() == TNOT) { 314 TRACE(("command: TNOT recognized\n")); 315 negate = !negate; 316 } 317 tokpushback++; 318 319 switch (readtoken()) { 320 case TIF: 321 n1 = (union node *)stalloc(sizeof (struct nif)); 322 n1->type = NIF; 323 n1->nif.test = list(0); 324 if (readtoken() != TTHEN) 325 synexpect(TTHEN); 326 n1->nif.ifpart = list(0); 327 n2 = n1; 328 while (readtoken() == TELIF) { 329 n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif)); 330 n2 = n2->nif.elsepart; 331 n2->type = NIF; 332 n2->nif.test = list(0); 333 if (readtoken() != TTHEN) 334 synexpect(TTHEN); 335 n2->nif.ifpart = list(0); 336 } 337 if (lasttoken == TELSE) 338 n2->nif.elsepart = list(0); 339 else { 340 n2->nif.elsepart = NULL; 341 tokpushback++; 342 } 343 if (readtoken() != TFI) 344 synexpect(TFI); 345 checkkwd = 1; 346 break; 347 case TWHILE: 348 case TUNTIL: { 349 int got; 350 n1 = (union node *)stalloc(sizeof (struct nbinary)); 351 n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL; 352 n1->nbinary.ch1 = list(0); 353 if ((got=readtoken()) != TDO) { 354 TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : "")); 355 synexpect(TDO); 356 } 357 n1->nbinary.ch2 = list(0); 358 if (readtoken() != TDONE) 359 synexpect(TDONE); 360 checkkwd = 1; 361 break; 362 } 363 case TFOR: 364 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext)) 365 synerror("Bad for loop variable"); 366 n1 = (union node *)stalloc(sizeof (struct nfor)); 367 n1->type = NFOR; 368 n1->nfor.var = wordtext; 369 if (readtoken() == TWORD && ! quoteflag && equal(wordtext, "in")) { 370 app = ≈ 371 while (readtoken() == TWORD) { 372 n2 = (union node *)stalloc(sizeof (struct narg)); 373 n2->type = NARG; 374 n2->narg.text = wordtext; 375 n2->narg.backquote = backquotelist; 376 *app = n2; 377 app = &n2->narg.next; 378 } 379 *app = NULL; 380 n1->nfor.args = ap; 381 if (lasttoken != TNL && lasttoken != TSEMI) 382 synexpect(-1); 383 } else { 384 static char argvars[5] = {CTLVAR, VSNORMAL|VSQUOTE, 385 '@', '=', '\0'}; 386 n2 = (union node *)stalloc(sizeof (struct narg)); 387 n2->type = NARG; 388 n2->narg.text = argvars; 389 n2->narg.backquote = NULL; 390 n2->narg.next = NULL; 391 n1->nfor.args = n2; 392 /* 393 * Newline or semicolon here is optional (but note 394 * that the original Bourne shell only allowed NL). 395 */ 396 if (lasttoken != TNL && lasttoken != TSEMI) 397 tokpushback++; 398 } 399 checkkwd = 2; 400 if ((t = readtoken()) == TDO) 401 t = TDONE; 402 else if (t == TBEGIN) 403 t = TEND; 404 else 405 synexpect(-1); 406 n1->nfor.body = list(0); 407 if (readtoken() != t) 408 synexpect(t); 409 checkkwd = 1; 410 break; 411 case TCASE: 412 n1 = (union node *)stalloc(sizeof (struct ncase)); 413 n1->type = NCASE; 414 if (readtoken() != TWORD) 415 synexpect(TWORD); 416 n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg)); 417 n2->type = NARG; 418 n2->narg.text = wordtext; 419 n2->narg.backquote = backquotelist; 420 n2->narg.next = NULL; 421 while (readtoken() == TNL); 422 if (lasttoken != TWORD || ! equal(wordtext, "in")) 423 synerror("expecting \"in\""); 424 cpp = &n1->ncase.cases; 425 noalias = 1; 426 checkkwd = 2, readtoken(); 427 do { 428 *cpp = cp = (union node *)stalloc(sizeof (struct nclist)); 429 cp->type = NCLIST; 430 app = &cp->nclist.pattern; 431 for (;;) { 432 *app = ap = (union node *)stalloc(sizeof (struct narg)); 433 ap->type = NARG; 434 ap->narg.text = wordtext; 435 ap->narg.backquote = backquotelist; 436 if (checkkwd = 2, readtoken() != TPIPE) 437 break; 438 app = &ap->narg.next; 439 readtoken(); 440 } 441 ap->narg.next = NULL; 442 noalias = 0; 443 if (lasttoken != TRP) { 444 synexpect(TRP); 445 } 446 cp->nclist.body = list(0); 447 448 checkkwd = 2; 449 if ((t = readtoken()) != TESAC) { 450 if (t != TENDCASE) { 451 noalias = 0; 452 synexpect(TENDCASE); 453 } else { 454 noalias = 1; 455 checkkwd = 2; 456 readtoken(); 457 } 458 } 459 cpp = &cp->nclist.next; 460 } while(lasttoken != TESAC); 461 noalias = 0; 462 *cpp = NULL; 463 checkkwd = 1; 464 break; 465 case TLP: 466 n1 = (union node *)stalloc(sizeof (struct nredir)); 467 n1->type = NSUBSHELL; 468 n1->nredir.n = list(0); 469 n1->nredir.redirect = NULL; 470 if (readtoken() != TRP) 471 synexpect(TRP); 472 checkkwd = 1; 473 break; 474 case TBEGIN: 475 n1 = list(0); 476 if (readtoken() != TEND) 477 synexpect(TEND); 478 checkkwd = 1; 479 break; 480 /* Handle an empty command like other simple commands. */ 481 case TSEMI: 482 /* 483 * An empty command before a ; doesn't make much sense, and 484 * should certainly be disallowed in the case of `if ;'. 485 */ 486 if (!redir) 487 synexpect(-1); 488 case TAND: 489 case TOR: 490 case TNL: 491 case TEOF: 492 case TWORD: 493 case TRP: 494 tokpushback++; 495 n1 = simplecmd(rpp, redir); 496 goto checkneg; 497 default: 498 synexpect(-1); 499 /* NOTREACHED */ 500 } 501 502 /* Now check for redirection which may follow command */ 503 while (readtoken() == TREDIR) { 504 *rpp = n2 = redirnode; 505 rpp = &n2->nfile.next; 506 parsefname(); 507 } 508 tokpushback++; 509 *rpp = NULL; 510 if (redir) { 511 if (n1->type != NSUBSHELL) { 512 n2 = (union node *)stalloc(sizeof (struct nredir)); 513 n2->type = NREDIR; 514 n2->nredir.n = n1; 515 n1 = n2; 516 } 517 n1->nredir.redirect = redir; 518 } 519 520 checkneg: 521 if (negate) { 522 n2 = (union node *)stalloc(sizeof (struct nnot)); 523 n2->type = NNOT; 524 n2->nnot.com = n1; 525 return n2; 526 } 527 else 528 return n1; 529 } 530 531 532 STATIC union node * 533 simplecmd(union node **rpp, union node *redir) 534 { 535 union node *args, **app; 536 union node **orig_rpp = rpp; 537 union node *n = NULL, *n2; 538 int negate = 0; 539 540 /* If we don't have any redirections already, then we must reset */ 541 /* rpp to be the address of the local redir variable. */ 542 if (redir == 0) 543 rpp = &redir; 544 545 args = NULL; 546 app = &args; 547 /* 548 * We save the incoming value, because we need this for shell 549 * functions. There can not be a redirect or an argument between 550 * the function name and the open parenthesis. 551 */ 552 orig_rpp = rpp; 553 554 while (readtoken() == TNOT) { 555 TRACE(("command: TNOT recognized\n")); 556 negate = !negate; 557 } 558 tokpushback++; 559 560 for (;;) { 561 if (readtoken() == TWORD) { 562 n = (union node *)stalloc(sizeof (struct narg)); 563 n->type = NARG; 564 n->narg.text = wordtext; 565 n->narg.backquote = backquotelist; 566 *app = n; 567 app = &n->narg.next; 568 } else if (lasttoken == TREDIR) { 569 *rpp = n = redirnode; 570 rpp = &n->nfile.next; 571 parsefname(); /* read name of redirection file */ 572 } else if (lasttoken == TLP && app == &args->narg.next 573 && rpp == orig_rpp) { 574 /* We have a function */ 575 if (readtoken() != TRP) 576 synexpect(TRP); 577 #ifdef notdef 578 if (! goodname(n->narg.text)) 579 synerror("Bad function name"); 580 #endif 581 n->type = NDEFUN; 582 n->narg.next = command(); 583 goto checkneg; 584 } else { 585 tokpushback++; 586 break; 587 } 588 } 589 *app = NULL; 590 *rpp = NULL; 591 n = (union node *)stalloc(sizeof (struct ncmd)); 592 n->type = NCMD; 593 n->ncmd.backgnd = 0; 594 n->ncmd.args = args; 595 n->ncmd.redirect = redir; 596 597 checkneg: 598 if (negate) { 599 n2 = (union node *)stalloc(sizeof (struct nnot)); 600 n2->type = NNOT; 601 n2->nnot.com = n; 602 return n2; 603 } 604 else 605 return n; 606 } 607 608 STATIC union node * 609 makename(void) 610 { 611 union node *n; 612 613 n = (union node *)stalloc(sizeof (struct narg)); 614 n->type = NARG; 615 n->narg.next = NULL; 616 n->narg.text = wordtext; 617 n->narg.backquote = backquotelist; 618 return n; 619 } 620 621 void fixredir(union node *n, const char *text, int err) 622 { 623 TRACE(("Fix redir %s %d\n", text, err)); 624 if (!err) 625 n->ndup.vname = NULL; 626 627 if (is_digit(text[0]) && text[1] == '\0') 628 n->ndup.dupfd = digit_val(text[0]); 629 else if (text[0] == '-' && text[1] == '\0') 630 n->ndup.dupfd = -1; 631 else { 632 633 if (err) 634 synerror("Bad fd number"); 635 else 636 n->ndup.vname = makename(); 637 } 638 } 639 640 641 STATIC void 642 parsefname(void) 643 { 644 union node *n = redirnode; 645 646 if (readtoken() != TWORD) 647 synexpect(-1); 648 if (n->type == NHERE) { 649 struct heredoc *here = heredoc; 650 struct heredoc *p; 651 int i; 652 653 if (quoteflag == 0) 654 n->type = NXHERE; 655 TRACE(("Here document %d\n", n->type)); 656 if (here->striptabs) { 657 while (*wordtext == '\t') 658 wordtext++; 659 } 660 if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN) 661 synerror("Illegal eof marker for << redirection"); 662 rmescapes(wordtext); 663 here->eofmark = wordtext; 664 here->next = NULL; 665 if (heredoclist == NULL) 666 heredoclist = here; 667 else { 668 for (p = heredoclist ; p->next ; p = p->next); 669 p->next = here; 670 } 671 } else if (n->type == NTOFD || n->type == NFROMFD) { 672 fixredir(n, wordtext, 0); 673 } else { 674 n->nfile.fname = makename(); 675 } 676 } 677 678 679 /* 680 * Input any here documents. 681 */ 682 683 STATIC void 684 parseheredoc(void) 685 { 686 struct heredoc *here; 687 union node *n; 688 689 while (heredoclist) { 690 here = heredoclist; 691 heredoclist = here->next; 692 if (needprompt) { 693 setprompt(2); 694 needprompt = 0; 695 } 696 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, 697 here->eofmark, here->striptabs); 698 n = (union node *)stalloc(sizeof (struct narg)); 699 n->narg.type = NARG; 700 n->narg.next = NULL; 701 n->narg.text = wordtext; 702 n->narg.backquote = backquotelist; 703 here->here->nhere.doc = n; 704 } 705 } 706 707 STATIC int 708 peektoken(void) 709 { 710 int t; 711 712 t = readtoken(); 713 tokpushback++; 714 return (t); 715 } 716 717 STATIC int 718 readtoken(void) 719 { 720 int t; 721 int savecheckkwd = checkkwd; 722 #ifdef DEBUG 723 int alreadyseen = tokpushback; 724 #endif 725 struct alias *ap; 726 727 top: 728 t = xxreadtoken(); 729 730 if (checkkwd) { 731 /* 732 * eat newlines 733 */ 734 if (checkkwd == 2) { 735 checkkwd = 0; 736 while (t == TNL) { 737 parseheredoc(); 738 t = xxreadtoken(); 739 } 740 } else 741 checkkwd = 0; 742 /* 743 * check for keywords and aliases 744 */ 745 if (t == TWORD && !quoteflag) 746 { 747 const char *const *pp; 748 749 for (pp = parsekwd; *pp; pp++) { 750 if (**pp == *wordtext && equal(*pp, wordtext)) 751 { 752 lasttoken = t = pp - 753 parsekwd + KWDOFFSET; 754 TRACE(("keyword %s recognized\n", tokname[t])); 755 goto out; 756 } 757 } 758 if(!noalias && 759 (ap = lookupalias(wordtext, 1)) != NULL) { 760 pushstring(ap->val, strlen(ap->val), ap); 761 checkkwd = savecheckkwd; 762 goto top; 763 } 764 } 765 out: 766 checkkwd = (t == TNOT) ? savecheckkwd : 0; 767 } 768 #ifdef DEBUG 769 if (!alreadyseen) 770 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 771 else 772 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 773 #endif 774 return (t); 775 } 776 777 778 /* 779 * Read the next input token. 780 * If the token is a word, we set backquotelist to the list of cmds in 781 * backquotes. We set quoteflag to true if any part of the word was 782 * quoted. 783 * If the token is TREDIR, then we set redirnode to a structure containing 784 * the redirection. 785 * In all cases, the variable startlinno is set to the number of the line 786 * on which the token starts. 787 * 788 * [Change comment: here documents and internal procedures] 789 * [Readtoken shouldn't have any arguments. Perhaps we should make the 790 * word parsing code into a separate routine. In this case, readtoken 791 * doesn't need to have any internal procedures, but parseword does. 792 * We could also make parseoperator in essence the main routine, and 793 * have parseword (readtoken1?) handle both words and redirection.] 794 */ 795 796 #define RETURN(token) return lasttoken = token 797 798 STATIC int 799 xxreadtoken(void) 800 { 801 int c; 802 803 if (tokpushback) { 804 tokpushback = 0; 805 return lasttoken; 806 } 807 if (needprompt) { 808 setprompt(2); 809 needprompt = 0; 810 } 811 startlinno = plinno; 812 for (;;) { /* until token or start of word found */ 813 c = pgetc_macro(); 814 if (c == ' ' || c == '\t') 815 continue; /* quick check for white space first */ 816 switch (c) { 817 case ' ': case '\t': 818 continue; 819 case '#': 820 while ((c = pgetc()) != '\n' && c != PEOF); 821 pungetc(); 822 continue; 823 case '\\': 824 if (pgetc() == '\n') { 825 startlinno = ++plinno; 826 if (doprompt) 827 setprompt(2); 828 else 829 setprompt(0); 830 continue; 831 } 832 pungetc(); 833 goto breakloop; 834 case '\n': 835 plinno++; 836 needprompt = doprompt; 837 RETURN(TNL); 838 case PEOF: 839 RETURN(TEOF); 840 case '&': 841 if (pgetc() == '&') 842 RETURN(TAND); 843 pungetc(); 844 RETURN(TBACKGND); 845 case '|': 846 if (pgetc() == '|') 847 RETURN(TOR); 848 pungetc(); 849 RETURN(TPIPE); 850 case ';': 851 if (pgetc() == ';') 852 RETURN(TENDCASE); 853 pungetc(); 854 RETURN(TSEMI); 855 case '(': 856 RETURN(TLP); 857 case ')': 858 RETURN(TRP); 859 default: 860 goto breakloop; 861 } 862 } 863 breakloop: 864 return readtoken1(c, BASESYNTAX, (char *)NULL, 0); 865 #undef RETURN 866 } 867 868 869 870 /* 871 * If eofmark is NULL, read a word or a redirection symbol. If eofmark 872 * is not NULL, read a here document. In the latter case, eofmark is the 873 * word which marks the end of the document and striptabs is true if 874 * leading tabs should be stripped from the document. The argument firstc 875 * is the first character of the input token or document. 876 * 877 * Because C does not have internal subroutines, I have simulated them 878 * using goto's to implement the subroutine linkage. The following macros 879 * will run code that appears at the end of readtoken1. 880 */ 881 882 #define CHECKEND() {goto checkend; checkend_return:;} 883 #define PARSEREDIR() {goto parseredir; parseredir_return:;} 884 #define PARSESUB() {goto parsesub; parsesub_return:;} 885 #define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;} 886 #define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;} 887 #define PARSEARITH() {goto parsearith; parsearith_return:;} 888 889 /* 890 * Keep track of nested doublequotes in dblquote and doublequotep. 891 * We use dblquote for the first 32 levels, and we expand to a malloc'ed 892 * region for levels above that. Usually we never need to malloc. 893 * This code assumes that an int is 32 bits. We don't use uint32_t, 894 * because the rest of the code does not. 895 */ 896 #define ISDBLQUOTE() ((varnest < 32) ? (dblquote & (1 << varnest)) : \ 897 (dblquotep[(varnest / 32) - 1] & (1 << (varnest % 32)))) 898 899 #define SETDBLQUOTE() \ 900 if (varnest < 32) \ 901 dblquote |= (1 << varnest); \ 902 else \ 903 dblquotep[(varnest / 32) - 1] |= (1 << (varnest % 32)) 904 905 #define CLRDBLQUOTE() \ 906 if (varnest < 32) \ 907 dblquote &= ~(1 << varnest); \ 908 else \ 909 dblquotep[(varnest / 32) - 1] &= ~(1 << (varnest % 32)) 910 911 STATIC int 912 readtoken1(int firstc, char const *syntax, char *eofmark, int striptabs) 913 { 914 int c = firstc; 915 char *out; 916 int len; 917 char line[EOFMARKLEN + 1]; 918 struct nodelist *bqlist; 919 int quotef; 920 int *dblquotep = NULL; 921 size_t maxnest = 32; 922 int dblquote; 923 int varnest; /* levels of variables expansion */ 924 int arinest; /* levels of arithmetic expansion */ 925 int parenlevel; /* levels of parens in arithmetic */ 926 int oldstyle; 927 char const *prevsyntax; /* syntax before arithmetic */ 928 #if __GNUC__ 929 /* Avoid longjmp clobbering */ 930 (void) &maxnest; 931 (void) &dblquotep; 932 (void) &out; 933 (void) "ef; 934 (void) &dblquote; 935 (void) &varnest; 936 (void) &arinest; 937 (void) &parenlevel; 938 (void) &oldstyle; 939 (void) &prevsyntax; 940 (void) &syntax; 941 #endif 942 943 startlinno = plinno; 944 dblquote = 0; 945 varnest = 0; 946 if (syntax == DQSYNTAX) { 947 SETDBLQUOTE(); 948 } 949 quotef = 0; 950 bqlist = NULL; 951 arinest = 0; 952 parenlevel = 0; 953 954 STARTSTACKSTR(out); 955 loop: { /* for each line, until end of word */ 956 #if ATTY 957 if (c == '\034' && doprompt 958 && attyset() && ! equal(termval(), "emacs")) { 959 attyline(); 960 if (syntax == BASESYNTAX) 961 return readtoken(); 962 c = pgetc(); 963 goto loop; 964 } 965 #endif 966 CHECKEND(); /* set c to PEOF if at end of here document */ 967 for (;;) { /* until end of line or end of word */ 968 CHECKSTRSPACE(3, out); /* permit 3 calls to USTPUTC */ 969 switch(syntax[c]) { 970 case CNL: /* '\n' */ 971 if (syntax == BASESYNTAX) 972 goto endword; /* exit outer loop */ 973 USTPUTC(c, out); 974 plinno++; 975 if (doprompt) 976 setprompt(2); 977 else 978 setprompt(0); 979 c = pgetc(); 980 goto loop; /* continue outer loop */ 981 case CWORD: 982 USTPUTC(c, out); 983 break; 984 case CCTL: 985 if (eofmark == NULL || ISDBLQUOTE()) 986 USTPUTC(CTLESC, out); 987 USTPUTC(c, out); 988 break; 989 case CBACK: /* backslash */ 990 c = pgetc(); 991 if (c == PEOF) { 992 USTPUTC('\\', out); 993 pungetc(); 994 } else if (c == '\n') { 995 if (doprompt) 996 setprompt(2); 997 else 998 setprompt(0); 999 } else { 1000 if (ISDBLQUOTE() && c != '\\' && 1001 c != '`' && c != '$' && 1002 (c != '"' || eofmark != NULL)) 1003 USTPUTC('\\', out); 1004 if (SQSYNTAX[c] == CCTL) 1005 USTPUTC(CTLESC, out); 1006 else if (eofmark == NULL) 1007 USTPUTC(CTLQUOTEMARK, out); 1008 USTPUTC(c, out); 1009 quotef++; 1010 } 1011 break; 1012 case CSQUOTE: 1013 if (syntax != SQSYNTAX) { 1014 if (eofmark == NULL) 1015 USTPUTC(CTLQUOTEMARK, out); 1016 syntax = SQSYNTAX; 1017 break; 1018 } 1019 /* FALLTHROUGH */ 1020 case CDQUOTE: 1021 if (eofmark != NULL && arinest == 0 && 1022 varnest == 0) { 1023 USTPUTC(c, out); 1024 } else { 1025 if (arinest) { 1026 if (c != '"' || ISDBLQUOTE()) { 1027 syntax = ARISYNTAX; 1028 CLRDBLQUOTE(); 1029 } else { 1030 syntax = DQSYNTAX; 1031 SETDBLQUOTE(); 1032 USTPUTC(CTLQUOTEMARK, out); 1033 } 1034 } else if (eofmark == NULL) { 1035 if (c != '"' || ISDBLQUOTE()) { 1036 syntax = BASESYNTAX; 1037 CLRDBLQUOTE(); 1038 } else { 1039 syntax = DQSYNTAX; 1040 SETDBLQUOTE(); 1041 USTPUTC(CTLQUOTEMARK, out); 1042 } 1043 } 1044 quotef++; 1045 } 1046 break; 1047 case CVAR: /* '$' */ 1048 PARSESUB(); /* parse substitution */ 1049 break; 1050 case CENDVAR: /* CLOSEBRACE */ 1051 if (varnest > 0 && !ISDBLQUOTE()) { 1052 varnest--; 1053 USTPUTC(CTLENDVAR, out); 1054 } else { 1055 USTPUTC(c, out); 1056 } 1057 break; 1058 case CLP: /* '(' in arithmetic */ 1059 parenlevel++; 1060 USTPUTC(c, out); 1061 break; 1062 case CRP: /* ')' in arithmetic */ 1063 if (parenlevel > 0) { 1064 USTPUTC(c, out); 1065 --parenlevel; 1066 } else { 1067 if (pgetc() == ')') { 1068 if (--arinest == 0) { 1069 USTPUTC(CTLENDARI, out); 1070 syntax = prevsyntax; 1071 if (syntax == DQSYNTAX) 1072 SETDBLQUOTE(); 1073 else 1074 CLRDBLQUOTE(); 1075 } else 1076 USTPUTC(')', out); 1077 } else { 1078 /* 1079 * unbalanced parens 1080 * (don't 2nd guess - no error) 1081 */ 1082 pungetc(); 1083 USTPUTC(')', out); 1084 } 1085 } 1086 break; 1087 case CBQUOTE: /* '`' */ 1088 PARSEBACKQOLD(); 1089 break; 1090 case CEOF: 1091 goto endword; /* exit outer loop */ 1092 default: 1093 if (varnest == 0) 1094 goto endword; /* exit outer loop */ 1095 USTPUTC(c, out); 1096 } 1097 c = pgetc_macro(); 1098 } 1099 } 1100 endword: 1101 if (syntax == ARISYNTAX) 1102 synerror("Missing '))'"); 1103 if (syntax != BASESYNTAX && ! parsebackquote && eofmark == NULL) 1104 synerror("Unterminated quoted string"); 1105 if (varnest != 0) { 1106 startlinno = plinno; 1107 /* { */ 1108 synerror("Missing '}'"); 1109 } 1110 USTPUTC('\0', out); 1111 len = out - stackblock(); 1112 out = stackblock(); 1113 if (eofmark == NULL) { 1114 if ((c == '>' || c == '<') 1115 && quotef == 0 1116 && len <= 2 1117 && (*out == '\0' || is_digit(*out))) { 1118 PARSEREDIR(); 1119 return lasttoken = TREDIR; 1120 } else { 1121 pungetc(); 1122 } 1123 } 1124 quoteflag = quotef; 1125 backquotelist = bqlist; 1126 grabstackblock(len); 1127 wordtext = out; 1128 if (dblquotep != NULL) 1129 ckfree(dblquotep); 1130 return lasttoken = TWORD; 1131 /* end of readtoken routine */ 1132 1133 1134 1135 /* 1136 * Check to see whether we are at the end of the here document. When this 1137 * is called, c is set to the first character of the next input line. If 1138 * we are at the end of the here document, this routine sets the c to PEOF. 1139 */ 1140 1141 checkend: { 1142 if (eofmark) { 1143 if (striptabs) { 1144 while (c == '\t') 1145 c = pgetc(); 1146 } 1147 if (c == *eofmark) { 1148 if (pfgets(line, sizeof line) != NULL) { 1149 char *p, *q; 1150 1151 p = line; 1152 for (q = eofmark + 1 ; *q && *p == *q ; p++, q++); 1153 if (*p == '\n' && *q == '\0') { 1154 c = PEOF; 1155 plinno++; 1156 needprompt = doprompt; 1157 } else { 1158 pushstring(line, strlen(line), NULL); 1159 } 1160 } 1161 } 1162 } 1163 goto checkend_return; 1164 } 1165 1166 1167 /* 1168 * Parse a redirection operator. The variable "out" points to a string 1169 * specifying the fd to be redirected. The variable "c" contains the 1170 * first character of the redirection operator. 1171 */ 1172 1173 parseredir: { 1174 char fd = *out; 1175 union node *np; 1176 1177 np = (union node *)stalloc(sizeof (struct nfile)); 1178 if (c == '>') { 1179 np->nfile.fd = 1; 1180 c = pgetc(); 1181 if (c == '>') 1182 np->type = NAPPEND; 1183 else if (c == '|') 1184 np->type = NCLOBBER; 1185 else if (c == '&') 1186 np->type = NTOFD; 1187 else { 1188 np->type = NTO; 1189 pungetc(); 1190 } 1191 } else { /* c == '<' */ 1192 np->nfile.fd = 0; 1193 switch (c = pgetc()) { 1194 case '<': 1195 if (sizeof (struct nfile) != sizeof (struct nhere)) { 1196 np = (union node *)stalloc(sizeof (struct nhere)); 1197 np->nfile.fd = 0; 1198 } 1199 np->type = NHERE; 1200 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); 1201 heredoc->here = np; 1202 if ((c = pgetc()) == '-') { 1203 heredoc->striptabs = 1; 1204 } else { 1205 heredoc->striptabs = 0; 1206 pungetc(); 1207 } 1208 break; 1209 1210 case '&': 1211 np->type = NFROMFD; 1212 break; 1213 1214 case '>': 1215 np->type = NFROMTO; 1216 break; 1217 1218 default: 1219 np->type = NFROM; 1220 pungetc(); 1221 break; 1222 } 1223 } 1224 if (fd != '\0') 1225 np->nfile.fd = digit_val(fd); 1226 redirnode = np; 1227 goto parseredir_return; 1228 } 1229 1230 1231 /* 1232 * Parse a substitution. At this point, we have read the dollar sign 1233 * and nothing else. 1234 */ 1235 1236 parsesub: { 1237 int subtype; 1238 int typeloc; 1239 int flags; 1240 char *p; 1241 static const char types[] = "}-+?="; 1242 1243 c = pgetc(); 1244 if (c != '(' && c != OPENBRACE && !is_name(c) && !is_special(c)) { 1245 USTPUTC('$', out); 1246 pungetc(); 1247 } else if (c == '(') { /* $(command) or $((arith)) */ 1248 if (pgetc() == '(') { 1249 PARSEARITH(); 1250 } else { 1251 pungetc(); 1252 PARSEBACKQNEW(); 1253 } 1254 } else { 1255 USTPUTC(CTLVAR, out); 1256 typeloc = out - stackblock(); 1257 USTPUTC(VSNORMAL, out); 1258 subtype = VSNORMAL; 1259 if (c == OPENBRACE) { 1260 c = pgetc(); 1261 if (c == '#') { 1262 if ((c = pgetc()) == CLOSEBRACE) 1263 c = '#'; 1264 else 1265 subtype = VSLENGTH; 1266 } 1267 else 1268 subtype = 0; 1269 } 1270 if (is_name(c)) { 1271 do { 1272 STPUTC(c, out); 1273 c = pgetc(); 1274 } while (is_in_name(c)); 1275 } else if (is_digit(c)) { 1276 do { 1277 USTPUTC(c, out); 1278 c = pgetc(); 1279 } while (is_digit(c)); 1280 } 1281 else if (is_special(c)) { 1282 USTPUTC(c, out); 1283 c = pgetc(); 1284 } 1285 else 1286 badsub: synerror("Bad substitution"); 1287 1288 STPUTC('=', out); 1289 flags = 0; 1290 if (subtype == 0) { 1291 switch (c) { 1292 case ':': 1293 flags = VSNUL; 1294 c = pgetc(); 1295 /*FALLTHROUGH*/ 1296 default: 1297 p = strchr(types, c); 1298 if (p == NULL) 1299 goto badsub; 1300 subtype = p - types + VSNORMAL; 1301 break; 1302 case '%': 1303 case '#': 1304 { 1305 int cc = c; 1306 subtype = c == '#' ? VSTRIMLEFT : 1307 VSTRIMRIGHT; 1308 c = pgetc(); 1309 if (c == cc) 1310 subtype++; 1311 else 1312 pungetc(); 1313 break; 1314 } 1315 } 1316 } else { 1317 pungetc(); 1318 } 1319 if (ISDBLQUOTE() || arinest) 1320 flags |= VSQUOTE; 1321 *(stackblock() + typeloc) = subtype | flags; 1322 if (subtype != VSNORMAL) { 1323 varnest++; 1324 if (varnest >= maxnest) { 1325 dblquotep = ckrealloc(dblquotep, maxnest / 8); 1326 dblquotep[(maxnest / 32) - 1] = 0; 1327 maxnest += 32; 1328 } 1329 } 1330 } 1331 goto parsesub_return; 1332 } 1333 1334 1335 /* 1336 * Called to parse command substitutions. Newstyle is set if the command 1337 * is enclosed inside $(...); nlpp is a pointer to the head of the linked 1338 * list of commands (passed by reference), and savelen is the number of 1339 * characters on the top of the stack which must be preserved. 1340 */ 1341 1342 parsebackq: { 1343 struct nodelist **nlpp; 1344 int savepbq; 1345 union node *n; 1346 char *volatile str; 1347 struct jmploc jmploc; 1348 struct jmploc *volatile savehandler; 1349 int savelen; 1350 int saveprompt; 1351 #ifdef __GNUC__ 1352 (void) &saveprompt; 1353 #endif 1354 1355 savepbq = parsebackquote; 1356 if (setjmp(jmploc.loc)) { 1357 if (str) 1358 ckfree(str); 1359 parsebackquote = 0; 1360 handler = savehandler; 1361 longjmp(handler->loc, 1); 1362 } 1363 INTOFF; 1364 str = NULL; 1365 savelen = out - stackblock(); 1366 if (savelen > 0) { 1367 str = ckmalloc(savelen); 1368 memcpy(str, stackblock(), savelen); 1369 } 1370 savehandler = handler; 1371 handler = &jmploc; 1372 INTON; 1373 if (oldstyle) { 1374 /* We must read until the closing backquote, giving special 1375 treatment to some slashes, and then push the string and 1376 reread it as input, interpreting it normally. */ 1377 char *pout; 1378 int pc; 1379 int psavelen; 1380 char *pstr; 1381 1382 1383 STARTSTACKSTR(pout); 1384 for (;;) { 1385 if (needprompt) { 1386 setprompt(2); 1387 needprompt = 0; 1388 } 1389 switch (pc = pgetc()) { 1390 case '`': 1391 goto done; 1392 1393 case '\\': 1394 if ((pc = pgetc()) == '\n') { 1395 plinno++; 1396 if (doprompt) 1397 setprompt(2); 1398 else 1399 setprompt(0); 1400 /* 1401 * If eating a newline, avoid putting 1402 * the newline into the new character 1403 * stream (via the STPUTC after the 1404 * switch). 1405 */ 1406 continue; 1407 } 1408 if (pc != '\\' && pc != '`' && pc != '$' 1409 && (!ISDBLQUOTE() || pc != '"')) 1410 STPUTC('\\', pout); 1411 break; 1412 1413 case '\n': 1414 plinno++; 1415 needprompt = doprompt; 1416 break; 1417 1418 case PEOF: 1419 startlinno = plinno; 1420 synerror("EOF in backquote substitution"); 1421 break; 1422 1423 default: 1424 break; 1425 } 1426 STPUTC(pc, pout); 1427 } 1428 done: 1429 STPUTC('\0', pout); 1430 psavelen = pout - stackblock(); 1431 if (psavelen > 0) { 1432 pstr = grabstackstr(pout); 1433 setinputstring(pstr, 1); 1434 } 1435 } 1436 nlpp = &bqlist; 1437 while (*nlpp) 1438 nlpp = &(*nlpp)->next; 1439 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 1440 (*nlpp)->next = NULL; 1441 parsebackquote = oldstyle; 1442 1443 if (oldstyle) { 1444 saveprompt = doprompt; 1445 doprompt = 0; 1446 } 1447 1448 n = list(0); 1449 1450 if (oldstyle) 1451 doprompt = saveprompt; 1452 else { 1453 if (readtoken() != TRP) 1454 synexpect(TRP); 1455 } 1456 1457 (*nlpp)->n = n; 1458 if (oldstyle) { 1459 /* 1460 * Start reading from old file again, ignoring any pushed back 1461 * tokens left from the backquote parsing 1462 */ 1463 popfile(); 1464 tokpushback = 0; 1465 } 1466 while (stackblocksize() <= savelen) 1467 growstackblock(); 1468 STARTSTACKSTR(out); 1469 if (str) { 1470 memcpy(out, str, savelen); 1471 STADJUST(savelen, out); 1472 INTOFF; 1473 ckfree(str); 1474 str = NULL; 1475 INTON; 1476 } 1477 parsebackquote = savepbq; 1478 handler = savehandler; 1479 if (arinest || ISDBLQUOTE()) 1480 USTPUTC(CTLBACKQ | CTLQUOTE, out); 1481 else 1482 USTPUTC(CTLBACKQ, out); 1483 if (oldstyle) 1484 goto parsebackq_oldreturn; 1485 else 1486 goto parsebackq_newreturn; 1487 } 1488 1489 /* 1490 * Parse an arithmetic expansion (indicate start of one and set state) 1491 */ 1492 parsearith: { 1493 1494 if (++arinest == 1) { 1495 prevsyntax = syntax; 1496 syntax = ARISYNTAX; 1497 USTPUTC(CTLARI, out); 1498 if (ISDBLQUOTE()) 1499 USTPUTC('"',out); 1500 else 1501 USTPUTC(' ',out); 1502 } else { 1503 /* 1504 * we collapse embedded arithmetic expansion to 1505 * parenthesis, which should be equivalent 1506 */ 1507 USTPUTC('(', out); 1508 } 1509 goto parsearith_return; 1510 } 1511 1512 } /* end of readtoken */ 1513 1514 1515 1516 #ifdef mkinit 1517 RESET { 1518 tokpushback = 0; 1519 checkkwd = 0; 1520 } 1521 #endif 1522 1523 /* 1524 * Returns true if the text contains nothing to expand (no dollar signs 1525 * or backquotes). 1526 */ 1527 1528 STATIC int 1529 noexpand(char *text) 1530 { 1531 char *p; 1532 char c; 1533 1534 p = text; 1535 while ((c = *p++) != '\0') { 1536 if (c == CTLQUOTEMARK) 1537 continue; 1538 if (c == CTLESC) 1539 p++; 1540 else if (BASESYNTAX[(int)c] == CCTL) 1541 return 0; 1542 } 1543 return 1; 1544 } 1545 1546 1547 /* 1548 * Return true if the argument is a legal variable name (a letter or 1549 * underscore followed by zero or more letters, underscores, and digits). 1550 */ 1551 1552 int 1553 goodname(char *name) 1554 { 1555 char *p; 1556 1557 p = name; 1558 if (! is_name(*p)) 1559 return 0; 1560 while (*++p) { 1561 if (! is_in_name(*p)) 1562 return 0; 1563 } 1564 return 1; 1565 } 1566 1567 1568 /* 1569 * Called when an unexpected token is read during the parse. The argument 1570 * is the token that is expected, or -1 if more than one type of token can 1571 * occur at this point. 1572 */ 1573 1574 STATIC void 1575 synexpect(int token) 1576 { 1577 char msg[64]; 1578 1579 if (token >= 0) { 1580 fmtstr(msg, 64, "%s unexpected (expecting %s)", 1581 tokname[lasttoken], tokname[token]); 1582 } else { 1583 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]); 1584 } 1585 synerror(msg); 1586 /* NOTREACHED */ 1587 } 1588 1589 1590 STATIC void 1591 synerror(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(int which) 1602 { 1603 whichprompt = which; 1604 1605 #ifndef SMALL 1606 if (!el) 1607 #endif 1608 out2str(getprompt(NULL)); 1609 } 1610 1611 /* 1612 * called by editline -- any expansions to the prompt 1613 * should be added here. 1614 */ 1615 const char * 1616 getprompt(void *unused) 1617 { 1618 switch (whichprompt) { 1619 case 0: 1620 return ""; 1621 case 1: 1622 return ps1val(); 1623 case 2: 1624 return ps2val(); 1625 default: 1626 return "<internal prompt error>"; 1627 } 1628 } 1629