1 /* $NetBSD: parser.c,v 1.40 1998/09/26 20:56:33 itohy 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 1.40 1998/09/26 20:56:33 itohy 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 "redir.h" /* defines copyfd() */ 55 #include "syntax.h" 56 #include "options.h" 57 #include "input.h" 58 #include "output.h" 59 #include "var.h" 60 #include "error.h" 61 #include "memalloc.h" 62 #include "mystring.h" 63 #include "alias.h" 64 #include "show.h" 65 #ifndef SMALL 66 #include "myhistedit.h" 67 #endif 68 69 /* 70 * Shell command parser. 71 */ 72 73 #define EOFMARKLEN 79 74 75 /* values returned by readtoken */ 76 #include "token.h" 77 78 79 80 struct heredoc { 81 struct heredoc *next; /* next here document in list */ 82 union node *here; /* redirection node */ 83 char *eofmark; /* string indicating end of input */ 84 int striptabs; /* if set, strip leading tabs */ 85 }; 86 87 88 89 struct heredoc *heredoclist; /* list of here documents to read */ 90 int parsebackquote; /* nonzero if we are inside backquotes */ 91 int doprompt; /* if set, prompt the user */ 92 int needprompt; /* true if interactive and at start of line */ 93 int lasttoken; /* last token read */ 94 MKINIT int tokpushback; /* last token pushed back */ 95 char *wordtext; /* text of last word returned by readtoken */ 96 MKINIT int checkkwd; /* 1 == check for kwds, 2 == also eat newlines */ 97 struct nodelist *backquotelist; 98 union node *redirnode; 99 struct heredoc *heredoc; 100 int quoteflag; /* set if (part of) last token was quoted */ 101 int startlinno; /* line # where last token started */ 102 103 104 #define GDB_HACK 1 /* avoid local declarations which gdb can't handle */ 105 #ifdef GDB_HACK 106 static const char argvars[5] = {(char)CTLVAR, (char)(VSNORMAL|VSQUOTE), 107 '@', '=', '\0'}; 108 static const char types[] = "}-+?="; 109 #endif 110 111 112 STATIC union node *list __P((int)); 113 STATIC union node *andor __P((void)); 114 STATIC union node *pipeline __P((void)); 115 STATIC union node *command __P((void)); 116 STATIC union node *simplecmd __P((union node **, union node *)); 117 STATIC union node *makename __P((void)); 118 STATIC void parsefname __P((void)); 119 STATIC void parseheredoc __P((void)); 120 STATIC int peektoken __P((void)); 121 STATIC int readtoken __P((void)); 122 STATIC int xxreadtoken __P((void)); 123 STATIC int readtoken1 __P((int, char const *, char *, int)); 124 STATIC int noexpand __P((char *)); 125 STATIC void synexpect __P((int)) __attribute__((noreturn)); 126 STATIC void synerror __P((char *)) __attribute__((noreturn)); 127 STATIC void setprompt __P((int)); 128 129 130 /* 131 * Read and parse a command. Returns NEOF on end of file. (NULL is a 132 * valid parse tree indicating a blank line.) 133 */ 134 135 union node * 136 parsecmd(interact) 137 int interact; 138 { 139 int t; 140 141 doprompt = interact; 142 if (doprompt) 143 setprompt(1); 144 else 145 setprompt(0); 146 needprompt = 0; 147 t = readtoken(); 148 if (t == TEOF) 149 return NEOF; 150 if (t == TNL) 151 return NULL; 152 tokpushback++; 153 return list(1); 154 } 155 156 157 STATIC union node * 158 list(nlflag) 159 int nlflag; 160 { 161 union node *n1, *n2, *n3; 162 int tok; 163 164 checkkwd = 2; 165 if (nlflag == 0 && tokendlist[peektoken()]) 166 return NULL; 167 n1 = NULL; 168 for (;;) { 169 n2 = andor(); 170 tok = readtoken(); 171 if (tok == TBACKGND) { 172 if (n2->type == NCMD || n2->type == NPIPE) { 173 n2->ncmd.backgnd = 1; 174 } else if (n2->type == NREDIR) { 175 n2->type = NBACKGND; 176 } else { 177 n3 = (union node *)stalloc(sizeof (struct nredir)); 178 n3->type = NBACKGND; 179 n3->nredir.n = n2; 180 n3->nredir.redirect = NULL; 181 n2 = n3; 182 } 183 } 184 if (n1 == NULL) { 185 n1 = n2; 186 } 187 else { 188 n3 = (union node *)stalloc(sizeof (struct nbinary)); 189 n3->type = NSEMI; 190 n3->nbinary.ch1 = n1; 191 n3->nbinary.ch2 = n2; 192 n1 = n3; 193 } 194 switch (tok) { 195 case TBACKGND: 196 case TSEMI: 197 tok = readtoken(); 198 /* fall through */ 199 case TNL: 200 if (tok == TNL) { 201 parseheredoc(); 202 if (nlflag) 203 return n1; 204 } else { 205 tokpushback++; 206 } 207 checkkwd = 2; 208 if (tokendlist[peektoken()]) 209 return n1; 210 break; 211 case TEOF: 212 if (heredoclist) 213 parseheredoc(); 214 else 215 pungetc(); /* push back EOF on input */ 216 return n1; 217 default: 218 if (nlflag) 219 synexpect(-1); 220 tokpushback++; 221 return n1; 222 } 223 } 224 } 225 226 227 228 STATIC union node * 229 andor() { 230 union node *n1, *n2, *n3; 231 int t; 232 233 n1 = pipeline(); 234 for (;;) { 235 if ((t = readtoken()) == TAND) { 236 t = NAND; 237 } else if (t == TOR) { 238 t = NOR; 239 } else { 240 tokpushback++; 241 return n1; 242 } 243 n2 = pipeline(); 244 n3 = (union node *)stalloc(sizeof (struct nbinary)); 245 n3->type = t; 246 n3->nbinary.ch1 = n1; 247 n3->nbinary.ch2 = n2; 248 n1 = n3; 249 } 250 } 251 252 253 254 STATIC union node * 255 pipeline() { 256 union node *n1, *pipenode; 257 struct nodelist *lp, *prev; 258 259 TRACE(("pipeline: entered\n")); 260 n1 = command(); 261 if (readtoken() == TPIPE) { 262 pipenode = (union node *)stalloc(sizeof (struct npipe)); 263 pipenode->type = NPIPE; 264 pipenode->npipe.backgnd = 0; 265 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 266 pipenode->npipe.cmdlist = lp; 267 lp->n = n1; 268 do { 269 prev = lp; 270 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 271 lp->n = command(); 272 prev->next = lp; 273 } while (readtoken() == TPIPE); 274 lp->next = NULL; 275 n1 = pipenode; 276 } 277 tokpushback++; 278 return n1; 279 } 280 281 282 283 STATIC union node * 284 command() { 285 union node *n1, *n2; 286 union node *ap, **app; 287 union node *cp, **cpp; 288 union node *redir, **rpp; 289 int t, negate = 0; 290 291 checkkwd = 2; 292 redir = NULL; 293 n1 = NULL; 294 rpp = &redir; 295 296 /* Check for redirection which may precede command */ 297 while (readtoken() == TREDIR) { 298 *rpp = n2 = redirnode; 299 rpp = &n2->nfile.next; 300 parsefname(); 301 } 302 tokpushback++; 303 304 while (readtoken() == TNOT) { 305 TRACE(("command: TNOT recognized\n")); 306 negate = !negate; 307 } 308 tokpushback++; 309 310 switch (readtoken()) { 311 case TIF: 312 n1 = (union node *)stalloc(sizeof (struct nif)); 313 n1->type = NIF; 314 n1->nif.test = list(0); 315 if (readtoken() != TTHEN) 316 synexpect(TTHEN); 317 n1->nif.ifpart = list(0); 318 n2 = n1; 319 while (readtoken() == TELIF) { 320 n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif)); 321 n2 = n2->nif.elsepart; 322 n2->type = NIF; 323 n2->nif.test = list(0); 324 if (readtoken() != TTHEN) 325 synexpect(TTHEN); 326 n2->nif.ifpart = list(0); 327 } 328 if (lasttoken == TELSE) 329 n2->nif.elsepart = list(0); 330 else { 331 n2->nif.elsepart = NULL; 332 tokpushback++; 333 } 334 if (readtoken() != TFI) 335 synexpect(TFI); 336 checkkwd = 1; 337 break; 338 case TWHILE: 339 case TUNTIL: { 340 int got; 341 n1 = (union node *)stalloc(sizeof (struct nbinary)); 342 n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL; 343 n1->nbinary.ch1 = list(0); 344 if ((got=readtoken()) != TDO) { 345 TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : "")); 346 synexpect(TDO); 347 } 348 n1->nbinary.ch2 = list(0); 349 if (readtoken() != TDONE) 350 synexpect(TDONE); 351 checkkwd = 1; 352 break; 353 } 354 case TFOR: 355 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext)) 356 synerror("Bad for loop variable"); 357 n1 = (union node *)stalloc(sizeof (struct nfor)); 358 n1->type = NFOR; 359 n1->nfor.var = wordtext; 360 if (readtoken() == TWORD && ! quoteflag && equal(wordtext, "in")) { 361 app = ≈ 362 while (readtoken() == TWORD) { 363 n2 = (union node *)stalloc(sizeof (struct narg)); 364 n2->type = NARG; 365 n2->narg.text = wordtext; 366 n2->narg.backquote = backquotelist; 367 *app = n2; 368 app = &n2->narg.next; 369 } 370 *app = NULL; 371 n1->nfor.args = ap; 372 if (lasttoken != TNL && lasttoken != TSEMI) 373 synexpect(-1); 374 } else { 375 #ifndef GDB_HACK 376 static const char argvars[5] = {CTLVAR, VSNORMAL|VSQUOTE, 377 '@', '=', '\0'}; 378 #endif 379 n2 = (union node *)stalloc(sizeof (struct narg)); 380 n2->type = NARG; 381 n2->narg.text = (char *)argvars; 382 n2->narg.backquote = NULL; 383 n2->narg.next = NULL; 384 n1->nfor.args = n2; 385 /* 386 * Newline or semicolon here is optional (but note 387 * that the original Bourne shell only allowed NL). 388 */ 389 if (lasttoken != TNL && lasttoken != TSEMI) 390 tokpushback++; 391 } 392 checkkwd = 2; 393 if ((t = readtoken()) == TDO) 394 t = TDONE; 395 else if (t == TBEGIN) 396 t = TEND; 397 else 398 synexpect(-1); 399 n1->nfor.body = list(0); 400 if (readtoken() != t) 401 synexpect(t); 402 checkkwd = 1; 403 break; 404 case TCASE: 405 n1 = (union node *)stalloc(sizeof (struct ncase)); 406 n1->type = NCASE; 407 if (readtoken() != TWORD) 408 synexpect(TWORD); 409 n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg)); 410 n2->type = NARG; 411 n2->narg.text = wordtext; 412 n2->narg.backquote = backquotelist; 413 n2->narg.next = NULL; 414 while (readtoken() == TNL); 415 if (lasttoken != TWORD || ! equal(wordtext, "in")) 416 synerror("expecting \"in\""); 417 cpp = &n1->ncase.cases; 418 checkkwd = 2, readtoken(); 419 do { 420 *cpp = cp = (union node *)stalloc(sizeof (struct nclist)); 421 cp->type = NCLIST; 422 app = &cp->nclist.pattern; 423 for (;;) { 424 *app = ap = (union node *)stalloc(sizeof (struct narg)); 425 ap->type = NARG; 426 ap->narg.text = wordtext; 427 ap->narg.backquote = backquotelist; 428 if (checkkwd = 2, readtoken() != TPIPE) 429 break; 430 app = &ap->narg.next; 431 readtoken(); 432 } 433 ap->narg.next = NULL; 434 if (lasttoken != TRP) 435 synexpect(TRP); 436 cp->nclist.body = list(0); 437 438 checkkwd = 2; 439 if ((t = readtoken()) != TESAC) { 440 if (t != TENDCASE) 441 synexpect(TENDCASE); 442 else 443 checkkwd = 2, readtoken(); 444 } 445 cpp = &cp->nclist.next; 446 } while(lasttoken != TESAC); 447 *cpp = NULL; 448 checkkwd = 1; 449 break; 450 case TLP: 451 n1 = (union node *)stalloc(sizeof (struct nredir)); 452 n1->type = NSUBSHELL; 453 n1->nredir.n = list(0); 454 n1->nredir.redirect = NULL; 455 if (readtoken() != TRP) 456 synexpect(TRP); 457 checkkwd = 1; 458 break; 459 case TBEGIN: 460 n1 = list(0); 461 if (readtoken() != TEND) 462 synexpect(TEND); 463 checkkwd = 1; 464 break; 465 /* Handle an empty command like other simple commands. */ 466 case TSEMI: 467 /* 468 * An empty command before a ; doesn't make much sense, and 469 * should certainly be disallowed in the case of `if ;'. 470 */ 471 if (!redir) 472 synexpect(-1); 473 case TAND: 474 case TOR: 475 case TNL: 476 case TEOF: 477 case TWORD: 478 case TRP: 479 tokpushback++; 480 n1 = simplecmd(rpp, redir); 481 goto checkneg; 482 default: 483 synexpect(-1); 484 /* NOTREACHED */ 485 } 486 487 /* Now check for redirection which may follow command */ 488 while (readtoken() == TREDIR) { 489 *rpp = n2 = redirnode; 490 rpp = &n2->nfile.next; 491 parsefname(); 492 } 493 tokpushback++; 494 *rpp = NULL; 495 if (redir) { 496 if (n1->type != NSUBSHELL) { 497 n2 = (union node *)stalloc(sizeof (struct nredir)); 498 n2->type = NREDIR; 499 n2->nredir.n = n1; 500 n1 = n2; 501 } 502 n1->nredir.redirect = redir; 503 } 504 505 checkneg: 506 if (negate) { 507 n2 = (union node *)stalloc(sizeof (struct nnot)); 508 n2->type = NNOT; 509 n2->nnot.com = n1; 510 return n2; 511 } 512 else 513 return n1; 514 } 515 516 517 STATIC union node * 518 simplecmd(rpp, redir) 519 union node **rpp, *redir; 520 { 521 union node *args, **app; 522 union node **orig_rpp = rpp; 523 union node *n = NULL, *n2; 524 int negate = 0; 525 526 /* If we don't have any redirections already, then we must reset */ 527 /* rpp to be the address of the local redir variable. */ 528 if (redir == 0) 529 rpp = &redir; 530 531 args = NULL; 532 app = &args; 533 /* 534 * We save the incoming value, because we need this for shell 535 * functions. There can not be a redirect or an argument between 536 * the function name and the open parenthesis. 537 */ 538 orig_rpp = rpp; 539 540 while (readtoken() == TNOT) { 541 TRACE(("command: TNOT recognized\n")); 542 negate = !negate; 543 } 544 tokpushback++; 545 546 for (;;) { 547 if (readtoken() == TWORD) { 548 n = (union node *)stalloc(sizeof (struct narg)); 549 n->type = NARG; 550 n->narg.text = wordtext; 551 n->narg.backquote = backquotelist; 552 *app = n; 553 app = &n->narg.next; 554 } else if (lasttoken == TREDIR) { 555 *rpp = n = redirnode; 556 rpp = &n->nfile.next; 557 parsefname(); /* read name of redirection file */ 558 } else if (lasttoken == TLP && app == &args->narg.next 559 && rpp == orig_rpp) { 560 /* We have a function */ 561 if (readtoken() != TRP) 562 synexpect(TRP); 563 #ifdef notdef 564 if (! goodname(n->narg.text)) 565 synerror("Bad function name"); 566 #endif 567 n->type = NDEFUN; 568 n->narg.next = command(); 569 goto checkneg; 570 } else { 571 tokpushback++; 572 break; 573 } 574 } 575 *app = NULL; 576 *rpp = NULL; 577 n = (union node *)stalloc(sizeof (struct ncmd)); 578 n->type = NCMD; 579 n->ncmd.backgnd = 0; 580 n->ncmd.args = args; 581 n->ncmd.redirect = redir; 582 583 checkneg: 584 if (negate) { 585 n2 = (union node *)stalloc(sizeof (struct nnot)); 586 n2->type = NNOT; 587 n2->nnot.com = n; 588 return n2; 589 } 590 else 591 return n; 592 } 593 594 STATIC union node * 595 makename() { 596 union node *n; 597 598 n = (union node *)stalloc(sizeof (struct narg)); 599 n->type = NARG; 600 n->narg.next = NULL; 601 n->narg.text = wordtext; 602 n->narg.backquote = backquotelist; 603 return n; 604 } 605 606 void fixredir(n, text, err) 607 union node *n; 608 const char *text; 609 int err; 610 { 611 TRACE(("Fix redir %s %d\n", text, err)); 612 if (!err) 613 n->ndup.vname = NULL; 614 615 if (is_digit(text[0]) && text[1] == '\0') 616 n->ndup.dupfd = digit_val(text[0]); 617 else if (text[0] == '-' && text[1] == '\0') 618 n->ndup.dupfd = -1; 619 else { 620 621 if (err) 622 synerror("Bad fd number"); 623 else 624 n->ndup.vname = makename(); 625 } 626 } 627 628 629 STATIC void 630 parsefname() { 631 union node *n = redirnode; 632 633 if (readtoken() != TWORD) 634 synexpect(-1); 635 if (n->type == NHERE) { 636 struct heredoc *here = heredoc; 637 struct heredoc *p; 638 int i; 639 640 if (quoteflag == 0) 641 n->type = NXHERE; 642 TRACE(("Here document %d\n", n->type)); 643 if (here->striptabs) { 644 while (*wordtext == '\t') 645 wordtext++; 646 } 647 if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN) 648 synerror("Illegal eof marker for << redirection"); 649 rmescapes(wordtext); 650 here->eofmark = wordtext; 651 here->next = NULL; 652 if (heredoclist == NULL) 653 heredoclist = here; 654 else { 655 for (p = heredoclist ; p->next ; p = p->next); 656 p->next = here; 657 } 658 } else if (n->type == NTOFD || n->type == NFROMFD) { 659 fixredir(n, wordtext, 0); 660 } else { 661 n->nfile.fname = makename(); 662 } 663 } 664 665 666 /* 667 * Input any here documents. 668 */ 669 670 STATIC void 671 parseheredoc() { 672 struct heredoc *here; 673 union node *n; 674 675 while (heredoclist) { 676 here = heredoclist; 677 heredoclist = here->next; 678 if (needprompt) { 679 setprompt(2); 680 needprompt = 0; 681 } 682 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, 683 here->eofmark, here->striptabs); 684 n = (union node *)stalloc(sizeof (struct narg)); 685 n->narg.type = NARG; 686 n->narg.next = NULL; 687 n->narg.text = wordtext; 688 n->narg.backquote = backquotelist; 689 here->here->nhere.doc = n; 690 } 691 } 692 693 STATIC int 694 peektoken() { 695 int t; 696 697 t = readtoken(); 698 tokpushback++; 699 return (t); 700 } 701 702 STATIC int 703 readtoken() { 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 == 2) { 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 char * const *pp; 732 733 for (pp = (char **)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 ((ap = lookupalias(wordtext, 1)) != NULL) { 742 pushstring(ap->val, strlen(ap->val), ap); 743 checkkwd = savecheckkwd; 744 goto top; 745 } 746 } 747 out: 748 checkkwd = (t == TNOT) ? savecheckkwd : 0; 749 } 750 #ifdef DEBUG 751 if (!alreadyseen) 752 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 753 else 754 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 755 #endif 756 return (t); 757 } 758 759 760 /* 761 * Read the next input token. 762 * If the token is a word, we set backquotelist to the list of cmds in 763 * backquotes. We set quoteflag to true if any part of the word was 764 * quoted. 765 * If the token is TREDIR, then we set redirnode to a structure containing 766 * the redirection. 767 * In all cases, the variable startlinno is set to the number of the line 768 * on which the token starts. 769 * 770 * [Change comment: here documents and internal procedures] 771 * [Readtoken shouldn't have any arguments. Perhaps we should make the 772 * word parsing code into a separate routine. In this case, readtoken 773 * doesn't need to have any internal procedures, but parseword does. 774 * We could also make parseoperator in essence the main routine, and 775 * have parseword (readtoken1?) handle both words and redirection.] 776 */ 777 778 #define RETURN(token) return lasttoken = token 779 780 STATIC int 781 xxreadtoken() { 782 int c; 783 784 if (tokpushback) { 785 tokpushback = 0; 786 return lasttoken; 787 } 788 if (needprompt) { 789 setprompt(2); 790 needprompt = 0; 791 } 792 startlinno = plinno; 793 for (;;) { /* until token or start of word found */ 794 c = pgetc_macro(); 795 if (c == ' ' || c == '\t') 796 continue; /* quick check for white space first */ 797 switch (c) { 798 case ' ': case '\t': 799 continue; 800 case '#': 801 while ((c = pgetc()) != '\n' && c != PEOF); 802 pungetc(); 803 continue; 804 case '\\': 805 if (pgetc() == '\n') { 806 startlinno = ++plinno; 807 if (doprompt) 808 setprompt(2); 809 else 810 setprompt(0); 811 continue; 812 } 813 pungetc(); 814 goto breakloop; 815 case '\n': 816 plinno++; 817 needprompt = doprompt; 818 RETURN(TNL); 819 case PEOF: 820 RETURN(TEOF); 821 case '&': 822 if (pgetc() == '&') 823 RETURN(TAND); 824 pungetc(); 825 RETURN(TBACKGND); 826 case '|': 827 if (pgetc() == '|') 828 RETURN(TOR); 829 pungetc(); 830 RETURN(TPIPE); 831 case ';': 832 if (pgetc() == ';') 833 RETURN(TENDCASE); 834 pungetc(); 835 RETURN(TSEMI); 836 case '(': 837 RETURN(TLP); 838 case ')': 839 RETURN(TRP); 840 default: 841 goto breakloop; 842 } 843 } 844 breakloop: 845 return readtoken1(c, BASESYNTAX, (char *)NULL, 0); 846 #undef RETURN 847 } 848 849 850 851 /* 852 * If eofmark is NULL, read a word or a redirection symbol. If eofmark 853 * is not NULL, read a here document. In the latter case, eofmark is the 854 * word which marks the end of the document and striptabs is true if 855 * leading tabs should be stripped from the document. The argument firstc 856 * is the first character of the input token or document. 857 * 858 * Because C does not have internal subroutines, I have simulated them 859 * using goto's to implement the subroutine linkage. The following macros 860 * will run code that appears at the end of readtoken1. 861 */ 862 863 #define CHECKEND() {goto checkend; checkend_return:;} 864 #define PARSEREDIR() {goto parseredir; parseredir_return:;} 865 #define PARSESUB() {goto parsesub; parsesub_return:;} 866 #define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;} 867 #define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;} 868 #define PARSEARITH() {goto parsearith; parsearith_return:;} 869 870 STATIC int 871 readtoken1(firstc, syntax, eofmark, striptabs) 872 int firstc; 873 char const *syntax; 874 char *eofmark; 875 int striptabs; 876 { 877 int c = firstc; 878 char *out; 879 int len; 880 char line[EOFMARKLEN + 1]; 881 struct nodelist *bqlist; 882 int quotef; 883 int dblquote; 884 int varnest; /* levels of variables expansion */ 885 int arinest; /* levels of arithmetic expansion */ 886 int parenlevel; /* levels of parens in arithmetic */ 887 int oldstyle; 888 char const *prevsyntax; /* syntax before arithmetic */ 889 #if __GNUC__ 890 /* Avoid longjmp clobbering */ 891 (void) &out; 892 (void) "ef; 893 (void) &dblquote; 894 (void) &varnest; 895 (void) &arinest; 896 (void) &parenlevel; 897 (void) &oldstyle; 898 (void) &prevsyntax; 899 (void) &syntax; 900 #endif 901 902 startlinno = plinno; 903 dblquote = 0; 904 if (syntax == DQSYNTAX) 905 dblquote = 1; 906 quotef = 0; 907 bqlist = NULL; 908 varnest = 0; 909 arinest = 0; 910 parenlevel = 0; 911 912 STARTSTACKSTR(out); 913 loop: { /* for each line, until end of word */ 914 #if ATTY 915 if (c == '\034' && doprompt 916 && attyset() && ! equal(termval(), "emacs")) { 917 attyline(); 918 if (syntax == BASESYNTAX) 919 return readtoken(); 920 c = pgetc(); 921 goto loop; 922 } 923 #endif 924 CHECKEND(); /* set c to PEOF if at end of here document */ 925 for (;;) { /* until end of line or end of word */ 926 CHECKSTRSPACE(3, out); /* permit 3 calls to USTPUTC */ 927 switch(syntax[c]) { 928 case CNL: /* '\n' */ 929 if (syntax == BASESYNTAX) 930 goto endword; /* exit outer loop */ 931 USTPUTC(c, out); 932 plinno++; 933 if (doprompt) 934 setprompt(2); 935 else 936 setprompt(0); 937 c = pgetc(); 938 goto loop; /* continue outer loop */ 939 case CWORD: 940 USTPUTC(c, out); 941 break; 942 case CCTL: 943 if (eofmark == NULL || dblquote) 944 USTPUTC(CTLESC, out); 945 USTPUTC(c, out); 946 break; 947 case CBACK: /* backslash */ 948 c = pgetc(); 949 if (c == PEOF) { 950 USTPUTC('\\', out); 951 pungetc(); 952 } else if (c == '\n') { 953 if (doprompt) 954 setprompt(2); 955 else 956 setprompt(0); 957 } else { 958 if (dblquote && c != '\\' && c != '`' && c != '$' 959 && (c != '"' || eofmark != NULL)) 960 USTPUTC('\\', out); 961 if (SQSYNTAX[c] == CCTL) 962 USTPUTC(CTLESC, out); 963 USTPUTC(c, out); 964 quotef++; 965 } 966 break; 967 case CSQUOTE: 968 syntax = SQSYNTAX; 969 break; 970 case CDQUOTE: 971 syntax = DQSYNTAX; 972 dblquote = 1; 973 break; 974 case CENDQUOTE: 975 if (eofmark) { 976 USTPUTC(c, out); 977 } else { 978 if (arinest) 979 syntax = ARISYNTAX; 980 else 981 syntax = BASESYNTAX; 982 quotef++; 983 dblquote = 0; 984 } 985 break; 986 case CVAR: /* '$' */ 987 PARSESUB(); /* parse substitution */ 988 break; 989 case CENDVAR: /* '}' */ 990 if (varnest > 0) { 991 varnest--; 992 USTPUTC(CTLENDVAR, out); 993 } else { 994 USTPUTC(c, out); 995 } 996 break; 997 case CLP: /* '(' in arithmetic */ 998 parenlevel++; 999 USTPUTC(c, out); 1000 break; 1001 case CRP: /* ')' in arithmetic */ 1002 if (parenlevel > 0) { 1003 USTPUTC(c, out); 1004 --parenlevel; 1005 } else { 1006 if (pgetc() == ')') { 1007 if (--arinest == 0) { 1008 USTPUTC(CTLENDARI, out); 1009 syntax = prevsyntax; 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 { 1118 np->type = NTO; 1119 pungetc(); 1120 } 1121 } else { /* c == '<' */ 1122 np->nfile.fd = 0; 1123 c = pgetc(); 1124 if (c == '<') { 1125 if (sizeof (struct nfile) != sizeof (struct nhere)) { 1126 np = (union node *)stalloc(sizeof (struct nhere)); 1127 np->nfile.fd = 0; 1128 } 1129 np->type = NHERE; 1130 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); 1131 heredoc->here = np; 1132 if ((c = pgetc()) == '-') { 1133 heredoc->striptabs = 1; 1134 } else { 1135 heredoc->striptabs = 0; 1136 pungetc(); 1137 } 1138 } else if (c == '&') 1139 np->type = NFROMFD; 1140 else { 1141 np->type = NFROM; 1142 pungetc(); 1143 } 1144 } 1145 if (fd != '\0') 1146 np->nfile.fd = digit_val(fd); 1147 redirnode = np; 1148 goto parseredir_return; 1149 } 1150 1151 1152 /* 1153 * Parse a substitution. At this point, we have read the dollar sign 1154 * and nothing else. 1155 */ 1156 1157 parsesub: { 1158 int subtype; 1159 int typeloc; 1160 int flags; 1161 char *p; 1162 #ifndef GDB_HACK 1163 static const char types[] = "}-+?="; 1164 #endif 1165 1166 c = pgetc(); 1167 if (c != '(' && c != '{' && !is_name(c) && !is_special(c)) { 1168 USTPUTC('$', out); 1169 pungetc(); 1170 } else if (c == '(') { /* $(command) or $((arith)) */ 1171 if (pgetc() == '(') { 1172 PARSEARITH(); 1173 } else { 1174 pungetc(); 1175 PARSEBACKQNEW(); 1176 } 1177 } else { 1178 USTPUTC(CTLVAR, out); 1179 typeloc = out - stackblock(); 1180 USTPUTC(VSNORMAL, out); 1181 subtype = VSNORMAL; 1182 if (c == '{') { 1183 c = pgetc(); 1184 if (c == '#') { 1185 if ((c = pgetc()) == '}') 1186 c = '#'; 1187 else 1188 subtype = VSLENGTH; 1189 } 1190 else 1191 subtype = 0; 1192 } 1193 if (is_name(c)) { 1194 do { 1195 STPUTC(c, out); 1196 c = pgetc(); 1197 } while (is_in_name(c)); 1198 } else if (is_digit(c)) { 1199 do { 1200 USTPUTC(c, out); 1201 c = pgetc(); 1202 } while (is_digit(c)); 1203 } 1204 else if (is_special(c)) { 1205 USTPUTC(c, out); 1206 c = pgetc(); 1207 } 1208 else 1209 badsub: synerror("Bad substitution"); 1210 1211 STPUTC('=', out); 1212 flags = 0; 1213 if (subtype == 0) { 1214 switch (c) { 1215 case ':': 1216 flags = VSNUL; 1217 c = pgetc(); 1218 /*FALLTHROUGH*/ 1219 default: 1220 p = strchr(types, c); 1221 if (p == NULL) 1222 goto badsub; 1223 subtype = p - types + VSNORMAL; 1224 break; 1225 case '%': 1226 case '#': 1227 { 1228 int cc = c; 1229 subtype = c == '#' ? VSTRIMLEFT : 1230 VSTRIMRIGHT; 1231 c = pgetc(); 1232 if (c == cc) 1233 subtype++; 1234 else 1235 pungetc(); 1236 break; 1237 } 1238 } 1239 } else { 1240 pungetc(); 1241 } 1242 if (dblquote || arinest) 1243 flags |= VSQUOTE; 1244 *(stackblock() + typeloc) = subtype | flags; 1245 if (subtype != VSNORMAL) 1246 varnest++; 1247 } 1248 goto parsesub_return; 1249 } 1250 1251 1252 /* 1253 * Called to parse command substitutions. Newstyle is set if the command 1254 * is enclosed inside $(...); nlpp is a pointer to the head of the linked 1255 * list of commands (passed by reference), and savelen is the number of 1256 * characters on the top of the stack which must be preserved. 1257 */ 1258 1259 parsebackq: { 1260 struct nodelist **nlpp; 1261 int savepbq; 1262 union node *n; 1263 char *volatile str; 1264 struct jmploc jmploc; 1265 struct jmploc *volatile savehandler; 1266 int savelen; 1267 int saveprompt; 1268 #ifdef __GNUC__ 1269 (void) &saveprompt; 1270 #endif 1271 1272 savepbq = parsebackquote; 1273 if (setjmp(jmploc.loc)) { 1274 if (str) 1275 ckfree(str); 1276 parsebackquote = 0; 1277 handler = savehandler; 1278 longjmp(handler->loc, 1); 1279 } 1280 INTOFF; 1281 str = NULL; 1282 savelen = out - stackblock(); 1283 if (savelen > 0) { 1284 str = ckmalloc(savelen); 1285 memcpy(str, stackblock(), savelen); 1286 } 1287 savehandler = handler; 1288 handler = &jmploc; 1289 INTON; 1290 if (oldstyle) { 1291 /* We must read until the closing backquote, giving special 1292 treatment to some slashes, and then push the string and 1293 reread it as input, interpreting it normally. */ 1294 char *out; 1295 int c; 1296 int savelen; 1297 char *str; 1298 1299 1300 STARTSTACKSTR(out); 1301 for (;;) { 1302 if (needprompt) { 1303 setprompt(2); 1304 needprompt = 0; 1305 } 1306 switch (c = pgetc()) { 1307 case '`': 1308 goto done; 1309 1310 case '\\': 1311 if ((c = pgetc()) == '\n') { 1312 plinno++; 1313 if (doprompt) 1314 setprompt(2); 1315 else 1316 setprompt(0); 1317 /* 1318 * If eating a newline, avoid putting 1319 * the newline into the new character 1320 * stream (via the STPUTC after the 1321 * switch). 1322 */ 1323 continue; 1324 } 1325 if (c != '\\' && c != '`' && c != '$' 1326 && (!dblquote || c != '"')) 1327 STPUTC('\\', out); 1328 break; 1329 1330 case '\n': 1331 plinno++; 1332 needprompt = doprompt; 1333 break; 1334 1335 case PEOF: 1336 startlinno = plinno; 1337 synerror("EOF in backquote substitution"); 1338 break; 1339 1340 default: 1341 break; 1342 } 1343 STPUTC(c, out); 1344 } 1345 done: 1346 STPUTC('\0', out); 1347 savelen = out - stackblock(); 1348 if (savelen > 0) { 1349 str = grabstackstr(out); 1350 setinputstring(str, 1); 1351 } 1352 } 1353 nlpp = &bqlist; 1354 while (*nlpp) 1355 nlpp = &(*nlpp)->next; 1356 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 1357 (*nlpp)->next = NULL; 1358 parsebackquote = oldstyle; 1359 1360 if (oldstyle) { 1361 saveprompt = doprompt; 1362 doprompt = 0; 1363 } 1364 1365 n = list(0); 1366 1367 if (oldstyle) 1368 doprompt = saveprompt; 1369 else { 1370 if (readtoken() != TRP) 1371 synexpect(TRP); 1372 } 1373 1374 (*nlpp)->n = n; 1375 if (oldstyle) { 1376 /* 1377 * Start reading from old file again, ignoring any pushed back 1378 * tokens left from the backquote parsing 1379 */ 1380 popfile(); 1381 tokpushback = 0; 1382 } 1383 while (stackblocksize() <= savelen) 1384 growstackblock(); 1385 STARTSTACKSTR(out); 1386 if (str) { 1387 memcpy(out, str, savelen); 1388 STADJUST(savelen, out); 1389 INTOFF; 1390 ckfree(str); 1391 str = NULL; 1392 INTON; 1393 } 1394 parsebackquote = savepbq; 1395 handler = savehandler; 1396 if (arinest || dblquote) 1397 USTPUTC(CTLBACKQ | CTLQUOTE, out); 1398 else 1399 USTPUTC(CTLBACKQ, out); 1400 if (oldstyle) 1401 goto parsebackq_oldreturn; 1402 else 1403 goto parsebackq_newreturn; 1404 } 1405 1406 /* 1407 * Parse an arithmetic expansion (indicate start of one and set state) 1408 */ 1409 parsearith: { 1410 1411 if (++arinest == 1) { 1412 prevsyntax = syntax; 1413 syntax = ARISYNTAX; 1414 USTPUTC(CTLARI, out); 1415 } else { 1416 /* 1417 * we collapse embedded arithmetic expansion to 1418 * parenthesis, which should be equivalent 1419 */ 1420 USTPUTC('(', out); 1421 } 1422 goto parsearith_return; 1423 } 1424 1425 } /* end of readtoken */ 1426 1427 1428 1429 #ifdef mkinit 1430 RESET { 1431 tokpushback = 0; 1432 checkkwd = 0; 1433 } 1434 #endif 1435 1436 /* 1437 * Returns true if the text contains nothing to expand (no dollar signs 1438 * or backquotes). 1439 */ 1440 1441 STATIC int 1442 noexpand(text) 1443 char *text; 1444 { 1445 char *p; 1446 char c; 1447 1448 p = text; 1449 while ((c = *p++) != '\0') { 1450 if (c == CTLESC) 1451 p++; 1452 else if (BASESYNTAX[(int)c] == CCTL) 1453 return 0; 1454 } 1455 return 1; 1456 } 1457 1458 1459 /* 1460 * Return true if the argument is a legal variable name (a letter or 1461 * underscore followed by zero or more letters, underscores, and digits). 1462 */ 1463 1464 int 1465 goodname(name) 1466 char *name; 1467 { 1468 char *p; 1469 1470 p = name; 1471 if (! is_name(*p)) 1472 return 0; 1473 while (*++p) { 1474 if (! is_in_name(*p)) 1475 return 0; 1476 } 1477 return 1; 1478 } 1479 1480 1481 /* 1482 * Called when an unexpected token is read during the parse. The argument 1483 * is the token that is expected, or -1 if more than one type of token can 1484 * occur at this point. 1485 */ 1486 1487 STATIC void 1488 synexpect(token) 1489 int token; 1490 { 1491 char msg[64]; 1492 1493 if (token >= 0) { 1494 fmtstr(msg, 64, "%s unexpected (expecting %s)", 1495 tokname[lasttoken], tokname[token]); 1496 } else { 1497 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]); 1498 } 1499 synerror(msg); 1500 /* NOTREACHED */ 1501 } 1502 1503 1504 STATIC void 1505 synerror(msg) 1506 char *msg; 1507 { 1508 if (commandname) 1509 outfmt(&errout, "%s: %d: ", commandname, startlinno); 1510 outfmt(&errout, "Syntax error: %s\n", msg); 1511 error((char *)NULL); 1512 /* NOTREACHED */ 1513 } 1514 1515 STATIC void 1516 setprompt(which) 1517 int which; 1518 { 1519 whichprompt = which; 1520 1521 #ifndef SMALL 1522 if (!el) 1523 #endif 1524 out2str(getprompt(NULL)); 1525 } 1526 1527 /* 1528 * called by editline -- any expansions to the prompt 1529 * should be added here. 1530 */ 1531 char * 1532 getprompt(unused) 1533 void *unused; 1534 { 1535 switch (whichprompt) { 1536 case 0: 1537 return ""; 1538 case 1: 1539 return ps1val(); 1540 case 2: 1541 return ps2val(); 1542 default: 1543 return "<internal prompt error>"; 1544 } 1545 } 1546