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