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 STATIC struct heredoc *heredoclist; /* list of here documents to read */ 88 STATIC int parsebackquote; /* nonzero if we are inside backquotes */ 89 STATIC int doprompt; /* if set, prompt the user */ 90 STATIC int needprompt; /* true if interactive and at start of line */ 91 STATIC int lasttoken; /* last token read */ 92 MKINIT int tokpushback; /* last token pushed back */ 93 STATIC char *wordtext; /* text of last word returned by readtoken */ 94 MKINIT int checkkwd; /* 1 == check for kwds, 2 == also eat newlines */ 95 STATIC struct nodelist *backquotelist; 96 STATIC union node *redirnode; 97 STATIC struct heredoc *heredoc; 98 STATIC int quoteflag; /* set if (part of) last token was quoted */ 99 STATIC 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 /* FALLTHROUGH */ 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 if ((n1->nif.test = list(0)) == NULL) 327 synexpect(-1); 328 if (readtoken() != TTHEN) 329 synexpect(TTHEN); 330 n1->nif.ifpart = list(0); 331 n2 = n1; 332 while (readtoken() == TELIF) { 333 n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif)); 334 n2 = n2->nif.elsepart; 335 n2->type = NIF; 336 if ((n2->nif.test = list(0)) == NULL) 337 synexpect(-1); 338 if (readtoken() != TTHEN) 339 synexpect(TTHEN); 340 n2->nif.ifpart = list(0); 341 } 342 if (lasttoken == TELSE) 343 n2->nif.elsepart = list(0); 344 else { 345 n2->nif.elsepart = NULL; 346 tokpushback++; 347 } 348 if (readtoken() != TFI) 349 synexpect(TFI); 350 checkkwd = 1; 351 break; 352 case TWHILE: 353 case TUNTIL: { 354 int got; 355 n1 = (union node *)stalloc(sizeof (struct nbinary)); 356 n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL; 357 if ((n1->nbinary.ch1 = list(0)) == NULL) 358 synexpect(-1); 359 if ((got=readtoken()) != TDO) { 360 TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : "")); 361 synexpect(TDO); 362 } 363 n1->nbinary.ch2 = list(0); 364 if (readtoken() != TDONE) 365 synexpect(TDONE); 366 checkkwd = 1; 367 break; 368 } 369 case TFOR: 370 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext)) 371 synerror("Bad for loop variable"); 372 n1 = (union node *)stalloc(sizeof (struct nfor)); 373 n1->type = NFOR; 374 n1->nfor.var = wordtext; 375 if (readtoken() == TWORD && ! quoteflag && equal(wordtext, "in")) { 376 app = ≈ 377 while (readtoken() == TWORD) { 378 n2 = (union node *)stalloc(sizeof (struct narg)); 379 n2->type = NARG; 380 n2->narg.text = wordtext; 381 n2->narg.backquote = backquotelist; 382 *app = n2; 383 app = &n2->narg.next; 384 } 385 *app = NULL; 386 n1->nfor.args = ap; 387 if (lasttoken != TNL && lasttoken != TSEMI) 388 synexpect(-1); 389 } else { 390 #ifndef GDB_HACK 391 static const char argvars[5] = {CTLVAR, VSNORMAL|VSQUOTE, 392 '@', '=', '\0'}; 393 #endif 394 n2 = (union node *)stalloc(sizeof (struct narg)); 395 n2->type = NARG; 396 n2->narg.text = (char *)argvars; 397 n2->narg.backquote = NULL; 398 n2->narg.next = NULL; 399 n1->nfor.args = n2; 400 /* 401 * Newline or semicolon here is optional (but note 402 * that the original Bourne shell only allowed NL). 403 */ 404 if (lasttoken != TNL && lasttoken != TSEMI) 405 tokpushback++; 406 } 407 checkkwd = 2; 408 if ((t = readtoken()) == TDO) 409 t = TDONE; 410 else if (t == TBEGIN) 411 t = TEND; 412 else 413 synexpect(-1); 414 n1->nfor.body = list(0); 415 if (readtoken() != t) 416 synexpect(t); 417 checkkwd = 1; 418 break; 419 case TCASE: 420 n1 = (union node *)stalloc(sizeof (struct ncase)); 421 n1->type = NCASE; 422 if (readtoken() != TWORD) 423 synexpect(TWORD); 424 n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg)); 425 n2->type = NARG; 426 n2->narg.text = wordtext; 427 n2->narg.backquote = backquotelist; 428 n2->narg.next = NULL; 429 while (readtoken() == TNL); 430 if (lasttoken != TWORD || ! equal(wordtext, "in")) 431 synerror("expecting \"in\""); 432 cpp = &n1->ncase.cases; 433 noaliases = 1; /* turn off alias expansion */ 434 checkkwd = 2, readtoken(); 435 while (lasttoken != TESAC) { 436 *cpp = cp = (union node *)stalloc(sizeof (struct nclist)); 437 cp->type = NCLIST; 438 app = &cp->nclist.pattern; 439 if (lasttoken == TLP) 440 readtoken(); 441 for (;;) { 442 *app = ap = (union node *)stalloc(sizeof (struct narg)); 443 ap->type = NARG; 444 ap->narg.text = wordtext; 445 ap->narg.backquote = backquotelist; 446 if (checkkwd = 2, readtoken() != TPIPE) 447 break; 448 app = &ap->narg.next; 449 readtoken(); 450 } 451 ap->narg.next = NULL; 452 if (lasttoken != TRP) 453 noaliases = 0, synexpect(TRP); 454 cp->nclist.body = list(0); 455 456 checkkwd = 2; 457 if ((t = readtoken()) != TESAC) { 458 if (t != TENDCASE) 459 noaliases = 0, synexpect(TENDCASE); 460 else 461 checkkwd = 2, readtoken(); 462 } 463 cpp = &cp->nclist.next; 464 } 465 noaliases = 0; /* reset alias expansion */ 466 *cpp = NULL; 467 checkkwd = 1; 468 break; 469 case TLP: 470 n1 = (union node *)stalloc(sizeof (struct nredir)); 471 n1->type = NSUBSHELL; 472 n1->nredir.n = list(0); 473 n1->nredir.redirect = NULL; 474 if (readtoken() != TRP) 475 synexpect(TRP); 476 checkkwd = 1; 477 break; 478 case TBEGIN: 479 n1 = list(0); 480 if (readtoken() != TEND) 481 synexpect(TEND); 482 checkkwd = 1; 483 break; 484 /* Handle an empty command like other simple commands. */ 485 case TSEMI: 486 case TAND: 487 case TOR: 488 /* 489 * An empty command before a ; doesn't make much sense, and 490 * should certainly be disallowed in the case of `if ;'. 491 */ 492 if (!redir) 493 synexpect(-1); 494 case TNL: 495 case TEOF: 496 case TWORD: 497 case TRP: 498 tokpushback++; 499 n1 = simplecmd(rpp, redir); 500 goto checkneg; 501 default: 502 synexpect(-1); 503 } 504 505 /* Now check for redirection which may follow command */ 506 while (readtoken() == TREDIR) { 507 *rpp = n2 = redirnode; 508 rpp = &n2->nfile.next; 509 parsefname(); 510 } 511 tokpushback++; 512 *rpp = NULL; 513 if (redir) { 514 if (n1->type != NSUBSHELL) { 515 n2 = (union node *)stalloc(sizeof (struct nredir)); 516 n2->type = NREDIR; 517 n2->nredir.n = n1; 518 n1 = n2; 519 } 520 n1->nredir.redirect = redir; 521 } 522 523 checkneg: 524 if (negate) { 525 n2 = (union node *)stalloc(sizeof (struct nnot)); 526 n2->type = NNOT; 527 n2->nnot.com = n1; 528 return n2; 529 } 530 else 531 return n1; 532 } 533 534 535 STATIC union node * 536 simplecmd(union node **rpp, union node *redir) 537 { 538 union node *args, **app; 539 union node **orig_rpp = rpp; 540 union node *n = NULL, *n2; 541 int negate = 0; 542 543 /* If we don't have any redirections already, then we must reset */ 544 /* rpp to be the address of the local redir variable. */ 545 if (redir == 0) 546 rpp = &redir; 547 548 args = NULL; 549 app = &args; 550 /* 551 * We save the incoming value, because we need this for shell 552 * functions. There can not be a redirect or an argument between 553 * the function name and the open parenthesis. 554 */ 555 orig_rpp = rpp; 556 557 while (readtoken() == TNOT) { 558 TRACE(("command: TNOT recognized\n")); 559 negate = !negate; 560 } 561 tokpushback++; 562 563 for (;;) { 564 if (readtoken() == TWORD) { 565 n = (union node *)stalloc(sizeof (struct narg)); 566 n->type = NARG; 567 n->narg.text = wordtext; 568 n->narg.backquote = backquotelist; 569 *app = n; 570 app = &n->narg.next; 571 } else if (lasttoken == TREDIR) { 572 *rpp = n = redirnode; 573 rpp = &n->nfile.next; 574 parsefname(); /* read name of redirection file */ 575 } else if (lasttoken == TLP && app == &args->narg.next 576 && rpp == orig_rpp) { 577 /* We have a function */ 578 if (readtoken() != TRP) 579 synexpect(TRP); 580 #ifdef notdef 581 if (! goodname(n->narg.text)) 582 synerror("Bad function name"); 583 #endif 584 n->type = NDEFUN; 585 n->narg.next = command(); 586 goto checkneg; 587 } else { 588 tokpushback++; 589 break; 590 } 591 } 592 *app = NULL; 593 *rpp = NULL; 594 n = (union node *)stalloc(sizeof (struct ncmd)); 595 n->type = NCMD; 596 n->ncmd.backgnd = 0; 597 n->ncmd.args = args; 598 n->ncmd.redirect = redir; 599 600 checkneg: 601 if (negate) { 602 n2 = (union node *)stalloc(sizeof (struct nnot)); 603 n2->type = NNOT; 604 n2->nnot.com = n; 605 return n2; 606 } 607 else 608 return n; 609 } 610 611 STATIC union node * 612 makename(void) 613 { 614 union node *n; 615 616 n = (union node *)stalloc(sizeof (struct narg)); 617 n->type = NARG; 618 n->narg.next = NULL; 619 n->narg.text = wordtext; 620 n->narg.backquote = backquotelist; 621 return n; 622 } 623 624 void fixredir(union node *n, const char *text, int err) 625 { 626 TRACE(("Fix redir %s %d\n", text, err)); 627 if (!err) 628 n->ndup.vname = NULL; 629 630 if (is_digit(text[0]) && text[1] == '\0') 631 n->ndup.dupfd = digit_val(text[0]); 632 else if (text[0] == '-' && text[1] == '\0') 633 n->ndup.dupfd = -1; 634 else { 635 636 if (err) 637 synerror("Bad fd number"); 638 else 639 n->ndup.vname = makename(); 640 } 641 } 642 643 644 STATIC void 645 parsefname(void) 646 { 647 union node *n = redirnode; 648 649 if (readtoken() != TWORD) 650 synexpect(-1); 651 if (n->type == NHERE) { 652 struct heredoc *here = heredoc; 653 struct heredoc *p; 654 int i; 655 656 if (quoteflag == 0) 657 n->type = NXHERE; 658 TRACE(("Here document %d\n", n->type)); 659 if (here->striptabs) { 660 while (*wordtext == '\t') 661 wordtext++; 662 } 663 if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN) 664 synerror("Illegal eof marker for << redirection"); 665 rmescapes(wordtext); 666 here->eofmark = wordtext; 667 here->next = NULL; 668 if (heredoclist == NULL) 669 heredoclist = here; 670 else { 671 for (p = heredoclist ; p->next ; p = p->next); 672 p->next = here; 673 } 674 } else if (n->type == NTOFD || n->type == NFROMFD) { 675 fixredir(n, wordtext, 0); 676 } else { 677 n->nfile.fname = makename(); 678 } 679 } 680 681 682 /* 683 * Input any here documents. 684 */ 685 686 STATIC void 687 parseheredoc(void) 688 { 689 struct heredoc *here; 690 union node *n; 691 692 while (heredoclist) { 693 here = heredoclist; 694 heredoclist = here->next; 695 if (needprompt) { 696 setprompt(2); 697 needprompt = 0; 698 } 699 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, 700 here->eofmark, here->striptabs); 701 n = (union node *)stalloc(sizeof (struct narg)); 702 n->narg.type = NARG; 703 n->narg.next = NULL; 704 n->narg.text = wordtext; 705 n->narg.backquote = backquotelist; 706 here->here->nhere.doc = n; 707 } 708 } 709 710 STATIC int 711 peektoken(void) 712 { 713 int t; 714 715 t = readtoken(); 716 tokpushback++; 717 return (t); 718 } 719 720 STATIC int 721 readtoken(void) 722 { 723 int t; 724 int savecheckkwd = checkkwd; 725 struct alias *ap; 726 #ifdef DEBUG 727 int alreadyseen = tokpushback; 728 #endif 729 730 top: 731 t = xxreadtoken(); 732 733 if (checkkwd) { 734 /* 735 * eat newlines 736 */ 737 if (checkkwd == 2) { 738 checkkwd = 0; 739 while (t == TNL) { 740 parseheredoc(); 741 t = xxreadtoken(); 742 } 743 } else 744 checkkwd = 0; 745 /* 746 * check for keywords and aliases 747 */ 748 if (t == TWORD && !quoteflag) 749 { 750 const char * const *pp; 751 752 for (pp = parsekwd; *pp; pp++) { 753 if (**pp == *wordtext && equal(*pp, wordtext)) 754 { 755 lasttoken = t = pp - parsekwd + KWDOFFSET; 756 TRACE(("keyword %s recognized\n", tokname[t])); 757 goto out; 758 } 759 } 760 if (noaliases == 0 && 761 (ap = lookupalias(wordtext, 1)) != NULL) { 762 pushstring(ap->val, strlen(ap->val), ap); 763 checkkwd = savecheckkwd; 764 goto top; 765 } 766 } 767 out: 768 checkkwd = (t == TNOT) ? savecheckkwd : 0; 769 } 770 #ifdef DEBUG 771 if (!alreadyseen) 772 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 773 else 774 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 775 #endif 776 return (t); 777 } 778 779 780 /* 781 * Read the next input token. 782 * If the token is a word, we set backquotelist to the list of cmds in 783 * backquotes. We set quoteflag to true if any part of the word was 784 * quoted. 785 * If the token is TREDIR, then we set redirnode to a structure containing 786 * the redirection. 787 * In all cases, the variable startlinno is set to the number of the line 788 * on which the token starts. 789 * 790 * [Change comment: here documents and internal procedures] 791 * [Readtoken shouldn't have any arguments. Perhaps we should make the 792 * word parsing code into a separate routine. In this case, readtoken 793 * doesn't need to have any internal procedures, but parseword does. 794 * We could also make parseoperator in essence the main routine, and 795 * have parseword (readtoken1?) handle both words and redirection.] 796 */ 797 798 #define RETURN(token) return lasttoken = token 799 800 STATIC int 801 xxreadtoken(void) 802 { 803 int c; 804 805 if (tokpushback) { 806 tokpushback = 0; 807 return lasttoken; 808 } 809 if (needprompt) { 810 setprompt(2); 811 needprompt = 0; 812 } 813 startlinno = plinno; 814 for (;;) { /* until token or start of word found */ 815 c = pgetc_macro(); 816 if (c == ' ' || c == '\t') 817 continue; /* quick check for white space first */ 818 switch (c) { 819 case ' ': case '\t': 820 continue; 821 case '#': 822 while ((c = pgetc()) != '\n' && c != PEOF); 823 pungetc(); 824 continue; 825 case '\\': 826 if (pgetc() == '\n') { 827 startlinno = ++plinno; 828 if (doprompt) 829 setprompt(2); 830 else 831 setprompt(0); 832 continue; 833 } 834 pungetc(); 835 goto breakloop; 836 case '\n': 837 plinno++; 838 needprompt = doprompt; 839 RETURN(TNL); 840 case PEOF: 841 RETURN(TEOF); 842 case '&': 843 if (pgetc() == '&') 844 RETURN(TAND); 845 pungetc(); 846 RETURN(TBACKGND); 847 case '|': 848 if (pgetc() == '|') 849 RETURN(TOR); 850 pungetc(); 851 RETURN(TPIPE); 852 case ';': 853 if (pgetc() == ';') 854 RETURN(TENDCASE); 855 pungetc(); 856 RETURN(TSEMI); 857 case '(': 858 RETURN(TLP); 859 case ')': 860 RETURN(TRP); 861 default: 862 goto breakloop; 863 } 864 } 865 breakloop: 866 return readtoken1(c, BASESYNTAX, (char *)NULL, 0); 867 #undef RETURN 868 } 869 870 871 872 /* 873 * If eofmark is NULL, read a word or a redirection symbol. If eofmark 874 * is not NULL, read a here document. In the latter case, eofmark is the 875 * word which marks the end of the document and striptabs is true if 876 * leading tabs should be stripped from the document. The argument firstc 877 * is the first character of the input token or document. 878 * 879 * Because C does not have internal subroutines, I have simulated them 880 * using goto's to implement the subroutine linkage. The following macros 881 * will run code that appears at the end of readtoken1. 882 */ 883 884 #define CHECKEND() {goto checkend; checkend_return:;} 885 #define PARSEREDIR() {goto parseredir; parseredir_return:;} 886 #define PARSESUB() {goto parsesub; parsesub_return:;} 887 #define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;} 888 #define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;} 889 #define PARSEARITH() {goto parsearith; parsearith_return:;} 890 891 STATIC int 892 readtoken1(int firstc, char const *syntax, char *eofmark, int striptabs) 893 { 894 int c = firstc; 895 char *out; 896 int len; 897 char line[EOFMARKLEN + 1]; 898 struct nodelist *bqlist; 899 int quotef; 900 int dblquote; 901 int varnest; /* levels of variables expansion */ 902 int arinest; /* levels of arithmetic expansion */ 903 int parenlevel; /* levels of parens in arithmetic */ 904 int oldstyle; 905 char const *prevsyntax; /* syntax before arithmetic */ 906 int synentry; 907 #if __GNUC__ 908 /* Avoid longjmp clobbering */ 909 (void) &out; 910 (void) "ef; 911 (void) &dblquote; 912 (void) &varnest; 913 (void) &arinest; 914 (void) &parenlevel; 915 (void) &oldstyle; 916 (void) &prevsyntax; 917 (void) &syntax; 918 (void) &synentry; 919 #endif 920 921 startlinno = plinno; 922 dblquote = 0; 923 if (syntax == DQSYNTAX) 924 dblquote = 1; 925 quotef = 0; 926 bqlist = NULL; 927 varnest = 0; 928 arinest = 0; 929 parenlevel = 0; 930 931 STARTSTACKSTR(out); 932 loop: { /* for each line, until end of word */ 933 CHECKEND(); /* set c to PEOF if at end of here document */ 934 for (;;) { /* until end of line or end of word */ 935 CHECKSTRSPACE(3, out); /* permit 3 calls to USTPUTC */ 936 937 synentry = syntax[c]; 938 939 switch(synentry) { 940 case CNL: /* '\n' */ 941 if (syntax == BASESYNTAX) 942 goto endword; /* exit outer loop */ 943 USTPUTC(c, out); 944 plinno++; 945 if (doprompt) 946 setprompt(2); 947 else 948 setprompt(0); 949 c = pgetc(); 950 goto loop; /* continue outer loop */ 951 case CWORD: 952 USTPUTC(c, out); 953 break; 954 case CCTL: 955 if (eofmark == NULL || dblquote) 956 USTPUTC(CTLESC, out); 957 USTPUTC(c, out); 958 break; 959 case CBACK: /* backslash */ 960 c = pgetc(); 961 if (c == PEOF) { 962 USTPUTC('\\', out); 963 pungetc(); 964 } else if (c == '\n') { 965 if (doprompt) 966 setprompt(2); 967 else 968 setprompt(0); 969 } else { 970 if (dblquote && c != '\\' && 971 c != '`' && c != '$' && 972 (c != '"' || eofmark != NULL)) 973 USTPUTC('\\', out); 974 if (SQSYNTAX[c] == CCTL) 975 USTPUTC(CTLESC, out); 976 else if (eofmark == NULL) 977 USTPUTC(CTLQUOTEMARK, out); 978 USTPUTC(c, out); 979 quotef++; 980 } 981 break; 982 case CSQUOTE: 983 if (eofmark == NULL) 984 USTPUTC(CTLQUOTEMARK, out); 985 syntax = SQSYNTAX; 986 break; 987 case CDQUOTE: 988 if (eofmark == NULL) 989 USTPUTC(CTLQUOTEMARK, out); 990 syntax = DQSYNTAX; 991 dblquote = 1; 992 break; 993 case CENDQUOTE: 994 if (eofmark != NULL && arinest == 0 && 995 varnest == 0) { 996 USTPUTC(c, out); 997 } else { 998 if (arinest) { 999 syntax = ARISYNTAX; 1000 dblquote = 0; 1001 } else if (eofmark == NULL) { 1002 syntax = BASESYNTAX; 1003 dblquote = 0; 1004 } 1005 quotef++; 1006 } 1007 break; 1008 case CVAR: /* '$' */ 1009 PARSESUB(); /* parse substitution */ 1010 break; 1011 case CENDVAR: /* '}' */ 1012 if (varnest > 0) { 1013 varnest--; 1014 USTPUTC(CTLENDVAR, out); 1015 } else { 1016 USTPUTC(c, out); 1017 } 1018 break; 1019 case CLP: /* '(' in arithmetic */ 1020 parenlevel++; 1021 USTPUTC(c, out); 1022 break; 1023 case CRP: /* ')' in arithmetic */ 1024 if (parenlevel > 0) { 1025 USTPUTC(c, out); 1026 --parenlevel; 1027 } else { 1028 if (pgetc() == ')') { 1029 if (--arinest == 0) { 1030 USTPUTC(CTLENDARI, out); 1031 syntax = prevsyntax; 1032 if (syntax == DQSYNTAX) 1033 dblquote = 1; 1034 else 1035 dblquote = 0; 1036 } else 1037 USTPUTC(')', out); 1038 } else { 1039 /* 1040 * unbalanced parens 1041 * (don't 2nd guess - no error) 1042 */ 1043 pungetc(); 1044 USTPUTC(')', out); 1045 } 1046 } 1047 break; 1048 case CBQUOTE: /* '`' */ 1049 PARSEBACKQOLD(); 1050 break; 1051 case CEOF: 1052 goto endword; /* exit outer loop */ 1053 default: 1054 if (varnest == 0) 1055 goto endword; /* exit outer loop */ 1056 USTPUTC(c, out); 1057 } 1058 c = pgetc_macro(); 1059 } 1060 } 1061 endword: 1062 if (syntax == ARISYNTAX) 1063 synerror("Missing '))'"); 1064 if (syntax != BASESYNTAX && ! parsebackquote && eofmark == NULL) 1065 synerror("Unterminated quoted string"); 1066 if (varnest != 0) { 1067 startlinno = plinno; 1068 synerror("Missing '}'"); 1069 } 1070 USTPUTC('\0', out); 1071 len = out - stackblock(); 1072 out = stackblock(); 1073 if (eofmark == NULL) { 1074 if ((c == '>' || c == '<') 1075 && quotef == 0 1076 && len <= 2 1077 && (*out == '\0' || is_digit(*out))) { 1078 PARSEREDIR(); 1079 return lasttoken = TREDIR; 1080 } else { 1081 pungetc(); 1082 } 1083 } 1084 quoteflag = quotef; 1085 backquotelist = bqlist; 1086 grabstackblock(len); 1087 wordtext = out; 1088 return lasttoken = TWORD; 1089 /* end of readtoken routine */ 1090 1091 1092 1093 /* 1094 * Check to see whether we are at the end of the here document. When this 1095 * is called, c is set to the first character of the next input line. If 1096 * we are at the end of the here document, this routine sets the c to PEOF. 1097 */ 1098 1099 checkend: { 1100 if (eofmark) { 1101 if (striptabs) { 1102 while (c == '\t') 1103 c = pgetc(); 1104 } 1105 if (c == *eofmark) { 1106 if (pfgets(line, sizeof line) != NULL) { 1107 char *p, *q; 1108 1109 p = line; 1110 for (q = eofmark + 1 ; *q && *p == *q ; p++, q++); 1111 if (*p == '\n' && *q == '\0') { 1112 c = PEOF; 1113 plinno++; 1114 needprompt = doprompt; 1115 } else { 1116 pushstring(line, strlen(line), NULL); 1117 } 1118 } 1119 } 1120 } 1121 goto checkend_return; 1122 } 1123 1124 1125 /* 1126 * Parse a redirection operator. The variable "out" points to a string 1127 * specifying the fd to be redirected. The variable "c" contains the 1128 * first character of the redirection operator. 1129 */ 1130 1131 parseredir: { 1132 char fd = *out; 1133 union node *np; 1134 1135 np = (union node *)stalloc(sizeof (struct nfile)); 1136 if (c == '>') { 1137 np->nfile.fd = 1; 1138 c = pgetc(); 1139 if (c == '>') 1140 np->type = NAPPEND; 1141 else if (c == '&') 1142 np->type = NTOFD; 1143 else if (c == '|') 1144 np->type = NCLOBBER; 1145 else { 1146 np->type = NTO; 1147 pungetc(); 1148 } 1149 } else { /* c == '<' */ 1150 np->nfile.fd = 0; 1151 c = pgetc(); 1152 if (c == '<') { 1153 if (sizeof (struct nfile) != sizeof (struct nhere)) { 1154 np = (union node *)stalloc(sizeof (struct nhere)); 1155 np->nfile.fd = 0; 1156 } 1157 np->type = NHERE; 1158 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); 1159 heredoc->here = np; 1160 if ((c = pgetc()) == '-') { 1161 heredoc->striptabs = 1; 1162 } else { 1163 heredoc->striptabs = 0; 1164 pungetc(); 1165 } 1166 } else if (c == '&') 1167 np->type = NFROMFD; 1168 else if (c == '>') 1169 np->type = NFROMTO; 1170 else { 1171 np->type = NFROM; 1172 pungetc(); 1173 } 1174 } 1175 if (fd != '\0') 1176 np->nfile.fd = digit_val(fd); 1177 redirnode = np; 1178 goto parseredir_return; 1179 } 1180 1181 1182 /* 1183 * Parse a substitution. At this point, we have read the dollar sign 1184 * and nothing else. 1185 */ 1186 1187 parsesub: { 1188 int subtype; 1189 int typeloc; 1190 int flags; 1191 char *p; 1192 #ifndef GDB_HACK 1193 static const char types[] = "}-+?="; 1194 #endif 1195 int bracketed_name = 0; /* used to handle ${[0-9]*} variables */ 1196 1197 c = pgetc(); 1198 if (c != '(' && c != '{' && !is_name(c) && !is_special(c)) { 1199 USTPUTC('$', out); 1200 pungetc(); 1201 } else if (c == '(') { /* $(command) or $((arith)) */ 1202 if (pgetc() == '(') { 1203 PARSEARITH(); 1204 } else { 1205 pungetc(); 1206 PARSEBACKQNEW(); 1207 } 1208 } else { 1209 USTPUTC(CTLVAR, out); 1210 typeloc = out - stackblock(); 1211 USTPUTC(VSNORMAL, out); 1212 subtype = VSNORMAL; 1213 if (c == '{') { 1214 bracketed_name = 1; 1215 c = pgetc(); 1216 if (c == '#') { 1217 if ((c = pgetc()) == '}') 1218 c = '#'; 1219 else 1220 subtype = VSLENGTH; 1221 } 1222 else 1223 subtype = 0; 1224 } 1225 if (is_name(c)) { 1226 do { 1227 STPUTC(c, out); 1228 c = pgetc(); 1229 } while (is_in_name(c)); 1230 } else if (is_digit(c)) { 1231 if (bracketed_name) { 1232 do { 1233 STPUTC(c, out); 1234 c = pgetc(); 1235 } while (is_digit(c)); 1236 } else { 1237 STPUTC(c, out); 1238 c = pgetc(); 1239 } 1240 } else { 1241 if (! is_special(c)) 1242 badsub: synerror("Bad substitution"); 1243 USTPUTC(c, out); 1244 c = pgetc(); 1245 } 1246 STPUTC('=', out); 1247 flags = 0; 1248 if (subtype == 0) { 1249 switch (c) { 1250 case ':': 1251 flags = VSNUL; 1252 c = pgetc(); 1253 /*FALLTHROUGH*/ 1254 default: 1255 p = strchr(types, c); 1256 if (p == NULL) 1257 goto badsub; 1258 subtype = p - types + VSNORMAL; 1259 break; 1260 case '%': 1261 case '#': 1262 { 1263 int cc = c; 1264 subtype = c == '#' ? VSTRIMLEFT : 1265 VSTRIMRIGHT; 1266 c = pgetc(); 1267 if (c == cc) 1268 subtype++; 1269 else 1270 pungetc(); 1271 break; 1272 } 1273 } 1274 } else { 1275 pungetc(); 1276 } 1277 if (subtype != VSLENGTH && (dblquote || arinest)) 1278 flags |= VSQUOTE; 1279 *(stackblock() + typeloc) = subtype | flags; 1280 if (subtype != VSNORMAL) 1281 varnest++; 1282 } 1283 goto parsesub_return; 1284 } 1285 1286 1287 /* 1288 * Called to parse command substitutions. Newstyle is set if the command 1289 * is enclosed inside $(...); nlpp is a pointer to the head of the linked 1290 * list of commands (passed by reference), and savelen is the number of 1291 * characters on the top of the stack which must be preserved. 1292 */ 1293 1294 parsebackq: { 1295 struct nodelist **nlpp; 1296 int savepbq; 1297 union node *n; 1298 char *volatile str; 1299 struct jmploc jmploc; 1300 struct jmploc *volatile savehandler; 1301 int savelen; 1302 int saveprompt; 1303 #if __GNUC__ 1304 /* Avoid longjmp clobbering */ 1305 (void) &saveprompt; 1306 #endif 1307 1308 savepbq = parsebackquote; 1309 if (setjmp(jmploc.loc)) { 1310 if (str) 1311 ckfree(str); 1312 parsebackquote = 0; 1313 handler = savehandler; 1314 longjmp(handler->loc, 1); 1315 } 1316 INTOFF; 1317 str = NULL; 1318 savelen = out - stackblock(); 1319 if (savelen > 0) { 1320 str = ckmalloc(savelen); 1321 memcpy(str, stackblock(), savelen); 1322 } 1323 savehandler = handler; 1324 handler = &jmploc; 1325 INTON; 1326 if (oldstyle) { 1327 /* We must read until the closing backquote, giving special 1328 treatment to some slashes, and then push the string and 1329 reread it as input, interpreting it normally. */ 1330 char *out; 1331 int c; 1332 int savelen; 1333 char *str; 1334 1335 1336 STARTSTACKSTR(out); 1337 for (;;) { 1338 if (needprompt) { 1339 setprompt(2); 1340 needprompt = 0; 1341 } 1342 switch (c = pgetc()) { 1343 case '`': 1344 goto done; 1345 1346 case '\\': 1347 if ((c = pgetc()) == '\n') { 1348 plinno++; 1349 if (doprompt) 1350 setprompt(2); 1351 else 1352 setprompt(0); 1353 /* 1354 * If eating a newline, avoid putting 1355 * the newline into the new character 1356 * stream (via the STPUTC after the 1357 * switch). 1358 */ 1359 continue; 1360 } 1361 if (c != '\\' && c != '`' && c != '$' 1362 && (!dblquote || c != '"')) 1363 STPUTC('\\', out); 1364 break; 1365 1366 case '\n': 1367 plinno++; 1368 needprompt = doprompt; 1369 break; 1370 1371 case PEOF: 1372 startlinno = plinno; 1373 synerror("EOF in backquote substitution"); 1374 break; 1375 1376 default: 1377 break; 1378 } 1379 STPUTC(c, out); 1380 } 1381 done: 1382 STPUTC('\0', out); 1383 savelen = out - stackblock(); 1384 if (savelen > 0) { 1385 str = ckmalloc(savelen); 1386 memcpy(str, stackblock(), savelen); 1387 setinputstring(str, 1); 1388 } 1389 } 1390 nlpp = &bqlist; 1391 while (*nlpp) 1392 nlpp = &(*nlpp)->next; 1393 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 1394 (*nlpp)->next = NULL; 1395 parsebackquote = oldstyle; 1396 1397 if (oldstyle) { 1398 saveprompt = doprompt; 1399 doprompt = 0; 1400 } 1401 1402 n = list(0); 1403 1404 if (oldstyle) 1405 doprompt = saveprompt; 1406 else { 1407 if (readtoken() != TRP) 1408 synexpect(TRP); 1409 } 1410 1411 (*nlpp)->n = n; 1412 if (oldstyle) { 1413 /* 1414 * Start reading from old file again, ignoring any pushed back 1415 * tokens left from the backquote parsing 1416 */ 1417 popfile(); 1418 tokpushback = 0; 1419 } 1420 while (stackblocksize() <= savelen) 1421 growstackblock(); 1422 STARTSTACKSTR(out); 1423 if (str) { 1424 memcpy(out, str, savelen); 1425 STADJUST(savelen, out); 1426 INTOFF; 1427 ckfree(str); 1428 str = NULL; 1429 INTON; 1430 } 1431 parsebackquote = savepbq; 1432 handler = savehandler; 1433 if (arinest || dblquote) 1434 USTPUTC(CTLBACKQ | CTLQUOTE, out); 1435 else 1436 USTPUTC(CTLBACKQ, out); 1437 if (oldstyle) 1438 goto parsebackq_oldreturn; 1439 else 1440 goto parsebackq_newreturn; 1441 } 1442 1443 /* 1444 * Parse an arithmetic expansion (indicate start of one and set state) 1445 */ 1446 parsearith: { 1447 1448 if (++arinest == 1) { 1449 prevsyntax = syntax; 1450 syntax = ARISYNTAX; 1451 USTPUTC(CTLARI, out); 1452 if (dblquote) 1453 USTPUTC('"',out); 1454 else 1455 USTPUTC(' ',out); 1456 } else { 1457 /* 1458 * we collapse embedded arithmetic expansion to 1459 * parenthesis, which should be equivalent 1460 */ 1461 USTPUTC('(', out); 1462 } 1463 goto parsearith_return; 1464 } 1465 1466 } /* end of readtoken */ 1467 1468 1469 1470 #ifdef mkinit 1471 RESET { 1472 tokpushback = 0; 1473 checkkwd = 0; 1474 } 1475 #endif 1476 1477 /* 1478 * Returns true if the text contains nothing to expand (no dollar signs 1479 * or backquotes). 1480 */ 1481 1482 STATIC int 1483 noexpand(char *text) 1484 { 1485 char *p; 1486 char c; 1487 1488 p = text; 1489 while ((c = *p++) != '\0') { 1490 if ( c == CTLQUOTEMARK) 1491 continue; 1492 if (c == CTLESC) 1493 p++; 1494 else if (BASESYNTAX[(int)c] == CCTL) 1495 return 0; 1496 } 1497 return 1; 1498 } 1499 1500 1501 /* 1502 * Return true if the argument is a legal variable name (a letter or 1503 * underscore followed by zero or more letters, underscores, and digits). 1504 */ 1505 1506 int 1507 goodname(char *name) 1508 { 1509 char *p; 1510 1511 p = name; 1512 if (! is_name(*p)) 1513 return 0; 1514 while (*++p) { 1515 if (! is_in_name(*p)) 1516 return 0; 1517 } 1518 return 1; 1519 } 1520 1521 1522 /* 1523 * Called when an unexpected token is read during the parse. The argument 1524 * is the token that is expected, or -1 if more than one type of token can 1525 * occur at this point. 1526 */ 1527 1528 STATIC void 1529 synexpect(int token) 1530 { 1531 char msg[64]; 1532 1533 if (token >= 0) { 1534 fmtstr(msg, 64, "%s unexpected (expecting %s)", 1535 tokname[lasttoken], tokname[token]); 1536 } else { 1537 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]); 1538 } 1539 synerror(msg); 1540 } 1541 1542 1543 STATIC void 1544 synerror(char *msg) 1545 { 1546 if (commandname) 1547 outfmt(&errout, "%s: %d: ", commandname, startlinno); 1548 outfmt(&errout, "Syntax error: %s\n", msg); 1549 error((char *)NULL); 1550 } 1551 1552 STATIC void 1553 setprompt(int which) 1554 { 1555 whichprompt = which; 1556 1557 #ifndef NO_HISTORY 1558 if (!el) 1559 #endif 1560 out2str(getprompt(NULL)); 1561 } 1562 1563 /* 1564 * called by editline -- any expansions to the prompt 1565 * should be added here. 1566 */ 1567 char * 1568 getprompt(void *unused __unused) 1569 { 1570 switch (whichprompt) { 1571 case 0: 1572 return ""; 1573 case 1: 1574 return ps1val(); 1575 case 2: 1576 return ps2val(); 1577 default: 1578 return "<internal prompt error>"; 1579 } 1580 } 1581