parser.c revision 75155
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 39static char sccsid[] = "@(#)parser.c 8.7 (Berkeley) 5/16/95"; 40#endif 41static const char rcsid[] = 42 "$FreeBSD: head/bin/sh/parser.c 75155 2001-04-04 09:30:50Z brian $"; 43#endif /* not lint */ 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 78struct 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 87struct heredoc *heredoclist; /* list of here documents to read */ 88int parsebackquote; /* nonzero if we are inside backquotes */ 89int doprompt; /* if set, prompt the user */ 90int needprompt; /* true if interactive and at start of line */ 91int lasttoken; /* last token read */ 92MKINIT int tokpushback; /* last token pushed back */ 93char *wordtext; /* text of last word returned by readtoken */ 94MKINIT int checkkwd; /* 1 == check for kwds, 2 == also eat newlines */ 95struct nodelist *backquotelist; 96union node *redirnode; 97struct heredoc *heredoc; 98int quoteflag; /* set if (part of) last token was quoted */ 99int startlinno; /* line # where last token started */ 100 101/* XXX When 'noaliases' is set to one, no alias expansion takes place. */ 102static int noaliases = 0; 103 104#define GDB_HACK 1 /* avoid local declarations which gdb can't handle */ 105#ifdef GDB_HACK 106static const char argvars[5] = {CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0'}; 107static const char types[] = "}-+?="; 108#endif 109 110 111STATIC union node *list __P((int)); 112STATIC union node *andor __P((void)); 113STATIC union node *pipeline __P((void)); 114STATIC union node *command __P((void)); 115STATIC union node *simplecmd __P((union node **, union node *)); 116STATIC union node *makename __P((void)); 117STATIC void parsefname __P((void)); 118STATIC void parseheredoc __P((void)); 119STATIC int peektoken __P((void)); 120STATIC int readtoken __P((void)); 121STATIC int xxreadtoken __P((void)); 122STATIC int readtoken1 __P((int, char const *, char *, int)); 123STATIC int noexpand __P((char *)); 124STATIC void synexpect __P((int)); 125STATIC void synerror __P((char *)); 126STATIC void setprompt __P((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 134union node * 135parsecmd(interact) 136 int interact; 137{ 138 int t; 139 140 tokpushback = 0; 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 157STATIC union node * 158list(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 228STATIC union node * 229andor() { 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 254STATIC union node * 255pipeline() { 256 union node *n1, *pipenode, *notnode; 257 struct nodelist *lp, *prev; 258 int negate = 0; 259 int savecheckkwd = checkkwd; 260 261 TRACE(("pipeline: entered\n")); 262 checkkwd = 2; 263 while (readtoken() == TNOT) { 264 TRACE(("pipeline: TNOT recognized\n")); 265 negate = !negate; 266 } 267 tokpushback++; 268 checkkwd = savecheckkwd; 269 n1 = command(); 270 if (readtoken() == TPIPE) { 271 pipenode = (union node *)stalloc(sizeof (struct npipe)); 272 pipenode->type = NPIPE; 273 pipenode->npipe.backgnd = 0; 274 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 275 pipenode->npipe.cmdlist = lp; 276 lp->n = n1; 277 do { 278 prev = lp; 279 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 280 lp->n = command(); 281 prev->next = lp; 282 } while (readtoken() == TPIPE); 283 lp->next = NULL; 284 n1 = pipenode; 285 } 286 tokpushback++; 287 if (negate) { 288 notnode = (union node *)stalloc(sizeof(struct nnot)); 289 notnode->type = NNOT; 290 notnode->nnot.com = n1; 291 n1 = notnode; 292 } 293 return n1; 294} 295 296 297 298STATIC union node * 299command() { 300 union node *n1, *n2; 301 union node *ap, **app; 302 union node *cp, **cpp; 303 union node *redir, **rpp; 304 int t; 305 306 checkkwd = 2; 307 redir = NULL; 308 n1 = NULL; 309 rpp = &redir; 310 311 /* Check for redirection which may precede command */ 312 while (readtoken() == TREDIR) { 313 *rpp = n2 = redirnode; 314 rpp = &n2->nfile.next; 315 parsefname(); 316 } 317 tokpushback++; 318 319 switch (readtoken()) { 320 case TIF: 321 n1 = (union node *)stalloc(sizeof (struct nif)); 322 n1->type = NIF; 323 n1->nif.test = list(0); 324 if (readtoken() != TTHEN) 325 synexpect(TTHEN); 326 n1->nif.ifpart = list(0); 327 n2 = n1; 328 while (readtoken() == TELIF) { 329 n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif)); 330 n2 = n2->nif.elsepart; 331 n2->type = NIF; 332 n2->nif.test = list(0); 333 if (readtoken() != TTHEN) 334 synexpect(TTHEN); 335 n2->nif.ifpart = list(0); 336 } 337 if (lasttoken == TELSE) 338 n2->nif.elsepart = list(0); 339 else { 340 n2->nif.elsepart = NULL; 341 tokpushback++; 342 } 343 if (readtoken() != TFI) 344 synexpect(TFI); 345 checkkwd = 1; 346 break; 347 case TWHILE: 348 case TUNTIL: { 349 int got; 350 n1 = (union node *)stalloc(sizeof (struct nbinary)); 351 n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL; 352 n1->nbinary.ch1 = list(0); 353 if ((got=readtoken()) != TDO) { 354TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : "")); 355 synexpect(TDO); 356 } 357 n1->nbinary.ch2 = list(0); 358 if (readtoken() != TDONE) 359 synexpect(TDONE); 360 checkkwd = 1; 361 break; 362 } 363 case TFOR: 364 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext)) 365 synerror("Bad for loop variable"); 366 n1 = (union node *)stalloc(sizeof (struct nfor)); 367 n1->type = NFOR; 368 n1->nfor.var = wordtext; 369 if (readtoken() == TWORD && ! quoteflag && equal(wordtext, "in")) { 370 app = ≈ 371 while (readtoken() == TWORD) { 372 n2 = (union node *)stalloc(sizeof (struct narg)); 373 n2->type = NARG; 374 n2->narg.text = wordtext; 375 n2->narg.backquote = backquotelist; 376 *app = n2; 377 app = &n2->narg.next; 378 } 379 *app = NULL; 380 n1->nfor.args = ap; 381 if (lasttoken != TNL && lasttoken != TSEMI) 382 synexpect(-1); 383 } else { 384#ifndef GDB_HACK 385 static const char argvars[5] = {CTLVAR, VSNORMAL|VSQUOTE, 386 '@', '=', '\0'}; 387#endif 388 n2 = (union node *)stalloc(sizeof (struct narg)); 389 n2->type = NARG; 390 n2->narg.text = (char *)argvars; 391 n2->narg.backquote = NULL; 392 n2->narg.next = NULL; 393 n1->nfor.args = n2; 394 /* 395 * Newline or semicolon here is optional (but note 396 * that the original Bourne shell only allowed NL). 397 */ 398 if (lasttoken != TNL && lasttoken != TSEMI) 399 tokpushback++; 400 } 401 checkkwd = 2; 402 if ((t = readtoken()) == TDO) 403 t = TDONE; 404 else if (t == TBEGIN) 405 t = TEND; 406 else 407 synexpect(-1); 408 n1->nfor.body = list(0); 409 if (readtoken() != t) 410 synexpect(t); 411 checkkwd = 1; 412 break; 413 case TCASE: 414 n1 = (union node *)stalloc(sizeof (struct ncase)); 415 n1->type = NCASE; 416 if (readtoken() != TWORD) 417 synexpect(TWORD); 418 n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg)); 419 n2->type = NARG; 420 n2->narg.text = wordtext; 421 n2->narg.backquote = backquotelist; 422 n2->narg.next = NULL; 423 while (readtoken() == TNL); 424 if (lasttoken != TWORD || ! equal(wordtext, "in")) 425 synerror("expecting \"in\""); 426 cpp = &n1->ncase.cases; 427 noaliases = 1; /* turn off alias expansion */ 428 checkkwd = 2, readtoken(); 429 do { 430 *cpp = cp = (union node *)stalloc(sizeof (struct nclist)); 431 cp->type = NCLIST; 432 app = &cp->nclist.pattern; 433 for (;;) { 434 *app = ap = (union node *)stalloc(sizeof (struct narg)); 435 ap->type = NARG; 436 ap->narg.text = wordtext; 437 ap->narg.backquote = backquotelist; 438 if (checkkwd = 2, readtoken() != TPIPE) 439 break; 440 app = &ap->narg.next; 441 readtoken(); 442 } 443 ap->narg.next = NULL; 444 if (lasttoken != TRP) 445 noaliases = 0, synexpect(TRP); 446 cp->nclist.body = list(0); 447 448 checkkwd = 2; 449 if ((t = readtoken()) != TESAC) { 450 if (t != TENDCASE) 451 noaliases = 0, synexpect(TENDCASE); 452 else 453 checkkwd = 2, readtoken(); 454 } 455 cpp = &cp->nclist.next; 456 } while(lasttoken != TESAC); 457 noaliases = 0; /* reset alias expansion */ 458 *cpp = NULL; 459 checkkwd = 1; 460 break; 461 case TLP: 462 n1 = (union node *)stalloc(sizeof (struct nredir)); 463 n1->type = NSUBSHELL; 464 n1->nredir.n = list(0); 465 n1->nredir.redirect = NULL; 466 if (readtoken() != TRP) 467 synexpect(TRP); 468 checkkwd = 1; 469 break; 470 case TBEGIN: 471 n1 = list(0); 472 if (readtoken() != TEND) 473 synexpect(TEND); 474 checkkwd = 1; 475 break; 476 /* Handle an empty command like other simple commands. */ 477 case TSEMI: 478 /* 479 * An empty command before a ; doesn't make much sense, and 480 * should certainly be disallowed in the case of `if ;'. 481 */ 482 if (!redir) 483 synexpect(-1); 484 case TAND: 485 case TOR: 486 case TNL: 487 case TEOF: 488 case TWORD: 489 case TRP: 490 tokpushback++; 491 return simplecmd(rpp, redir); 492 default: 493 synexpect(-1); 494 } 495 496 /* Now check for redirection which may follow command */ 497 while (readtoken() == TREDIR) { 498 *rpp = n2 = redirnode; 499 rpp = &n2->nfile.next; 500 parsefname(); 501 } 502 tokpushback++; 503 *rpp = NULL; 504 if (redir) { 505 if (n1->type != NSUBSHELL) { 506 n2 = (union node *)stalloc(sizeof (struct nredir)); 507 n2->type = NREDIR; 508 n2->nredir.n = n1; 509 n1 = n2; 510 } 511 n1->nredir.redirect = redir; 512 } 513 return n1; 514} 515 516 517STATIC union node * 518simplecmd(rpp, redir) 519 union node **rpp, *redir; 520 { 521 union node *args, **app; 522 union node **orig_rpp = rpp; 523 union node *n = NULL; 524 525 /* If we don't have any redirections already, then we must reset */ 526 /* rpp to be the address of the local redir variable. */ 527 if (redir == 0) 528 rpp = &redir; 529 530 args = NULL; 531 app = &args; 532 /* 533 * We save the incoming value, because we need this for shell 534 * functions. There can not be a redirect or an argument between 535 * the function name and the open parenthesis. 536 */ 537 orig_rpp = rpp; 538 539 for (;;) { 540 if (readtoken() == TWORD) { 541 n = (union node *)stalloc(sizeof (struct narg)); 542 n->type = NARG; 543 n->narg.text = wordtext; 544 n->narg.backquote = backquotelist; 545 *app = n; 546 app = &n->narg.next; 547 } else if (lasttoken == TREDIR) { 548 *rpp = n = redirnode; 549 rpp = &n->nfile.next; 550 parsefname(); /* read name of redirection file */ 551 } else if (lasttoken == TLP && app == &args->narg.next 552 && rpp == orig_rpp) { 553 /* We have a function */ 554 if (readtoken() != TRP) 555 synexpect(TRP); 556#ifdef notdef 557 if (! goodname(n->narg.text)) 558 synerror("Bad function name"); 559#endif 560 n->type = NDEFUN; 561 n->narg.next = command(); 562 return n; 563 } else { 564 tokpushback++; 565 break; 566 } 567 } 568 *app = NULL; 569 *rpp = NULL; 570 n = (union node *)stalloc(sizeof (struct ncmd)); 571 n->type = NCMD; 572 n->ncmd.backgnd = 0; 573 n->ncmd.args = args; 574 n->ncmd.redirect = redir; 575 return n; 576} 577 578STATIC union node * 579makename() { 580 union node *n; 581 582 n = (union node *)stalloc(sizeof (struct narg)); 583 n->type = NARG; 584 n->narg.next = NULL; 585 n->narg.text = wordtext; 586 n->narg.backquote = backquotelist; 587 return n; 588} 589 590void fixredir(n, text, err) 591 union node *n; 592 const char *text; 593 int err; 594 { 595 TRACE(("Fix redir %s %d\n", text, err)); 596 if (!err) 597 n->ndup.vname = NULL; 598 599 if (is_digit(text[0]) && text[1] == '\0') 600 n->ndup.dupfd = digit_val(text[0]); 601 else if (text[0] == '-' && text[1] == '\0') 602 n->ndup.dupfd = -1; 603 else { 604 605 if (err) 606 synerror("Bad fd number"); 607 else 608 n->ndup.vname = makename(); 609 } 610} 611 612 613STATIC void 614parsefname() { 615 union node *n = redirnode; 616 617 if (readtoken() != TWORD) 618 synexpect(-1); 619 if (n->type == NHERE) { 620 struct heredoc *here = heredoc; 621 struct heredoc *p; 622 int i; 623 624 if (quoteflag == 0) 625 n->type = NXHERE; 626 TRACE(("Here document %d\n", n->type)); 627 if (here->striptabs) { 628 while (*wordtext == '\t') 629 wordtext++; 630 } 631 if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN) 632 synerror("Illegal eof marker for << redirection"); 633 rmescapes(wordtext); 634 here->eofmark = wordtext; 635 here->next = NULL; 636 if (heredoclist == NULL) 637 heredoclist = here; 638 else { 639 for (p = heredoclist ; p->next ; p = p->next); 640 p->next = here; 641 } 642 } else if (n->type == NTOFD || n->type == NFROMFD) { 643 fixredir(n, wordtext, 0); 644 } else { 645 n->nfile.fname = makename(); 646 } 647} 648 649 650/* 651 * Input any here documents. 652 */ 653 654STATIC void 655parseheredoc() { 656 struct heredoc *here; 657 union node *n; 658 659 while (heredoclist) { 660 here = heredoclist; 661 heredoclist = here->next; 662 if (needprompt) { 663 setprompt(2); 664 needprompt = 0; 665 } 666 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, 667 here->eofmark, here->striptabs); 668 n = (union node *)stalloc(sizeof (struct narg)); 669 n->narg.type = NARG; 670 n->narg.next = NULL; 671 n->narg.text = wordtext; 672 n->narg.backquote = backquotelist; 673 here->here->nhere.doc = n; 674 } 675} 676 677STATIC int 678peektoken() { 679 int t; 680 681 t = readtoken(); 682 tokpushback++; 683 return (t); 684} 685 686STATIC int 687readtoken() { 688 int t; 689 int savecheckkwd = checkkwd; 690 struct alias *ap; 691#ifdef DEBUG 692 int alreadyseen = tokpushback; 693#endif 694 695 top: 696 t = xxreadtoken(); 697 698 if (checkkwd) { 699 /* 700 * eat newlines 701 */ 702 if (checkkwd == 2) { 703 checkkwd = 0; 704 while (t == TNL) { 705 parseheredoc(); 706 t = xxreadtoken(); 707 } 708 } else 709 checkkwd = 0; 710 /* 711 * check for keywords and aliases 712 */ 713 if (t == TWORD && !quoteflag) 714 { 715 char * const *pp; 716 717 for (pp = (char **)parsekwd; *pp; pp++) { 718 if (**pp == *wordtext && equal(*pp, wordtext)) 719 { 720 lasttoken = t = pp - parsekwd + KWDOFFSET; 721 TRACE(("keyword %s recognized\n", tokname[t])); 722 goto out; 723 } 724 } 725 if (noaliases == 0 && 726 (ap = lookupalias(wordtext, 1)) != NULL) { 727 pushstring(ap->val, strlen(ap->val), ap); 728 checkkwd = savecheckkwd; 729 goto top; 730 } 731 } 732out: 733 checkkwd = 0; 734 } 735#ifdef DEBUG 736 if (!alreadyseen) 737 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 738 else 739 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 740#endif 741 return (t); 742} 743 744 745/* 746 * Read the next input token. 747 * If the token is a word, we set backquotelist to the list of cmds in 748 * backquotes. We set quoteflag to true if any part of the word was 749 * quoted. 750 * If the token is TREDIR, then we set redirnode to a structure containing 751 * the redirection. 752 * In all cases, the variable startlinno is set to the number of the line 753 * on which the token starts. 754 * 755 * [Change comment: here documents and internal procedures] 756 * [Readtoken shouldn't have any arguments. Perhaps we should make the 757 * word parsing code into a separate routine. In this case, readtoken 758 * doesn't need to have any internal procedures, but parseword does. 759 * We could also make parseoperator in essence the main routine, and 760 * have parseword (readtoken1?) handle both words and redirection.] 761 */ 762 763#define RETURN(token) return lasttoken = token 764 765STATIC int 766xxreadtoken() { 767 int c; 768 769 if (tokpushback) { 770 tokpushback = 0; 771 return lasttoken; 772 } 773 if (needprompt) { 774 setprompt(2); 775 needprompt = 0; 776 } 777 startlinno = plinno; 778 for (;;) { /* until token or start of word found */ 779 c = pgetc_macro(); 780 if (c == ' ' || c == '\t') 781 continue; /* quick check for white space first */ 782 switch (c) { 783 case ' ': case '\t': 784 continue; 785 case '#': 786 while ((c = pgetc()) != '\n' && c != PEOF); 787 pungetc(); 788 continue; 789 case '\\': 790 if (pgetc() == '\n') { 791 startlinno = ++plinno; 792 if (doprompt) 793 setprompt(2); 794 else 795 setprompt(0); 796 continue; 797 } 798 pungetc(); 799 goto breakloop; 800 case '\n': 801 plinno++; 802 needprompt = doprompt; 803 RETURN(TNL); 804 case PEOF: 805 RETURN(TEOF); 806 case '&': 807 if (pgetc() == '&') 808 RETURN(TAND); 809 pungetc(); 810 RETURN(TBACKGND); 811 case '|': 812 if (pgetc() == '|') 813 RETURN(TOR); 814 pungetc(); 815 RETURN(TPIPE); 816 case ';': 817 if (pgetc() == ';') 818 RETURN(TENDCASE); 819 pungetc(); 820 RETURN(TSEMI); 821 case '(': 822 RETURN(TLP); 823 case ')': 824 RETURN(TRP); 825 default: 826 goto breakloop; 827 } 828 } 829breakloop: 830 return readtoken1(c, BASESYNTAX, (char *)NULL, 0); 831#undef RETURN 832} 833 834 835 836/* 837 * If eofmark is NULL, read a word or a redirection symbol. If eofmark 838 * is not NULL, read a here document. In the latter case, eofmark is the 839 * word which marks the end of the document and striptabs is true if 840 * leading tabs should be stripped from the document. The argument firstc 841 * is the first character of the input token or document. 842 * 843 * Because C does not have internal subroutines, I have simulated them 844 * using goto's to implement the subroutine linkage. The following macros 845 * will run code that appears at the end of readtoken1. 846 */ 847 848#define CHECKEND() {goto checkend; checkend_return:;} 849#define PARSEREDIR() {goto parseredir; parseredir_return:;} 850#define PARSESUB() {goto parsesub; parsesub_return:;} 851#define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;} 852#define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;} 853#define PARSEARITH() {goto parsearith; parsearith_return:;} 854 855STATIC int 856readtoken1(firstc, syntax, eofmark, striptabs) 857 int firstc; 858 char const *syntax; 859 char *eofmark; 860 int striptabs; 861 { 862 int c = firstc; 863 char *out; 864 int len; 865 char line[EOFMARKLEN + 1]; 866 struct nodelist *bqlist; 867 int quotef; 868 int dblquote; 869 int varnest; /* levels of variables expansion */ 870 int arinest; /* levels of arithmetic expansion */ 871 int parenlevel; /* levels of parens in arithmetic */ 872 int oldstyle; 873 char const *prevsyntax; /* syntax before arithmetic */ 874 int synentry; 875#if __GNUC__ 876 /* Avoid longjmp clobbering */ 877 (void) &out; 878 (void) "ef; 879 (void) &dblquote; 880 (void) &varnest; 881 (void) &arinest; 882 (void) &parenlevel; 883 (void) &oldstyle; 884 (void) &prevsyntax; 885 (void) &syntax; 886 (void) &synentry; 887#endif 888 889 startlinno = plinno; 890 dblquote = 0; 891 if (syntax == DQSYNTAX) 892 dblquote = 1; 893 quotef = 0; 894 bqlist = NULL; 895 varnest = 0; 896 arinest = 0; 897 parenlevel = 0; 898 899 STARTSTACKSTR(out); 900 loop: { /* for each line, until end of word */ 901#if ATTY 902 if (c == '\034' && doprompt 903 && attyset() && ! equal(termval(), "emacs")) { 904 attyline(); 905 if (syntax == BASESYNTAX) 906 return readtoken(); 907 c = pgetc(); 908 goto loop; 909 } 910#endif 911 CHECKEND(); /* set c to PEOF if at end of here document */ 912 for (;;) { /* until end of line or end of word */ 913 CHECKSTRSPACE(3, out); /* permit 3 calls to USTPUTC */ 914 915 synentry = syntax[c]; 916 917 switch(synentry) { 918 case CNL: /* '\n' */ 919 if (syntax == BASESYNTAX) 920 goto endword; /* exit outer loop */ 921 USTPUTC(c, out); 922 plinno++; 923 if (doprompt) 924 setprompt(2); 925 else 926 setprompt(0); 927 c = pgetc(); 928 goto loop; /* continue outer loop */ 929 case CWORD: 930 USTPUTC(c, out); 931 break; 932 case CCTL: 933 if (eofmark == NULL || dblquote) 934 USTPUTC(CTLESC, out); 935 USTPUTC(c, out); 936 break; 937 case CBACK: /* backslash */ 938 c = pgetc(); 939 if (c == PEOF) { 940 USTPUTC('\\', out); 941 pungetc(); 942 } else if (c == '\n') { 943 if (doprompt) 944 setprompt(2); 945 else 946 setprompt(0); 947 } else { 948 if (dblquote && c != '\\' && 949 c != '`' && c != '$' && 950 (c != '"' || eofmark != NULL)) 951 USTPUTC('\\', out); 952 if (c >= 0 && SQSYNTAX[c] == CCTL) 953 USTPUTC(CTLESC, out); 954 else if (eofmark == NULL) 955 USTPUTC(CTLQUOTEMARK, out); 956 USTPUTC(c, out); 957 quotef++; 958 } 959 break; 960 case CSQUOTE: 961 if (eofmark == NULL) 962 USTPUTC(CTLQUOTEMARK, out); 963 syntax = SQSYNTAX; 964 break; 965 case CDQUOTE: 966 if (eofmark == NULL) 967 USTPUTC(CTLQUOTEMARK, out); 968 syntax = DQSYNTAX; 969 dblquote = 1; 970 break; 971 case CENDQUOTE: 972 if (eofmark != NULL && arinest == 0 && 973 varnest == 0) { 974 USTPUTC(c, out); 975 } else { 976 if (arinest) { 977 syntax = ARISYNTAX; 978 dblquote = 0; 979 } else if (eofmark == NULL) { 980 syntax = BASESYNTAX; 981 dblquote = 0; 982 } 983 quotef++; 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 if (syntax == DQSYNTAX) 1011 dblquote = 1; 1012 else 1013 dblquote = 0; 1014 } else 1015 USTPUTC(')', out); 1016 } else { 1017 /* 1018 * unbalanced parens 1019 * (don't 2nd guess - no error) 1020 */ 1021 pungetc(); 1022 USTPUTC(')', out); 1023 } 1024 } 1025 break; 1026 case CBQUOTE: /* '`' */ 1027 PARSEBACKQOLD(); 1028 break; 1029 case CEOF: 1030 goto endword; /* exit outer loop */ 1031 default: 1032 if (varnest == 0) 1033 goto endword; /* exit outer loop */ 1034 USTPUTC(c, out); 1035 } 1036 c = pgetc_macro(); 1037 } 1038 } 1039endword: 1040 if (syntax == ARISYNTAX) 1041 synerror("Missing '))'"); 1042 if (syntax != BASESYNTAX && ! parsebackquote && eofmark == NULL) 1043 synerror("Unterminated quoted string"); 1044 if (varnest != 0) { 1045 startlinno = plinno; 1046 synerror("Missing '}'"); 1047 } 1048 USTPUTC('\0', out); 1049 len = out - stackblock(); 1050 out = stackblock(); 1051 if (eofmark == NULL) { 1052 if ((c == '>' || c == '<') 1053 && quotef == 0 1054 && len <= 2 1055 && (*out == '\0' || is_digit(*out))) { 1056 PARSEREDIR(); 1057 return lasttoken = TREDIR; 1058 } else { 1059 pungetc(); 1060 } 1061 } 1062 quoteflag = quotef; 1063 backquotelist = bqlist; 1064 grabstackblock(len); 1065 wordtext = out; 1066 return lasttoken = TWORD; 1067/* end of readtoken routine */ 1068 1069 1070 1071/* 1072 * Check to see whether we are at the end of the here document. When this 1073 * is called, c is set to the first character of the next input line. If 1074 * we are at the end of the here document, this routine sets the c to PEOF. 1075 */ 1076 1077checkend: { 1078 if (eofmark) { 1079 if (striptabs) { 1080 while (c == '\t') 1081 c = pgetc(); 1082 } 1083 if (c == *eofmark) { 1084 if (pfgets(line, sizeof line) != NULL) { 1085 char *p, *q; 1086 1087 p = line; 1088 for (q = eofmark + 1 ; *q && *p == *q ; p++, q++); 1089 if (*p == '\n' && *q == '\0') { 1090 c = PEOF; 1091 plinno++; 1092 needprompt = doprompt; 1093 } else { 1094 pushstring(line, strlen(line), NULL); 1095 } 1096 } 1097 } 1098 } 1099 goto checkend_return; 1100} 1101 1102 1103/* 1104 * Parse a redirection operator. The variable "out" points to a string 1105 * specifying the fd to be redirected. The variable "c" contains the 1106 * first character of the redirection operator. 1107 */ 1108 1109parseredir: { 1110 char fd = *out; 1111 union node *np; 1112 1113 np = (union node *)stalloc(sizeof (struct nfile)); 1114 if (c == '>') { 1115 np->nfile.fd = 1; 1116 c = pgetc(); 1117 if (c == '>') 1118 np->type = NAPPEND; 1119 else if (c == '&') 1120 np->type = NTOFD; 1121 else { 1122 np->type = NTO; 1123 pungetc(); 1124 } 1125 } else { /* c == '<' */ 1126 np->nfile.fd = 0; 1127 c = pgetc(); 1128 if (c == '<') { 1129 if (sizeof (struct nfile) != sizeof (struct nhere)) { 1130 np = (union node *)stalloc(sizeof (struct nhere)); 1131 np->nfile.fd = 0; 1132 } 1133 np->type = NHERE; 1134 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); 1135 heredoc->here = np; 1136 if ((c = pgetc()) == '-') { 1137 heredoc->striptabs = 1; 1138 } else { 1139 heredoc->striptabs = 0; 1140 pungetc(); 1141 } 1142 } else if (c == '&') 1143 np->type = NFROMFD; 1144 else if (c == '>') 1145 np->type = NFROMTO; 1146 else { 1147 np->type = NFROM; 1148 pungetc(); 1149 } 1150 } 1151 if (fd != '\0') 1152 np->nfile.fd = digit_val(fd); 1153 redirnode = np; 1154 goto parseredir_return; 1155} 1156 1157 1158/* 1159 * Parse a substitution. At this point, we have read the dollar sign 1160 * and nothing else. 1161 */ 1162 1163parsesub: { 1164 int subtype; 1165 int typeloc; 1166 int flags; 1167 char *p; 1168#ifndef GDB_HACK 1169 static const char types[] = "}-+?="; 1170#endif 1171 int bracketed_name = 0; /* used to handle ${[0-9]*} variables */ 1172 1173 c = pgetc(); 1174 if (c != '(' && c != '{' && !is_name(c) && !is_special(c)) { 1175 USTPUTC('$', out); 1176 pungetc(); 1177 } else if (c == '(') { /* $(command) or $((arith)) */ 1178 if (pgetc() == '(') { 1179 PARSEARITH(); 1180 } else { 1181 pungetc(); 1182 PARSEBACKQNEW(); 1183 } 1184 } else { 1185 USTPUTC(CTLVAR, out); 1186 typeloc = out - stackblock(); 1187 USTPUTC(VSNORMAL, out); 1188 subtype = VSNORMAL; 1189 if (c == '{') { 1190 bracketed_name = 1; 1191 c = pgetc(); 1192 if (c == '#') { 1193 if ((c = pgetc()) == '}') 1194 c = '#'; 1195 else 1196 subtype = VSLENGTH; 1197 } 1198 else 1199 subtype = 0; 1200 } 1201 if (is_name(c)) { 1202 do { 1203 STPUTC(c, out); 1204 c = pgetc(); 1205 } while (is_in_name(c)); 1206 } else if (is_digit(c)) { 1207 if (bracketed_name) { 1208 do { 1209 STPUTC(c, out); 1210 c = pgetc(); 1211 } while (is_digit(c)); 1212 } else { 1213 STPUTC(c, out); 1214 c = pgetc(); 1215 } 1216 } else { 1217 if (! is_special(c)) 1218badsub: synerror("Bad substitution"); 1219 USTPUTC(c, out); 1220 c = pgetc(); 1221 } 1222 STPUTC('=', out); 1223 flags = 0; 1224 if (subtype == 0) { 1225 switch (c) { 1226 case ':': 1227 flags = VSNUL; 1228 c = pgetc(); 1229 /*FALLTHROUGH*/ 1230 default: 1231 p = strchr(types, c); 1232 if (p == NULL) 1233 goto badsub; 1234 subtype = p - types + VSNORMAL; 1235 break; 1236 case '%': 1237 case '#': 1238 { 1239 int cc = c; 1240 subtype = c == '#' ? VSTRIMLEFT : 1241 VSTRIMRIGHT; 1242 c = pgetc(); 1243 if (c == cc) 1244 subtype++; 1245 else 1246 pungetc(); 1247 break; 1248 } 1249 } 1250 } else { 1251 pungetc(); 1252 } 1253 if (subtype != VSLENGTH && (dblquote || arinest)) 1254 flags |= VSQUOTE; 1255 *(stackblock() + typeloc) = subtype | flags; 1256 if (subtype != VSNORMAL) 1257 varnest++; 1258 } 1259 goto parsesub_return; 1260} 1261 1262 1263/* 1264 * Called to parse command substitutions. Newstyle is set if the command 1265 * is enclosed inside $(...); nlpp is a pointer to the head of the linked 1266 * list of commands (passed by reference), and savelen is the number of 1267 * characters on the top of the stack which must be preserved. 1268 */ 1269 1270parsebackq: { 1271 struct nodelist **nlpp; 1272 int savepbq; 1273 union node *n; 1274 char *volatile str; 1275 struct jmploc jmploc; 1276 struct jmploc *volatile savehandler; 1277 int savelen; 1278 int saveprompt; 1279#if __GNUC__ 1280 /* Avoid longjmp clobbering */ 1281 (void) &saveprompt; 1282#endif 1283 1284 savepbq = parsebackquote; 1285 if (setjmp(jmploc.loc)) { 1286 if (str) 1287 ckfree(str); 1288 parsebackquote = 0; 1289 handler = savehandler; 1290 longjmp(handler->loc, 1); 1291 } 1292 INTOFF; 1293 str = NULL; 1294 savelen = out - stackblock(); 1295 if (savelen > 0) { 1296 str = ckmalloc(savelen); 1297 memcpy(str, stackblock(), savelen); 1298 } 1299 savehandler = handler; 1300 handler = &jmploc; 1301 INTON; 1302 if (oldstyle) { 1303 /* We must read until the closing backquote, giving special 1304 treatment to some slashes, and then push the string and 1305 reread it as input, interpreting it normally. */ 1306 char *out; 1307 int c; 1308 int savelen; 1309 char *str; 1310 1311 1312 STARTSTACKSTR(out); 1313 for (;;) { 1314 if (needprompt) { 1315 setprompt(2); 1316 needprompt = 0; 1317 } 1318 switch (c = pgetc()) { 1319 case '`': 1320 goto done; 1321 1322 case '\\': 1323 if ((c = pgetc()) == '\n') { 1324 plinno++; 1325 if (doprompt) 1326 setprompt(2); 1327 else 1328 setprompt(0); 1329 /* 1330 * If eating a newline, avoid putting 1331 * the newline into the new character 1332 * stream (via the STPUTC after the 1333 * switch). 1334 */ 1335 continue; 1336 } 1337 if (c != '\\' && c != '`' && c != '$' 1338 && (!dblquote || c != '"')) 1339 STPUTC('\\', out); 1340 break; 1341 1342 case '\n': 1343 plinno++; 1344 needprompt = doprompt; 1345 break; 1346 1347 case PEOF: 1348 startlinno = plinno; 1349 synerror("EOF in backquote substitution"); 1350 break; 1351 1352 default: 1353 break; 1354 } 1355 STPUTC(c, out); 1356 } 1357done: 1358 STPUTC('\0', out); 1359 savelen = out - stackblock(); 1360 if (savelen > 0) { 1361 str = ckmalloc(savelen); 1362 memcpy(str, stackblock(), savelen); 1363 setinputstring(str, 1); 1364 } 1365 } 1366 nlpp = &bqlist; 1367 while (*nlpp) 1368 nlpp = &(*nlpp)->next; 1369 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 1370 (*nlpp)->next = NULL; 1371 parsebackquote = oldstyle; 1372 1373 if (oldstyle) { 1374 saveprompt = doprompt; 1375 doprompt = 0; 1376 } 1377 1378 n = list(0); 1379 1380 if (oldstyle) 1381 doprompt = saveprompt; 1382 else { 1383 if (readtoken() != TRP) 1384 synexpect(TRP); 1385 } 1386 1387 (*nlpp)->n = n; 1388 if (oldstyle) { 1389 /* 1390 * Start reading from old file again, ignoring any pushed back 1391 * tokens left from the backquote parsing 1392 */ 1393 popfile(); 1394 tokpushback = 0; 1395 } 1396 while (stackblocksize() <= savelen) 1397 growstackblock(); 1398 STARTSTACKSTR(out); 1399 if (str) { 1400 memcpy(out, str, savelen); 1401 STADJUST(savelen, out); 1402 INTOFF; 1403 ckfree(str); 1404 str = NULL; 1405 INTON; 1406 } 1407 parsebackquote = savepbq; 1408 handler = savehandler; 1409 if (arinest || dblquote) 1410 USTPUTC(CTLBACKQ | CTLQUOTE, out); 1411 else 1412 USTPUTC(CTLBACKQ, out); 1413 if (oldstyle) 1414 goto parsebackq_oldreturn; 1415 else 1416 goto parsebackq_newreturn; 1417} 1418 1419/* 1420 * Parse an arithmetic expansion (indicate start of one and set state) 1421 */ 1422parsearith: { 1423 1424 if (++arinest == 1) { 1425 prevsyntax = syntax; 1426 syntax = ARISYNTAX; 1427 USTPUTC(CTLARI, out); 1428 if (dblquote) 1429 USTPUTC('"',out); 1430 else 1431 USTPUTC(' ',out); 1432 } else { 1433 /* 1434 * we collapse embedded arithmetic expansion to 1435 * parenthesis, which should be equivalent 1436 */ 1437 USTPUTC('(', out); 1438 } 1439 goto parsearith_return; 1440} 1441 1442} /* end of readtoken */ 1443 1444 1445 1446#ifdef mkinit 1447RESET { 1448 tokpushback = 0; 1449 checkkwd = 0; 1450} 1451#endif 1452 1453/* 1454 * Returns true if the text contains nothing to expand (no dollar signs 1455 * or backquotes). 1456 */ 1457 1458STATIC int 1459noexpand(text) 1460 char *text; 1461 { 1462 char *p; 1463 char c; 1464 1465 p = text; 1466 while ((c = *p++) != '\0') { 1467 if ( c == CTLQUOTEMARK) 1468 continue; 1469 if (c == CTLESC) 1470 p++; 1471 else if (c >= 0 && BASESYNTAX[(int)c] == CCTL) 1472 return 0; 1473 } 1474 return 1; 1475} 1476 1477 1478/* 1479 * Return true if the argument is a legal variable name (a letter or 1480 * underscore followed by zero or more letters, underscores, and digits). 1481 */ 1482 1483int 1484goodname(name) 1485 char *name; 1486 { 1487 char *p; 1488 1489 p = name; 1490 if (! is_name(*p)) 1491 return 0; 1492 while (*++p) { 1493 if (! is_in_name(*p)) 1494 return 0; 1495 } 1496 return 1; 1497} 1498 1499 1500/* 1501 * Called when an unexpected token is read during the parse. The argument 1502 * is the token that is expected, or -1 if more than one type of token can 1503 * occur at this point. 1504 */ 1505 1506STATIC void 1507synexpect(token) 1508 int token; 1509{ 1510 char msg[64]; 1511 1512 if (token >= 0) { 1513 fmtstr(msg, 64, "%s unexpected (expecting %s)", 1514 tokname[lasttoken], tokname[token]); 1515 } else { 1516 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]); 1517 } 1518 synerror(msg); 1519} 1520 1521 1522STATIC void 1523synerror(msg) 1524 char *msg; 1525 { 1526 if (commandname) 1527 outfmt(&errout, "%s: %d: ", commandname, startlinno); 1528 outfmt(&errout, "Syntax error: %s\n", msg); 1529 error((char *)NULL); 1530} 1531 1532STATIC void 1533setprompt(which) 1534 int which; 1535 { 1536 whichprompt = which; 1537 1538#ifndef NO_HISTORY 1539 if (!el) 1540#endif 1541 out2str(getprompt(NULL)); 1542} 1543 1544/* 1545 * called by editline -- any expansions to the prompt 1546 * should be added here. 1547 */ 1548char * 1549getprompt(unused) 1550 void *unused __unused; 1551{ 1552 switch (whichprompt) { 1553 case 0: 1554 return ""; 1555 case 1: 1556 return ps1val(); 1557 case 2: 1558 return ps2val(); 1559 default: 1560 return "<internal prompt error>"; 1561 } 1562} 1563