parser.c revision 301140
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 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33#ifndef lint 34#if 0 35static char sccsid[] = "@(#)parser.c 8.7 (Berkeley) 5/16/95"; 36#endif 37#endif /* not lint */ 38#include <sys/cdefs.h> 39__FBSDID("$FreeBSD: stable/10/bin/sh/parser.c 301140 2016-06-01 17:09:50Z truckman $"); 40 41#include <stdlib.h> 42#include <unistd.h> 43#include <stdio.h> 44 45#include "shell.h" 46#include "parser.h" 47#include "nodes.h" 48#include "expand.h" /* defines rmescapes() */ 49#include "syntax.h" 50#include "options.h" 51#include "input.h" 52#include "output.h" 53#include "var.h" 54#include "error.h" 55#include "memalloc.h" 56#include "mystring.h" 57#include "alias.h" 58#include "show.h" 59#include "eval.h" 60#include "exec.h" /* to check for special builtins */ 61#ifndef NO_HISTORY 62#include "myhistedit.h" 63#endif 64 65/* 66 * Shell command parser. 67 */ 68 69#define EOFMARKLEN 79 70#define PROMPTLEN 128 71 72/* values of checkkwd variable */ 73#define CHKALIAS 0x1 74#define CHKKWD 0x2 75#define CHKNL 0x4 76 77/* values returned by readtoken */ 78#include "token.h" 79 80 81 82struct heredoc { 83 struct heredoc *next; /* next here document in list */ 84 union node *here; /* redirection node */ 85 char *eofmark; /* string indicating end of input */ 86 int striptabs; /* if set, strip leading tabs */ 87}; 88 89struct parser_temp { 90 struct parser_temp *next; 91 void *data; 92}; 93 94 95static struct heredoc *heredoclist; /* list of here documents to read */ 96static int doprompt; /* if set, prompt the user */ 97static int needprompt; /* true if interactive and at start of line */ 98static int lasttoken; /* last token read */ 99static int tokpushback; /* last token pushed back */ 100static char *wordtext; /* text of last word returned by readtoken */ 101static int checkkwd; 102static struct nodelist *backquotelist; 103static union node *redirnode; 104static struct heredoc *heredoc; 105static int quoteflag; /* set if (part of) last token was quoted */ 106static int startlinno; /* line # where last token started */ 107static int funclinno; /* line # where the current function started */ 108static struct parser_temp *parser_temp; 109 110 111static union node *list(int); 112static union node *andor(void); 113static union node *pipeline(void); 114static union node *command(void); 115static union node *simplecmd(union node **, union node *); 116static union node *makename(void); 117static union node *makebinary(int type, union node *n1, union node *n2); 118static void parsefname(void); 119static void parseheredoc(void); 120static int peektoken(void); 121static int readtoken(void); 122static int xxreadtoken(void); 123static int readtoken1(int, const char *, const char *, int); 124static int noexpand(char *); 125static void consumetoken(int); 126static void synexpect(int) __dead2; 127static void synerror(const char *) __dead2; 128static void setprompt(int); 129 130 131static void * 132parser_temp_alloc(size_t len) 133{ 134 struct parser_temp *t; 135 136 INTOFF; 137 t = ckmalloc(sizeof(*t)); 138 t->data = NULL; 139 t->next = parser_temp; 140 parser_temp = t; 141 t->data = ckmalloc(len); 142 INTON; 143 return t->data; 144} 145 146 147static void * 148parser_temp_realloc(void *ptr, size_t len) 149{ 150 struct parser_temp *t; 151 152 INTOFF; 153 t = parser_temp; 154 if (ptr != t->data) 155 error("bug: parser_temp_realloc misused"); 156 t->data = ckrealloc(t->data, len); 157 INTON; 158 return t->data; 159} 160 161 162static void 163parser_temp_free_upto(void *ptr) 164{ 165 struct parser_temp *t; 166 int done = 0; 167 168 INTOFF; 169 while (parser_temp != NULL && !done) { 170 t = parser_temp; 171 parser_temp = t->next; 172 done = t->data == ptr; 173 ckfree(t->data); 174 ckfree(t); 175 } 176 INTON; 177 if (!done) 178 error("bug: parser_temp_free_upto misused"); 179} 180 181 182static void 183parser_temp_free_all(void) 184{ 185 struct parser_temp *t; 186 187 INTOFF; 188 while (parser_temp != NULL) { 189 t = parser_temp; 190 parser_temp = t->next; 191 ckfree(t->data); 192 ckfree(t); 193 } 194 INTON; 195} 196 197 198/* 199 * Read and parse a command. Returns NEOF on end of file. (NULL is a 200 * valid parse tree indicating a blank line.) 201 */ 202 203union node * 204parsecmd(int interact) 205{ 206 int t; 207 208 /* This assumes the parser is not re-entered, 209 * which could happen if we add command substitution on PS1/PS2. 210 */ 211 parser_temp_free_all(); 212 heredoclist = NULL; 213 214 tokpushback = 0; 215 checkkwd = 0; 216 doprompt = interact; 217 if (doprompt) 218 setprompt(1); 219 else 220 setprompt(0); 221 needprompt = 0; 222 t = readtoken(); 223 if (t == TEOF) 224 return NEOF; 225 if (t == TNL) 226 return NULL; 227 tokpushback++; 228 return list(1); 229} 230 231 232/* 233 * Read and parse words for wordexp. 234 * Returns a list of NARG nodes; NULL if there are no words. 235 */ 236union node * 237parsewordexp(void) 238{ 239 union node *n, *first = NULL, **pnext; 240 int t; 241 242 /* This assumes the parser is not re-entered, 243 * which could happen if we add command substitution on PS1/PS2. 244 */ 245 parser_temp_free_all(); 246 heredoclist = NULL; 247 248 tokpushback = 0; 249 checkkwd = 0; 250 doprompt = 0; 251 setprompt(0); 252 needprompt = 0; 253 pnext = &first; 254 while ((t = readtoken()) != TEOF) { 255 if (t != TWORD) 256 synexpect(TWORD); 257 n = makename(); 258 *pnext = n; 259 pnext = &n->narg.next; 260 } 261 return first; 262} 263 264 265static union node * 266list(int nlflag) 267{ 268 union node *ntop, *n1, *n2, *n3; 269 int tok; 270 271 checkkwd = CHKNL | CHKKWD | CHKALIAS; 272 if (!nlflag && tokendlist[peektoken()]) 273 return NULL; 274 ntop = n1 = NULL; 275 for (;;) { 276 n2 = andor(); 277 tok = readtoken(); 278 if (tok == TBACKGND) { 279 if (n2 != NULL && n2->type == NPIPE) { 280 n2->npipe.backgnd = 1; 281 } else if (n2 != NULL && n2->type == NREDIR) { 282 n2->type = NBACKGND; 283 } else { 284 n3 = (union node *)stalloc(sizeof (struct nredir)); 285 n3->type = NBACKGND; 286 n3->nredir.n = n2; 287 n3->nredir.redirect = NULL; 288 n2 = n3; 289 } 290 } 291 if (ntop == NULL) 292 ntop = n2; 293 else if (n1 == NULL) { 294 n1 = makebinary(NSEMI, ntop, n2); 295 ntop = n1; 296 } 297 else { 298 n3 = makebinary(NSEMI, n1->nbinary.ch2, n2); 299 n1->nbinary.ch2 = n3; 300 n1 = n3; 301 } 302 switch (tok) { 303 case TBACKGND: 304 case TSEMI: 305 tok = readtoken(); 306 /* FALLTHROUGH */ 307 case TNL: 308 if (tok == TNL) { 309 parseheredoc(); 310 if (nlflag) 311 return ntop; 312 } else if (tok == TEOF && nlflag) { 313 parseheredoc(); 314 return ntop; 315 } else { 316 tokpushback++; 317 } 318 checkkwd = CHKNL | CHKKWD | CHKALIAS; 319 if (!nlflag && tokendlist[peektoken()]) 320 return ntop; 321 break; 322 case TEOF: 323 if (heredoclist) 324 parseheredoc(); 325 else 326 pungetc(); /* push back EOF on input */ 327 return ntop; 328 default: 329 if (nlflag) 330 synexpect(-1); 331 tokpushback++; 332 return ntop; 333 } 334 } 335} 336 337 338 339static union node * 340andor(void) 341{ 342 union node *n; 343 int t; 344 345 n = pipeline(); 346 for (;;) { 347 if ((t = readtoken()) == TAND) { 348 t = NAND; 349 } else if (t == TOR) { 350 t = NOR; 351 } else { 352 tokpushback++; 353 return n; 354 } 355 n = makebinary(t, n, pipeline()); 356 } 357} 358 359 360 361static union node * 362pipeline(void) 363{ 364 union node *n1, *n2, *pipenode; 365 struct nodelist *lp, *prev; 366 int negate, t; 367 368 negate = 0; 369 checkkwd = CHKNL | CHKKWD | CHKALIAS; 370 TRACE(("pipeline: entered\n")); 371 while (readtoken() == TNOT) 372 negate = !negate; 373 tokpushback++; 374 n1 = command(); 375 if (readtoken() == TPIPE) { 376 pipenode = (union node *)stalloc(sizeof (struct npipe)); 377 pipenode->type = NPIPE; 378 pipenode->npipe.backgnd = 0; 379 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 380 pipenode->npipe.cmdlist = lp; 381 lp->n = n1; 382 do { 383 prev = lp; 384 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 385 checkkwd = CHKNL | CHKKWD | CHKALIAS; 386 t = readtoken(); 387 tokpushback++; 388 if (t == TNOT) 389 lp->n = pipeline(); 390 else 391 lp->n = command(); 392 prev->next = lp; 393 } while (readtoken() == TPIPE); 394 lp->next = NULL; 395 n1 = pipenode; 396 } 397 tokpushback++; 398 if (negate) { 399 n2 = (union node *)stalloc(sizeof (struct nnot)); 400 n2->type = NNOT; 401 n2->nnot.com = n1; 402 return n2; 403 } else 404 return n1; 405} 406 407 408 409static union node * 410command(void) 411{ 412 union node *n1, *n2; 413 union node *ap, **app; 414 union node *cp, **cpp; 415 union node *redir, **rpp; 416 int t; 417 int is_subshell; 418 419 checkkwd = CHKNL | CHKKWD | CHKALIAS; 420 is_subshell = 0; 421 redir = NULL; 422 n1 = NULL; 423 rpp = &redir; 424 425 /* Check for redirection which may precede command */ 426 while (readtoken() == TREDIR) { 427 *rpp = n2 = redirnode; 428 rpp = &n2->nfile.next; 429 parsefname(); 430 } 431 tokpushback++; 432 433 switch (readtoken()) { 434 case TIF: 435 n1 = (union node *)stalloc(sizeof (struct nif)); 436 n1->type = NIF; 437 if ((n1->nif.test = list(0)) == NULL) 438 synexpect(-1); 439 consumetoken(TTHEN); 440 n1->nif.ifpart = list(0); 441 n2 = n1; 442 while (readtoken() == TELIF) { 443 n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif)); 444 n2 = n2->nif.elsepart; 445 n2->type = NIF; 446 if ((n2->nif.test = list(0)) == NULL) 447 synexpect(-1); 448 consumetoken(TTHEN); 449 n2->nif.ifpart = list(0); 450 } 451 if (lasttoken == TELSE) 452 n2->nif.elsepart = list(0); 453 else { 454 n2->nif.elsepart = NULL; 455 tokpushback++; 456 } 457 consumetoken(TFI); 458 checkkwd = CHKKWD | CHKALIAS; 459 break; 460 case TWHILE: 461 case TUNTIL: 462 t = lasttoken; 463 if ((n1 = list(0)) == NULL) 464 synexpect(-1); 465 consumetoken(TDO); 466 n1 = makebinary((t == TWHILE)? NWHILE : NUNTIL, n1, list(0)); 467 consumetoken(TDONE); 468 checkkwd = CHKKWD | CHKALIAS; 469 break; 470 case TFOR: 471 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext)) 472 synerror("Bad for loop variable"); 473 n1 = (union node *)stalloc(sizeof (struct nfor)); 474 n1->type = NFOR; 475 n1->nfor.var = wordtext; 476 while (readtoken() == TNL) 477 ; 478 if (lasttoken == TWORD && ! quoteflag && equal(wordtext, "in")) { 479 app = ≈ 480 while (readtoken() == TWORD) { 481 n2 = makename(); 482 *app = n2; 483 app = &n2->narg.next; 484 } 485 *app = NULL; 486 n1->nfor.args = ap; 487 if (lasttoken != TNL && lasttoken != TSEMI) 488 synexpect(-1); 489 } else { 490 static char argvars[5] = { 491 CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0' 492 }; 493 n2 = (union node *)stalloc(sizeof (struct narg)); 494 n2->type = NARG; 495 n2->narg.text = argvars; 496 n2->narg.backquote = NULL; 497 n2->narg.next = NULL; 498 n1->nfor.args = n2; 499 /* 500 * Newline or semicolon here is optional (but note 501 * that the original Bourne shell only allowed NL). 502 */ 503 if (lasttoken != TNL && lasttoken != TSEMI) 504 tokpushback++; 505 } 506 checkkwd = CHKNL | CHKKWD | CHKALIAS; 507 if ((t = readtoken()) == TDO) 508 t = TDONE; 509 else if (t == TBEGIN) 510 t = TEND; 511 else 512 synexpect(-1); 513 n1->nfor.body = list(0); 514 consumetoken(t); 515 checkkwd = CHKKWD | CHKALIAS; 516 break; 517 case TCASE: 518 n1 = (union node *)stalloc(sizeof (struct ncase)); 519 n1->type = NCASE; 520 consumetoken(TWORD); 521 n1->ncase.expr = makename(); 522 while (readtoken() == TNL); 523 if (lasttoken != TWORD || ! equal(wordtext, "in")) 524 synerror("expecting \"in\""); 525 cpp = &n1->ncase.cases; 526 checkkwd = CHKNL | CHKKWD, readtoken(); 527 while (lasttoken != TESAC) { 528 *cpp = cp = (union node *)stalloc(sizeof (struct nclist)); 529 cp->type = NCLIST; 530 app = &cp->nclist.pattern; 531 if (lasttoken == TLP) 532 readtoken(); 533 for (;;) { 534 *app = ap = makename(); 535 checkkwd = CHKNL | CHKKWD; 536 if (readtoken() != TPIPE) 537 break; 538 app = &ap->narg.next; 539 readtoken(); 540 } 541 ap->narg.next = NULL; 542 if (lasttoken != TRP) 543 synexpect(TRP); 544 cp->nclist.body = list(0); 545 546 checkkwd = CHKNL | CHKKWD | CHKALIAS; 547 if ((t = readtoken()) != TESAC) { 548 if (t == TENDCASE) 549 ; 550 else if (t == TFALLTHRU) 551 cp->type = NCLISTFALLTHRU; 552 else 553 synexpect(TENDCASE); 554 checkkwd = CHKNL | CHKKWD, readtoken(); 555 } 556 cpp = &cp->nclist.next; 557 } 558 *cpp = NULL; 559 checkkwd = CHKKWD | CHKALIAS; 560 break; 561 case TLP: 562 n1 = (union node *)stalloc(sizeof (struct nredir)); 563 n1->type = NSUBSHELL; 564 n1->nredir.n = list(0); 565 n1->nredir.redirect = NULL; 566 consumetoken(TRP); 567 checkkwd = CHKKWD | CHKALIAS; 568 is_subshell = 1; 569 break; 570 case TBEGIN: 571 n1 = list(0); 572 consumetoken(TEND); 573 checkkwd = CHKKWD | CHKALIAS; 574 break; 575 /* A simple command must have at least one redirection or word. */ 576 case TBACKGND: 577 case TSEMI: 578 case TAND: 579 case TOR: 580 case TPIPE: 581 case TENDCASE: 582 case TFALLTHRU: 583 case TEOF: 584 case TNL: 585 case TRP: 586 if (!redir) 587 synexpect(-1); 588 case TWORD: 589 tokpushback++; 590 n1 = simplecmd(rpp, redir); 591 return n1; 592 default: 593 synexpect(-1); 594 } 595 596 /* Now check for redirection which may follow command */ 597 while (readtoken() == TREDIR) { 598 *rpp = n2 = redirnode; 599 rpp = &n2->nfile.next; 600 parsefname(); 601 } 602 tokpushback++; 603 *rpp = NULL; 604 if (redir) { 605 if (!is_subshell) { 606 n2 = (union node *)stalloc(sizeof (struct nredir)); 607 n2->type = NREDIR; 608 n2->nredir.n = n1; 609 n1 = n2; 610 } 611 n1->nredir.redirect = redir; 612 } 613 614 return n1; 615} 616 617 618static union node * 619simplecmd(union node **rpp, union node *redir) 620{ 621 union node *args, **app; 622 union node **orig_rpp = rpp; 623 union node *n = NULL; 624 int special; 625 int savecheckkwd; 626 627 /* If we don't have any redirections already, then we must reset */ 628 /* rpp to be the address of the local redir variable. */ 629 if (redir == 0) 630 rpp = &redir; 631 632 args = NULL; 633 app = &args; 634 /* 635 * We save the incoming value, because we need this for shell 636 * functions. There can not be a redirect or an argument between 637 * the function name and the open parenthesis. 638 */ 639 orig_rpp = rpp; 640 641 savecheckkwd = CHKALIAS; 642 643 for (;;) { 644 checkkwd = savecheckkwd; 645 if (readtoken() == TWORD) { 646 n = makename(); 647 *app = n; 648 app = &n->narg.next; 649 if (savecheckkwd != 0 && !isassignment(wordtext)) 650 savecheckkwd = 0; 651 } else if (lasttoken == TREDIR) { 652 *rpp = n = redirnode; 653 rpp = &n->nfile.next; 654 parsefname(); /* read name of redirection file */ 655 } else if (lasttoken == TLP && app == &args->narg.next 656 && rpp == orig_rpp) { 657 /* We have a function */ 658 consumetoken(TRP); 659 funclinno = plinno; 660 /* 661 * - Require plain text. 662 * - Functions with '/' cannot be called. 663 * - Reject name=(). 664 * - Reject ksh extended glob patterns. 665 */ 666 if (!noexpand(n->narg.text) || quoteflag || 667 strchr(n->narg.text, '/') || 668 strchr("!%*+-=?@}~", 669 n->narg.text[strlen(n->narg.text) - 1])) 670 synerror("Bad function name"); 671 rmescapes(n->narg.text); 672 if (find_builtin(n->narg.text, &special) >= 0 && 673 special) 674 synerror("Cannot override a special builtin with a function"); 675 n->type = NDEFUN; 676 n->narg.next = command(); 677 funclinno = 0; 678 return n; 679 } else { 680 tokpushback++; 681 break; 682 } 683 } 684 *app = NULL; 685 *rpp = NULL; 686 n = (union node *)stalloc(sizeof (struct ncmd)); 687 n->type = NCMD; 688 n->ncmd.args = args; 689 n->ncmd.redirect = redir; 690 return n; 691} 692 693static union node * 694makename(void) 695{ 696 union node *n; 697 698 n = (union node *)stalloc(sizeof (struct narg)); 699 n->type = NARG; 700 n->narg.next = NULL; 701 n->narg.text = wordtext; 702 n->narg.backquote = backquotelist; 703 return n; 704} 705 706static union node * 707makebinary(int type, union node *n1, union node *n2) 708{ 709 union node *n; 710 711 n = (union node *)stalloc(sizeof (struct nbinary)); 712 n->type = type; 713 n->nbinary.ch1 = n1; 714 n->nbinary.ch2 = n2; 715 return (n); 716} 717 718void 719forcealias(void) 720{ 721 checkkwd |= CHKALIAS; 722} 723 724void 725fixredir(union node *n, const char *text, int err) 726{ 727 TRACE(("Fix redir %s %d\n", text, err)); 728 if (!err) 729 n->ndup.vname = NULL; 730 731 if (is_digit(text[0]) && text[1] == '\0') 732 n->ndup.dupfd = digit_val(text[0]); 733 else if (text[0] == '-' && text[1] == '\0') 734 n->ndup.dupfd = -1; 735 else { 736 737 if (err) 738 synerror("Bad fd number"); 739 else 740 n->ndup.vname = makename(); 741 } 742} 743 744 745static void 746parsefname(void) 747{ 748 union node *n = redirnode; 749 750 consumetoken(TWORD); 751 if (n->type == NHERE) { 752 struct heredoc *here = heredoc; 753 struct heredoc *p; 754 int i; 755 756 if (quoteflag == 0) 757 n->type = NXHERE; 758 TRACE(("Here document %d\n", n->type)); 759 if (here->striptabs) { 760 while (*wordtext == '\t') 761 wordtext++; 762 } 763 if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN) 764 synerror("Illegal eof marker for << redirection"); 765 rmescapes(wordtext); 766 here->eofmark = wordtext; 767 here->next = NULL; 768 if (heredoclist == NULL) 769 heredoclist = here; 770 else { 771 for (p = heredoclist ; p->next ; p = p->next); 772 p->next = here; 773 } 774 } else if (n->type == NTOFD || n->type == NFROMFD) { 775 fixredir(n, wordtext, 0); 776 } else { 777 n->nfile.fname = makename(); 778 } 779} 780 781 782/* 783 * Input any here documents. 784 */ 785 786static void 787parseheredoc(void) 788{ 789 struct heredoc *here; 790 union node *n; 791 792 while (heredoclist) { 793 here = heredoclist; 794 heredoclist = here->next; 795 if (needprompt) { 796 setprompt(2); 797 needprompt = 0; 798 } 799 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, 800 here->eofmark, here->striptabs); 801 n = makename(); 802 here->here->nhere.doc = n; 803 } 804} 805 806static int 807peektoken(void) 808{ 809 int t; 810 811 t = readtoken(); 812 tokpushback++; 813 return (t); 814} 815 816static int 817readtoken(void) 818{ 819 int t; 820 struct alias *ap; 821#ifdef DEBUG 822 int alreadyseen = tokpushback; 823#endif 824 825 top: 826 t = xxreadtoken(); 827 828 /* 829 * eat newlines 830 */ 831 if (checkkwd & CHKNL) { 832 while (t == TNL) { 833 parseheredoc(); 834 t = xxreadtoken(); 835 } 836 } 837 838 /* 839 * check for keywords and aliases 840 */ 841 if (t == TWORD && !quoteflag) 842 { 843 const char * const *pp; 844 845 if (checkkwd & CHKKWD) 846 for (pp = parsekwd; *pp; pp++) { 847 if (**pp == *wordtext && equal(*pp, wordtext)) 848 { 849 lasttoken = t = pp - parsekwd + KWDOFFSET; 850 TRACE(("keyword %s recognized\n", tokname[t])); 851 goto out; 852 } 853 } 854 if (checkkwd & CHKALIAS && 855 (ap = lookupalias(wordtext, 1)) != NULL) { 856 pushstring(ap->val, strlen(ap->val), ap); 857 goto top; 858 } 859 } 860out: 861 if (t != TNOT) 862 checkkwd = 0; 863 864#ifdef DEBUG 865 if (!alreadyseen) 866 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 867 else 868 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 869#endif 870 return (t); 871} 872 873 874/* 875 * Read the next input token. 876 * If the token is a word, we set backquotelist to the list of cmds in 877 * backquotes. We set quoteflag to true if any part of the word was 878 * quoted. 879 * If the token is TREDIR, then we set redirnode to a structure containing 880 * the redirection. 881 * In all cases, the variable startlinno is set to the number of the line 882 * on which the token starts. 883 * 884 * [Change comment: here documents and internal procedures] 885 * [Readtoken shouldn't have any arguments. Perhaps we should make the 886 * word parsing code into a separate routine. In this case, readtoken 887 * doesn't need to have any internal procedures, but parseword does. 888 * We could also make parseoperator in essence the main routine, and 889 * have parseword (readtoken1?) handle both words and redirection.] 890 */ 891 892#define RETURN(token) return lasttoken = token 893 894static int 895xxreadtoken(void) 896{ 897 int c; 898 899 if (tokpushback) { 900 tokpushback = 0; 901 return lasttoken; 902 } 903 if (needprompt) { 904 setprompt(2); 905 needprompt = 0; 906 } 907 startlinno = plinno; 908 for (;;) { /* until token or start of word found */ 909 c = pgetc_macro(); 910 switch (c) { 911 case ' ': case '\t': 912 continue; 913 case '#': 914 while ((c = pgetc()) != '\n' && c != PEOF); 915 pungetc(); 916 continue; 917 case '\\': 918 if (pgetc() == '\n') { 919 startlinno = ++plinno; 920 if (doprompt) 921 setprompt(2); 922 else 923 setprompt(0); 924 continue; 925 } 926 pungetc(); 927 goto breakloop; 928 case '\n': 929 plinno++; 930 needprompt = doprompt; 931 RETURN(TNL); 932 case PEOF: 933 RETURN(TEOF); 934 case '&': 935 if (pgetc() == '&') 936 RETURN(TAND); 937 pungetc(); 938 RETURN(TBACKGND); 939 case '|': 940 if (pgetc() == '|') 941 RETURN(TOR); 942 pungetc(); 943 RETURN(TPIPE); 944 case ';': 945 c = pgetc(); 946 if (c == ';') 947 RETURN(TENDCASE); 948 else if (c == '&') 949 RETURN(TFALLTHRU); 950 pungetc(); 951 RETURN(TSEMI); 952 case '(': 953 RETURN(TLP); 954 case ')': 955 RETURN(TRP); 956 default: 957 goto breakloop; 958 } 959 } 960breakloop: 961 return readtoken1(c, BASESYNTAX, (char *)NULL, 0); 962#undef RETURN 963} 964 965 966#define MAXNEST_static 8 967struct tokenstate 968{ 969 const char *syntax; /* *SYNTAX */ 970 int parenlevel; /* levels of parentheses in arithmetic */ 971 enum tokenstate_category 972 { 973 TSTATE_TOP, 974 TSTATE_VAR_OLD, /* ${var+-=?}, inherits dquotes */ 975 TSTATE_VAR_NEW, /* other ${var...}, own dquote state */ 976 TSTATE_ARITH 977 } category; 978}; 979 980 981/* 982 * Called to parse command substitutions. 983 */ 984 985static char * 986parsebackq(char *out, struct nodelist **pbqlist, 987 int oldstyle, int dblquote, int quoted) 988{ 989 struct nodelist **nlpp; 990 union node *n; 991 char *volatile str; 992 struct jmploc jmploc; 993 struct jmploc *const savehandler = handler; 994 size_t savelen; 995 int saveprompt; 996 const int bq_startlinno = plinno; 997 char *volatile ostr = NULL; 998 struct parsefile *const savetopfile = getcurrentfile(); 999 struct heredoc *const saveheredoclist = heredoclist; 1000 struct heredoc *here; 1001 1002 str = NULL; 1003 if (setjmp(jmploc.loc)) { 1004 popfilesupto(savetopfile); 1005 if (str) 1006 ckfree(str); 1007 if (ostr) 1008 ckfree(ostr); 1009 heredoclist = saveheredoclist; 1010 handler = savehandler; 1011 if (exception == EXERROR) { 1012 startlinno = bq_startlinno; 1013 synerror("Error in command substitution"); 1014 } 1015 longjmp(handler->loc, 1); 1016 } 1017 INTOFF; 1018 savelen = out - stackblock(); 1019 if (savelen > 0) { 1020 str = ckmalloc(savelen); 1021 memcpy(str, stackblock(), savelen); 1022 } 1023 handler = &jmploc; 1024 heredoclist = NULL; 1025 INTON; 1026 if (oldstyle) { 1027 /* We must read until the closing backquote, giving special 1028 treatment to some slashes, and then push the string and 1029 reread it as input, interpreting it normally. */ 1030 char *oout; 1031 int c; 1032 int olen; 1033 1034 1035 STARTSTACKSTR(oout); 1036 for (;;) { 1037 if (needprompt) { 1038 setprompt(2); 1039 needprompt = 0; 1040 } 1041 CHECKSTRSPACE(2, oout); 1042 switch (c = pgetc()) { 1043 case '`': 1044 goto done; 1045 1046 case '\\': 1047 if ((c = pgetc()) == '\n') { 1048 plinno++; 1049 if (doprompt) 1050 setprompt(2); 1051 else 1052 setprompt(0); 1053 /* 1054 * If eating a newline, avoid putting 1055 * the newline into the new character 1056 * stream (via the USTPUTC after the 1057 * switch). 1058 */ 1059 continue; 1060 } 1061 if (c != '\\' && c != '`' && c != '$' 1062 && (!dblquote || c != '"')) 1063 USTPUTC('\\', oout); 1064 break; 1065 1066 case '\n': 1067 plinno++; 1068 needprompt = doprompt; 1069 break; 1070 1071 case PEOF: 1072 startlinno = plinno; 1073 synerror("EOF in backquote substitution"); 1074 break; 1075 1076 default: 1077 break; 1078 } 1079 USTPUTC(c, oout); 1080 } 1081done: 1082 USTPUTC('\0', oout); 1083 olen = oout - stackblock(); 1084 INTOFF; 1085 ostr = ckmalloc(olen); 1086 memcpy(ostr, stackblock(), olen); 1087 setinputstring(ostr, 1); 1088 INTON; 1089 } 1090 nlpp = pbqlist; 1091 while (*nlpp) 1092 nlpp = &(*nlpp)->next; 1093 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 1094 (*nlpp)->next = NULL; 1095 1096 if (oldstyle) { 1097 saveprompt = doprompt; 1098 doprompt = 0; 1099 } 1100 1101 n = list(0); 1102 1103 if (oldstyle) { 1104 if (peektoken() != TEOF) 1105 synexpect(-1); 1106 doprompt = saveprompt; 1107 } else 1108 consumetoken(TRP); 1109 1110 (*nlpp)->n = n; 1111 if (oldstyle) { 1112 /* 1113 * Start reading from old file again, ignoring any pushed back 1114 * tokens left from the backquote parsing 1115 */ 1116 popfile(); 1117 tokpushback = 0; 1118 } 1119 STARTSTACKSTR(out); 1120 CHECKSTRSPACE(savelen + 1, out); 1121 INTOFF; 1122 if (str) { 1123 memcpy(out, str, savelen); 1124 STADJUST(savelen, out); 1125 ckfree(str); 1126 str = NULL; 1127 } 1128 if (ostr) { 1129 ckfree(ostr); 1130 ostr = NULL; 1131 } 1132 here = saveheredoclist; 1133 if (here != NULL) { 1134 while (here->next != NULL) 1135 here = here->next; 1136 here->next = heredoclist; 1137 heredoclist = saveheredoclist; 1138 } 1139 handler = savehandler; 1140 INTON; 1141 if (quoted) 1142 USTPUTC(CTLBACKQ | CTLQUOTE, out); 1143 else 1144 USTPUTC(CTLBACKQ, out); 1145 return out; 1146} 1147 1148 1149/* 1150 * Called to parse a backslash escape sequence inside $'...'. 1151 * The backslash has already been read. 1152 */ 1153static char * 1154readcstyleesc(char *out) 1155{ 1156 int c, v, i, n; 1157 1158 c = pgetc(); 1159 switch (c) { 1160 case '\0': 1161 synerror("Unterminated quoted string"); 1162 case '\n': 1163 plinno++; 1164 if (doprompt) 1165 setprompt(2); 1166 else 1167 setprompt(0); 1168 return out; 1169 case '\\': 1170 case '\'': 1171 case '"': 1172 v = c; 1173 break; 1174 case 'a': v = '\a'; break; 1175 case 'b': v = '\b'; break; 1176 case 'e': v = '\033'; break; 1177 case 'f': v = '\f'; break; 1178 case 'n': v = '\n'; break; 1179 case 'r': v = '\r'; break; 1180 case 't': v = '\t'; break; 1181 case 'v': v = '\v'; break; 1182 case 'x': 1183 v = 0; 1184 for (;;) { 1185 c = pgetc(); 1186 if (c >= '0' && c <= '9') 1187 v = (v << 4) + c - '0'; 1188 else if (c >= 'A' && c <= 'F') 1189 v = (v << 4) + c - 'A' + 10; 1190 else if (c >= 'a' && c <= 'f') 1191 v = (v << 4) + c - 'a' + 10; 1192 else 1193 break; 1194 } 1195 pungetc(); 1196 break; 1197 case '0': case '1': case '2': case '3': 1198 case '4': case '5': case '6': case '7': 1199 v = c - '0'; 1200 c = pgetc(); 1201 if (c >= '0' && c <= '7') { 1202 v <<= 3; 1203 v += c - '0'; 1204 c = pgetc(); 1205 if (c >= '0' && c <= '7') { 1206 v <<= 3; 1207 v += c - '0'; 1208 } else 1209 pungetc(); 1210 } else 1211 pungetc(); 1212 break; 1213 case 'c': 1214 c = pgetc(); 1215 if (c < 0x3f || c > 0x7a || c == 0x60) 1216 synerror("Bad escape sequence"); 1217 if (c == '\\' && pgetc() != '\\') 1218 synerror("Bad escape sequence"); 1219 if (c == '?') 1220 v = 127; 1221 else 1222 v = c & 0x1f; 1223 break; 1224 case 'u': 1225 case 'U': 1226 n = c == 'U' ? 8 : 4; 1227 v = 0; 1228 for (i = 0; i < n; i++) { 1229 c = pgetc(); 1230 if (c >= '0' && c <= '9') 1231 v = (v << 4) + c - '0'; 1232 else if (c >= 'A' && c <= 'F') 1233 v = (v << 4) + c - 'A' + 10; 1234 else if (c >= 'a' && c <= 'f') 1235 v = (v << 4) + c - 'a' + 10; 1236 else 1237 synerror("Bad escape sequence"); 1238 } 1239 if (v == 0 || (v >= 0xd800 && v <= 0xdfff)) 1240 synerror("Bad escape sequence"); 1241 /* We really need iconv here. */ 1242 if (initial_localeisutf8 && v > 127) { 1243 CHECKSTRSPACE(4, out); 1244 /* 1245 * We cannot use wctomb() as the locale may have 1246 * changed. 1247 */ 1248 if (v <= 0x7ff) { 1249 USTPUTC(0xc0 | v >> 6, out); 1250 USTPUTC(0x80 | (v & 0x3f), out); 1251 return out; 1252 } else if (v <= 0xffff) { 1253 USTPUTC(0xe0 | v >> 12, out); 1254 USTPUTC(0x80 | ((v >> 6) & 0x3f), out); 1255 USTPUTC(0x80 | (v & 0x3f), out); 1256 return out; 1257 } else if (v <= 0x10ffff) { 1258 USTPUTC(0xf0 | v >> 18, out); 1259 USTPUTC(0x80 | ((v >> 12) & 0x3f), out); 1260 USTPUTC(0x80 | ((v >> 6) & 0x3f), out); 1261 USTPUTC(0x80 | (v & 0x3f), out); 1262 return out; 1263 } 1264 } 1265 if (v > 127) 1266 v = '?'; 1267 break; 1268 default: 1269 synerror("Bad escape sequence"); 1270 } 1271 v = (char)v; 1272 /* 1273 * We can't handle NUL bytes. 1274 * POSIX says we should skip till the closing quote. 1275 */ 1276 if (v == '\0') { 1277 while ((c = pgetc()) != '\'') { 1278 if (c == '\\') 1279 c = pgetc(); 1280 if (c == PEOF) 1281 synerror("Unterminated quoted string"); 1282 } 1283 pungetc(); 1284 return out; 1285 } 1286 if (SQSYNTAX[v] == CCTL) 1287 USTPUTC(CTLESC, out); 1288 USTPUTC(v, out); 1289 return out; 1290} 1291 1292 1293/* 1294 * If eofmark is NULL, read a word or a redirection symbol. If eofmark 1295 * is not NULL, read a here document. In the latter case, eofmark is the 1296 * word which marks the end of the document and striptabs is true if 1297 * leading tabs should be stripped from the document. The argument firstc 1298 * is the first character of the input token or document. 1299 * 1300 * Because C does not have internal subroutines, I have simulated them 1301 * using goto's to implement the subroutine linkage. The following macros 1302 * will run code that appears at the end of readtoken1. 1303 */ 1304 1305#define CHECKEND() {goto checkend; checkend_return:;} 1306#define PARSEREDIR() {goto parseredir; parseredir_return:;} 1307#define PARSESUB() {goto parsesub; parsesub_return:;} 1308#define PARSEARITH() {goto parsearith; parsearith_return:;} 1309 1310static int 1311readtoken1(int firstc, char const *initialsyntax, const char *eofmark, 1312 int striptabs) 1313{ 1314 int c = firstc; 1315 char *out; 1316 int len; 1317 char line[EOFMARKLEN + 1]; 1318 struct nodelist *bqlist; 1319 int quotef; 1320 int newvarnest; 1321 int level; 1322 int synentry; 1323 struct tokenstate state_static[MAXNEST_static]; 1324 int maxnest = MAXNEST_static; 1325 struct tokenstate *state = state_static; 1326 int sqiscstyle = 0; 1327 1328 startlinno = plinno; 1329 quotef = 0; 1330 bqlist = NULL; 1331 newvarnest = 0; 1332 level = 0; 1333 state[level].syntax = initialsyntax; 1334 state[level].parenlevel = 0; 1335 state[level].category = TSTATE_TOP; 1336 1337 STARTSTACKSTR(out); 1338 loop: { /* for each line, until end of word */ 1339 CHECKEND(); /* set c to PEOF if at end of here document */ 1340 for (;;) { /* until end of line or end of word */ 1341 CHECKSTRSPACE(4, out); /* permit 4 calls to USTPUTC */ 1342 1343 synentry = state[level].syntax[c]; 1344 1345 switch(synentry) { 1346 case CNL: /* '\n' */ 1347 if (state[level].syntax == BASESYNTAX) 1348 goto endword; /* exit outer loop */ 1349 USTPUTC(c, out); 1350 plinno++; 1351 if (doprompt) 1352 setprompt(2); 1353 else 1354 setprompt(0); 1355 c = pgetc(); 1356 goto loop; /* continue outer loop */ 1357 case CSBACK: 1358 if (sqiscstyle) { 1359 out = readcstyleesc(out); 1360 break; 1361 } 1362 /* FALLTHROUGH */ 1363 case CWORD: 1364 USTPUTC(c, out); 1365 break; 1366 case CCTL: 1367 if (eofmark == NULL || initialsyntax != SQSYNTAX) 1368 USTPUTC(CTLESC, out); 1369 USTPUTC(c, out); 1370 break; 1371 case CBACK: /* backslash */ 1372 c = pgetc(); 1373 if (c == PEOF) { 1374 USTPUTC('\\', out); 1375 pungetc(); 1376 } else if (c == '\n') { 1377 plinno++; 1378 if (doprompt) 1379 setprompt(2); 1380 else 1381 setprompt(0); 1382 } else { 1383 if (state[level].syntax == DQSYNTAX && 1384 c != '\\' && c != '`' && c != '$' && 1385 (c != '"' || (eofmark != NULL && 1386 newvarnest == 0)) && 1387 (c != '}' || state[level].category != TSTATE_VAR_OLD)) 1388 USTPUTC('\\', out); 1389 if ((eofmark == NULL || 1390 newvarnest > 0) && 1391 state[level].syntax == BASESYNTAX) 1392 USTPUTC(CTLQUOTEMARK, out); 1393 if (SQSYNTAX[c] == CCTL) 1394 USTPUTC(CTLESC, out); 1395 USTPUTC(c, out); 1396 if ((eofmark == NULL || 1397 newvarnest > 0) && 1398 state[level].syntax == BASESYNTAX && 1399 state[level].category == TSTATE_VAR_OLD) 1400 USTPUTC(CTLQUOTEEND, out); 1401 quotef++; 1402 } 1403 break; 1404 case CSQUOTE: 1405 USTPUTC(CTLQUOTEMARK, out); 1406 state[level].syntax = SQSYNTAX; 1407 sqiscstyle = 0; 1408 break; 1409 case CDQUOTE: 1410 USTPUTC(CTLQUOTEMARK, out); 1411 state[level].syntax = DQSYNTAX; 1412 break; 1413 case CENDQUOTE: 1414 if (eofmark != NULL && newvarnest == 0) 1415 USTPUTC(c, out); 1416 else { 1417 if (state[level].category == TSTATE_VAR_OLD) 1418 USTPUTC(CTLQUOTEEND, out); 1419 state[level].syntax = BASESYNTAX; 1420 quotef++; 1421 } 1422 break; 1423 case CVAR: /* '$' */ 1424 PARSESUB(); /* parse substitution */ 1425 break; 1426 case CENDVAR: /* '}' */ 1427 if (level > 0 && 1428 ((state[level].category == TSTATE_VAR_OLD && 1429 state[level].syntax == 1430 state[level - 1].syntax) || 1431 (state[level].category == TSTATE_VAR_NEW && 1432 state[level].syntax == BASESYNTAX))) { 1433 if (state[level].category == TSTATE_VAR_NEW) 1434 newvarnest--; 1435 level--; 1436 USTPUTC(CTLENDVAR, out); 1437 } else { 1438 USTPUTC(c, out); 1439 } 1440 break; 1441 case CLP: /* '(' in arithmetic */ 1442 state[level].parenlevel++; 1443 USTPUTC(c, out); 1444 break; 1445 case CRP: /* ')' in arithmetic */ 1446 if (state[level].parenlevel > 0) { 1447 USTPUTC(c, out); 1448 --state[level].parenlevel; 1449 } else { 1450 if (pgetc() == ')') { 1451 if (level > 0 && 1452 state[level].category == TSTATE_ARITH) { 1453 level--; 1454 USTPUTC(CTLENDARI, out); 1455 } else 1456 USTPUTC(')', out); 1457 } else { 1458 /* 1459 * unbalanced parens 1460 * (don't 2nd guess - no error) 1461 */ 1462 pungetc(); 1463 USTPUTC(')', out); 1464 } 1465 } 1466 break; 1467 case CBQUOTE: /* '`' */ 1468 out = parsebackq(out, &bqlist, 1, 1469 state[level].syntax == DQSYNTAX && 1470 (eofmark == NULL || newvarnest > 0), 1471 state[level].syntax == DQSYNTAX || state[level].syntax == ARISYNTAX); 1472 break; 1473 case CEOF: 1474 goto endword; /* exit outer loop */ 1475 case CIGN: 1476 break; 1477 default: 1478 if (level == 0) 1479 goto endword; /* exit outer loop */ 1480 USTPUTC(c, out); 1481 } 1482 c = pgetc_macro(); 1483 } 1484 } 1485endword: 1486 if (state[level].syntax == ARISYNTAX) 1487 synerror("Missing '))'"); 1488 if (state[level].syntax != BASESYNTAX && eofmark == NULL) 1489 synerror("Unterminated quoted string"); 1490 if (state[level].category == TSTATE_VAR_OLD || 1491 state[level].category == TSTATE_VAR_NEW) { 1492 startlinno = plinno; 1493 synerror("Missing '}'"); 1494 } 1495 if (state != state_static) 1496 parser_temp_free_upto(state); 1497 USTPUTC('\0', out); 1498 len = out - stackblock(); 1499 out = stackblock(); 1500 if (eofmark == NULL) { 1501 if ((c == '>' || c == '<') 1502 && quotef == 0 1503 && len <= 2 1504 && (*out == '\0' || is_digit(*out))) { 1505 PARSEREDIR(); 1506 return lasttoken = TREDIR; 1507 } else { 1508 pungetc(); 1509 } 1510 } 1511 quoteflag = quotef; 1512 backquotelist = bqlist; 1513 grabstackblock(len); 1514 wordtext = out; 1515 return lasttoken = TWORD; 1516/* end of readtoken routine */ 1517 1518 1519/* 1520 * Check to see whether we are at the end of the here document. When this 1521 * is called, c is set to the first character of the next input line. If 1522 * we are at the end of the here document, this routine sets the c to PEOF. 1523 */ 1524 1525checkend: { 1526 if (eofmark) { 1527 if (striptabs) { 1528 while (c == '\t') 1529 c = pgetc(); 1530 } 1531 if (c == *eofmark) { 1532 if (pfgets(line, sizeof line) != NULL) { 1533 const char *p, *q; 1534 1535 p = line; 1536 for (q = eofmark + 1 ; *q && *p == *q ; p++, q++); 1537 if ((*p == '\0' || *p == '\n') && *q == '\0') { 1538 c = PEOF; 1539 if (*p == '\n') { 1540 plinno++; 1541 needprompt = doprompt; 1542 } 1543 } else { 1544 pushstring(line, strlen(line), NULL); 1545 } 1546 } 1547 } 1548 } 1549 goto checkend_return; 1550} 1551 1552 1553/* 1554 * Parse a redirection operator. The variable "out" points to a string 1555 * specifying the fd to be redirected. The variable "c" contains the 1556 * first character of the redirection operator. 1557 */ 1558 1559parseredir: { 1560 char fd = *out; 1561 union node *np; 1562 1563 np = (union node *)stalloc(sizeof (struct nfile)); 1564 if (c == '>') { 1565 np->nfile.fd = 1; 1566 c = pgetc(); 1567 if (c == '>') 1568 np->type = NAPPEND; 1569 else if (c == '&') 1570 np->type = NTOFD; 1571 else if (c == '|') 1572 np->type = NCLOBBER; 1573 else { 1574 np->type = NTO; 1575 pungetc(); 1576 } 1577 } else { /* c == '<' */ 1578 np->nfile.fd = 0; 1579 c = pgetc(); 1580 if (c == '<') { 1581 if (sizeof (struct nfile) != sizeof (struct nhere)) { 1582 np = (union node *)stalloc(sizeof (struct nhere)); 1583 np->nfile.fd = 0; 1584 } 1585 np->type = NHERE; 1586 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); 1587 heredoc->here = np; 1588 if ((c = pgetc()) == '-') { 1589 heredoc->striptabs = 1; 1590 } else { 1591 heredoc->striptabs = 0; 1592 pungetc(); 1593 } 1594 } else if (c == '&') 1595 np->type = NFROMFD; 1596 else if (c == '>') 1597 np->type = NFROMTO; 1598 else { 1599 np->type = NFROM; 1600 pungetc(); 1601 } 1602 } 1603 if (fd != '\0') 1604 np->nfile.fd = digit_val(fd); 1605 redirnode = np; 1606 goto parseredir_return; 1607} 1608 1609 1610/* 1611 * Parse a substitution. At this point, we have read the dollar sign 1612 * and nothing else. 1613 */ 1614 1615parsesub: { 1616 char buf[10]; 1617 int subtype; 1618 int typeloc; 1619 int flags; 1620 char *p; 1621 static const char types[] = "}-+?="; 1622 int bracketed_name = 0; /* used to handle ${[0-9]*} variables */ 1623 int linno; 1624 int length; 1625 int c1; 1626 1627 c = pgetc(); 1628 if (c == '(') { /* $(command) or $((arith)) */ 1629 if (pgetc() == '(') { 1630 PARSEARITH(); 1631 } else { 1632 pungetc(); 1633 out = parsebackq(out, &bqlist, 0, 1634 state[level].syntax == DQSYNTAX && 1635 (eofmark == NULL || newvarnest > 0), 1636 state[level].syntax == DQSYNTAX || 1637 state[level].syntax == ARISYNTAX); 1638 } 1639 } else if (c == '{' || is_name(c) || is_special(c)) { 1640 USTPUTC(CTLVAR, out); 1641 typeloc = out - stackblock(); 1642 USTPUTC(VSNORMAL, out); 1643 subtype = VSNORMAL; 1644 flags = 0; 1645 if (c == '{') { 1646 bracketed_name = 1; 1647 c = pgetc(); 1648 subtype = 0; 1649 } 1650varname: 1651 if (!is_eof(c) && is_name(c)) { 1652 length = 0; 1653 do { 1654 STPUTC(c, out); 1655 c = pgetc(); 1656 length++; 1657 } while (!is_eof(c) && is_in_name(c)); 1658 if (length == 6 && 1659 strncmp(out - length, "LINENO", length) == 0) { 1660 /* Replace the variable name with the 1661 * current line number. */ 1662 linno = plinno; 1663 if (funclinno != 0) 1664 linno -= funclinno - 1; 1665 snprintf(buf, sizeof(buf), "%d", linno); 1666 STADJUST(-6, out); 1667 STPUTS(buf, out); 1668 flags |= VSLINENO; 1669 } 1670 } else if (is_digit(c)) { 1671 if (bracketed_name) { 1672 do { 1673 STPUTC(c, out); 1674 c = pgetc(); 1675 } while (is_digit(c)); 1676 } else { 1677 STPUTC(c, out); 1678 c = pgetc(); 1679 } 1680 } else if (is_special(c)) { 1681 c1 = c; 1682 c = pgetc(); 1683 if (subtype == 0 && c1 == '#') { 1684 subtype = VSLENGTH; 1685 if (strchr(types, c) == NULL && c != ':' && 1686 c != '#' && c != '%') 1687 goto varname; 1688 c1 = c; 1689 c = pgetc(); 1690 if (c1 != '}' && c == '}') { 1691 pungetc(); 1692 c = c1; 1693 goto varname; 1694 } 1695 pungetc(); 1696 c = c1; 1697 c1 = '#'; 1698 subtype = 0; 1699 } 1700 USTPUTC(c1, out); 1701 } else { 1702 subtype = VSERROR; 1703 if (c == '}') 1704 pungetc(); 1705 else if (c == '\n' || c == PEOF) 1706 synerror("Unexpected end of line in substitution"); 1707 else if (BASESYNTAX[c] != CCTL) 1708 USTPUTC(c, out); 1709 } 1710 if (subtype == 0) { 1711 switch (c) { 1712 case ':': 1713 flags |= VSNUL; 1714 c = pgetc(); 1715 /*FALLTHROUGH*/ 1716 default: 1717 p = strchr(types, c); 1718 if (p == NULL) { 1719 if (c == '\n' || c == PEOF) 1720 synerror("Unexpected end of line in substitution"); 1721 if (flags == VSNUL) 1722 STPUTC(':', out); 1723 if (BASESYNTAX[c] != CCTL) 1724 STPUTC(c, out); 1725 subtype = VSERROR; 1726 } else 1727 subtype = p - types + VSNORMAL; 1728 break; 1729 case '%': 1730 case '#': 1731 { 1732 int cc = c; 1733 subtype = c == '#' ? VSTRIMLEFT : 1734 VSTRIMRIGHT; 1735 c = pgetc(); 1736 if (c == cc) 1737 subtype++; 1738 else 1739 pungetc(); 1740 break; 1741 } 1742 } 1743 } else if (subtype != VSERROR) { 1744 if (subtype == VSLENGTH && c != '}') 1745 subtype = VSERROR; 1746 pungetc(); 1747 } 1748 STPUTC('=', out); 1749 if (state[level].syntax == DQSYNTAX || 1750 state[level].syntax == ARISYNTAX) 1751 flags |= VSQUOTE; 1752 *(stackblock() + typeloc) = subtype | flags; 1753 if (subtype != VSNORMAL) { 1754 if (level + 1 >= maxnest) { 1755 maxnest *= 2; 1756 if (state == state_static) { 1757 state = parser_temp_alloc( 1758 maxnest * sizeof(*state)); 1759 memcpy(state, state_static, 1760 MAXNEST_static * sizeof(*state)); 1761 } else 1762 state = parser_temp_realloc(state, 1763 maxnest * sizeof(*state)); 1764 } 1765 level++; 1766 state[level].parenlevel = 0; 1767 if (subtype == VSMINUS || subtype == VSPLUS || 1768 subtype == VSQUESTION || subtype == VSASSIGN) { 1769 /* 1770 * For operators that were in the Bourne shell, 1771 * inherit the double-quote state. 1772 */ 1773 state[level].syntax = state[level - 1].syntax; 1774 state[level].category = TSTATE_VAR_OLD; 1775 } else { 1776 /* 1777 * The other operators take a pattern, 1778 * so go to BASESYNTAX. 1779 * Also, ' and " are now special, even 1780 * in here documents. 1781 */ 1782 state[level].syntax = BASESYNTAX; 1783 state[level].category = TSTATE_VAR_NEW; 1784 newvarnest++; 1785 } 1786 } 1787 } else if (c == '\'' && state[level].syntax == BASESYNTAX) { 1788 /* $'cstylequotes' */ 1789 USTPUTC(CTLQUOTEMARK, out); 1790 state[level].syntax = SQSYNTAX; 1791 sqiscstyle = 1; 1792 } else { 1793 USTPUTC('$', out); 1794 pungetc(); 1795 } 1796 goto parsesub_return; 1797} 1798 1799 1800/* 1801 * Parse an arithmetic expansion (indicate start of one and set state) 1802 */ 1803parsearith: { 1804 1805 if (level + 1 >= maxnest) { 1806 maxnest *= 2; 1807 if (state == state_static) { 1808 state = parser_temp_alloc( 1809 maxnest * sizeof(*state)); 1810 memcpy(state, state_static, 1811 MAXNEST_static * sizeof(*state)); 1812 } else 1813 state = parser_temp_realloc(state, 1814 maxnest * sizeof(*state)); 1815 } 1816 level++; 1817 state[level].syntax = ARISYNTAX; 1818 state[level].parenlevel = 0; 1819 state[level].category = TSTATE_ARITH; 1820 USTPUTC(CTLARI, out); 1821 if (state[level - 1].syntax == DQSYNTAX) 1822 USTPUTC('"',out); 1823 else 1824 USTPUTC(' ',out); 1825 goto parsearith_return; 1826} 1827 1828} /* end of readtoken */ 1829 1830 1831/* 1832 * Returns true if the text contains nothing to expand (no dollar signs 1833 * or backquotes). 1834 */ 1835 1836static int 1837noexpand(char *text) 1838{ 1839 char *p; 1840 char c; 1841 1842 p = text; 1843 while ((c = *p++) != '\0') { 1844 if ( c == CTLQUOTEMARK) 1845 continue; 1846 if (c == CTLESC) 1847 p++; 1848 else if (BASESYNTAX[(int)c] == CCTL) 1849 return 0; 1850 } 1851 return 1; 1852} 1853 1854 1855/* 1856 * Return true if the argument is a legal variable name (a letter or 1857 * underscore followed by zero or more letters, underscores, and digits). 1858 */ 1859 1860int 1861goodname(const char *name) 1862{ 1863 const char *p; 1864 1865 p = name; 1866 if (! is_name(*p)) 1867 return 0; 1868 while (*++p) { 1869 if (! is_in_name(*p)) 1870 return 0; 1871 } 1872 return 1; 1873} 1874 1875 1876int 1877isassignment(const char *p) 1878{ 1879 if (!is_name(*p)) 1880 return 0; 1881 p++; 1882 for (;;) { 1883 if (*p == '=') 1884 return 1; 1885 else if (!is_in_name(*p)) 1886 return 0; 1887 p++; 1888 } 1889} 1890 1891 1892static void 1893consumetoken(int token) 1894{ 1895 if (readtoken() != token) 1896 synexpect(token); 1897} 1898 1899 1900/* 1901 * Called when an unexpected token is read during the parse. The argument 1902 * is the token that is expected, or -1 if more than one type of token can 1903 * occur at this point. 1904 */ 1905 1906static void 1907synexpect(int token) 1908{ 1909 char msg[64]; 1910 1911 if (token >= 0) { 1912 fmtstr(msg, 64, "%s unexpected (expecting %s)", 1913 tokname[lasttoken], tokname[token]); 1914 } else { 1915 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]); 1916 } 1917 synerror(msg); 1918} 1919 1920 1921static void 1922synerror(const char *msg) 1923{ 1924 if (commandname) 1925 outfmt(out2, "%s: %d: ", commandname, startlinno); 1926 outfmt(out2, "Syntax error: %s\n", msg); 1927 error((char *)NULL); 1928} 1929 1930static void 1931setprompt(int which) 1932{ 1933 whichprompt = which; 1934 1935#ifndef NO_HISTORY 1936 if (!el) 1937#endif 1938 { 1939 out2str(getprompt(NULL)); 1940 flushout(out2); 1941 } 1942} 1943 1944/* 1945 * called by editline -- any expansions to the prompt 1946 * should be added here. 1947 */ 1948char * 1949getprompt(void *unused __unused) 1950{ 1951 static char ps[PROMPTLEN]; 1952 char *fmt; 1953 const char *pwd; 1954 int i, trim; 1955 static char internal_error[] = "??"; 1956 1957 /* 1958 * Select prompt format. 1959 */ 1960 switch (whichprompt) { 1961 case 0: 1962 fmt = nullstr; 1963 break; 1964 case 1: 1965 fmt = ps1val(); 1966 break; 1967 case 2: 1968 fmt = ps2val(); 1969 break; 1970 default: 1971 return internal_error; 1972 } 1973 1974 /* 1975 * Format prompt string. 1976 */ 1977 for (i = 0; (i < PROMPTLEN - 1) && (*fmt != '\0'); i++, fmt++) 1978 if (*fmt == '\\') 1979 switch (*++fmt) { 1980 1981 /* 1982 * Hostname. 1983 * 1984 * \h specifies just the local hostname, 1985 * \H specifies fully-qualified hostname. 1986 */ 1987 case 'h': 1988 case 'H': 1989 ps[i] = '\0'; 1990 gethostname(&ps[i], PROMPTLEN - i - 1); 1991 ps[PROMPTLEN - 1] = '\0'; 1992 /* Skip to end of hostname. */ 1993 trim = (*fmt == 'h') ? '.' : '\0'; 1994 while ((ps[i] != '\0') && (ps[i] != trim)) 1995 i++; 1996 --i; 1997 break; 1998 1999 /* 2000 * Working directory. 2001 * 2002 * \W specifies just the final component, 2003 * \w specifies the entire path. 2004 */ 2005 case 'W': 2006 case 'w': 2007 pwd = lookupvar("PWD"); 2008 if (pwd == NULL || *pwd == '\0') 2009 pwd = "?"; 2010 if (*fmt == 'W' && 2011 *pwd == '/' && pwd[1] != '\0') 2012 strlcpy(&ps[i], strrchr(pwd, '/') + 1, 2013 PROMPTLEN - i); 2014 else 2015 strlcpy(&ps[i], pwd, PROMPTLEN - i); 2016 /* Skip to end of path. */ 2017 while (ps[i + 1] != '\0') 2018 i++; 2019 break; 2020 2021 /* 2022 * Superuser status. 2023 * 2024 * '$' for normal users, '#' for root. 2025 */ 2026 case '$': 2027 ps[i] = (geteuid() != 0) ? '$' : '#'; 2028 break; 2029 2030 /* 2031 * A literal \. 2032 */ 2033 case '\\': 2034 ps[i] = '\\'; 2035 break; 2036 2037 /* 2038 * Emit unrecognized formats verbatim. 2039 */ 2040 default: 2041 ps[i] = '\\'; 2042 if (i < PROMPTLEN - 1) 2043 ps[++i] = *fmt; 2044 break; 2045 } 2046 else 2047 ps[i] = *fmt; 2048 ps[i] = '\0'; 2049 return (ps); 2050} 2051 2052 2053const char * 2054expandstr(const char *ps) 2055{ 2056 union node n; 2057 struct jmploc jmploc; 2058 struct jmploc *const savehandler = handler; 2059 const int saveprompt = doprompt; 2060 struct parsefile *const savetopfile = getcurrentfile(); 2061 struct parser_temp *const saveparser_temp = parser_temp; 2062 const char *result = NULL; 2063 2064 if (!setjmp(jmploc.loc)) { 2065 handler = &jmploc; 2066 parser_temp = NULL; 2067 setinputstring(ps, 1); 2068 doprompt = 0; 2069 readtoken1(pgetc(), DQSYNTAX, "\n\n", 0); 2070 if (backquotelist != NULL) 2071 error("Command substitution not allowed here"); 2072 2073 n.narg.type = NARG; 2074 n.narg.next = NULL; 2075 n.narg.text = wordtext; 2076 n.narg.backquote = backquotelist; 2077 2078 expandarg(&n, NULL, 0); 2079 result = stackblock(); 2080 INTOFF; 2081 } 2082 handler = savehandler; 2083 doprompt = saveprompt; 2084 popfilesupto(savetopfile); 2085 if (parser_temp != saveparser_temp) { 2086 parser_temp_free_all(); 2087 parser_temp = saveparser_temp; 2088 } 2089 if (result != NULL) { 2090 INTON; 2091 } else if (exception == EXINT) 2092 raise(SIGINT); 2093 return result; 2094} 2095