1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Kenneth Almquist. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #ifndef lint 36 #if 0 37 static char sccsid[] = "@(#)parser.c 8.7 (Berkeley) 5/16/95"; 38 #endif 39 #endif /* not lint */ 40 #include <sys/cdefs.h> 41 __FBSDID("$FreeBSD$"); 42 43 #include <stdlib.h> 44 #include <unistd.h> 45 #include <stdio.h> 46 47 #include "shell.h" 48 #include "parser.h" 49 #include "nodes.h" 50 #include "expand.h" /* defines rmescapes() */ 51 #include "syntax.h" 52 #include "options.h" 53 #include "input.h" 54 #include "output.h" 55 #include "var.h" 56 #include "error.h" 57 #include "memalloc.h" 58 #include "mystring.h" 59 #include "alias.h" 60 #include "show.h" 61 #include "eval.h" 62 #include "exec.h" /* to check for special builtins */ 63 #ifndef NO_HISTORY 64 #include "myhistedit.h" 65 #endif 66 67 /* 68 * Shell command parser. 69 */ 70 71 #define PROMPTLEN 128 72 73 /* values of checkkwd variable */ 74 #define CHKALIAS 0x1 75 #define CHKKWD 0x2 76 #define CHKNL 0x4 77 78 /* values returned by readtoken */ 79 #include "token.h" 80 81 82 83 struct heredoc { 84 struct heredoc *next; /* next here document in list */ 85 union node *here; /* redirection node */ 86 char *eofmark; /* string indicating end of input */ 87 int striptabs; /* if set, strip leading tabs */ 88 }; 89 90 struct parser_temp { 91 struct parser_temp *next; 92 void *data; 93 }; 94 95 96 static struct heredoc *heredoclist; /* list of here documents to read */ 97 static int doprompt; /* if set, prompt the user */ 98 static int needprompt; /* true if interactive and at start of line */ 99 static int lasttoken; /* last token read */ 100 static int tokpushback; /* last token pushed back */ 101 static char *wordtext; /* text of last word returned by readtoken */ 102 static int checkkwd; 103 static struct nodelist *backquotelist; 104 static union node *redirnode; 105 static struct heredoc *heredoc; 106 static int quoteflag; /* set if (part of) last token was quoted */ 107 static int startlinno; /* line # where last token started */ 108 static int funclinno; /* line # where the current function started */ 109 static struct parser_temp *parser_temp; 110 111 #define NOEOFMARK ((const char *)&heredoclist) 112 113 114 static union node *list(int); 115 static union node *andor(void); 116 static union node *pipeline(void); 117 static union node *command(void); 118 static union node *simplecmd(union node **, union node *); 119 static union node *makename(void); 120 static union node *makebinary(int type, union node *n1, union node *n2); 121 static void parsefname(void); 122 static void parseheredoc(void); 123 static int peektoken(void); 124 static int readtoken(void); 125 static int xxreadtoken(void); 126 static int readtoken1(int, const char *, const char *, int); 127 static int noexpand(char *); 128 static void consumetoken(int); 129 static void synexpect(int) __dead2; 130 static void synerror(const char *) __dead2; 131 static void setprompt(int); 132 static int pgetc_linecont(void); 133 134 135 static void * 136 parser_temp_alloc(size_t len) 137 { 138 struct parser_temp *t; 139 140 INTOFF; 141 t = ckmalloc(sizeof(*t)); 142 t->data = NULL; 143 t->next = parser_temp; 144 parser_temp = t; 145 t->data = ckmalloc(len); 146 INTON; 147 return t->data; 148 } 149 150 151 static void * 152 parser_temp_realloc(void *ptr, size_t len) 153 { 154 struct parser_temp *t; 155 156 INTOFF; 157 t = parser_temp; 158 if (ptr != t->data) 159 error("bug: parser_temp_realloc misused"); 160 t->data = ckrealloc(t->data, len); 161 INTON; 162 return t->data; 163 } 164 165 166 static void 167 parser_temp_free_upto(void *ptr) 168 { 169 struct parser_temp *t; 170 int done = 0; 171 172 INTOFF; 173 while (parser_temp != NULL && !done) { 174 t = parser_temp; 175 parser_temp = t->next; 176 done = t->data == ptr; 177 ckfree(t->data); 178 ckfree(t); 179 } 180 INTON; 181 if (!done) 182 error("bug: parser_temp_free_upto misused"); 183 } 184 185 186 static void 187 parser_temp_free_all(void) 188 { 189 struct parser_temp *t; 190 191 INTOFF; 192 while (parser_temp != NULL) { 193 t = parser_temp; 194 parser_temp = t->next; 195 ckfree(t->data); 196 ckfree(t); 197 } 198 INTON; 199 } 200 201 202 /* 203 * Read and parse a command. Returns NEOF on end of file. (NULL is a 204 * valid parse tree indicating a blank line.) 205 */ 206 207 union node * 208 parsecmd(int interact) 209 { 210 int t; 211 212 /* This assumes the parser is not re-entered, 213 * which could happen if we add command substitution on PS1/PS2. 214 */ 215 parser_temp_free_all(); 216 heredoclist = NULL; 217 218 tokpushback = 0; 219 checkkwd = 0; 220 doprompt = interact; 221 if (doprompt) 222 setprompt(1); 223 else 224 setprompt(0); 225 needprompt = 0; 226 t = readtoken(); 227 if (t == TEOF) 228 return NEOF; 229 if (t == TNL) 230 return NULL; 231 tokpushback++; 232 return list(1); 233 } 234 235 236 /* 237 * Read and parse words for wordexp. 238 * Returns a list of NARG nodes; NULL if there are no words. 239 */ 240 union node * 241 parsewordexp(void) 242 { 243 union node *n, *first = NULL, **pnext; 244 int t; 245 246 /* This assumes the parser is not re-entered, 247 * which could happen if we add command substitution on PS1/PS2. 248 */ 249 parser_temp_free_all(); 250 heredoclist = NULL; 251 252 tokpushback = 0; 253 checkkwd = 0; 254 doprompt = 0; 255 setprompt(0); 256 needprompt = 0; 257 pnext = &first; 258 while ((t = readtoken()) != TEOF) { 259 if (t != TWORD) 260 synexpect(TWORD); 261 n = makename(); 262 *pnext = n; 263 pnext = &n->narg.next; 264 } 265 return first; 266 } 267 268 269 static union node * 270 list(int nlflag) 271 { 272 union node *ntop, *n1, *n2, *n3; 273 int tok; 274 275 checkkwd = CHKNL | CHKKWD | CHKALIAS; 276 if (!nlflag && tokendlist[peektoken()]) 277 return NULL; 278 ntop = n1 = NULL; 279 for (;;) { 280 n2 = andor(); 281 tok = readtoken(); 282 if (tok == TBACKGND) { 283 if (n2 != NULL && n2->type == NPIPE) { 284 n2->npipe.backgnd = 1; 285 } else if (n2 != NULL && n2->type == NREDIR) { 286 n2->type = NBACKGND; 287 } else { 288 n3 = (union node *)stalloc(sizeof (struct nredir)); 289 n3->type = NBACKGND; 290 n3->nredir.n = n2; 291 n3->nredir.redirect = NULL; 292 n2 = n3; 293 } 294 } 295 if (ntop == NULL) 296 ntop = n2; 297 else if (n1 == NULL) { 298 n1 = makebinary(NSEMI, ntop, n2); 299 ntop = n1; 300 } 301 else { 302 n3 = makebinary(NSEMI, n1->nbinary.ch2, n2); 303 n1->nbinary.ch2 = n3; 304 n1 = n3; 305 } 306 switch (tok) { 307 case TBACKGND: 308 case TSEMI: 309 tok = readtoken(); 310 /* FALLTHROUGH */ 311 case TNL: 312 if (tok == TNL) { 313 parseheredoc(); 314 if (nlflag) 315 return ntop; 316 } else if (tok == TEOF && nlflag) { 317 parseheredoc(); 318 return ntop; 319 } else { 320 tokpushback++; 321 } 322 checkkwd = CHKNL | CHKKWD | CHKALIAS; 323 if (!nlflag && tokendlist[peektoken()]) 324 return ntop; 325 break; 326 case TEOF: 327 if (heredoclist) 328 parseheredoc(); 329 else 330 pungetc(); /* push back EOF on input */ 331 return ntop; 332 default: 333 if (nlflag) 334 synexpect(-1); 335 tokpushback++; 336 return ntop; 337 } 338 } 339 } 340 341 342 343 static union node * 344 andor(void) 345 { 346 union node *n; 347 int t; 348 349 n = pipeline(); 350 for (;;) { 351 if ((t = readtoken()) == TAND) { 352 t = NAND; 353 } else if (t == TOR) { 354 t = NOR; 355 } else { 356 tokpushback++; 357 return n; 358 } 359 n = makebinary(t, n, pipeline()); 360 } 361 } 362 363 364 365 static union node * 366 pipeline(void) 367 { 368 union node *n1, *n2, *pipenode; 369 struct nodelist *lp, *prev; 370 int negate, t; 371 372 negate = 0; 373 checkkwd = CHKNL | CHKKWD | CHKALIAS; 374 TRACE(("pipeline: entered\n")); 375 while (readtoken() == TNOT) 376 negate = !negate; 377 tokpushback++; 378 n1 = command(); 379 if (readtoken() == TPIPE) { 380 pipenode = (union node *)stalloc(sizeof (struct npipe)); 381 pipenode->type = NPIPE; 382 pipenode->npipe.backgnd = 0; 383 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 384 pipenode->npipe.cmdlist = lp; 385 lp->n = n1; 386 do { 387 prev = lp; 388 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 389 checkkwd = CHKNL | CHKKWD | CHKALIAS; 390 t = readtoken(); 391 tokpushback++; 392 if (t == TNOT) 393 lp->n = pipeline(); 394 else 395 lp->n = command(); 396 prev->next = lp; 397 } while (readtoken() == TPIPE); 398 lp->next = NULL; 399 n1 = pipenode; 400 } 401 tokpushback++; 402 if (negate) { 403 n2 = (union node *)stalloc(sizeof (struct nnot)); 404 n2->type = NNOT; 405 n2->nnot.com = n1; 406 return n2; 407 } else 408 return n1; 409 } 410 411 412 413 static union node * 414 command(void) 415 { 416 union node *n1, *n2; 417 union node *ap, **app; 418 union node *cp, **cpp; 419 union node *redir, **rpp; 420 int t; 421 int is_subshell; 422 423 checkkwd = CHKNL | CHKKWD | CHKALIAS; 424 is_subshell = 0; 425 redir = NULL; 426 n1 = NULL; 427 rpp = &redir; 428 429 /* Check for redirection which may precede command */ 430 while (readtoken() == TREDIR) { 431 *rpp = n2 = redirnode; 432 rpp = &n2->nfile.next; 433 parsefname(); 434 } 435 tokpushback++; 436 437 switch (readtoken()) { 438 case TIF: 439 n1 = (union node *)stalloc(sizeof (struct nif)); 440 n1->type = NIF; 441 if ((n1->nif.test = list(0)) == NULL) 442 synexpect(-1); 443 consumetoken(TTHEN); 444 n1->nif.ifpart = list(0); 445 n2 = n1; 446 while (readtoken() == TELIF) { 447 n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif)); 448 n2 = n2->nif.elsepart; 449 n2->type = NIF; 450 if ((n2->nif.test = list(0)) == NULL) 451 synexpect(-1); 452 consumetoken(TTHEN); 453 n2->nif.ifpart = list(0); 454 } 455 if (lasttoken == TELSE) 456 n2->nif.elsepart = list(0); 457 else { 458 n2->nif.elsepart = NULL; 459 tokpushback++; 460 } 461 consumetoken(TFI); 462 checkkwd = CHKKWD | CHKALIAS; 463 break; 464 case TWHILE: 465 case TUNTIL: 466 t = lasttoken; 467 if ((n1 = list(0)) == NULL) 468 synexpect(-1); 469 consumetoken(TDO); 470 n1 = makebinary((t == TWHILE)? NWHILE : NUNTIL, n1, list(0)); 471 consumetoken(TDONE); 472 checkkwd = CHKKWD | CHKALIAS; 473 break; 474 case TFOR: 475 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext)) 476 synerror("Bad for loop variable"); 477 n1 = (union node *)stalloc(sizeof (struct nfor)); 478 n1->type = NFOR; 479 n1->nfor.var = wordtext; 480 while (readtoken() == TNL) 481 ; 482 if (lasttoken == TWORD && ! quoteflag && equal(wordtext, "in")) { 483 app = ≈ 484 while (readtoken() == TWORD) { 485 n2 = makename(); 486 *app = n2; 487 app = &n2->narg.next; 488 } 489 *app = NULL; 490 n1->nfor.args = ap; 491 if (lasttoken != TNL && lasttoken != TSEMI) 492 synexpect(-1); 493 } else { 494 static char argvars[5] = { 495 CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0' 496 }; 497 n2 = (union node *)stalloc(sizeof (struct narg)); 498 n2->type = NARG; 499 n2->narg.text = argvars; 500 n2->narg.backquote = NULL; 501 n2->narg.next = NULL; 502 n1->nfor.args = n2; 503 /* 504 * Newline or semicolon here is optional (but note 505 * that the original Bourne shell only allowed NL). 506 */ 507 if (lasttoken != TNL && lasttoken != TSEMI) 508 tokpushback++; 509 } 510 checkkwd = CHKNL | CHKKWD | CHKALIAS; 511 if ((t = readtoken()) == TDO) 512 t = TDONE; 513 else if (t == TBEGIN) 514 t = TEND; 515 else 516 synexpect(-1); 517 n1->nfor.body = list(0); 518 consumetoken(t); 519 checkkwd = CHKKWD | CHKALIAS; 520 break; 521 case TCASE: 522 n1 = (union node *)stalloc(sizeof (struct ncase)); 523 n1->type = NCASE; 524 consumetoken(TWORD); 525 n1->ncase.expr = makename(); 526 while (readtoken() == TNL); 527 if (lasttoken != TWORD || ! equal(wordtext, "in")) 528 synerror("expecting \"in\""); 529 cpp = &n1->ncase.cases; 530 checkkwd = CHKNL | CHKKWD, readtoken(); 531 while (lasttoken != TESAC) { 532 *cpp = cp = (union node *)stalloc(sizeof (struct nclist)); 533 cp->type = NCLIST; 534 app = &cp->nclist.pattern; 535 if (lasttoken == TLP) 536 readtoken(); 537 for (;;) { 538 *app = ap = makename(); 539 checkkwd = CHKNL | CHKKWD; 540 if (readtoken() != TPIPE) 541 break; 542 app = &ap->narg.next; 543 readtoken(); 544 } 545 ap->narg.next = NULL; 546 if (lasttoken != TRP) 547 synexpect(TRP); 548 cp->nclist.body = list(0); 549 550 checkkwd = CHKNL | CHKKWD | CHKALIAS; 551 if ((t = readtoken()) != TESAC) { 552 if (t == TENDCASE) 553 ; 554 else if (t == TFALLTHRU) 555 cp->type = NCLISTFALLTHRU; 556 else 557 synexpect(TENDCASE); 558 checkkwd = CHKNL | CHKKWD, readtoken(); 559 } 560 cpp = &cp->nclist.next; 561 } 562 *cpp = NULL; 563 checkkwd = CHKKWD | CHKALIAS; 564 break; 565 case TLP: 566 n1 = (union node *)stalloc(sizeof (struct nredir)); 567 n1->type = NSUBSHELL; 568 n1->nredir.n = list(0); 569 n1->nredir.redirect = NULL; 570 consumetoken(TRP); 571 checkkwd = CHKKWD | CHKALIAS; 572 is_subshell = 1; 573 break; 574 case TBEGIN: 575 n1 = list(0); 576 consumetoken(TEND); 577 checkkwd = CHKKWD | CHKALIAS; 578 break; 579 /* A simple command must have at least one redirection or word. */ 580 case TBACKGND: 581 case TSEMI: 582 case TAND: 583 case TOR: 584 case TPIPE: 585 case TENDCASE: 586 case TFALLTHRU: 587 case TEOF: 588 case TNL: 589 case TRP: 590 if (!redir) 591 synexpect(-1); 592 case TWORD: 593 tokpushback++; 594 n1 = simplecmd(rpp, redir); 595 return n1; 596 default: 597 synexpect(-1); 598 } 599 600 /* Now check for redirection which may follow command */ 601 while (readtoken() == TREDIR) { 602 *rpp = n2 = redirnode; 603 rpp = &n2->nfile.next; 604 parsefname(); 605 } 606 tokpushback++; 607 *rpp = NULL; 608 if (redir) { 609 if (!is_subshell) { 610 n2 = (union node *)stalloc(sizeof (struct nredir)); 611 n2->type = NREDIR; 612 n2->nredir.n = n1; 613 n1 = n2; 614 } 615 n1->nredir.redirect = redir; 616 } 617 618 return n1; 619 } 620 621 622 static union node * 623 simplecmd(union node **rpp, union node *redir) 624 { 625 union node *args, **app; 626 union node **orig_rpp = rpp; 627 union node *n = NULL; 628 int special; 629 int savecheckkwd; 630 631 /* If we don't have any redirections already, then we must reset */ 632 /* rpp to be the address of the local redir variable. */ 633 if (redir == NULL) 634 rpp = &redir; 635 636 args = NULL; 637 app = &args; 638 /* 639 * We save the incoming value, because we need this for shell 640 * functions. There can not be a redirect or an argument between 641 * the function name and the open parenthesis. 642 */ 643 orig_rpp = rpp; 644 645 savecheckkwd = CHKALIAS; 646 647 for (;;) { 648 checkkwd = savecheckkwd; 649 if (readtoken() == TWORD) { 650 n = makename(); 651 *app = n; 652 app = &n->narg.next; 653 if (savecheckkwd != 0 && !isassignment(wordtext)) 654 savecheckkwd = 0; 655 } else if (lasttoken == TREDIR) { 656 *rpp = n = redirnode; 657 rpp = &n->nfile.next; 658 parsefname(); /* read name of redirection file */ 659 } else if (lasttoken == TLP && app == &args->narg.next 660 && rpp == orig_rpp) { 661 /* We have a function */ 662 consumetoken(TRP); 663 funclinno = plinno; 664 /* 665 * - Require plain text. 666 * - Functions with '/' cannot be called. 667 * - Reject name=(). 668 * - Reject ksh extended glob patterns. 669 */ 670 if (!noexpand(n->narg.text) || quoteflag || 671 strchr(n->narg.text, '/') || 672 strchr("!%*+-=?@}~", 673 n->narg.text[strlen(n->narg.text) - 1])) 674 synerror("Bad function name"); 675 rmescapes(n->narg.text); 676 if (find_builtin(n->narg.text, &special) >= 0 && 677 special) 678 synerror("Cannot override a special builtin with a function"); 679 n->type = NDEFUN; 680 n->narg.next = command(); 681 funclinno = 0; 682 return n; 683 } else { 684 tokpushback++; 685 break; 686 } 687 } 688 *app = NULL; 689 *rpp = NULL; 690 n = (union node *)stalloc(sizeof (struct ncmd)); 691 n->type = NCMD; 692 n->ncmd.args = args; 693 n->ncmd.redirect = redir; 694 return n; 695 } 696 697 static union node * 698 makename(void) 699 { 700 union node *n; 701 702 n = (union node *)stalloc(sizeof (struct narg)); 703 n->type = NARG; 704 n->narg.next = NULL; 705 n->narg.text = wordtext; 706 n->narg.backquote = backquotelist; 707 return n; 708 } 709 710 static union node * 711 makebinary(int type, union node *n1, union node *n2) 712 { 713 union node *n; 714 715 n = (union node *)stalloc(sizeof (struct nbinary)); 716 n->type = type; 717 n->nbinary.ch1 = n1; 718 n->nbinary.ch2 = n2; 719 return (n); 720 } 721 722 void 723 forcealias(void) 724 { 725 checkkwd |= CHKALIAS; 726 } 727 728 void 729 fixredir(union node *n, const char *text, int err) 730 { 731 TRACE(("Fix redir %s %d\n", text, err)); 732 if (!err) 733 n->ndup.vname = NULL; 734 735 if (is_digit(text[0]) && text[1] == '\0') 736 n->ndup.dupfd = digit_val(text[0]); 737 else if (text[0] == '-' && text[1] == '\0') 738 n->ndup.dupfd = -1; 739 else { 740 741 if (err) 742 synerror("Bad fd number"); 743 else 744 n->ndup.vname = makename(); 745 } 746 } 747 748 749 static void 750 parsefname(void) 751 { 752 union node *n = redirnode; 753 754 consumetoken(TWORD); 755 if (n->type == NHERE) { 756 struct heredoc *here = heredoc; 757 struct heredoc *p; 758 759 if (quoteflag == 0) 760 n->type = NXHERE; 761 TRACE(("Here document %d\n", n->type)); 762 if (here->striptabs) { 763 while (*wordtext == '\t') 764 wordtext++; 765 } 766 if (! noexpand(wordtext)) 767 synerror("Illegal eof marker for << redirection"); 768 rmescapes(wordtext); 769 here->eofmark = wordtext; 770 here->next = NULL; 771 if (heredoclist == NULL) 772 heredoclist = here; 773 else { 774 for (p = heredoclist ; p->next ; p = p->next); 775 p->next = here; 776 } 777 } else if (n->type == NTOFD || n->type == NFROMFD) { 778 fixredir(n, wordtext, 0); 779 } else { 780 n->nfile.fname = makename(); 781 } 782 } 783 784 785 /* 786 * Input any here documents. 787 */ 788 789 static void 790 parseheredoc(void) 791 { 792 struct heredoc *here; 793 union node *n; 794 795 while (heredoclist) { 796 here = heredoclist; 797 heredoclist = here->next; 798 if (needprompt) { 799 setprompt(2); 800 needprompt = 0; 801 } 802 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, 803 here->eofmark, here->striptabs); 804 n = makename(); 805 here->here->nhere.doc = n; 806 } 807 } 808 809 static int 810 peektoken(void) 811 { 812 int t; 813 814 t = readtoken(); 815 tokpushback++; 816 return (t); 817 } 818 819 static int 820 readtoken(void) 821 { 822 int t; 823 struct alias *ap; 824 #ifdef DEBUG 825 int alreadyseen = tokpushback; 826 #endif 827 828 top: 829 t = xxreadtoken(); 830 831 /* 832 * eat newlines 833 */ 834 if (checkkwd & CHKNL) { 835 while (t == TNL) { 836 parseheredoc(); 837 t = xxreadtoken(); 838 } 839 } 840 841 /* 842 * check for keywords and aliases 843 */ 844 if (t == TWORD && !quoteflag) 845 { 846 const char * const *pp; 847 848 if (checkkwd & CHKKWD) 849 for (pp = parsekwd; *pp; pp++) { 850 if (**pp == *wordtext && equal(*pp, wordtext)) 851 { 852 lasttoken = t = pp - parsekwd + KWDOFFSET; 853 TRACE(("keyword %s recognized\n", tokname[t])); 854 goto out; 855 } 856 } 857 if (checkkwd & CHKALIAS && 858 (ap = lookupalias(wordtext, 1)) != NULL) { 859 pushstring(ap->val, strlen(ap->val), ap); 860 goto top; 861 } 862 } 863 out: 864 if (t != TNOT) 865 checkkwd = 0; 866 867 #ifdef DEBUG 868 if (!alreadyseen) 869 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 870 else 871 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 872 #endif 873 return (t); 874 } 875 876 877 /* 878 * Read the next input token. 879 * If the token is a word, we set backquotelist to the list of cmds in 880 * backquotes. We set quoteflag to true if any part of the word was 881 * quoted. 882 * If the token is TREDIR, then we set redirnode to a structure containing 883 * the redirection. 884 * In all cases, the variable startlinno is set to the number of the line 885 * on which the token starts. 886 * 887 * [Change comment: here documents and internal procedures] 888 * [Readtoken shouldn't have any arguments. Perhaps we should make the 889 * word parsing code into a separate routine. In this case, readtoken 890 * doesn't need to have any internal procedures, but parseword does. 891 * We could also make parseoperator in essence the main routine, and 892 * have parseword (readtoken1?) handle both words and redirection.] 893 */ 894 895 #define RETURN(token) return lasttoken = token 896 897 static int 898 xxreadtoken(void) 899 { 900 int c; 901 902 if (tokpushback) { 903 tokpushback = 0; 904 return lasttoken; 905 } 906 if (needprompt) { 907 setprompt(2); 908 needprompt = 0; 909 } 910 startlinno = plinno; 911 for (;;) { /* until token or start of word found */ 912 c = pgetc_macro(); 913 switch (c) { 914 case ' ': case '\t': 915 continue; 916 case '#': 917 while ((c = pgetc()) != '\n' && c != PEOF); 918 pungetc(); 919 continue; 920 case '\\': 921 if (pgetc() == '\n') { 922 startlinno = ++plinno; 923 if (doprompt) 924 setprompt(2); 925 else 926 setprompt(0); 927 continue; 928 } 929 pungetc(); 930 /* FALLTHROUGH */ 931 default: 932 return readtoken1(c, BASESYNTAX, (char *)NULL, 0); 933 case '\n': 934 plinno++; 935 needprompt = doprompt; 936 RETURN(TNL); 937 case PEOF: 938 RETURN(TEOF); 939 case '&': 940 if (pgetc_linecont() == '&') 941 RETURN(TAND); 942 pungetc(); 943 RETURN(TBACKGND); 944 case '|': 945 if (pgetc_linecont() == '|') 946 RETURN(TOR); 947 pungetc(); 948 RETURN(TPIPE); 949 case ';': 950 c = pgetc_linecont(); 951 if (c == ';') 952 RETURN(TENDCASE); 953 else if (c == '&') 954 RETURN(TFALLTHRU); 955 pungetc(); 956 RETURN(TSEMI); 957 case '(': 958 RETURN(TLP); 959 case ')': 960 RETURN(TRP); 961 } 962 } 963 #undef RETURN 964 } 965 966 967 #define MAXNEST_static 8 968 struct tokenstate 969 { 970 const char *syntax; /* *SYNTAX */ 971 int parenlevel; /* levels of parentheses in arithmetic */ 972 enum tokenstate_category 973 { 974 TSTATE_TOP, 975 TSTATE_VAR_OLD, /* ${var+-=?}, inherits dquotes */ 976 TSTATE_VAR_NEW, /* other ${var...}, own dquote state */ 977 TSTATE_ARITH 978 } category; 979 }; 980 981 982 /* 983 * Check to see whether we are at the end of the here document. When this 984 * is called, c is set to the first character of the next input line. If 985 * we are at the end of the here document, this routine sets the c to PEOF. 986 * The new value of c is returned. 987 */ 988 989 static int 990 checkend(int c, const char *eofmark, int striptabs) 991 { 992 if (striptabs) { 993 while (c == '\t') 994 c = pgetc(); 995 } 996 if (c == *eofmark) { 997 int c2; 998 const char *q; 999 1000 for (q = eofmark + 1; c2 = pgetc(), *q != '\0' && c2 == *q; q++) 1001 ; 1002 if ((c2 == PEOF || c2 == '\n') && *q == '\0') { 1003 c = PEOF; 1004 if (c2 == '\n') { 1005 plinno++; 1006 needprompt = doprompt; 1007 } 1008 } else { 1009 pungetc(); 1010 pushstring(eofmark + 1, q - (eofmark + 1), NULL); 1011 } 1012 } else if (c == '\n' && *eofmark == '\0') { 1013 c = PEOF; 1014 plinno++; 1015 needprompt = doprompt; 1016 } 1017 return (c); 1018 } 1019 1020 1021 /* 1022 * Parse a redirection operator. The variable "out" points to a string 1023 * specifying the fd to be redirected. The variable "c" contains the 1024 * first character of the redirection operator. 1025 */ 1026 1027 static void 1028 parseredir(char *out, int c) 1029 { 1030 char fd = *out; 1031 union node *np; 1032 1033 np = (union node *)stalloc(sizeof (struct nfile)); 1034 if (c == '>') { 1035 np->nfile.fd = 1; 1036 c = pgetc_linecont(); 1037 if (c == '>') 1038 np->type = NAPPEND; 1039 else if (c == '&') 1040 np->type = NTOFD; 1041 else if (c == '|') 1042 np->type = NCLOBBER; 1043 else { 1044 np->type = NTO; 1045 pungetc(); 1046 } 1047 } else { /* c == '<' */ 1048 np->nfile.fd = 0; 1049 c = pgetc_linecont(); 1050 if (c == '<') { 1051 if (sizeof (struct nfile) != sizeof (struct nhere)) { 1052 np = (union node *)stalloc(sizeof (struct nhere)); 1053 np->nfile.fd = 0; 1054 } 1055 np->type = NHERE; 1056 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); 1057 heredoc->here = np; 1058 if ((c = pgetc_linecont()) == '-') { 1059 heredoc->striptabs = 1; 1060 } else { 1061 heredoc->striptabs = 0; 1062 pungetc(); 1063 } 1064 } else if (c == '&') 1065 np->type = NFROMFD; 1066 else if (c == '>') 1067 np->type = NFROMTO; 1068 else { 1069 np->type = NFROM; 1070 pungetc(); 1071 } 1072 } 1073 if (fd != '\0') 1074 np->nfile.fd = digit_val(fd); 1075 redirnode = np; 1076 } 1077 1078 /* 1079 * Called to parse command substitutions. 1080 */ 1081 1082 static char * 1083 parsebackq(char *out, struct nodelist **pbqlist, 1084 int oldstyle, int dblquote, int quoted) 1085 { 1086 struct nodelist **nlpp; 1087 union node *n; 1088 char *volatile str; 1089 struct jmploc jmploc; 1090 struct jmploc *const savehandler = handler; 1091 size_t savelen; 1092 int saveprompt; 1093 const int bq_startlinno = plinno; 1094 char *volatile ostr = NULL; 1095 struct parsefile *const savetopfile = getcurrentfile(); 1096 struct heredoc *const saveheredoclist = heredoclist; 1097 struct heredoc *here; 1098 1099 str = NULL; 1100 if (setjmp(jmploc.loc)) { 1101 popfilesupto(savetopfile); 1102 if (str) 1103 ckfree(str); 1104 if (ostr) 1105 ckfree(ostr); 1106 heredoclist = saveheredoclist; 1107 handler = savehandler; 1108 if (exception == EXERROR) { 1109 startlinno = bq_startlinno; 1110 synerror("Error in command substitution"); 1111 } 1112 longjmp(handler->loc, 1); 1113 } 1114 INTOFF; 1115 savelen = out - stackblock(); 1116 if (savelen > 0) { 1117 str = ckmalloc(savelen); 1118 memcpy(str, stackblock(), savelen); 1119 } 1120 handler = &jmploc; 1121 heredoclist = NULL; 1122 INTON; 1123 if (oldstyle) { 1124 /* We must read until the closing backquote, giving special 1125 treatment to some slashes, and then push the string and 1126 reread it as input, interpreting it normally. */ 1127 char *oout; 1128 int c; 1129 int olen; 1130 1131 1132 STARTSTACKSTR(oout); 1133 for (;;) { 1134 if (needprompt) { 1135 setprompt(2); 1136 needprompt = 0; 1137 } 1138 CHECKSTRSPACE(2, oout); 1139 c = pgetc_linecont(); 1140 if (c == '`') 1141 break; 1142 switch (c) { 1143 case '\\': 1144 c = pgetc(); 1145 if (c != '\\' && c != '`' && c != '$' 1146 && (!dblquote || c != '"')) 1147 USTPUTC('\\', oout); 1148 break; 1149 1150 case '\n': 1151 plinno++; 1152 needprompt = doprompt; 1153 break; 1154 1155 case PEOF: 1156 startlinno = plinno; 1157 synerror("EOF in backquote substitution"); 1158 break; 1159 1160 default: 1161 break; 1162 } 1163 USTPUTC(c, oout); 1164 } 1165 USTPUTC('\0', oout); 1166 olen = oout - stackblock(); 1167 INTOFF; 1168 ostr = ckmalloc(olen); 1169 memcpy(ostr, stackblock(), olen); 1170 setinputstring(ostr, 1); 1171 INTON; 1172 } 1173 nlpp = pbqlist; 1174 while (*nlpp) 1175 nlpp = &(*nlpp)->next; 1176 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 1177 (*nlpp)->next = NULL; 1178 1179 if (oldstyle) { 1180 saveprompt = doprompt; 1181 doprompt = 0; 1182 } 1183 1184 n = list(0); 1185 1186 if (oldstyle) { 1187 if (peektoken() != TEOF) 1188 synexpect(-1); 1189 doprompt = saveprompt; 1190 } else 1191 consumetoken(TRP); 1192 1193 (*nlpp)->n = n; 1194 if (oldstyle) { 1195 /* 1196 * Start reading from old file again, ignoring any pushed back 1197 * tokens left from the backquote parsing 1198 */ 1199 popfile(); 1200 tokpushback = 0; 1201 } 1202 STARTSTACKSTR(out); 1203 CHECKSTRSPACE(savelen + 1, out); 1204 INTOFF; 1205 if (str) { 1206 memcpy(out, str, savelen); 1207 STADJUST(savelen, out); 1208 ckfree(str); 1209 str = NULL; 1210 } 1211 if (ostr) { 1212 ckfree(ostr); 1213 ostr = NULL; 1214 } 1215 here = saveheredoclist; 1216 if (here != NULL) { 1217 while (here->next != NULL) 1218 here = here->next; 1219 here->next = heredoclist; 1220 heredoclist = saveheredoclist; 1221 } 1222 handler = savehandler; 1223 INTON; 1224 if (quoted) 1225 USTPUTC(CTLBACKQ | CTLQUOTE, out); 1226 else 1227 USTPUTC(CTLBACKQ, out); 1228 return out; 1229 } 1230 1231 1232 /* 1233 * Called to parse a backslash escape sequence inside $'...'. 1234 * The backslash has already been read. 1235 */ 1236 static char * 1237 readcstyleesc(char *out) 1238 { 1239 int c, vc, i, n; 1240 unsigned int v; 1241 1242 c = pgetc(); 1243 switch (c) { 1244 case '\0': 1245 synerror("Unterminated quoted string"); 1246 case '\n': 1247 plinno++; 1248 if (doprompt) 1249 setprompt(2); 1250 else 1251 setprompt(0); 1252 return out; 1253 case '\\': 1254 case '\'': 1255 case '"': 1256 v = c; 1257 break; 1258 case 'a': v = '\a'; break; 1259 case 'b': v = '\b'; break; 1260 case 'e': v = '\033'; break; 1261 case 'f': v = '\f'; break; 1262 case 'n': v = '\n'; break; 1263 case 'r': v = '\r'; break; 1264 case 't': v = '\t'; break; 1265 case 'v': v = '\v'; break; 1266 case 'x': 1267 v = 0; 1268 for (;;) { 1269 c = pgetc(); 1270 if (c >= '0' && c <= '9') 1271 v = (v << 4) + c - '0'; 1272 else if (c >= 'A' && c <= 'F') 1273 v = (v << 4) + c - 'A' + 10; 1274 else if (c >= 'a' && c <= 'f') 1275 v = (v << 4) + c - 'a' + 10; 1276 else 1277 break; 1278 } 1279 pungetc(); 1280 break; 1281 case '0': case '1': case '2': case '3': 1282 case '4': case '5': case '6': case '7': 1283 v = c - '0'; 1284 c = pgetc(); 1285 if (c >= '0' && c <= '7') { 1286 v <<= 3; 1287 v += c - '0'; 1288 c = pgetc(); 1289 if (c >= '0' && c <= '7') { 1290 v <<= 3; 1291 v += c - '0'; 1292 } else 1293 pungetc(); 1294 } else 1295 pungetc(); 1296 break; 1297 case 'c': 1298 c = pgetc(); 1299 if (c < 0x3f || c > 0x7a || c == 0x60) 1300 synerror("Bad escape sequence"); 1301 if (c == '\\' && pgetc() != '\\') 1302 synerror("Bad escape sequence"); 1303 if (c == '?') 1304 v = 127; 1305 else 1306 v = c & 0x1f; 1307 break; 1308 case 'u': 1309 case 'U': 1310 n = c == 'U' ? 8 : 4; 1311 v = 0; 1312 for (i = 0; i < n; i++) { 1313 c = pgetc(); 1314 if (c >= '0' && c <= '9') 1315 v = (v << 4) + c - '0'; 1316 else if (c >= 'A' && c <= 'F') 1317 v = (v << 4) + c - 'A' + 10; 1318 else if (c >= 'a' && c <= 'f') 1319 v = (v << 4) + c - 'a' + 10; 1320 else 1321 synerror("Bad escape sequence"); 1322 } 1323 if (v == 0 || (v >= 0xd800 && v <= 0xdfff)) 1324 synerror("Bad escape sequence"); 1325 /* We really need iconv here. */ 1326 if (initial_localeisutf8 && v > 127) { 1327 CHECKSTRSPACE(4, out); 1328 /* 1329 * We cannot use wctomb() as the locale may have 1330 * changed. 1331 */ 1332 if (v <= 0x7ff) { 1333 USTPUTC(0xc0 | v >> 6, out); 1334 USTPUTC(0x80 | (v & 0x3f), out); 1335 return out; 1336 } else if (v <= 0xffff) { 1337 USTPUTC(0xe0 | v >> 12, out); 1338 USTPUTC(0x80 | ((v >> 6) & 0x3f), out); 1339 USTPUTC(0x80 | (v & 0x3f), out); 1340 return out; 1341 } else if (v <= 0x10ffff) { 1342 USTPUTC(0xf0 | v >> 18, out); 1343 USTPUTC(0x80 | ((v >> 12) & 0x3f), out); 1344 USTPUTC(0x80 | ((v >> 6) & 0x3f), out); 1345 USTPUTC(0x80 | (v & 0x3f), out); 1346 return out; 1347 } 1348 } 1349 if (v > 127) 1350 v = '?'; 1351 break; 1352 default: 1353 synerror("Bad escape sequence"); 1354 } 1355 vc = (char)v; 1356 /* 1357 * We can't handle NUL bytes. 1358 * POSIX says we should skip till the closing quote. 1359 */ 1360 if (vc == '\0') { 1361 while ((c = pgetc()) != '\'') { 1362 if (c == '\\') 1363 c = pgetc(); 1364 if (c == PEOF) 1365 synerror("Unterminated quoted string"); 1366 if (c == '\n') { 1367 plinno++; 1368 if (doprompt) 1369 setprompt(2); 1370 else 1371 setprompt(0); 1372 } 1373 } 1374 pungetc(); 1375 return out; 1376 } 1377 if (SQSYNTAX[vc] == CCTL) 1378 USTPUTC(CTLESC, out); 1379 USTPUTC(vc, out); 1380 return out; 1381 } 1382 1383 1384 /* 1385 * If eofmark is NULL, read a word or a redirection symbol. If eofmark 1386 * is not NULL, read a here document. In the latter case, eofmark is the 1387 * word which marks the end of the document and striptabs is true if 1388 * leading tabs should be stripped from the document. The argument firstc 1389 * is the first character of the input token or document. 1390 * 1391 * Because C does not have internal subroutines, I have simulated them 1392 * using goto's to implement the subroutine linkage. The following macros 1393 * will run code that appears at the end of readtoken1. 1394 */ 1395 1396 #define PARSESUB() {goto parsesub; parsesub_return:;} 1397 #define PARSEARITH() {goto parsearith; parsearith_return:;} 1398 1399 static int 1400 readtoken1(int firstc, char const *initialsyntax, const char *eofmark, 1401 int striptabs) 1402 { 1403 int c = firstc; 1404 char *out; 1405 int len; 1406 struct nodelist *bqlist; 1407 int quotef; 1408 int newvarnest; 1409 int level; 1410 int synentry; 1411 struct tokenstate state_static[MAXNEST_static]; 1412 int maxnest = MAXNEST_static; 1413 struct tokenstate *state = state_static; 1414 int sqiscstyle = 0; 1415 1416 startlinno = plinno; 1417 quotef = 0; 1418 bqlist = NULL; 1419 newvarnest = 0; 1420 level = 0; 1421 state[level].syntax = initialsyntax; 1422 state[level].parenlevel = 0; 1423 state[level].category = TSTATE_TOP; 1424 1425 STARTSTACKSTR(out); 1426 loop: { /* for each line, until end of word */ 1427 if (eofmark && eofmark != NOEOFMARK) 1428 /* set c to PEOF if at end of here document */ 1429 c = checkend(c, eofmark, striptabs); 1430 for (;;) { /* until end of line or end of word */ 1431 CHECKSTRSPACE(4, out); /* permit 4 calls to USTPUTC */ 1432 1433 synentry = state[level].syntax[c]; 1434 1435 switch(synentry) { 1436 case CNL: /* '\n' */ 1437 if (state[level].syntax == BASESYNTAX) 1438 goto endword; /* exit outer loop */ 1439 USTPUTC(c, out); 1440 plinno++; 1441 if (doprompt) 1442 setprompt(2); 1443 else 1444 setprompt(0); 1445 c = pgetc(); 1446 goto loop; /* continue outer loop */ 1447 case CSBACK: 1448 if (sqiscstyle) { 1449 out = readcstyleesc(out); 1450 break; 1451 } 1452 /* FALLTHROUGH */ 1453 case CWORD: 1454 USTPUTC(c, out); 1455 break; 1456 case CCTL: 1457 if (eofmark == NULL || initialsyntax != SQSYNTAX) 1458 USTPUTC(CTLESC, out); 1459 USTPUTC(c, out); 1460 break; 1461 case CBACK: /* backslash */ 1462 c = pgetc(); 1463 if (c == PEOF) { 1464 USTPUTC('\\', out); 1465 pungetc(); 1466 } else if (c == '\n') { 1467 plinno++; 1468 if (doprompt) 1469 setprompt(2); 1470 else 1471 setprompt(0); 1472 } else { 1473 if (state[level].syntax == DQSYNTAX && 1474 c != '\\' && c != '`' && c != '$' && 1475 (c != '"' || (eofmark != NULL && 1476 newvarnest == 0)) && 1477 (c != '}' || state[level].category != TSTATE_VAR_OLD)) 1478 USTPUTC('\\', out); 1479 if ((eofmark == NULL || 1480 newvarnest > 0) && 1481 state[level].syntax == BASESYNTAX) 1482 USTPUTC(CTLQUOTEMARK, out); 1483 if (SQSYNTAX[c] == CCTL) 1484 USTPUTC(CTLESC, out); 1485 USTPUTC(c, out); 1486 if ((eofmark == NULL || 1487 newvarnest > 0) && 1488 state[level].syntax == BASESYNTAX && 1489 state[level].category == TSTATE_VAR_OLD) 1490 USTPUTC(CTLQUOTEEND, out); 1491 quotef++; 1492 } 1493 break; 1494 case CSQUOTE: 1495 USTPUTC(CTLQUOTEMARK, out); 1496 state[level].syntax = SQSYNTAX; 1497 sqiscstyle = 0; 1498 break; 1499 case CDQUOTE: 1500 USTPUTC(CTLQUOTEMARK, out); 1501 state[level].syntax = DQSYNTAX; 1502 break; 1503 case CENDQUOTE: 1504 if (eofmark != NULL && newvarnest == 0) 1505 USTPUTC(c, out); 1506 else { 1507 if (state[level].category == TSTATE_VAR_OLD) 1508 USTPUTC(CTLQUOTEEND, out); 1509 state[level].syntax = BASESYNTAX; 1510 quotef++; 1511 } 1512 break; 1513 case CVAR: /* '$' */ 1514 PARSESUB(); /* parse substitution */ 1515 break; 1516 case CENDVAR: /* '}' */ 1517 if (level > 0 && 1518 ((state[level].category == TSTATE_VAR_OLD && 1519 state[level].syntax == 1520 state[level - 1].syntax) || 1521 (state[level].category == TSTATE_VAR_NEW && 1522 state[level].syntax == BASESYNTAX))) { 1523 if (state[level].category == TSTATE_VAR_NEW) 1524 newvarnest--; 1525 level--; 1526 USTPUTC(CTLENDVAR, out); 1527 } else { 1528 USTPUTC(c, out); 1529 } 1530 break; 1531 case CLP: /* '(' in arithmetic */ 1532 state[level].parenlevel++; 1533 USTPUTC(c, out); 1534 break; 1535 case CRP: /* ')' in arithmetic */ 1536 if (state[level].parenlevel > 0) { 1537 USTPUTC(c, out); 1538 --state[level].parenlevel; 1539 } else { 1540 if (pgetc_linecont() == ')') { 1541 if (level > 0 && 1542 state[level].category == TSTATE_ARITH) { 1543 level--; 1544 USTPUTC(CTLENDARI, out); 1545 } else 1546 USTPUTC(')', out); 1547 } else { 1548 /* 1549 * unbalanced parens 1550 * (don't 2nd guess - no error) 1551 */ 1552 pungetc(); 1553 USTPUTC(')', out); 1554 } 1555 } 1556 break; 1557 case CBQUOTE: /* '`' */ 1558 out = parsebackq(out, &bqlist, 1, 1559 state[level].syntax == DQSYNTAX && 1560 (eofmark == NULL || newvarnest > 0), 1561 state[level].syntax == DQSYNTAX || state[level].syntax == ARISYNTAX); 1562 break; 1563 case CEOF: 1564 goto endword; /* exit outer loop */ 1565 case CIGN: 1566 break; 1567 default: 1568 if (level == 0) 1569 goto endword; /* exit outer loop */ 1570 USTPUTC(c, out); 1571 } 1572 c = pgetc_macro(); 1573 } 1574 } 1575 endword: 1576 if (state[level].syntax == ARISYNTAX) 1577 synerror("Missing '))'"); 1578 if (state[level].syntax != BASESYNTAX && eofmark == NULL) 1579 synerror("Unterminated quoted string"); 1580 if (state[level].category == TSTATE_VAR_OLD || 1581 state[level].category == TSTATE_VAR_NEW) { 1582 startlinno = plinno; 1583 synerror("Missing '}'"); 1584 } 1585 if (state != state_static) 1586 parser_temp_free_upto(state); 1587 USTPUTC('\0', out); 1588 len = out - stackblock(); 1589 out = stackblock(); 1590 if (eofmark == NULL) { 1591 if ((c == '>' || c == '<') 1592 && quotef == 0 1593 && len <= 2 1594 && (*out == '\0' || is_digit(*out))) { 1595 parseredir(out, c); 1596 return lasttoken = TREDIR; 1597 } else { 1598 pungetc(); 1599 } 1600 } 1601 quoteflag = quotef; 1602 backquotelist = bqlist; 1603 grabstackblock(len); 1604 wordtext = out; 1605 return lasttoken = TWORD; 1606 /* end of readtoken routine */ 1607 1608 1609 /* 1610 * Parse a substitution. At this point, we have read the dollar sign 1611 * and nothing else. 1612 */ 1613 1614 parsesub: { 1615 int subtype; 1616 int typeloc; 1617 int flags; 1618 char *p; 1619 static const char types[] = "}-+?="; 1620 int linno; 1621 int length; 1622 int c1; 1623 1624 c = pgetc_linecont(); 1625 if (c == '(') { /* $(command) or $((arith)) */ 1626 if (pgetc_linecont() == '(') { 1627 PARSEARITH(); 1628 } else { 1629 pungetc(); 1630 out = parsebackq(out, &bqlist, 0, 1631 state[level].syntax == DQSYNTAX && 1632 (eofmark == NULL || newvarnest > 0), 1633 state[level].syntax == DQSYNTAX || 1634 state[level].syntax == ARISYNTAX); 1635 } 1636 } else if (c == '{' || is_name(c) || is_special(c)) { 1637 USTPUTC(CTLVAR, out); 1638 typeloc = out - stackblock(); 1639 USTPUTC(VSNORMAL, out); 1640 subtype = VSNORMAL; 1641 flags = 0; 1642 if (c == '{') { 1643 c = pgetc_linecont(); 1644 subtype = 0; 1645 } 1646 varname: 1647 if (!is_eof(c) && is_name(c)) { 1648 length = 0; 1649 do { 1650 STPUTC(c, out); 1651 c = pgetc_linecont(); 1652 length++; 1653 } while (!is_eof(c) && is_in_name(c)); 1654 if (length == 6 && 1655 strncmp(out - length, "LINENO", length) == 0) { 1656 /* Replace the variable name with the 1657 * current line number. */ 1658 STADJUST(-6, out); 1659 CHECKSTRSPACE(11, out); 1660 linno = plinno; 1661 if (funclinno != 0) 1662 linno -= funclinno - 1; 1663 length = snprintf(out, 11, "%d", linno); 1664 if (length > 10) 1665 length = 10; 1666 out += length; 1667 flags |= VSLINENO; 1668 } 1669 } else if (is_digit(c)) { 1670 if (subtype != VSNORMAL) { 1671 do { 1672 STPUTC(c, out); 1673 c = pgetc_linecont(); 1674 } while (is_digit(c)); 1675 } else { 1676 USTPUTC(c, out); 1677 c = pgetc_linecont(); 1678 } 1679 } else if (is_special(c)) { 1680 c1 = c; 1681 c = pgetc_linecont(); 1682 if (subtype == 0 && c1 == '#') { 1683 subtype = VSLENGTH; 1684 if (strchr(types, c) == NULL && c != ':' && 1685 c != '#' && c != '%') 1686 goto varname; 1687 c1 = c; 1688 c = pgetc_linecont(); 1689 if (c1 != '}' && c == '}') { 1690 pungetc(); 1691 c = c1; 1692 goto varname; 1693 } 1694 pungetc(); 1695 c = c1; 1696 c1 = '#'; 1697 subtype = 0; 1698 } 1699 USTPUTC(c1, out); 1700 } else { 1701 subtype = VSERROR; 1702 if (c == '}') 1703 pungetc(); 1704 else if (c == '\n' || c == PEOF) 1705 synerror("Unexpected end of line in substitution"); 1706 else if (BASESYNTAX[c] != CCTL) 1707 USTPUTC(c, out); 1708 } 1709 if (subtype == 0) { 1710 switch (c) { 1711 case ':': 1712 flags |= VSNUL; 1713 c = pgetc_linecont(); 1714 /*FALLTHROUGH*/ 1715 default: 1716 p = strchr(types, c); 1717 if (p == NULL) { 1718 if (c == '\n' || c == PEOF) 1719 synerror("Unexpected end of line in substitution"); 1720 if (flags == VSNUL) 1721 STPUTC(':', out); 1722 if (BASESYNTAX[c] != CCTL) 1723 STPUTC(c, out); 1724 subtype = VSERROR; 1725 } else 1726 subtype = p - types + VSNORMAL; 1727 break; 1728 case '%': 1729 case '#': 1730 { 1731 int cc = c; 1732 subtype = c == '#' ? VSTRIMLEFT : 1733 VSTRIMRIGHT; 1734 c = pgetc_linecont(); 1735 if (c == cc) 1736 subtype++; 1737 else 1738 pungetc(); 1739 break; 1740 } 1741 } 1742 } else if (subtype != VSERROR) { 1743 if (subtype == VSLENGTH && c != '}') 1744 subtype = VSERROR; 1745 pungetc(); 1746 } 1747 STPUTC('=', out); 1748 if (state[level].syntax == DQSYNTAX || 1749 state[level].syntax == ARISYNTAX) 1750 flags |= VSQUOTE; 1751 *(stackblock() + typeloc) = subtype | flags; 1752 if (subtype != VSNORMAL) { 1753 if (level + 1 >= maxnest) { 1754 maxnest *= 2; 1755 if (state == state_static) { 1756 state = parser_temp_alloc( 1757 maxnest * sizeof(*state)); 1758 memcpy(state, state_static, 1759 MAXNEST_static * sizeof(*state)); 1760 } else 1761 state = parser_temp_realloc(state, 1762 maxnest * sizeof(*state)); 1763 } 1764 level++; 1765 state[level].parenlevel = 0; 1766 if (subtype == VSMINUS || subtype == VSPLUS || 1767 subtype == VSQUESTION || subtype == VSASSIGN) { 1768 /* 1769 * For operators that were in the Bourne shell, 1770 * inherit the double-quote state. 1771 */ 1772 state[level].syntax = state[level - 1].syntax; 1773 state[level].category = TSTATE_VAR_OLD; 1774 } else { 1775 /* 1776 * The other operators take a pattern, 1777 * so go to BASESYNTAX. 1778 * Also, ' and " are now special, even 1779 * in here documents. 1780 */ 1781 state[level].syntax = BASESYNTAX; 1782 state[level].category = TSTATE_VAR_NEW; 1783 newvarnest++; 1784 } 1785 } 1786 } else if (c == '\'' && state[level].syntax == BASESYNTAX) { 1787 /* $'cstylequotes' */ 1788 USTPUTC(CTLQUOTEMARK, out); 1789 state[level].syntax = SQSYNTAX; 1790 sqiscstyle = 1; 1791 } else { 1792 USTPUTC('$', out); 1793 pungetc(); 1794 } 1795 goto parsesub_return; 1796 } 1797 1798 1799 /* 1800 * Parse an arithmetic expansion (indicate start of one and set state) 1801 */ 1802 parsearith: { 1803 1804 if (level + 1 >= maxnest) { 1805 maxnest *= 2; 1806 if (state == state_static) { 1807 state = parser_temp_alloc( 1808 maxnest * sizeof(*state)); 1809 memcpy(state, state_static, 1810 MAXNEST_static * sizeof(*state)); 1811 } else 1812 state = parser_temp_realloc(state, 1813 maxnest * sizeof(*state)); 1814 } 1815 level++; 1816 state[level].syntax = ARISYNTAX; 1817 state[level].parenlevel = 0; 1818 state[level].category = TSTATE_ARITH; 1819 USTPUTC(CTLARI, out); 1820 if (state[level - 1].syntax == DQSYNTAX) 1821 USTPUTC('"',out); 1822 else 1823 USTPUTC(' ',out); 1824 goto parsearith_return; 1825 } 1826 1827 } /* end of readtoken */ 1828 1829 1830 /* 1831 * Returns true if the text contains nothing to expand (no dollar signs 1832 * or backquotes). 1833 */ 1834 1835 static int 1836 noexpand(char *text) 1837 { 1838 char *p; 1839 char c; 1840 1841 p = text; 1842 while ((c = *p++) != '\0') { 1843 if ( c == CTLQUOTEMARK) 1844 continue; 1845 if (c == CTLESC) 1846 p++; 1847 else if (BASESYNTAX[(int)c] == CCTL) 1848 return 0; 1849 } 1850 return 1; 1851 } 1852 1853 1854 /* 1855 * Return true if the argument is a legal variable name (a letter or 1856 * underscore followed by zero or more letters, underscores, and digits). 1857 */ 1858 1859 int 1860 goodname(const char *name) 1861 { 1862 const char *p; 1863 1864 p = name; 1865 if (! is_name(*p)) 1866 return 0; 1867 while (*++p) { 1868 if (! is_in_name(*p)) 1869 return 0; 1870 } 1871 return 1; 1872 } 1873 1874 1875 int 1876 isassignment(const char *p) 1877 { 1878 if (!is_name(*p)) 1879 return 0; 1880 p++; 1881 for (;;) { 1882 if (*p == '=') 1883 return 1; 1884 else if (!is_in_name(*p)) 1885 return 0; 1886 p++; 1887 } 1888 } 1889 1890 1891 static void 1892 consumetoken(int token) 1893 { 1894 if (readtoken() != token) 1895 synexpect(token); 1896 } 1897 1898 1899 /* 1900 * Called when an unexpected token is read during the parse. The argument 1901 * is the token that is expected, or -1 if more than one type of token can 1902 * occur at this point. 1903 */ 1904 1905 static void 1906 synexpect(int token) 1907 { 1908 char msg[64]; 1909 1910 if (token >= 0) { 1911 fmtstr(msg, 64, "%s unexpected (expecting %s)", 1912 tokname[lasttoken], tokname[token]); 1913 } else { 1914 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]); 1915 } 1916 synerror(msg); 1917 } 1918 1919 1920 static void 1921 synerror(const char *msg) 1922 { 1923 if (commandname) 1924 outfmt(out2, "%s: %d: ", commandname, startlinno); 1925 else if (arg0) 1926 outfmt(out2, "%s: ", arg0); 1927 outfmt(out2, "Syntax error: %s\n", msg); 1928 error((char *)NULL); 1929 } 1930 1931 static void 1932 setprompt(int which) 1933 { 1934 whichprompt = which; 1935 if (which == 0) 1936 return; 1937 1938 #ifndef NO_HISTORY 1939 if (!el) 1940 #endif 1941 { 1942 out2str(getprompt(NULL)); 1943 flushout(out2); 1944 } 1945 } 1946 1947 static int 1948 pgetc_linecont(void) 1949 { 1950 int c; 1951 1952 while ((c = pgetc_macro()) == '\\') { 1953 c = pgetc(); 1954 if (c == '\n') { 1955 plinno++; 1956 if (doprompt) 1957 setprompt(2); 1958 else 1959 setprompt(0); 1960 } else { 1961 pungetc(); 1962 /* Allow the backslash to be pushed back. */ 1963 pushstring("\\", 1, NULL); 1964 return (pgetc()); 1965 } 1966 } 1967 return (c); 1968 } 1969 1970 /* 1971 * called by editline -- any expansions to the prompt 1972 * should be added here. 1973 */ 1974 char * 1975 getprompt(void *unused __unused) 1976 { 1977 static char ps[PROMPTLEN]; 1978 const char *fmt; 1979 const char *pwd; 1980 int i, trim; 1981 static char internal_error[] = "??"; 1982 1983 /* 1984 * Select prompt format. 1985 */ 1986 switch (whichprompt) { 1987 case 0: 1988 fmt = ""; 1989 break; 1990 case 1: 1991 fmt = ps1val(); 1992 break; 1993 case 2: 1994 fmt = ps2val(); 1995 break; 1996 default: 1997 return internal_error; 1998 } 1999 2000 /* 2001 * Format prompt string. 2002 */ 2003 for (i = 0; (i < PROMPTLEN - 1) && (*fmt != '\0'); i++, fmt++) 2004 if (*fmt == '\\') 2005 switch (*++fmt) { 2006 2007 /* 2008 * Hostname. 2009 * 2010 * \h specifies just the local hostname, 2011 * \H specifies fully-qualified hostname. 2012 */ 2013 case 'h': 2014 case 'H': 2015 ps[i] = '\0'; 2016 gethostname(&ps[i], PROMPTLEN - i - 1); 2017 ps[PROMPTLEN - 1] = '\0'; 2018 /* Skip to end of hostname. */ 2019 trim = (*fmt == 'h') ? '.' : '\0'; 2020 while ((ps[i] != '\0') && (ps[i] != trim)) 2021 i++; 2022 --i; 2023 break; 2024 2025 /* 2026 * Working directory. 2027 * 2028 * \W specifies just the final component, 2029 * \w specifies the entire path. 2030 */ 2031 case 'W': 2032 case 'w': 2033 pwd = lookupvar("PWD"); 2034 if (pwd == NULL || *pwd == '\0') 2035 pwd = "?"; 2036 if (*fmt == 'W' && 2037 *pwd == '/' && pwd[1] != '\0') 2038 strlcpy(&ps[i], strrchr(pwd, '/') + 1, 2039 PROMPTLEN - i); 2040 else 2041 strlcpy(&ps[i], pwd, PROMPTLEN - i); 2042 /* Skip to end of path. */ 2043 while (ps[i + 1] != '\0') 2044 i++; 2045 break; 2046 2047 /* 2048 * Superuser status. 2049 * 2050 * '$' for normal users, '#' for root. 2051 */ 2052 case '$': 2053 ps[i] = (geteuid() != 0) ? '$' : '#'; 2054 break; 2055 2056 /* 2057 * A literal \. 2058 */ 2059 case '\\': 2060 ps[i] = '\\'; 2061 break; 2062 2063 /* 2064 * Emit unrecognized formats verbatim. 2065 */ 2066 default: 2067 ps[i] = '\\'; 2068 if (i < PROMPTLEN - 2) 2069 ps[++i] = *fmt; 2070 break; 2071 } 2072 else 2073 ps[i] = *fmt; 2074 ps[i] = '\0'; 2075 return (ps); 2076 } 2077 2078 2079 const char * 2080 expandstr(const char *ps) 2081 { 2082 union node n; 2083 struct jmploc jmploc; 2084 struct jmploc *const savehandler = handler; 2085 const int saveprompt = doprompt; 2086 struct parsefile *const savetopfile = getcurrentfile(); 2087 struct parser_temp *const saveparser_temp = parser_temp; 2088 const char *result = NULL; 2089 2090 if (!setjmp(jmploc.loc)) { 2091 handler = &jmploc; 2092 parser_temp = NULL; 2093 setinputstring(ps, 1); 2094 doprompt = 0; 2095 readtoken1(pgetc(), DQSYNTAX, NOEOFMARK, 0); 2096 if (backquotelist != NULL) 2097 error("Command substitution not allowed here"); 2098 2099 n.narg.type = NARG; 2100 n.narg.next = NULL; 2101 n.narg.text = wordtext; 2102 n.narg.backquote = backquotelist; 2103 2104 expandarg(&n, NULL, 0); 2105 result = stackblock(); 2106 INTOFF; 2107 } 2108 handler = savehandler; 2109 doprompt = saveprompt; 2110 popfilesupto(savetopfile); 2111 if (parser_temp != saveparser_temp) { 2112 parser_temp_free_all(); 2113 parser_temp = saveparser_temp; 2114 } 2115 if (result != NULL) { 2116 INTON; 2117 } else if (exception == EXINT) 2118 raise(SIGINT); 2119 return result; 2120 } 2121