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