1 /*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kenneth Almquist. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. 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 PROMPTLEN 128 70 71 /* values of checkkwd variable */ 72 #define CHKALIAS 0x1 73 #define CHKKWD 0x2 74 #define CHKNL 0x4 75 76 /* values returned by readtoken */ 77 #include "token.h" 78 79 80 81 struct heredoc { 82 struct heredoc *next; /* next here document in list */ 83 union node *here; /* redirection node */ 84 char *eofmark; /* string indicating end of input */ 85 int striptabs; /* if set, strip leading tabs */ 86 }; 87 88 struct parser_temp { 89 struct parser_temp *next; 90 void *data; 91 }; 92 93 94 static struct heredoc *heredoclist; /* list of here documents to read */ 95 static int doprompt; /* if set, prompt the user */ 96 static int needprompt; /* true if interactive and at start of line */ 97 static int lasttoken; /* last token read */ 98 static int tokpushback; /* last token pushed back */ 99 static char *wordtext; /* text of last word returned by readtoken */ 100 static int checkkwd; 101 static struct nodelist *backquotelist; 102 static union node *redirnode; 103 static struct heredoc *heredoc; 104 static int quoteflag; /* set if (part of) last token was quoted */ 105 static int startlinno; /* line # where last token started */ 106 static int funclinno; /* line # where the current function started */ 107 static struct parser_temp *parser_temp; 108 109 110 static union node *list(int); 111 static union node *andor(void); 112 static union node *pipeline(void); 113 static union node *command(void); 114 static union node *simplecmd(union node **, union node *); 115 static union node *makename(void); 116 static union node *makebinary(int type, union node *n1, union node *n2); 117 static void parsefname(void); 118 static void parseheredoc(void); 119 static int peektoken(void); 120 static int readtoken(void); 121 static int xxreadtoken(void); 122 static int readtoken1(int, const char *, const char *, int); 123 static int noexpand(char *); 124 static void consumetoken(int); 125 static void synexpect(int) __dead2; 126 static void synerror(const char *) __dead2; 127 static void setprompt(int); 128 static int pgetc_linecont(void); 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 forcealias(void) 687 { 688 checkkwd |= CHKALIAS; 689 } 690 691 void 692 fixredir(union node *n, const char *text, int err) 693 { 694 TRACE(("Fix redir %s %d\n", text, err)); 695 if (!err) 696 n->ndup.vname = NULL; 697 698 if (is_digit(text[0]) && text[1] == '\0') 699 n->ndup.dupfd = digit_val(text[0]); 700 else if (text[0] == '-' && text[1] == '\0') 701 n->ndup.dupfd = -1; 702 else { 703 704 if (err) 705 synerror("Bad fd number"); 706 else 707 n->ndup.vname = makename(); 708 } 709 } 710 711 712 static void 713 parsefname(void) 714 { 715 union node *n = redirnode; 716 717 consumetoken(TWORD); 718 if (n->type == NHERE) { 719 struct heredoc *here = heredoc; 720 struct heredoc *p; 721 722 if (quoteflag == 0) 723 n->type = NXHERE; 724 TRACE(("Here document %d\n", n->type)); 725 if (here->striptabs) { 726 while (*wordtext == '\t') 727 wordtext++; 728 } 729 if (! noexpand(wordtext)) 730 synerror("Illegal eof marker for << redirection"); 731 rmescapes(wordtext); 732 here->eofmark = wordtext; 733 here->next = NULL; 734 if (heredoclist == NULL) 735 heredoclist = here; 736 else { 737 for (p = heredoclist ; p->next ; p = p->next); 738 p->next = here; 739 } 740 } else if (n->type == NTOFD || n->type == NFROMFD) { 741 fixredir(n, wordtext, 0); 742 } else { 743 n->nfile.fname = makename(); 744 } 745 } 746 747 748 /* 749 * Input any here documents. 750 */ 751 752 static void 753 parseheredoc(void) 754 { 755 struct heredoc *here; 756 union node *n; 757 758 while (heredoclist) { 759 here = heredoclist; 760 heredoclist = here->next; 761 if (needprompt) { 762 setprompt(2); 763 needprompt = 0; 764 } 765 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, 766 here->eofmark, here->striptabs); 767 n = makename(); 768 here->here->nhere.doc = n; 769 } 770 } 771 772 static int 773 peektoken(void) 774 { 775 int t; 776 777 t = readtoken(); 778 tokpushback++; 779 return (t); 780 } 781 782 static int 783 readtoken(void) 784 { 785 int t; 786 struct alias *ap; 787 #ifdef DEBUG 788 int alreadyseen = tokpushback; 789 #endif 790 791 top: 792 t = xxreadtoken(); 793 794 /* 795 * eat newlines 796 */ 797 if (checkkwd & CHKNL) { 798 while (t == TNL) { 799 parseheredoc(); 800 t = xxreadtoken(); 801 } 802 } 803 804 /* 805 * check for keywords and aliases 806 */ 807 if (t == TWORD && !quoteflag) 808 { 809 const char * const *pp; 810 811 if (checkkwd & CHKKWD) 812 for (pp = parsekwd; *pp; pp++) { 813 if (**pp == *wordtext && equal(*pp, wordtext)) 814 { 815 lasttoken = t = pp - parsekwd + KWDOFFSET; 816 TRACE(("keyword %s recognized\n", tokname[t])); 817 goto out; 818 } 819 } 820 if (checkkwd & CHKALIAS && 821 (ap = lookupalias(wordtext, 1)) != NULL) { 822 pushstring(ap->val, strlen(ap->val), ap); 823 goto top; 824 } 825 } 826 out: 827 if (t != TNOT) 828 checkkwd = 0; 829 830 #ifdef DEBUG 831 if (!alreadyseen) 832 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 833 else 834 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 835 #endif 836 return (t); 837 } 838 839 840 /* 841 * Read the next input token. 842 * If the token is a word, we set backquotelist to the list of cmds in 843 * backquotes. We set quoteflag to true if any part of the word was 844 * quoted. 845 * If the token is TREDIR, then we set redirnode to a structure containing 846 * the redirection. 847 * In all cases, the variable startlinno is set to the number of the line 848 * on which the token starts. 849 * 850 * [Change comment: here documents and internal procedures] 851 * [Readtoken shouldn't have any arguments. Perhaps we should make the 852 * word parsing code into a separate routine. In this case, readtoken 853 * doesn't need to have any internal procedures, but parseword does. 854 * We could also make parseoperator in essence the main routine, and 855 * have parseword (readtoken1?) handle both words and redirection.] 856 */ 857 858 #define RETURN(token) return lasttoken = token 859 860 static int 861 xxreadtoken(void) 862 { 863 int c; 864 865 if (tokpushback) { 866 tokpushback = 0; 867 return lasttoken; 868 } 869 if (needprompt) { 870 setprompt(2); 871 needprompt = 0; 872 } 873 startlinno = plinno; 874 for (;;) { /* until token or start of word found */ 875 c = pgetc_macro(); 876 switch (c) { 877 case ' ': case '\t': 878 continue; 879 case '#': 880 while ((c = pgetc()) != '\n' && c != PEOF); 881 pungetc(); 882 continue; 883 case '\\': 884 if (pgetc() == '\n') { 885 startlinno = ++plinno; 886 if (doprompt) 887 setprompt(2); 888 else 889 setprompt(0); 890 continue; 891 } 892 pungetc(); 893 /* FALLTHROUGH */ 894 default: 895 return readtoken1(c, BASESYNTAX, (char *)NULL, 0); 896 case '\n': 897 plinno++; 898 needprompt = doprompt; 899 RETURN(TNL); 900 case PEOF: 901 RETURN(TEOF); 902 case '&': 903 if (pgetc_linecont() == '&') 904 RETURN(TAND); 905 pungetc(); 906 RETURN(TBACKGND); 907 case '|': 908 if (pgetc_linecont() == '|') 909 RETURN(TOR); 910 pungetc(); 911 RETURN(TPIPE); 912 case ';': 913 c = pgetc_linecont(); 914 if (c == ';') 915 RETURN(TENDCASE); 916 else if (c == '&') 917 RETURN(TFALLTHRU); 918 pungetc(); 919 RETURN(TSEMI); 920 case '(': 921 RETURN(TLP); 922 case ')': 923 RETURN(TRP); 924 } 925 } 926 #undef RETURN 927 } 928 929 930 #define MAXNEST_static 8 931 struct tokenstate 932 { 933 const char *syntax; /* *SYNTAX */ 934 int parenlevel; /* levels of parentheses in arithmetic */ 935 enum tokenstate_category 936 { 937 TSTATE_TOP, 938 TSTATE_VAR_OLD, /* ${var+-=?}, inherits dquotes */ 939 TSTATE_VAR_NEW, /* other ${var...}, own dquote state */ 940 TSTATE_ARITH 941 } category; 942 }; 943 944 945 /* 946 * Check to see whether we are at the end of the here document. When this 947 * is called, c is set to the first character of the next input line. If 948 * we are at the end of the here document, this routine sets the c to PEOF. 949 * The new value of c is returned. 950 */ 951 952 static int 953 checkend(int c, const char *eofmark, int striptabs) 954 { 955 if (striptabs) { 956 while (c == '\t') 957 c = pgetc(); 958 } 959 if (c == *eofmark) { 960 int c2; 961 const char *q; 962 963 for (q = eofmark + 1; c2 = pgetc(), *q != '\0' && c2 == *q; q++) 964 ; 965 if ((c2 == PEOF || c2 == '\n') && *q == '\0') { 966 c = PEOF; 967 if (c2 == '\n') { 968 plinno++; 969 needprompt = doprompt; 970 } 971 } else { 972 pungetc(); 973 pushstring(eofmark + 1, q - (eofmark + 1), NULL); 974 } 975 } 976 return (c); 977 } 978 979 980 /* 981 * Parse a redirection operator. The variable "out" points to a string 982 * specifying the fd to be redirected. The variable "c" contains the 983 * first character of the redirection operator. 984 */ 985 986 static void 987 parseredir(char *out, int c) 988 { 989 char fd = *out; 990 union node *np; 991 992 np = (union node *)stalloc(sizeof (struct nfile)); 993 if (c == '>') { 994 np->nfile.fd = 1; 995 c = pgetc_linecont(); 996 if (c == '>') 997 np->type = NAPPEND; 998 else if (c == '&') 999 np->type = NTOFD; 1000 else if (c == '|') 1001 np->type = NCLOBBER; 1002 else { 1003 np->type = NTO; 1004 pungetc(); 1005 } 1006 } else { /* c == '<' */ 1007 np->nfile.fd = 0; 1008 c = pgetc_linecont(); 1009 if (c == '<') { 1010 if (sizeof (struct nfile) != sizeof (struct nhere)) { 1011 np = (union node *)stalloc(sizeof (struct nhere)); 1012 np->nfile.fd = 0; 1013 } 1014 np->type = NHERE; 1015 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); 1016 heredoc->here = np; 1017 if ((c = pgetc_linecont()) == '-') { 1018 heredoc->striptabs = 1; 1019 } else { 1020 heredoc->striptabs = 0; 1021 pungetc(); 1022 } 1023 } else if (c == '&') 1024 np->type = NFROMFD; 1025 else if (c == '>') 1026 np->type = NFROMTO; 1027 else { 1028 np->type = NFROM; 1029 pungetc(); 1030 } 1031 } 1032 if (fd != '\0') 1033 np->nfile.fd = digit_val(fd); 1034 redirnode = np; 1035 } 1036 1037 /* 1038 * Called to parse command substitutions. 1039 */ 1040 1041 static char * 1042 parsebackq(char *out, struct nodelist **pbqlist, 1043 int oldstyle, int dblquote, int quoted) 1044 { 1045 struct nodelist **nlpp; 1046 union node *n; 1047 char *volatile str; 1048 struct jmploc jmploc; 1049 struct jmploc *const savehandler = handler; 1050 size_t savelen; 1051 int saveprompt; 1052 const int bq_startlinno = plinno; 1053 char *volatile ostr = NULL; 1054 struct parsefile *const savetopfile = getcurrentfile(); 1055 struct heredoc *const saveheredoclist = heredoclist; 1056 struct heredoc *here; 1057 1058 str = NULL; 1059 if (setjmp(jmploc.loc)) { 1060 popfilesupto(savetopfile); 1061 if (str) 1062 ckfree(str); 1063 if (ostr) 1064 ckfree(ostr); 1065 heredoclist = saveheredoclist; 1066 handler = savehandler; 1067 if (exception == EXERROR) { 1068 startlinno = bq_startlinno; 1069 synerror("Error in command substitution"); 1070 } 1071 longjmp(handler->loc, 1); 1072 } 1073 INTOFF; 1074 savelen = out - stackblock(); 1075 if (savelen > 0) { 1076 str = ckmalloc(savelen); 1077 memcpy(str, stackblock(), savelen); 1078 } 1079 handler = &jmploc; 1080 heredoclist = NULL; 1081 INTON; 1082 if (oldstyle) { 1083 /* We must read until the closing backquote, giving special 1084 treatment to some slashes, and then push the string and 1085 reread it as input, interpreting it normally. */ 1086 char *oout; 1087 int c; 1088 int olen; 1089 1090 1091 STARTSTACKSTR(oout); 1092 for (;;) { 1093 if (needprompt) { 1094 setprompt(2); 1095 needprompt = 0; 1096 } 1097 CHECKSTRSPACE(2, oout); 1098 c = pgetc_linecont(); 1099 if (c == '`') 1100 break; 1101 switch (c) { 1102 case '\\': 1103 c = pgetc(); 1104 if (c != '\\' && c != '`' && c != '$' 1105 && (!dblquote || c != '"')) 1106 USTPUTC('\\', oout); 1107 break; 1108 1109 case '\n': 1110 plinno++; 1111 needprompt = doprompt; 1112 break; 1113 1114 case PEOF: 1115 startlinno = plinno; 1116 synerror("EOF in backquote substitution"); 1117 break; 1118 1119 default: 1120 break; 1121 } 1122 USTPUTC(c, oout); 1123 } 1124 USTPUTC('\0', oout); 1125 olen = oout - stackblock(); 1126 INTOFF; 1127 ostr = ckmalloc(olen); 1128 memcpy(ostr, stackblock(), olen); 1129 setinputstring(ostr, 1); 1130 INTON; 1131 } 1132 nlpp = pbqlist; 1133 while (*nlpp) 1134 nlpp = &(*nlpp)->next; 1135 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 1136 (*nlpp)->next = NULL; 1137 1138 if (oldstyle) { 1139 saveprompt = doprompt; 1140 doprompt = 0; 1141 } 1142 1143 n = list(0); 1144 1145 if (oldstyle) { 1146 if (peektoken() != TEOF) 1147 synexpect(-1); 1148 doprompt = saveprompt; 1149 } else 1150 consumetoken(TRP); 1151 1152 (*nlpp)->n = n; 1153 if (oldstyle) { 1154 /* 1155 * Start reading from old file again, ignoring any pushed back 1156 * tokens left from the backquote parsing 1157 */ 1158 popfile(); 1159 tokpushback = 0; 1160 } 1161 STARTSTACKSTR(out); 1162 CHECKSTRSPACE(savelen + 1, out); 1163 INTOFF; 1164 if (str) { 1165 memcpy(out, str, savelen); 1166 STADJUST(savelen, out); 1167 ckfree(str); 1168 str = NULL; 1169 } 1170 if (ostr) { 1171 ckfree(ostr); 1172 ostr = NULL; 1173 } 1174 here = saveheredoclist; 1175 if (here != NULL) { 1176 while (here->next != NULL) 1177 here = here->next; 1178 here->next = heredoclist; 1179 heredoclist = saveheredoclist; 1180 } 1181 handler = savehandler; 1182 INTON; 1183 if (quoted) 1184 USTPUTC(CTLBACKQ | CTLQUOTE, out); 1185 else 1186 USTPUTC(CTLBACKQ, out); 1187 return out; 1188 } 1189 1190 1191 /* 1192 * Called to parse a backslash escape sequence inside $'...'. 1193 * The backslash has already been read. 1194 */ 1195 static char * 1196 readcstyleesc(char *out) 1197 { 1198 int c, v, i, n; 1199 1200 c = pgetc(); 1201 switch (c) { 1202 case '\0': 1203 synerror("Unterminated quoted string"); 1204 case '\n': 1205 plinno++; 1206 if (doprompt) 1207 setprompt(2); 1208 else 1209 setprompt(0); 1210 return out; 1211 case '\\': 1212 case '\'': 1213 case '"': 1214 v = c; 1215 break; 1216 case 'a': v = '\a'; break; 1217 case 'b': v = '\b'; break; 1218 case 'e': v = '\033'; break; 1219 case 'f': v = '\f'; break; 1220 case 'n': v = '\n'; break; 1221 case 'r': v = '\r'; break; 1222 case 't': v = '\t'; break; 1223 case 'v': v = '\v'; break; 1224 case 'x': 1225 v = 0; 1226 for (;;) { 1227 c = pgetc(); 1228 if (c >= '0' && c <= '9') 1229 v = (v << 4) + c - '0'; 1230 else if (c >= 'A' && c <= 'F') 1231 v = (v << 4) + c - 'A' + 10; 1232 else if (c >= 'a' && c <= 'f') 1233 v = (v << 4) + c - 'a' + 10; 1234 else 1235 break; 1236 } 1237 pungetc(); 1238 break; 1239 case '0': case '1': case '2': case '3': 1240 case '4': case '5': case '6': case '7': 1241 v = c - '0'; 1242 c = pgetc(); 1243 if (c >= '0' && c <= '7') { 1244 v <<= 3; 1245 v += c - '0'; 1246 c = pgetc(); 1247 if (c >= '0' && c <= '7') { 1248 v <<= 3; 1249 v += c - '0'; 1250 } else 1251 pungetc(); 1252 } else 1253 pungetc(); 1254 break; 1255 case 'c': 1256 c = pgetc(); 1257 if (c < 0x3f || c > 0x7a || c == 0x60) 1258 synerror("Bad escape sequence"); 1259 if (c == '\\' && pgetc() != '\\') 1260 synerror("Bad escape sequence"); 1261 if (c == '?') 1262 v = 127; 1263 else 1264 v = c & 0x1f; 1265 break; 1266 case 'u': 1267 case 'U': 1268 n = c == 'U' ? 8 : 4; 1269 v = 0; 1270 for (i = 0; i < n; i++) { 1271 c = pgetc(); 1272 if (c >= '0' && c <= '9') 1273 v = (v << 4) + c - '0'; 1274 else if (c >= 'A' && c <= 'F') 1275 v = (v << 4) + c - 'A' + 10; 1276 else if (c >= 'a' && c <= 'f') 1277 v = (v << 4) + c - 'a' + 10; 1278 else 1279 synerror("Bad escape sequence"); 1280 } 1281 if (v == 0 || (v >= 0xd800 && v <= 0xdfff)) 1282 synerror("Bad escape sequence"); 1283 /* We really need iconv here. */ 1284 if (initial_localeisutf8 && v > 127) { 1285 CHECKSTRSPACE(4, out); 1286 /* 1287 * We cannot use wctomb() as the locale may have 1288 * changed. 1289 */ 1290 if (v <= 0x7ff) { 1291 USTPUTC(0xc0 | v >> 6, out); 1292 USTPUTC(0x80 | (v & 0x3f), out); 1293 return out; 1294 } else if (v <= 0xffff) { 1295 USTPUTC(0xe0 | v >> 12, out); 1296 USTPUTC(0x80 | ((v >> 6) & 0x3f), out); 1297 USTPUTC(0x80 | (v & 0x3f), out); 1298 return out; 1299 } else if (v <= 0x10ffff) { 1300 USTPUTC(0xf0 | v >> 18, out); 1301 USTPUTC(0x80 | ((v >> 12) & 0x3f), out); 1302 USTPUTC(0x80 | ((v >> 6) & 0x3f), out); 1303 USTPUTC(0x80 | (v & 0x3f), out); 1304 return out; 1305 } 1306 } 1307 if (v > 127) 1308 v = '?'; 1309 break; 1310 default: 1311 synerror("Bad escape sequence"); 1312 } 1313 v = (char)v; 1314 /* 1315 * We can't handle NUL bytes. 1316 * POSIX says we should skip till the closing quote. 1317 */ 1318 if (v == '\0') { 1319 while ((c = pgetc()) != '\'') { 1320 if (c == '\\') 1321 c = pgetc(); 1322 if (c == PEOF) 1323 synerror("Unterminated quoted string"); 1324 if (c == '\n') { 1325 plinno++; 1326 if (doprompt) 1327 setprompt(2); 1328 else 1329 setprompt(0); 1330 } 1331 } 1332 pungetc(); 1333 return out; 1334 } 1335 if (SQSYNTAX[v] == CCTL) 1336 USTPUTC(CTLESC, out); 1337 USTPUTC(v, out); 1338 return out; 1339 } 1340 1341 1342 /* 1343 * If eofmark is NULL, read a word or a redirection symbol. If eofmark 1344 * is not NULL, read a here document. In the latter case, eofmark is the 1345 * word which marks the end of the document and striptabs is true if 1346 * leading tabs should be stripped from the document. The argument firstc 1347 * is the first character of the input token or document. 1348 * 1349 * Because C does not have internal subroutines, I have simulated them 1350 * using goto's to implement the subroutine linkage. The following macros 1351 * will run code that appears at the end of readtoken1. 1352 */ 1353 1354 #define PARSESUB() {goto parsesub; parsesub_return:;} 1355 #define PARSEARITH() {goto parsearith; parsearith_return:;} 1356 1357 static int 1358 readtoken1(int firstc, char const *initialsyntax, const char *eofmark, 1359 int striptabs) 1360 { 1361 int c = firstc; 1362 char *out; 1363 int len; 1364 struct nodelist *bqlist; 1365 int quotef; 1366 int newvarnest; 1367 int level; 1368 int synentry; 1369 struct tokenstate state_static[MAXNEST_static]; 1370 int maxnest = MAXNEST_static; 1371 struct tokenstate *state = state_static; 1372 int sqiscstyle = 0; 1373 1374 startlinno = plinno; 1375 quotef = 0; 1376 bqlist = NULL; 1377 newvarnest = 0; 1378 level = 0; 1379 state[level].syntax = initialsyntax; 1380 state[level].parenlevel = 0; 1381 state[level].category = TSTATE_TOP; 1382 1383 STARTSTACKSTR(out); 1384 loop: { /* for each line, until end of word */ 1385 if (eofmark) 1386 /* set c to PEOF if at end of here document */ 1387 c = checkend(c, eofmark, striptabs); 1388 for (;;) { /* until end of line or end of word */ 1389 CHECKSTRSPACE(4, out); /* permit 4 calls to USTPUTC */ 1390 1391 synentry = state[level].syntax[c]; 1392 1393 switch(synentry) { 1394 case CNL: /* '\n' */ 1395 if (state[level].syntax == BASESYNTAX) 1396 goto endword; /* exit outer loop */ 1397 USTPUTC(c, out); 1398 plinno++; 1399 if (doprompt) 1400 setprompt(2); 1401 else 1402 setprompt(0); 1403 c = pgetc(); 1404 goto loop; /* continue outer loop */ 1405 case CSBACK: 1406 if (sqiscstyle) { 1407 out = readcstyleesc(out); 1408 break; 1409 } 1410 /* FALLTHROUGH */ 1411 case CWORD: 1412 USTPUTC(c, out); 1413 break; 1414 case CCTL: 1415 if (eofmark == NULL || initialsyntax != SQSYNTAX) 1416 USTPUTC(CTLESC, out); 1417 USTPUTC(c, out); 1418 break; 1419 case CBACK: /* backslash */ 1420 c = pgetc(); 1421 if (c == PEOF) { 1422 USTPUTC('\\', out); 1423 pungetc(); 1424 } else if (c == '\n') { 1425 plinno++; 1426 if (doprompt) 1427 setprompt(2); 1428 else 1429 setprompt(0); 1430 } else { 1431 if (state[level].syntax == DQSYNTAX && 1432 c != '\\' && c != '`' && c != '$' && 1433 (c != '"' || (eofmark != NULL && 1434 newvarnest == 0)) && 1435 (c != '}' || state[level].category != TSTATE_VAR_OLD)) 1436 USTPUTC('\\', out); 1437 if ((eofmark == NULL || 1438 newvarnest > 0) && 1439 state[level].syntax == BASESYNTAX) 1440 USTPUTC(CTLQUOTEMARK, out); 1441 if (SQSYNTAX[c] == CCTL) 1442 USTPUTC(CTLESC, out); 1443 USTPUTC(c, out); 1444 if ((eofmark == NULL || 1445 newvarnest > 0) && 1446 state[level].syntax == BASESYNTAX && 1447 state[level].category == TSTATE_VAR_OLD) 1448 USTPUTC(CTLQUOTEEND, out); 1449 quotef++; 1450 } 1451 break; 1452 case CSQUOTE: 1453 USTPUTC(CTLQUOTEMARK, out); 1454 state[level].syntax = SQSYNTAX; 1455 sqiscstyle = 0; 1456 break; 1457 case CDQUOTE: 1458 USTPUTC(CTLQUOTEMARK, out); 1459 state[level].syntax = DQSYNTAX; 1460 break; 1461 case CENDQUOTE: 1462 if (eofmark != NULL && newvarnest == 0) 1463 USTPUTC(c, out); 1464 else { 1465 if (state[level].category == TSTATE_VAR_OLD) 1466 USTPUTC(CTLQUOTEEND, out); 1467 state[level].syntax = BASESYNTAX; 1468 quotef++; 1469 } 1470 break; 1471 case CVAR: /* '$' */ 1472 PARSESUB(); /* parse substitution */ 1473 break; 1474 case CENDVAR: /* '}' */ 1475 if (level > 0 && 1476 ((state[level].category == TSTATE_VAR_OLD && 1477 state[level].syntax == 1478 state[level - 1].syntax) || 1479 (state[level].category == TSTATE_VAR_NEW && 1480 state[level].syntax == BASESYNTAX))) { 1481 if (state[level].category == TSTATE_VAR_NEW) 1482 newvarnest--; 1483 level--; 1484 USTPUTC(CTLENDVAR, out); 1485 } else { 1486 USTPUTC(c, out); 1487 } 1488 break; 1489 case CLP: /* '(' in arithmetic */ 1490 state[level].parenlevel++; 1491 USTPUTC(c, out); 1492 break; 1493 case CRP: /* ')' in arithmetic */ 1494 if (state[level].parenlevel > 0) { 1495 USTPUTC(c, out); 1496 --state[level].parenlevel; 1497 } else { 1498 if (pgetc_linecont() == ')') { 1499 if (level > 0 && 1500 state[level].category == TSTATE_ARITH) { 1501 level--; 1502 USTPUTC(CTLENDARI, out); 1503 } else 1504 USTPUTC(')', out); 1505 } else { 1506 /* 1507 * unbalanced parens 1508 * (don't 2nd guess - no error) 1509 */ 1510 pungetc(); 1511 USTPUTC(')', out); 1512 } 1513 } 1514 break; 1515 case CBQUOTE: /* '`' */ 1516 out = parsebackq(out, &bqlist, 1, 1517 state[level].syntax == DQSYNTAX && 1518 (eofmark == NULL || newvarnest > 0), 1519 state[level].syntax == DQSYNTAX || state[level].syntax == ARISYNTAX); 1520 break; 1521 case CEOF: 1522 goto endword; /* exit outer loop */ 1523 case CIGN: 1524 break; 1525 default: 1526 if (level == 0) 1527 goto endword; /* exit outer loop */ 1528 USTPUTC(c, out); 1529 } 1530 c = pgetc_macro(); 1531 } 1532 } 1533 endword: 1534 if (state[level].syntax == ARISYNTAX) 1535 synerror("Missing '))'"); 1536 if (state[level].syntax != BASESYNTAX && eofmark == NULL) 1537 synerror("Unterminated quoted string"); 1538 if (state[level].category == TSTATE_VAR_OLD || 1539 state[level].category == TSTATE_VAR_NEW) { 1540 startlinno = plinno; 1541 synerror("Missing '}'"); 1542 } 1543 if (state != state_static) 1544 parser_temp_free_upto(state); 1545 USTPUTC('\0', out); 1546 len = out - stackblock(); 1547 out = stackblock(); 1548 if (eofmark == NULL) { 1549 if ((c == '>' || c == '<') 1550 && quotef == 0 1551 && len <= 2 1552 && (*out == '\0' || is_digit(*out))) { 1553 parseredir(out, c); 1554 return lasttoken = TREDIR; 1555 } else { 1556 pungetc(); 1557 } 1558 } 1559 quoteflag = quotef; 1560 backquotelist = bqlist; 1561 grabstackblock(len); 1562 wordtext = out; 1563 return lasttoken = TWORD; 1564 /* end of readtoken routine */ 1565 1566 1567 /* 1568 * Parse a substitution. At this point, we have read the dollar sign 1569 * and nothing else. 1570 */ 1571 1572 parsesub: { 1573 char buf[10]; 1574 int subtype; 1575 int typeloc; 1576 int flags; 1577 char *p; 1578 static const char types[] = "}-+?="; 1579 int bracketed_name = 0; /* used to handle ${[0-9]*} variables */ 1580 int linno; 1581 int length; 1582 int c1; 1583 1584 c = pgetc_linecont(); 1585 if (c == '(') { /* $(command) or $((arith)) */ 1586 if (pgetc_linecont() == '(') { 1587 PARSEARITH(); 1588 } else { 1589 pungetc(); 1590 out = parsebackq(out, &bqlist, 0, 1591 state[level].syntax == DQSYNTAX && 1592 (eofmark == NULL || newvarnest > 0), 1593 state[level].syntax == DQSYNTAX || 1594 state[level].syntax == ARISYNTAX); 1595 } 1596 } else if (c == '{' || is_name(c) || is_special(c)) { 1597 USTPUTC(CTLVAR, out); 1598 typeloc = out - stackblock(); 1599 USTPUTC(VSNORMAL, out); 1600 subtype = VSNORMAL; 1601 flags = 0; 1602 if (c == '{') { 1603 bracketed_name = 1; 1604 c = pgetc_linecont(); 1605 subtype = 0; 1606 } 1607 varname: 1608 if (!is_eof(c) && is_name(c)) { 1609 length = 0; 1610 do { 1611 STPUTC(c, out); 1612 c = pgetc_linecont(); 1613 length++; 1614 } while (!is_eof(c) && is_in_name(c)); 1615 if (length == 6 && 1616 strncmp(out - length, "LINENO", length) == 0) { 1617 /* Replace the variable name with the 1618 * current line number. */ 1619 linno = plinno; 1620 if (funclinno != 0) 1621 linno -= funclinno - 1; 1622 snprintf(buf, sizeof(buf), "%d", linno); 1623 STADJUST(-6, out); 1624 STPUTS(buf, out); 1625 flags |= VSLINENO; 1626 } 1627 } else if (is_digit(c)) { 1628 if (bracketed_name) { 1629 do { 1630 STPUTC(c, out); 1631 c = pgetc_linecont(); 1632 } while (is_digit(c)); 1633 } else { 1634 STPUTC(c, out); 1635 c = pgetc_linecont(); 1636 } 1637 } else if (is_special(c)) { 1638 c1 = c; 1639 c = pgetc_linecont(); 1640 if (subtype == 0 && c1 == '#') { 1641 subtype = VSLENGTH; 1642 if (strchr(types, c) == NULL && c != ':' && 1643 c != '#' && c != '%') 1644 goto varname; 1645 c1 = c; 1646 c = pgetc_linecont(); 1647 if (c1 != '}' && c == '}') { 1648 pungetc(); 1649 c = c1; 1650 goto varname; 1651 } 1652 pungetc(); 1653 c = c1; 1654 c1 = '#'; 1655 subtype = 0; 1656 } 1657 USTPUTC(c1, out); 1658 } else { 1659 subtype = VSERROR; 1660 if (c == '}') 1661 pungetc(); 1662 else if (c == '\n' || c == PEOF) 1663 synerror("Unexpected end of line in substitution"); 1664 else 1665 USTPUTC(c, out); 1666 } 1667 if (subtype == 0) { 1668 switch (c) { 1669 case ':': 1670 flags |= VSNUL; 1671 c = pgetc_linecont(); 1672 /*FALLTHROUGH*/ 1673 default: 1674 p = strchr(types, c); 1675 if (p == NULL) { 1676 if (c == '\n' || c == PEOF) 1677 synerror("Unexpected end of line in substitution"); 1678 if (flags == VSNUL) 1679 STPUTC(':', out); 1680 STPUTC(c, out); 1681 subtype = VSERROR; 1682 } else 1683 subtype = p - types + VSNORMAL; 1684 break; 1685 case '%': 1686 case '#': 1687 { 1688 int cc = c; 1689 subtype = c == '#' ? VSTRIMLEFT : 1690 VSTRIMRIGHT; 1691 c = pgetc_linecont(); 1692 if (c == cc) 1693 subtype++; 1694 else 1695 pungetc(); 1696 break; 1697 } 1698 } 1699 } else if (subtype != VSERROR) { 1700 if (subtype == VSLENGTH && c != '}') 1701 subtype = VSERROR; 1702 pungetc(); 1703 } 1704 STPUTC('=', out); 1705 if (state[level].syntax == DQSYNTAX || 1706 state[level].syntax == ARISYNTAX) 1707 flags |= VSQUOTE; 1708 *(stackblock() + typeloc) = subtype | flags; 1709 if (subtype != VSNORMAL) { 1710 if (level + 1 >= maxnest) { 1711 maxnest *= 2; 1712 if (state == state_static) { 1713 state = parser_temp_alloc( 1714 maxnest * sizeof(*state)); 1715 memcpy(state, state_static, 1716 MAXNEST_static * sizeof(*state)); 1717 } else 1718 state = parser_temp_realloc(state, 1719 maxnest * sizeof(*state)); 1720 } 1721 level++; 1722 state[level].parenlevel = 0; 1723 if (subtype == VSMINUS || subtype == VSPLUS || 1724 subtype == VSQUESTION || subtype == VSASSIGN) { 1725 /* 1726 * For operators that were in the Bourne shell, 1727 * inherit the double-quote state. 1728 */ 1729 state[level].syntax = state[level - 1].syntax; 1730 state[level].category = TSTATE_VAR_OLD; 1731 } else { 1732 /* 1733 * The other operators take a pattern, 1734 * so go to BASESYNTAX. 1735 * Also, ' and " are now special, even 1736 * in here documents. 1737 */ 1738 state[level].syntax = BASESYNTAX; 1739 state[level].category = TSTATE_VAR_NEW; 1740 newvarnest++; 1741 } 1742 } 1743 } else if (c == '\'' && state[level].syntax == BASESYNTAX) { 1744 /* $'cstylequotes' */ 1745 USTPUTC(CTLQUOTEMARK, out); 1746 state[level].syntax = SQSYNTAX; 1747 sqiscstyle = 1; 1748 } else { 1749 USTPUTC('$', out); 1750 pungetc(); 1751 } 1752 goto parsesub_return; 1753 } 1754 1755 1756 /* 1757 * Parse an arithmetic expansion (indicate start of one and set state) 1758 */ 1759 parsearith: { 1760 1761 if (level + 1 >= maxnest) { 1762 maxnest *= 2; 1763 if (state == state_static) { 1764 state = parser_temp_alloc( 1765 maxnest * sizeof(*state)); 1766 memcpy(state, state_static, 1767 MAXNEST_static * sizeof(*state)); 1768 } else 1769 state = parser_temp_realloc(state, 1770 maxnest * sizeof(*state)); 1771 } 1772 level++; 1773 state[level].syntax = ARISYNTAX; 1774 state[level].parenlevel = 0; 1775 state[level].category = TSTATE_ARITH; 1776 USTPUTC(CTLARI, out); 1777 if (state[level - 1].syntax == DQSYNTAX) 1778 USTPUTC('"',out); 1779 else 1780 USTPUTC(' ',out); 1781 goto parsearith_return; 1782 } 1783 1784 } /* end of readtoken */ 1785 1786 1787 /* 1788 * Returns true if the text contains nothing to expand (no dollar signs 1789 * or backquotes). 1790 */ 1791 1792 static int 1793 noexpand(char *text) 1794 { 1795 char *p; 1796 char c; 1797 1798 p = text; 1799 while ((c = *p++) != '\0') { 1800 if ( c == CTLQUOTEMARK) 1801 continue; 1802 if (c == CTLESC) 1803 p++; 1804 else if (BASESYNTAX[(int)c] == CCTL) 1805 return 0; 1806 } 1807 return 1; 1808 } 1809 1810 1811 /* 1812 * Return true if the argument is a legal variable name (a letter or 1813 * underscore followed by zero or more letters, underscores, and digits). 1814 */ 1815 1816 int 1817 goodname(const char *name) 1818 { 1819 const char *p; 1820 1821 p = name; 1822 if (! is_name(*p)) 1823 return 0; 1824 while (*++p) { 1825 if (! is_in_name(*p)) 1826 return 0; 1827 } 1828 return 1; 1829 } 1830 1831 1832 int 1833 isassignment(const char *p) 1834 { 1835 if (!is_name(*p)) 1836 return 0; 1837 p++; 1838 for (;;) { 1839 if (*p == '=') 1840 return 1; 1841 else if (!is_in_name(*p)) 1842 return 0; 1843 p++; 1844 } 1845 } 1846 1847 1848 static void 1849 consumetoken(int token) 1850 { 1851 if (readtoken() != token) 1852 synexpect(token); 1853 } 1854 1855 1856 /* 1857 * Called when an unexpected token is read during the parse. The argument 1858 * is the token that is expected, or -1 if more than one type of token can 1859 * occur at this point. 1860 */ 1861 1862 static void 1863 synexpect(int token) 1864 { 1865 char msg[64]; 1866 1867 if (token >= 0) { 1868 fmtstr(msg, 64, "%s unexpected (expecting %s)", 1869 tokname[lasttoken], tokname[token]); 1870 } else { 1871 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]); 1872 } 1873 synerror(msg); 1874 } 1875 1876 1877 static void 1878 synerror(const char *msg) 1879 { 1880 if (commandname) 1881 outfmt(out2, "%s: %d: ", commandname, startlinno); 1882 else if (arg0) 1883 outfmt(out2, "%s: ", arg0); 1884 outfmt(out2, "Syntax error: %s\n", msg); 1885 error((char *)NULL); 1886 } 1887 1888 static void 1889 setprompt(int which) 1890 { 1891 whichprompt = which; 1892 1893 #ifndef NO_HISTORY 1894 if (!el) 1895 #endif 1896 { 1897 out2str(getprompt(NULL)); 1898 flushout(out2); 1899 } 1900 } 1901 1902 static int 1903 pgetc_linecont(void) 1904 { 1905 int c; 1906 1907 while ((c = pgetc_macro()) == '\\') { 1908 c = pgetc(); 1909 if (c == '\n') { 1910 plinno++; 1911 if (doprompt) 1912 setprompt(2); 1913 else 1914 setprompt(0); 1915 } else { 1916 pungetc(); 1917 /* Allow the backslash to be pushed back. */ 1918 pushstring("\\", 1, NULL); 1919 return (pgetc()); 1920 } 1921 } 1922 return (c); 1923 } 1924 1925 /* 1926 * called by editline -- any expansions to the prompt 1927 * should be added here. 1928 */ 1929 char * 1930 getprompt(void *unused __unused) 1931 { 1932 static char ps[PROMPTLEN]; 1933 const char *fmt; 1934 const char *pwd; 1935 int i, trim; 1936 static char internal_error[] = "??"; 1937 1938 /* 1939 * Select prompt format. 1940 */ 1941 switch (whichprompt) { 1942 case 0: 1943 fmt = ""; 1944 break; 1945 case 1: 1946 fmt = ps1val(); 1947 break; 1948 case 2: 1949 fmt = ps2val(); 1950 break; 1951 default: 1952 return internal_error; 1953 } 1954 1955 /* 1956 * Format prompt string. 1957 */ 1958 for (i = 0; (i < 127) && (*fmt != '\0'); i++, fmt++) 1959 if (*fmt == '\\') 1960 switch (*++fmt) { 1961 1962 /* 1963 * Hostname. 1964 * 1965 * \h specifies just the local hostname, 1966 * \H specifies fully-qualified hostname. 1967 */ 1968 case 'h': 1969 case 'H': 1970 ps[i] = '\0'; 1971 gethostname(&ps[i], PROMPTLEN - i); 1972 /* Skip to end of hostname. */ 1973 trim = (*fmt == 'h') ? '.' : '\0'; 1974 while ((ps[i+1] != '\0') && (ps[i+1] != trim)) 1975 i++; 1976 break; 1977 1978 /* 1979 * Working directory. 1980 * 1981 * \W specifies just the final component, 1982 * \w specifies the entire path. 1983 */ 1984 case 'W': 1985 case 'w': 1986 pwd = lookupvar("PWD"); 1987 if (pwd == NULL) 1988 pwd = "?"; 1989 if (*fmt == 'W' && 1990 *pwd == '/' && pwd[1] != '\0') 1991 strlcpy(&ps[i], strrchr(pwd, '/') + 1, 1992 PROMPTLEN - i); 1993 else 1994 strlcpy(&ps[i], pwd, PROMPTLEN - i); 1995 /* Skip to end of path. */ 1996 while (ps[i + 1] != '\0') 1997 i++; 1998 break; 1999 2000 /* 2001 * Superuser status. 2002 * 2003 * '$' for normal users, '#' for root. 2004 */ 2005 case '$': 2006 ps[i] = (geteuid() != 0) ? '$' : '#'; 2007 break; 2008 2009 /* 2010 * A literal \. 2011 */ 2012 case '\\': 2013 ps[i] = '\\'; 2014 break; 2015 2016 /* 2017 * Emit unrecognized formats verbatim. 2018 */ 2019 default: 2020 ps[i++] = '\\'; 2021 ps[i] = *fmt; 2022 break; 2023 } 2024 else 2025 ps[i] = *fmt; 2026 ps[i] = '\0'; 2027 return (ps); 2028 } 2029 2030 2031 const char * 2032 expandstr(const char *ps) 2033 { 2034 union node n; 2035 struct jmploc jmploc; 2036 struct jmploc *const savehandler = handler; 2037 const int saveprompt = doprompt; 2038 struct parsefile *const savetopfile = getcurrentfile(); 2039 struct parser_temp *const saveparser_temp = parser_temp; 2040 const char *result = NULL; 2041 2042 if (!setjmp(jmploc.loc)) { 2043 handler = &jmploc; 2044 parser_temp = NULL; 2045 setinputstring(ps, 1); 2046 doprompt = 0; 2047 readtoken1(pgetc(), DQSYNTAX, "", 0); 2048 if (backquotelist != NULL) 2049 error("Command substitution not allowed here"); 2050 2051 n.narg.type = NARG; 2052 n.narg.next = NULL; 2053 n.narg.text = wordtext; 2054 n.narg.backquote = backquotelist; 2055 2056 expandarg(&n, NULL, 0); 2057 result = stackblock(); 2058 INTOFF; 2059 } 2060 handler = savehandler; 2061 doprompt = saveprompt; 2062 popfilesupto(savetopfile); 2063 if (parser_temp != saveparser_temp) { 2064 parser_temp_free_all(); 2065 parser_temp = saveparser_temp; 2066 } 2067 if (result != NULL) { 2068 INTON; 2069 } else if (exception == EXINT) 2070 raise(SIGINT); 2071 return result; 2072 } 2073