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 * @(#)parser.c 8.7 (Berkeley) 5/16/95 33 * $FreeBSD: head/bin/sh/parser.c 253659 2013-07-25 20:50:35Z jilles $ 34 */ 35 36 #include <stdio.h> 37 #include <stdlib.h> 38 #include <unistd.h> 39 40 #include "shell.h" 41 #include "parser.h" 42 #include "nodes.h" 43 #include "expand.h" /* defines rmescapes() */ 44 #include "syntax.h" 45 #include "options.h" 46 #include "input.h" 47 #include "output.h" 48 #include "var.h" 49 #include "error.h" 50 #include "memalloc.h" 51 #include "mystring.h" 52 #include "alias.h" 53 #include "show.h" 54 #include "eval.h" 55 #include "exec.h" /* to check for special builtins */ 56 #ifndef NO_HISTORY 57 #include "myhistedit.h" 58 #endif 59 60 /* 61 * Shell command parser. 62 */ 63 64 #define EOFMARKLEN 79 65 #define PROMPTLEN 128 66 67 /* values of checkkwd variable */ 68 #define CHKALIAS 0x1 69 #define CHKKWD 0x2 70 #define CHKNL 0x4 71 72 /* values returned by readtoken */ 73 #include "token.h" 74 75 76 77 struct heredoc { 78 struct heredoc *next; /* next here document in list */ 79 union node *here; /* redirection node */ 80 char *eofmark; /* string indicating end of input */ 81 int striptabs; /* if set, strip leading tabs */ 82 }; 83 84 struct parser_temp { 85 struct parser_temp *next; 86 void *data; 87 }; 88 89 90 static struct heredoc *heredoclist; /* list of here documents to read */ 91 static int doprompt; /* if set, prompt the user */ 92 static int needprompt; /* true if interactive and at start of line */ 93 static int lasttoken; /* last token read */ 94 int tokpushback; /* last token pushed back */ 95 static char *wordtext; /* text of last word returned by readtoken */ 96 static int checkkwd; 97 static struct nodelist *backquotelist; 98 static union node *redirnode; 99 static struct heredoc *heredoc; 100 static int quoteflag; /* set if (part of) last token was quoted */ 101 static int startlinno; /* line # where last token started */ 102 static int funclinno; /* line # where the current function started */ 103 static struct parser_temp *parser_temp; 104 105 106 static union node *list(int, int); 107 static union node *andor(void); 108 static union node *pipeline(void); 109 static union node *command(void); 110 static union node *simplecmd(union node **, union node *); 111 static union node *makename(void); 112 static void parsefname(void); 113 static void parseheredoc(void); 114 static int peektoken(void); 115 static int readtoken(void); 116 static int xxreadtoken(void); 117 static int readtoken1(int, const char *, const char *, int); 118 static int noexpand(char *); 119 static void synexpect(int) __dead2; 120 static void synerror(const char *) __dead2; 121 static void setprompt(int); 122 123 124 static void * 125 parser_temp_alloc(size_t len) 126 { 127 struct parser_temp *t; 128 129 INTOFF; 130 t = ckmalloc(sizeof(*t)); 131 t->data = NULL; 132 t->next = parser_temp; 133 parser_temp = t; 134 t->data = ckmalloc(len); 135 INTON; 136 return t->data; 137 } 138 139 140 static void * 141 parser_temp_realloc(void *ptr, size_t len) 142 { 143 struct parser_temp *t; 144 145 INTOFF; 146 t = parser_temp; 147 if (ptr != t->data) 148 error("bug: parser_temp_realloc misused"); 149 t->data = ckrealloc(t->data, len); 150 INTON; 151 return t->data; 152 } 153 154 155 static void 156 parser_temp_free_upto(void *ptr) 157 { 158 struct parser_temp *t; 159 int done = 0; 160 161 INTOFF; 162 while (parser_temp != NULL && !done) { 163 t = parser_temp; 164 parser_temp = t->next; 165 done = t->data == ptr; 166 ckfree(t->data); 167 ckfree(t); 168 } 169 INTON; 170 if (!done) 171 error("bug: parser_temp_free_upto misused"); 172 } 173 174 175 static void 176 parser_temp_free_all(void) 177 { 178 struct parser_temp *t; 179 180 INTOFF; 181 while (parser_temp != NULL) { 182 t = parser_temp; 183 parser_temp = t->next; 184 ckfree(t->data); 185 ckfree(t); 186 } 187 INTON; 188 } 189 190 191 /* 192 * Read and parse a command. Returns NEOF on end of file. (NULL is a 193 * valid parse tree indicating a blank line.) 194 */ 195 196 union node * 197 parsecmd(int interact) 198 { 199 int t; 200 201 /* This assumes the parser is not re-entered, 202 * which could happen if we add command substitution on PS1/PS2. 203 */ 204 parser_temp_free_all(); 205 heredoclist = NULL; 206 207 tokpushback = 0; 208 doprompt = interact; 209 if (doprompt) 210 setprompt(1); 211 else 212 setprompt(0); 213 needprompt = 0; 214 t = readtoken(); 215 if (t == TEOF) 216 return NEOF; 217 if (t == TNL) 218 return NULL; 219 tokpushback++; 220 return list(1, 1); 221 } 222 223 224 static union node * 225 list(int nlflag, int erflag) 226 { 227 union node *ntop, *n1, *n2, *n3; 228 int tok; 229 230 checkkwd = CHKNL | CHKKWD | CHKALIAS; 231 if (!nlflag && !erflag && tokendlist[peektoken()]) 232 return NULL; 233 ntop = n1 = NULL; 234 for (;;) { 235 n2 = andor(); 236 tok = readtoken(); 237 if (tok == TBACKGND) { 238 if (n2 != NULL && n2->type == NPIPE) { 239 n2->npipe.backgnd = 1; 240 } else if (n2 != NULL && n2->type == NREDIR) { 241 n2->type = NBACKGND; 242 } else { 243 n3 = (union node *)stalloc(sizeof (struct nredir)); 244 n3->type = NBACKGND; 245 n3->nredir.n = n2; 246 n3->nredir.redirect = NULL; 247 n2 = n3; 248 } 249 } 250 if (ntop == NULL) 251 ntop = n2; 252 else if (n1 == NULL) { 253 n1 = (union node *)stalloc(sizeof (struct nbinary)); 254 n1->type = NSEMI; 255 n1->nbinary.ch1 = ntop; 256 n1->nbinary.ch2 = n2; 257 ntop = n1; 258 } 259 else { 260 n3 = (union node *)stalloc(sizeof (struct nbinary)); 261 n3->type = NSEMI; 262 n3->nbinary.ch1 = n1->nbinary.ch2; 263 n3->nbinary.ch2 = n2; 264 n1->nbinary.ch2 = n3; 265 n1 = n3; 266 } 267 switch (tok) { 268 case TBACKGND: 269 case TSEMI: 270 tok = readtoken(); 271 /* FALLTHROUGH */ 272 case TNL: 273 if (tok == TNL) { 274 parseheredoc(); 275 if (nlflag) 276 return ntop; 277 } else if (tok == TEOF && nlflag) { 278 parseheredoc(); 279 return ntop; 280 } else { 281 tokpushback++; 282 } 283 checkkwd = CHKNL | CHKKWD | CHKALIAS; 284 if (!nlflag && (erflag ? peektoken() == TEOF : 285 tokendlist[peektoken()])) 286 return ntop; 287 break; 288 case TEOF: 289 if (heredoclist) 290 parseheredoc(); 291 else 292 pungetc(); /* push back EOF on input */ 293 return ntop; 294 default: 295 if (nlflag || erflag) 296 synexpect(-1); 297 tokpushback++; 298 return ntop; 299 } 300 } 301 } 302 303 304 305 static union node * 306 andor(void) 307 { 308 union node *n1, *n2, *n3; 309 int t; 310 311 n1 = pipeline(); 312 for (;;) { 313 if ((t = readtoken()) == TAND) { 314 t = NAND; 315 } else if (t == TOR) { 316 t = NOR; 317 } else { 318 tokpushback++; 319 return n1; 320 } 321 n2 = pipeline(); 322 n3 = (union node *)stalloc(sizeof (struct nbinary)); 323 n3->type = t; 324 n3->nbinary.ch1 = n1; 325 n3->nbinary.ch2 = n2; 326 n1 = n3; 327 } 328 } 329 330 331 332 static union node * 333 pipeline(void) 334 { 335 union node *n1, *n2, *pipenode; 336 struct nodelist *lp, *prev; 337 int negate, t; 338 339 negate = 0; 340 checkkwd = CHKNL | CHKKWD | CHKALIAS; 341 TRACE(("pipeline: entered\n")); 342 while (readtoken() == TNOT) 343 negate = !negate; 344 tokpushback++; 345 n1 = command(); 346 if (readtoken() == TPIPE) { 347 pipenode = (union node *)stalloc(sizeof (struct npipe)); 348 pipenode->type = NPIPE; 349 pipenode->npipe.backgnd = 0; 350 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 351 pipenode->npipe.cmdlist = lp; 352 lp->n = n1; 353 do { 354 prev = lp; 355 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 356 checkkwd = CHKNL | CHKKWD | CHKALIAS; 357 t = readtoken(); 358 tokpushback++; 359 if (t == TNOT) 360 lp->n = pipeline(); 361 else 362 lp->n = command(); 363 prev->next = lp; 364 } while (readtoken() == TPIPE); 365 lp->next = NULL; 366 n1 = pipenode; 367 } 368 tokpushback++; 369 if (negate) { 370 n2 = (union node *)stalloc(sizeof (struct nnot)); 371 n2->type = NNOT; 372 n2->nnot.com = n1; 373 return n2; 374 } else 375 return n1; 376 } 377 378 379 380 static union node * 381 command(void) 382 { 383 union node *n1, *n2; 384 union node *ap, **app; 385 union node *cp, **cpp; 386 union node *redir, **rpp; 387 int t; 388 int is_subshell; 389 390 checkkwd = CHKNL | CHKKWD | CHKALIAS; 391 is_subshell = 0; 392 redir = NULL; 393 n1 = NULL; 394 rpp = &redir; 395 396 /* Check for redirection which may precede command */ 397 while (readtoken() == TREDIR) { 398 *rpp = n2 = redirnode; 399 rpp = &n2->nfile.next; 400 parsefname(); 401 } 402 tokpushback++; 403 404 switch (readtoken()) { 405 case TIF: 406 n1 = (union node *)stalloc(sizeof (struct nif)); 407 n1->type = NIF; 408 if ((n1->nif.test = list(0, 0)) == NULL) 409 synexpect(-1); 410 if (readtoken() != TTHEN) 411 synexpect(TTHEN); 412 n1->nif.ifpart = list(0, 0); 413 n2 = n1; 414 while (readtoken() == TELIF) { 415 n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif)); 416 n2 = n2->nif.elsepart; 417 n2->type = NIF; 418 if ((n2->nif.test = list(0, 0)) == NULL) 419 synexpect(-1); 420 if (readtoken() != TTHEN) 421 synexpect(TTHEN); 422 n2->nif.ifpart = list(0, 0); 423 } 424 if (lasttoken == TELSE) 425 n2->nif.elsepart = list(0, 0); 426 else { 427 n2->nif.elsepart = NULL; 428 tokpushback++; 429 } 430 if (readtoken() != TFI) 431 synexpect(TFI); 432 checkkwd = CHKKWD | CHKALIAS; 433 break; 434 case TWHILE: 435 case TUNTIL: { 436 int got; 437 n1 = (union node *)stalloc(sizeof (struct nbinary)); 438 n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL; 439 if ((n1->nbinary.ch1 = list(0, 0)) == NULL) 440 synexpect(-1); 441 if ((got=readtoken()) != TDO) { 442 TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : "")); 443 synexpect(TDO); 444 } 445 n1->nbinary.ch2 = list(0, 0); 446 if (readtoken() != TDONE) 447 synexpect(TDONE); 448 checkkwd = CHKKWD | CHKALIAS; 449 break; 450 } 451 case TFOR: 452 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext)) 453 synerror("Bad for loop variable"); 454 n1 = (union node *)stalloc(sizeof (struct nfor)); 455 n1->type = NFOR; 456 n1->nfor.var = wordtext; 457 while (readtoken() == TNL) 458 ; 459 if (lasttoken == TWORD && ! quoteflag && equal(wordtext, "in")) { 460 app = ≈ 461 while (readtoken() == TWORD) { 462 n2 = (union node *)stalloc(sizeof (struct narg)); 463 n2->type = NARG; 464 n2->narg.text = wordtext; 465 n2->narg.backquote = backquotelist; 466 *app = n2; 467 app = &n2->narg.next; 468 } 469 *app = NULL; 470 n1->nfor.args = ap; 471 if (lasttoken != TNL && lasttoken != TSEMI) 472 synexpect(-1); 473 } else { 474 static char argvars[5] = { 475 CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0' 476 }; 477 n2 = (union node *)stalloc(sizeof (struct narg)); 478 n2->type = NARG; 479 n2->narg.text = argvars; 480 n2->narg.backquote = NULL; 481 n2->narg.next = NULL; 482 n1->nfor.args = n2; 483 /* 484 * Newline or semicolon here is optional (but note 485 * that the original Bourne shell only allowed NL). 486 */ 487 if (lasttoken != TNL && lasttoken != TSEMI) 488 tokpushback++; 489 } 490 checkkwd = CHKNL | CHKKWD | CHKALIAS; 491 if ((t = readtoken()) == TDO) 492 t = TDONE; 493 else if (t == TBEGIN) 494 t = TEND; 495 else 496 synexpect(-1); 497 n1->nfor.body = list(0, 0); 498 if (readtoken() != t) 499 synexpect(t); 500 checkkwd = CHKKWD | CHKALIAS; 501 break; 502 case TCASE: 503 n1 = (union node *)stalloc(sizeof (struct ncase)); 504 n1->type = NCASE; 505 if (readtoken() != TWORD) 506 synexpect(TWORD); 507 n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg)); 508 n2->type = NARG; 509 n2->narg.text = wordtext; 510 n2->narg.backquote = backquotelist; 511 n2->narg.next = NULL; 512 while (readtoken() == TNL); 513 if (lasttoken != TWORD || ! equal(wordtext, "in")) 514 synerror("expecting \"in\""); 515 cpp = &n1->ncase.cases; 516 checkkwd = CHKNL | CHKKWD, readtoken(); 517 while (lasttoken != TESAC) { 518 *cpp = cp = (union node *)stalloc(sizeof (struct nclist)); 519 cp->type = NCLIST; 520 app = &cp->nclist.pattern; 521 if (lasttoken == TLP) 522 readtoken(); 523 for (;;) { 524 *app = ap = (union node *)stalloc(sizeof (struct narg)); 525 ap->type = NARG; 526 ap->narg.text = wordtext; 527 ap->narg.backquote = backquotelist; 528 checkkwd = CHKNL | CHKKWD; 529 if (readtoken() != TPIPE) 530 break; 531 app = &ap->narg.next; 532 readtoken(); 533 } 534 ap->narg.next = NULL; 535 if (lasttoken != TRP) 536 synexpect(TRP); 537 cp->nclist.body = list(0, 0); 538 539 checkkwd = CHKNL | CHKKWD | CHKALIAS; 540 if ((t = readtoken()) != TESAC) { 541 if (t == TENDCASE) 542 ; 543 else if (t == TFALLTHRU) 544 cp->type = NCLISTFALLTHRU; 545 else 546 synexpect(TENDCASE); 547 checkkwd = CHKNL | CHKKWD, readtoken(); 548 } 549 cpp = &cp->nclist.next; 550 } 551 *cpp = NULL; 552 checkkwd = CHKKWD | CHKALIAS; 553 break; 554 case TLP: 555 n1 = (union node *)stalloc(sizeof (struct nredir)); 556 n1->type = NSUBSHELL; 557 n1->nredir.n = list(0, 0); 558 n1->nredir.redirect = NULL; 559 if (readtoken() != TRP) 560 synexpect(TRP); 561 checkkwd = CHKKWD | CHKALIAS; 562 is_subshell = 1; 563 break; 564 case TBEGIN: 565 n1 = list(0, 0); 566 if (readtoken() != TEND) 567 synexpect(TEND); 568 checkkwd = CHKKWD | CHKALIAS; 569 break; 570 /* Handle an empty command like other simple commands. */ 571 case TBACKGND: 572 case TSEMI: 573 case TAND: 574 case TOR: 575 /* 576 * An empty command before a ; doesn't make much sense, and 577 * should certainly be disallowed in the case of `if ;'. 578 */ 579 if (!redir) 580 synexpect(-1); 581 case TNL: 582 case TEOF: 583 case TWORD: 584 case TRP: 585 tokpushback++; 586 n1 = simplecmd(rpp, redir); 587 return n1; 588 default: 589 synexpect(-1); 590 } 591 592 /* Now check for redirection which may follow command */ 593 while (readtoken() == TREDIR) { 594 *rpp = n2 = redirnode; 595 rpp = &n2->nfile.next; 596 parsefname(); 597 } 598 tokpushback++; 599 *rpp = NULL; 600 if (redir) { 601 if (!is_subshell) { 602 n2 = (union node *)stalloc(sizeof (struct nredir)); 603 n2->type = NREDIR; 604 n2->nredir.n = n1; 605 n1 = n2; 606 } 607 n1->nredir.redirect = redir; 608 } 609 610 return n1; 611 } 612 613 614 static union node * 615 simplecmd(union node **rpp, union node *redir) 616 { 617 union node *args, **app; 618 union node **orig_rpp = rpp; 619 union node *n = NULL; 620 int special; 621 int savecheckkwd; 622 623 /* If we don't have any redirections already, then we must reset */ 624 /* rpp to be the address of the local redir variable. */ 625 if (redir == NULL) 626 rpp = &redir; 627 628 args = NULL; 629 app = &args; 630 /* 631 * We save the incoming value, because we need this for shell 632 * functions. There can not be a redirect or an argument between 633 * the function name and the open parenthesis. 634 */ 635 orig_rpp = rpp; 636 637 savecheckkwd = CHKALIAS; 638 639 for (;;) { 640 checkkwd = savecheckkwd; 641 if (readtoken() == TWORD) { 642 n = (union node *)stalloc(sizeof (struct narg)); 643 n->type = NARG; 644 n->narg.text = wordtext; 645 n->narg.backquote = backquotelist; 646 *app = n; 647 app = &n->narg.next; 648 if (savecheckkwd != 0 && !isassignment(wordtext)) 649 savecheckkwd = 0; 650 } else if (lasttoken == TREDIR) { 651 *rpp = n = redirnode; 652 rpp = &n->nfile.next; 653 parsefname(); /* read name of redirection file */ 654 } else if (lasttoken == TLP && app == &args->narg.next 655 && rpp == orig_rpp) { 656 /* We have a function */ 657 if (readtoken() != TRP) 658 synexpect(TRP); 659 funclinno = plinno; 660 /* 661 * - Require plain text. 662 * - Functions with '/' cannot be called. 663 * - Reject name=(). 664 * - Reject ksh extended glob patterns. 665 */ 666 if (!noexpand(n->narg.text) || quoteflag || 667 strchr(n->narg.text, '/') || 668 strchr("!%*+-=?@}~", 669 n->narg.text[strlen(n->narg.text) - 1])) 670 synerror("Bad function name"); 671 rmescapes(n->narg.text); 672 if (find_builtin(n->narg.text, &special) >= 0 && 673 special) 674 synerror("Cannot override a special builtin with a function"); 675 n->type = NDEFUN; 676 n->narg.next = command(); 677 funclinno = 0; 678 return n; 679 } else { 680 tokpushback++; 681 break; 682 } 683 } 684 *app = NULL; 685 *rpp = NULL; 686 n = (union node *)stalloc(sizeof (struct ncmd)); 687 n->type = NCMD; 688 n->ncmd.args = args; 689 n->ncmd.redirect = redir; 690 return n; 691 } 692 693 static union node * 694 makename(void) 695 { 696 union node *n; 697 698 n = (union node *)stalloc(sizeof (struct narg)); 699 n->type = NARG; 700 n->narg.next = NULL; 701 n->narg.text = wordtext; 702 n->narg.backquote = backquotelist; 703 return n; 704 } 705 706 void 707 fixredir(union node *n, const char *text, int err) 708 { 709 TRACE(("Fix redir %s %d\n", text, err)); 710 if (!err) 711 n->ndup.vname = NULL; 712 713 if (is_digit(text[0]) && text[1] == '\0') 714 n->ndup.dupfd = digit_val(text[0]); 715 else if (text[0] == '-' && text[1] == '\0') 716 n->ndup.dupfd = -1; 717 else { 718 719 if (err) 720 synerror("Bad fd number"); 721 else 722 n->ndup.vname = makename(); 723 } 724 } 725 726 727 static void 728 parsefname(void) 729 { 730 union node *n = redirnode; 731 732 if (readtoken() != TWORD) 733 synexpect(-1); 734 if (n->type == NHERE) { 735 struct heredoc *here = heredoc; 736 struct heredoc *p; 737 int i; 738 739 if (quoteflag == 0) 740 n->type = NXHERE; 741 TRACE(("Here document %d\n", n->type)); 742 if (here->striptabs) { 743 while (*wordtext == '\t') 744 wordtext++; 745 } 746 if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN) 747 synerror("Illegal eof marker for << redirection"); 748 rmescapes(wordtext); 749 here->eofmark = wordtext; 750 here->next = NULL; 751 if (heredoclist == NULL) 752 heredoclist = here; 753 else { 754 for (p = heredoclist ; p->next ; p = p->next); 755 p->next = here; 756 } 757 } else if (n->type == NTOFD || n->type == NFROMFD) { 758 fixredir(n, wordtext, 0); 759 } else { 760 n->nfile.fname = makename(); 761 } 762 } 763 764 765 /* 766 * Input any here documents. 767 */ 768 769 static void 770 parseheredoc(void) 771 { 772 struct heredoc *here; 773 union node *n; 774 775 while (heredoclist) { 776 here = heredoclist; 777 heredoclist = here->next; 778 if (needprompt) { 779 setprompt(2); 780 needprompt = 0; 781 } 782 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, 783 here->eofmark, here->striptabs); 784 n = (union node *)stalloc(sizeof (struct narg)); 785 n->narg.type = NARG; 786 n->narg.next = NULL; 787 n->narg.text = wordtext; 788 n->narg.backquote = backquotelist; 789 here->here->nhere.doc = n; 790 } 791 } 792 793 static int 794 peektoken(void) 795 { 796 int t; 797 798 t = readtoken(); 799 tokpushback++; 800 return (t); 801 } 802 803 static int 804 readtoken(void) 805 { 806 int t; 807 struct alias *ap; 808 #ifdef DEBUG 809 int alreadyseen = tokpushback; 810 #endif 811 812 top: 813 t = xxreadtoken(); 814 815 /* 816 * eat newlines 817 */ 818 if (checkkwd & CHKNL) { 819 while (t == TNL) { 820 parseheredoc(); 821 t = xxreadtoken(); 822 } 823 } 824 825 /* 826 * check for keywords and aliases 827 */ 828 if (t == TWORD && !quoteflag) 829 { 830 const char * const *pp; 831 832 if (checkkwd & CHKKWD) 833 for (pp = parsekwd; *pp; pp++) { 834 if (**pp == *wordtext && equal(*pp, wordtext)) 835 { 836 lasttoken = t = pp - parsekwd + KWDOFFSET; 837 TRACE(("keyword %s recognized\n", tokname[t])); 838 goto out; 839 } 840 } 841 if (checkkwd & CHKALIAS && 842 (ap = lookupalias(wordtext, 1)) != NULL) { 843 pushstring(ap->val, strlen(ap->val), ap); 844 goto top; 845 } 846 } 847 out: 848 if (t != TNOT) 849 checkkwd = 0; 850 851 #ifdef DEBUG 852 if (!alreadyseen) 853 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 854 else 855 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 856 #endif 857 return (t); 858 } 859 860 861 /* 862 * Read the next input token. 863 * If the token is a word, we set backquotelist to the list of cmds in 864 * backquotes. We set quoteflag to true if any part of the word was 865 * quoted. 866 * If the token is TREDIR, then we set redirnode to a structure containing 867 * the redirection. 868 * In all cases, the variable startlinno is set to the number of the line 869 * on which the token starts. 870 * 871 * [Change comment: here documents and internal procedures] 872 * [Readtoken shouldn't have any arguments. Perhaps we should make the 873 * word parsing code into a separate routine. In this case, readtoken 874 * doesn't need to have any internal procedures, but parseword does. 875 * We could also make parseoperator in essence the main routine, and 876 * have parseword (readtoken1?) handle both words and redirection.] 877 */ 878 879 #define RETURN(token) return lasttoken = token 880 881 static int 882 xxreadtoken(void) 883 { 884 int c; 885 886 if (tokpushback) { 887 tokpushback = 0; 888 return lasttoken; 889 } 890 if (needprompt) { 891 setprompt(2); 892 needprompt = 0; 893 } 894 startlinno = plinno; 895 for (;;) { /* until token or start of word found */ 896 c = pgetc_macro(); 897 switch (c) { 898 case ' ': case '\t': 899 continue; 900 case '#': 901 while ((c = pgetc()) != '\n' && c != PEOF); 902 pungetc(); 903 continue; 904 case '\\': 905 if (pgetc() == '\n') { 906 startlinno = ++plinno; 907 if (doprompt) 908 setprompt(2); 909 else 910 setprompt(0); 911 continue; 912 } 913 pungetc(); 914 goto breakloop; 915 case '\n': 916 plinno++; 917 needprompt = doprompt; 918 RETURN(TNL); 919 case PEOF: 920 RETURN(TEOF); 921 case '&': 922 if (pgetc() == '&') 923 RETURN(TAND); 924 pungetc(); 925 RETURN(TBACKGND); 926 case '|': 927 if (pgetc() == '|') 928 RETURN(TOR); 929 pungetc(); 930 RETURN(TPIPE); 931 case ';': 932 c = pgetc(); 933 if (c == ';') 934 RETURN(TENDCASE); 935 else if (c == '&') 936 RETURN(TFALLTHRU); 937 pungetc(); 938 RETURN(TSEMI); 939 case '(': 940 RETURN(TLP); 941 case ')': 942 RETURN(TRP); 943 default: 944 goto breakloop; 945 } 946 } 947 breakloop: 948 return readtoken1(c, BASESYNTAX, NULL, 0); 949 #undef RETURN 950 } 951 952 953 #define MAXNEST_STATIC 8 954 struct tokenstate 955 { 956 const char *syntax; /* *SYNTAX */ 957 int parenlevel; /* levels of parentheses in arithmetic */ 958 enum tokenstate_category 959 { 960 TSTATE_TOP, 961 TSTATE_VAR_OLD, /* ${var+-=?}, inherits dquotes */ 962 TSTATE_VAR_NEW, /* other ${var...}, own dquote state */ 963 TSTATE_ARITH 964 } category; 965 }; 966 967 968 /* 969 * Called to parse command substitutions. 970 */ 971 972 static char * 973 parsebackq(char *out, struct nodelist **pbqlist, 974 int oldstyle, int dblquote, int quoted) 975 { 976 struct nodelist **nlpp; 977 union node *n; 978 char *volatile str; 979 struct jmploc jmploc; 980 struct jmploc *const savehandler = handler; 981 size_t savelen; 982 int saveprompt; 983 const int bq_startlinno = plinno; 984 char *volatile ostr = NULL; 985 struct parsefile *const savetopfile = getcurrentfile(); 986 struct heredoc *const saveheredoclist = heredoclist; 987 struct heredoc *here; 988 989 str = NULL; 990 if (setjmp(jmploc.loc)) { 991 popfilesupto(savetopfile); 992 if (str) 993 ckfree(str); 994 if (ostr) 995 ckfree(ostr); 996 heredoclist = saveheredoclist; 997 handler = savehandler; 998 if (exception == EXERROR) { 999 startlinno = bq_startlinno; 1000 synerror("Error in command substitution"); 1001 } 1002 longjmp(handler->loc, 1); 1003 } 1004 INTOFF; 1005 savelen = out - stackblock(); 1006 if (savelen > 0) { 1007 str = ckmalloc(savelen); 1008 memcpy(str, stackblock(), savelen); 1009 } 1010 handler = &jmploc; 1011 heredoclist = NULL; 1012 INTON; 1013 if (oldstyle) { 1014 /* 1015 * We must read until the closing backquote, giving special 1016 * treatment to some slashes, and then push the string and 1017 * reread it as input, interpreting it normally. 1018 */ 1019 char *oout; 1020 int c, olen; 1021 1022 STARTSTACKSTR(oout); 1023 for (;;) { 1024 if (needprompt) { 1025 setprompt(2); 1026 needprompt = 0; 1027 } 1028 CHECKSTRSPACE(2, oout); 1029 switch (c = pgetc()) { 1030 case '`': 1031 goto done; 1032 1033 case '\\': 1034 if ((c = pgetc()) == '\n') { 1035 plinno++; 1036 if (doprompt) 1037 setprompt(2); 1038 else 1039 setprompt(0); 1040 /* 1041 * If eating a newline, avoid putting 1042 * the newline into the new character 1043 * stream (via the USTPUTC after the 1044 * switch). 1045 */ 1046 continue; 1047 } 1048 if (c != '\\' && c != '`' && c != '$' 1049 && (!dblquote || c != '"')) 1050 USTPUTC('\\', oout); 1051 break; 1052 1053 case '\n': 1054 plinno++; 1055 needprompt = doprompt; 1056 break; 1057 1058 case PEOF: 1059 startlinno = plinno; 1060 synerror("EOF in backquote substitution"); 1061 break; 1062 1063 default: 1064 break; 1065 } 1066 USTPUTC(c, oout); 1067 } 1068 done: 1069 USTPUTC('\0', oout); 1070 olen = oout - stackblock(); 1071 INTOFF; 1072 ostr = ckmalloc(olen); 1073 memcpy(ostr, stackblock(), olen); 1074 setinputstring(ostr, 1); 1075 INTON; 1076 } 1077 nlpp = pbqlist; 1078 while (*nlpp) 1079 nlpp = &(*nlpp)->next; 1080 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 1081 (*nlpp)->next = NULL; 1082 1083 if (oldstyle) { 1084 saveprompt = doprompt; 1085 doprompt = 0; 1086 } 1087 1088 n = list(0, oldstyle); 1089 1090 if (oldstyle) 1091 doprompt = saveprompt; 1092 else { 1093 if (readtoken() != TRP) 1094 synexpect(TRP); 1095 } 1096 1097 (*nlpp)->n = n; 1098 if (oldstyle) { 1099 /* 1100 * Start reading from old file again, ignoring any pushed back 1101 * tokens left from the backquote parsing 1102 */ 1103 popfile(); 1104 tokpushback = 0; 1105 } 1106 STARTSTACKSTR(out); 1107 CHECKSTRSPACE(savelen + 1, out); 1108 INTOFF; 1109 if (str) { 1110 memcpy(out, str, savelen); 1111 STADJUST(savelen, out); 1112 ckfree(str); 1113 str = NULL; 1114 } 1115 if (ostr) { 1116 ckfree(ostr); 1117 ostr = NULL; 1118 } 1119 here = saveheredoclist; 1120 if (here != NULL) { 1121 while (here->next != NULL) 1122 here = here->next; 1123 here->next = heredoclist; 1124 heredoclist = saveheredoclist; 1125 } 1126 handler = savehandler; 1127 INTON; 1128 if (quoted) 1129 USTPUTC(CTLBACKQ | CTLQUOTE, out); 1130 else 1131 USTPUTC(CTLBACKQ, out); 1132 return out; 1133 } 1134 1135 1136 /* 1137 * Called to parse a backslash escape sequence inside $'...'. 1138 * The backslash has already been read. 1139 */ 1140 static char * 1141 readcstyleesc(char *out) 1142 { 1143 int c, v, i, n; 1144 1145 c = pgetc(); 1146 switch (c) { 1147 case '\0': 1148 synerror("Unterminated quoted string"); 1149 case '\n': 1150 plinno++; 1151 if (doprompt) 1152 setprompt(2); 1153 else 1154 setprompt(0); 1155 return out; 1156 case '\\': 1157 case '\'': 1158 case '"': 1159 v = c; 1160 break; 1161 case 'a': v = '\a'; break; 1162 case 'b': v = '\b'; break; 1163 case 'e': v = '\033'; break; 1164 case 'f': v = '\f'; break; 1165 case 'n': v = '\n'; break; 1166 case 'r': v = '\r'; break; 1167 case 't': v = '\t'; break; 1168 case 'v': v = '\v'; break; 1169 case 'x': 1170 v = 0; 1171 for (;;) { 1172 c = pgetc(); 1173 if (c >= '0' && c <= '9') 1174 v = (v << 4) + c - '0'; 1175 else if (c >= 'A' && c <= 'F') 1176 v = (v << 4) + c - 'A' + 10; 1177 else if (c >= 'a' && c <= 'f') 1178 v = (v << 4) + c - 'a' + 10; 1179 else 1180 break; 1181 } 1182 pungetc(); 1183 break; 1184 case '0': case '1': case '2': case '3': 1185 case '4': case '5': case '6': case '7': 1186 v = c - '0'; 1187 c = pgetc(); 1188 if (c >= '0' && c <= '7') { 1189 v <<= 3; 1190 v += c - '0'; 1191 c = pgetc(); 1192 if (c >= '0' && c <= '7') { 1193 v <<= 3; 1194 v += c - '0'; 1195 } else 1196 pungetc(); 1197 } else 1198 pungetc(); 1199 break; 1200 case 'c': 1201 c = pgetc(); 1202 if (c < 0x3f || c > 0x7a || c == 0x60) 1203 synerror("Bad escape sequence"); 1204 if (c == '\\' && pgetc() != '\\') 1205 synerror("Bad escape sequence"); 1206 if (c == '?') 1207 v = 127; 1208 else 1209 v = c & 0x1f; 1210 break; 1211 case 'u': 1212 case 'U': 1213 n = c == 'U' ? 8 : 4; 1214 v = 0; 1215 for (i = 0; i < n; i++) { 1216 c = pgetc(); 1217 if (c >= '0' && c <= '9') 1218 v = (v << 4) + c - '0'; 1219 else if (c >= 'A' && c <= 'F') 1220 v = (v << 4) + c - 'A' + 10; 1221 else if (c >= 'a' && c <= 'f') 1222 v = (v << 4) + c - 'a' + 10; 1223 else 1224 synerror("Bad escape sequence"); 1225 } 1226 if (v == 0 || (v >= 0xd800 && v <= 0xdfff)) 1227 synerror("Bad escape sequence"); 1228 /* We really need iconv here. */ 1229 if (initial_localeisutf8 && v > 127) { 1230 CHECKSTRSPACE(4, out); 1231 /* 1232 * We cannot use wctomb() as the locale may have 1233 * changed. 1234 */ 1235 if (v <= 0x7ff) { 1236 USTPUTC(0xc0 | v >> 6, out); 1237 USTPUTC(0x80 | (v & 0x3f), out); 1238 return out; 1239 } else if (v <= 0xffff) { 1240 USTPUTC(0xe0 | v >> 12, out); 1241 USTPUTC(0x80 | ((v >> 6) & 0x3f), out); 1242 USTPUTC(0x80 | (v & 0x3f), out); 1243 return out; 1244 } else if (v <= 0x10ffff) { 1245 USTPUTC(0xf0 | v >> 18, out); 1246 USTPUTC(0x80 | ((v >> 12) & 0x3f), out); 1247 USTPUTC(0x80 | ((v >> 6) & 0x3f), out); 1248 USTPUTC(0x80 | (v & 0x3f), out); 1249 return out; 1250 } 1251 } 1252 if (v > 127) 1253 v = '?'; 1254 break; 1255 default: 1256 synerror("Bad escape sequence"); 1257 } 1258 v = (char)v; 1259 /* 1260 * We can't handle NUL bytes. 1261 * POSIX says we should skip till the closing quote. 1262 */ 1263 if (v == '\0') { 1264 while ((c = pgetc()) != '\'') { 1265 if (c == '\\') 1266 c = pgetc(); 1267 if (c == PEOF) 1268 synerror("Unterminated quoted string"); 1269 } 1270 pungetc(); 1271 return out; 1272 } 1273 if (SQSYNTAX[v] == CCTL) 1274 USTPUTC(CTLESC, out); 1275 USTPUTC(v, out); 1276 return out; 1277 } 1278 1279 1280 /* 1281 * If eofmark is NULL, read a word or a redirection symbol. If eofmark 1282 * is not NULL, read a here document. In the latter case, eofmark is the 1283 * word which marks the end of the document and striptabs is true if 1284 * leading tabs should be stripped from the document. The argument firstc 1285 * is the first character of the input token or document. 1286 * 1287 * Because C does not have internal subroutines, I have simulated them 1288 * using goto's to implement the subroutine linkage. The following macros 1289 * will run code that appears at the end of readtoken1. 1290 */ 1291 1292 #define CHECKEND() {goto checkend; checkend_return:;} 1293 #define PARSEREDIR() {goto parseredir; parseredir_return:;} 1294 #define PARSESUB() {goto parsesub; parsesub_return:;} 1295 #define PARSEARITH() {goto parsearith; parsearith_return:;} 1296 1297 static int 1298 readtoken1(int firstc, char const *initialsyntax, const char *eofmark, 1299 int striptabs) 1300 { 1301 int c = firstc; 1302 char * volatile out; 1303 int len; 1304 char line[EOFMARKLEN + 1]; 1305 struct nodelist *bqlist; 1306 volatile int quotef; 1307 int newvarnest; 1308 int level; 1309 int synentry; 1310 struct tokenstate state_static[MAXNEST_STATIC]; 1311 int maxnest = MAXNEST_STATIC; 1312 struct tokenstate *state = state_static; 1313 int sqiscstyle = 0; 1314 1315 startlinno = plinno; 1316 quotef = 0; 1317 bqlist = NULL; 1318 newvarnest = 0; 1319 level = 0; 1320 state[level].syntax = initialsyntax; 1321 state[level].parenlevel = 0; 1322 state[level].category = TSTATE_TOP; 1323 1324 STARTSTACKSTR(out); 1325 loop: { /* for each line, until end of word */ 1326 CHECKEND(); /* set c to PEOF if at end of here document */ 1327 for (;;) { /* until end of line or end of word */ 1328 CHECKSTRSPACE(4, out); /* permit 4 calls to USTPUTC */ 1329 1330 synentry = state[level].syntax[c]; 1331 1332 switch(synentry) { 1333 case CNL: /* '\n' */ 1334 if (state[level].syntax == BASESYNTAX) 1335 goto endword; /* exit outer loop */ 1336 USTPUTC(c, out); 1337 plinno++; 1338 if (doprompt) 1339 setprompt(2); 1340 else 1341 setprompt(0); 1342 c = pgetc(); 1343 goto loop; /* continue outer loop */ 1344 case CSBACK: 1345 if (sqiscstyle) { 1346 out = readcstyleesc(out); 1347 break; 1348 } 1349 /* FALLTHROUGH */ 1350 case CWORD: 1351 USTPUTC(c, out); 1352 break; 1353 case CCTL: 1354 if (eofmark == NULL || initialsyntax != SQSYNTAX) 1355 USTPUTC(CTLESC, out); 1356 USTPUTC(c, out); 1357 break; 1358 case CBACK: /* backslash */ 1359 c = pgetc(); 1360 if (c == PEOF) { 1361 USTPUTC('\\', out); 1362 pungetc(); 1363 } else if (c == '\n') { 1364 plinno++; 1365 if (doprompt) 1366 setprompt(2); 1367 else 1368 setprompt(0); 1369 } else { 1370 if (state[level].syntax == DQSYNTAX && 1371 c != '\\' && c != '`' && c != '$' && 1372 (c != '"' || (eofmark != NULL && 1373 newvarnest == 0)) && 1374 (c != '}' || state[level].category != TSTATE_VAR_OLD)) 1375 USTPUTC('\\', out); 1376 if ((eofmark == NULL || 1377 newvarnest > 0) && 1378 state[level].syntax == BASESYNTAX) 1379 USTPUTC(CTLQUOTEMARK, out); 1380 if (SQSYNTAX[c] == CCTL) 1381 USTPUTC(CTLESC, out); 1382 USTPUTC(c, out); 1383 if ((eofmark == NULL || 1384 newvarnest > 0) && 1385 state[level].syntax == BASESYNTAX && 1386 state[level].category == TSTATE_VAR_OLD) 1387 USTPUTC(CTLQUOTEEND, out); 1388 quotef++; 1389 } 1390 break; 1391 case CSQUOTE: 1392 USTPUTC(CTLQUOTEMARK, out); 1393 state[level].syntax = SQSYNTAX; 1394 sqiscstyle = 0; 1395 break; 1396 case CDQUOTE: 1397 USTPUTC(CTLQUOTEMARK, out); 1398 state[level].syntax = DQSYNTAX; 1399 break; 1400 case CENDQUOTE: 1401 if (eofmark != NULL && newvarnest == 0) 1402 USTPUTC(c, out); 1403 else { 1404 if (state[level].category == TSTATE_VAR_OLD) 1405 USTPUTC(CTLQUOTEEND, out); 1406 state[level].syntax = BASESYNTAX; 1407 quotef++; 1408 } 1409 break; 1410 case CVAR: /* '$' */ 1411 PARSESUB(); /* parse substitution */ 1412 break; 1413 case CENDVAR: /* '}' */ 1414 if (level > 0 && 1415 ((state[level].category == TSTATE_VAR_OLD && 1416 state[level].syntax == 1417 state[level - 1].syntax) || 1418 (state[level].category == TSTATE_VAR_NEW && 1419 state[level].syntax == BASESYNTAX))) { 1420 if (state[level].category == TSTATE_VAR_NEW) 1421 newvarnest--; 1422 level--; 1423 USTPUTC(CTLENDVAR, out); 1424 } else { 1425 USTPUTC(c, out); 1426 } 1427 break; 1428 case CLP: /* '(' in arithmetic */ 1429 state[level].parenlevel++; 1430 USTPUTC(c, out); 1431 break; 1432 case CRP: /* ')' in arithmetic */ 1433 if (state[level].parenlevel > 0) { 1434 USTPUTC(c, out); 1435 --state[level].parenlevel; 1436 } else { 1437 if (pgetc() == ')') { 1438 if (level > 0 && 1439 state[level].category == TSTATE_ARITH) { 1440 level--; 1441 USTPUTC(CTLENDARI, out); 1442 } else 1443 USTPUTC(')', out); 1444 } else { 1445 /* 1446 * unbalanced parens 1447 * (don't 2nd guess - no error) 1448 */ 1449 pungetc(); 1450 USTPUTC(')', out); 1451 } 1452 } 1453 break; 1454 case CBQUOTE: /* '`' */ 1455 out = parsebackq(out, &bqlist, 1, 1456 state[level].syntax == DQSYNTAX && 1457 (eofmark == NULL || newvarnest > 0), 1458 state[level].syntax == DQSYNTAX || state[level].syntax == ARISYNTAX); 1459 break; 1460 case CEOF: 1461 goto endword; /* exit outer loop */ 1462 case CIGN: 1463 break; 1464 default: 1465 if (level == 0) 1466 goto endword; /* exit outer loop */ 1467 USTPUTC(c, out); 1468 } 1469 c = pgetc_macro(); 1470 } 1471 } 1472 endword: 1473 if (state[level].syntax == ARISYNTAX) 1474 synerror("Missing '))'"); 1475 if (state[level].syntax != BASESYNTAX && eofmark == NULL) 1476 synerror("Unterminated quoted string"); 1477 if (state[level].category == TSTATE_VAR_OLD || 1478 state[level].category == TSTATE_VAR_NEW) { 1479 startlinno = plinno; 1480 synerror("Missing '}'"); 1481 } 1482 if (state != state_static) 1483 parser_temp_free_upto(state); 1484 USTPUTC('\0', out); 1485 len = out - stackblock(); 1486 out = stackblock(); 1487 if (eofmark == NULL) { 1488 if ((c == '>' || c == '<') 1489 && quotef == 0 1490 && len <= 2 1491 && (*out == '\0' || is_digit(*out))) { 1492 PARSEREDIR(); 1493 return lasttoken = TREDIR; 1494 } else { 1495 pungetc(); 1496 } 1497 } 1498 quoteflag = quotef; 1499 backquotelist = bqlist; 1500 grabstackblock(len); 1501 wordtext = out; 1502 return lasttoken = TWORD; 1503 /* end of readtoken routine */ 1504 1505 1506 /* 1507 * Check to see whether we are at the end of the here document. When this 1508 * is called, c is set to the first character of the next input line. If 1509 * we are at the end of the here document, this routine sets the c to PEOF. 1510 */ 1511 1512 checkend: { 1513 if (eofmark) { 1514 if (striptabs) { 1515 while (c == '\t') 1516 c = pgetc(); 1517 } 1518 if (c == *eofmark) { 1519 if (pfgets(line, sizeof line) != NULL) { 1520 const char *p, *q; 1521 1522 p = line; 1523 for (q = eofmark + 1 ; *q && *p == *q ; p++, q++); 1524 if ((*p == '\0' || *p == '\n') && *q == '\0') { 1525 c = PEOF; 1526 if (*p == '\n') { 1527 plinno++; 1528 needprompt = doprompt; 1529 } 1530 } else { 1531 pushstring(line, strlen(line), NULL); 1532 } 1533 } 1534 } 1535 } 1536 goto checkend_return; 1537 } 1538 1539 1540 /* 1541 * Parse a redirection operator. The variable "out" points to a string 1542 * specifying the fd to be redirected. The variable "c" contains the 1543 * first character of the redirection operator. 1544 */ 1545 1546 parseredir: { 1547 char fd = *out; 1548 union node *np; 1549 1550 np = (union node *)stalloc(sizeof (struct nfile)); 1551 if (c == '>') { 1552 np->nfile.fd = 1; 1553 c = pgetc(); 1554 if (c == '>') 1555 np->type = NAPPEND; 1556 else if (c == '&') 1557 np->type = NTOFD; 1558 else if (c == '|') 1559 np->type = NCLOBBER; 1560 else { 1561 np->type = NTO; 1562 pungetc(); 1563 } 1564 } else { /* c == '<' */ 1565 np->nfile.fd = 0; 1566 c = pgetc(); 1567 if (c == '<') { 1568 if (sizeof (struct nfile) != sizeof (struct nhere)) { 1569 np = (union node *)stalloc(sizeof (struct nhere)); 1570 np->nfile.fd = 0; 1571 } 1572 np->type = NHERE; 1573 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); 1574 heredoc->here = np; 1575 if ((c = pgetc()) == '-') { 1576 heredoc->striptabs = 1; 1577 } else { 1578 heredoc->striptabs = 0; 1579 pungetc(); 1580 } 1581 } else if (c == '&') 1582 np->type = NFROMFD; 1583 else if (c == '>') 1584 np->type = NFROMTO; 1585 else { 1586 np->type = NFROM; 1587 pungetc(); 1588 } 1589 } 1590 if (fd != '\0') 1591 np->nfile.fd = digit_val(fd); 1592 redirnode = np; 1593 goto parseredir_return; 1594 } 1595 1596 1597 /* 1598 * Parse a substitution. At this point, we have read the dollar sign 1599 * and nothing else. 1600 */ 1601 1602 parsesub: { 1603 char buf[10]; 1604 int subtype; 1605 int typeloc; 1606 int flags; 1607 char *p; 1608 static const char types[] = "}-+?="; 1609 int bracketed_name = 0; /* used to handle ${[0-9]*} variables */ 1610 int linno; 1611 int length; 1612 int c1; 1613 1614 c = pgetc(); 1615 if (c == '(') { /* $(command) or $((arith)) */ 1616 if (pgetc() == '(') { 1617 PARSEARITH(); 1618 } else { 1619 pungetc(); 1620 out = parsebackq(out, &bqlist, 0, 1621 state[level].syntax == DQSYNTAX && 1622 (eofmark == NULL || newvarnest > 0), 1623 state[level].syntax == DQSYNTAX || 1624 state[level].syntax == ARISYNTAX); 1625 } 1626 } else if (c == '{' || is_name(c) || is_special(c)) { 1627 USTPUTC(CTLVAR, out); 1628 typeloc = out - stackblock(); 1629 USTPUTC(VSNORMAL, out); 1630 subtype = VSNORMAL; 1631 flags = 0; 1632 if (c == '{') { 1633 bracketed_name = 1; 1634 c = pgetc(); 1635 subtype = 0; 1636 } 1637 varname: 1638 if (!is_eof(c) && is_name(c)) { 1639 length = 0; 1640 do { 1641 STPUTC(c, out); 1642 c = pgetc(); 1643 length++; 1644 } while (!is_eof(c) && is_in_name(c)); 1645 if (length == 6 && 1646 strncmp(out - length, "LINENO", length) == 0) { 1647 /* Replace the variable name with the 1648 * current line number. */ 1649 linno = plinno; 1650 if (funclinno != 0) 1651 linno -= funclinno - 1; 1652 snprintf(buf, sizeof(buf), "%d", linno); 1653 STADJUST(-6, out); 1654 STPUTS(buf, out); 1655 flags |= VSLINENO; 1656 } 1657 } else if (is_digit(c)) { 1658 if (bracketed_name) { 1659 do { 1660 STPUTC(c, out); 1661 c = pgetc(); 1662 } while (is_digit(c)); 1663 } else { 1664 STPUTC(c, out); 1665 c = pgetc(); 1666 } 1667 } else if (is_special(c)) { 1668 c1 = c; 1669 c = pgetc(); 1670 if (subtype == 0 && c1 == '#') { 1671 subtype = VSLENGTH; 1672 if (strchr(types, c) == NULL && c != ':' && 1673 c != '#' && c != '%') 1674 goto varname; 1675 c1 = c; 1676 c = pgetc(); 1677 if (c1 != '}' && c == '}') { 1678 pungetc(); 1679 c = c1; 1680 goto varname; 1681 } 1682 pungetc(); 1683 c = c1; 1684 c1 = '#'; 1685 subtype = 0; 1686 } 1687 USTPUTC(c1, out); 1688 } else { 1689 subtype = VSERROR; 1690 if (c == '}') 1691 pungetc(); 1692 else if (c == '\n' || c == PEOF) 1693 synerror("Unexpected end of line in substitution"); 1694 else 1695 USTPUTC(c, out); 1696 } 1697 if (subtype == 0) { 1698 switch (c) { 1699 case ':': 1700 flags |= VSNUL; 1701 c = pgetc(); 1702 /*FALLTHROUGH*/ 1703 default: 1704 p = strchr(types, c); 1705 if (p == NULL) { 1706 if (c == '\n' || c == PEOF) 1707 synerror("Unexpected end of line in substitution"); 1708 if (flags == VSNUL) 1709 STPUTC(':', out); 1710 STPUTC(c, out); 1711 subtype = VSERROR; 1712 } else 1713 subtype = p - types + VSNORMAL; 1714 break; 1715 case '%': 1716 case '#': 1717 { 1718 int cc = c; 1719 subtype = c == '#' ? VSTRIMLEFT : 1720 VSTRIMRIGHT; 1721 c = pgetc(); 1722 if (c == cc) 1723 subtype++; 1724 else 1725 pungetc(); 1726 break; 1727 } 1728 } 1729 } else if (subtype != VSERROR) { 1730 if (subtype == VSLENGTH && c != '}') 1731 subtype = VSERROR; 1732 pungetc(); 1733 } 1734 STPUTC('=', out); 1735 if (state[level].syntax == DQSYNTAX || 1736 state[level].syntax == ARISYNTAX) 1737 flags |= VSQUOTE; 1738 *(stackblock() + typeloc) = subtype | flags; 1739 if (subtype != VSNORMAL) { 1740 if (level + 1 >= maxnest) { 1741 maxnest *= 2; 1742 if (state == state_static) { 1743 state = parser_temp_alloc( 1744 maxnest * sizeof(*state)); 1745 memcpy(state, state_static, 1746 MAXNEST_STATIC * sizeof(*state)); 1747 } else 1748 state = parser_temp_realloc(state, 1749 maxnest * sizeof(*state)); 1750 } 1751 level++; 1752 state[level].parenlevel = 0; 1753 if (subtype == VSMINUS || subtype == VSPLUS || 1754 subtype == VSQUESTION || subtype == VSASSIGN) { 1755 /* 1756 * For operators that were in the Bourne shell, 1757 * inherit the double-quote state. 1758 */ 1759 state[level].syntax = state[level - 1].syntax; 1760 state[level].category = TSTATE_VAR_OLD; 1761 } else { 1762 /* 1763 * The other operators take a pattern, 1764 * so go to BASESYNTAX. 1765 * Also, ' and " are now special, even 1766 * in here documents. 1767 */ 1768 state[level].syntax = BASESYNTAX; 1769 state[level].category = TSTATE_VAR_NEW; 1770 newvarnest++; 1771 } 1772 } 1773 } else if (c == '\'' && state[level].syntax == BASESYNTAX) { 1774 /* $'cstylequotes' */ 1775 USTPUTC(CTLQUOTEMARK, out); 1776 state[level].syntax = SQSYNTAX; 1777 sqiscstyle = 1; 1778 } else { 1779 USTPUTC('$', out); 1780 pungetc(); 1781 } 1782 goto parsesub_return; 1783 } 1784 1785 1786 /* 1787 * Parse an arithmetic expansion (indicate start of one and set state) 1788 */ 1789 parsearith: { 1790 1791 if (level + 1 >= maxnest) { 1792 maxnest *= 2; 1793 if (state == state_static) { 1794 state = parser_temp_alloc( 1795 maxnest * sizeof(*state)); 1796 memcpy(state, state_static, 1797 MAXNEST_STATIC * sizeof(*state)); 1798 } else 1799 state = parser_temp_realloc(state, 1800 maxnest * sizeof(*state)); 1801 } 1802 level++; 1803 state[level].syntax = ARISYNTAX; 1804 state[level].parenlevel = 0; 1805 state[level].category = TSTATE_ARITH; 1806 USTPUTC(CTLARI, out); 1807 if (state[level - 1].syntax == DQSYNTAX) 1808 USTPUTC('"',out); 1809 else 1810 USTPUTC(' ',out); 1811 goto parsearith_return; 1812 } 1813 1814 } /* end of readtoken */ 1815 1816 1817 void 1818 resetparser(void) 1819 { 1820 tokpushback = 0; 1821 checkkwd = 0; 1822 } 1823 1824 1825 /* 1826 * Returns true if the text contains nothing to expand (no dollar signs 1827 * or backquotes). 1828 */ 1829 1830 static int 1831 noexpand(char *text) 1832 { 1833 char *p; 1834 char c; 1835 1836 p = text; 1837 while ((c = *p++) != '\0') { 1838 if ( c == CTLQUOTEMARK) 1839 continue; 1840 if (c == CTLESC) 1841 p++; 1842 else if (BASESYNTAX[(int)c] == CCTL) 1843 return 0; 1844 } 1845 return 1; 1846 } 1847 1848 1849 /* 1850 * Return true if the argument is a legal variable name (a letter or 1851 * underscore followed by zero or more letters, underscores, and digits). 1852 */ 1853 1854 int 1855 goodname(const char *name) 1856 { 1857 const char *p; 1858 1859 p = name; 1860 if (! is_name(*p)) 1861 return 0; 1862 while (*++p) { 1863 if (! is_in_name(*p)) 1864 return 0; 1865 } 1866 return 1; 1867 } 1868 1869 1870 int 1871 isassignment(const char *p) 1872 { 1873 if (!is_name(*p)) 1874 return 0; 1875 p++; 1876 for (;;) { 1877 if (*p == '=') 1878 return 1; 1879 else if (!is_in_name(*p)) 1880 return 0; 1881 p++; 1882 } 1883 } 1884 1885 1886 /* 1887 * Called when an unexpected token is read during the parse. The argument 1888 * is the token that is expected, or -1 if more than one type of token can 1889 * occur at this point. 1890 */ 1891 1892 static void 1893 synexpect(int token) 1894 { 1895 char msg[64]; 1896 1897 if (token >= 0) { 1898 fmtstr(msg, 64, "%s unexpected (expecting %s)", 1899 tokname[lasttoken], tokname[token]); 1900 } else { 1901 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]); 1902 } 1903 synerror(msg); 1904 } 1905 1906 1907 static void 1908 synerror(const char *msg) 1909 { 1910 if (commandname) 1911 outfmt(out2, "%s: %d: ", commandname, startlinno); 1912 outfmt(out2, "Syntax error: %s\n", msg); 1913 error(NULL); 1914 } 1915 1916 static void 1917 setprompt(int which) 1918 { 1919 whichprompt = which; 1920 1921 #ifndef NO_HISTORY 1922 if (!el) 1923 #endif 1924 { 1925 out2str(getprompt(NULL)); 1926 flushout(out2); 1927 } 1928 } 1929 1930 /* 1931 * called by editline -- any expansions to the prompt 1932 * should be added here. 1933 */ 1934 const char * 1935 getprompt(void *unused __unused) 1936 { 1937 static char ps[PROMPTLEN]; 1938 const char *fmt; 1939 const char *pwd; 1940 int i, trim; 1941 1942 /* 1943 * Select prompt format. 1944 */ 1945 switch (whichprompt) { 1946 case 0: 1947 fmt = ""; 1948 break; 1949 case 1: 1950 fmt = ps1val(); 1951 break; 1952 case 2: 1953 fmt = ps2val(); 1954 break; 1955 default: 1956 return "??"; 1957 } 1958 1959 /* 1960 * Format prompt string. 1961 */ 1962 for (i = 0; (i < 127) && (*fmt != '\0'); i++, fmt++) 1963 if (*fmt == '\\') 1964 switch (*++fmt) { 1965 1966 /* 1967 * Hostname. 1968 * 1969 * \h specifies just the local hostname, 1970 * \H specifies fully-qualified hostname. 1971 */ 1972 case 'h': 1973 case 'H': 1974 ps[i] = '\0'; 1975 gethostname(&ps[i], PROMPTLEN - i); 1976 /* Skip to end of hostname. */ 1977 trim = (*fmt == 'h') ? '.' : '\0'; 1978 while ((ps[i+1] != '\0') && (ps[i+1] != trim)) 1979 i++; 1980 break; 1981 1982 /* 1983 * Working directory. 1984 * 1985 * \W specifies just the final component, 1986 * \w specifies the entire path. 1987 */ 1988 case 'W': 1989 case 'w': 1990 pwd = lookupvar("PWD"); 1991 if (pwd == NULL) 1992 pwd = "?"; 1993 if (*fmt == 'W' && 1994 *pwd == '/' && pwd[1] != '\0') 1995 strlcpy(&ps[i], strrchr(pwd, '/') + 1, 1996 PROMPTLEN - i); 1997 else 1998 strlcpy(&ps[i], pwd, PROMPTLEN - i); 1999 /* Skip to end of path. */ 2000 while (ps[i + 1] != '\0') 2001 i++; 2002 break; 2003 2004 /* 2005 * Superuser status. 2006 * 2007 * '$' for normal users, '#' for root. 2008 */ 2009 case '$': 2010 ps[i] = (geteuid() != 0) ? '$' : '#'; 2011 break; 2012 2013 /* 2014 * A literal \. 2015 */ 2016 case '\\': 2017 ps[i] = '\\'; 2018 break; 2019 2020 /* 2021 * Emit unrecognized formats verbatim. 2022 */ 2023 default: 2024 ps[i++] = '\\'; 2025 ps[i] = *fmt; 2026 break; 2027 } 2028 else 2029 ps[i] = *fmt; 2030 ps[i] = '\0'; 2031 return (ps); 2032 } 2033 2034 2035 const char * 2036 expandstr(const char *ps) 2037 { 2038 union node n; 2039 struct jmploc jmploc; 2040 struct jmploc *const savehandler = handler; 2041 const int saveprompt = doprompt; 2042 struct parsefile *const savetopfile = getcurrentfile(); 2043 struct parser_temp *const saveparser_temp = parser_temp; 2044 const char *result = NULL; 2045 2046 if (!setjmp(jmploc.loc)) { 2047 handler = &jmploc; 2048 parser_temp = NULL; 2049 setinputstring(ps, 1); 2050 doprompt = 0; 2051 readtoken1(pgetc(), DQSYNTAX, __DECONST(char *, "\n\n"), 0); 2052 if (backquotelist != NULL) 2053 error("Command substitution not allowed here"); 2054 2055 n.narg.type = NARG; 2056 n.narg.next = NULL; 2057 n.narg.text = wordtext; 2058 n.narg.backquote = backquotelist; 2059 2060 expandarg(&n, NULL, 0); 2061 result = stackblock(); 2062 INTOFF; 2063 } 2064 handler = savehandler; 2065 doprompt = saveprompt; 2066 popfilesupto(savetopfile); 2067 if (parser_temp != saveparser_temp) { 2068 parser_temp_free_all(); 2069 parser_temp = saveparser_temp; 2070 } 2071 if (result != NULL) { 2072 INTON; 2073 } else if (exception == EXINT) 2074 raise(SIGINT); 2075 return result; 2076 } 2077