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