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. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)parser.c 8.7 (Berkeley) 5/16/95 37 * $FreeBSD: src/bin/sh/parser.c,v 1.112 2011/05/21 22:03:06 jilles Exp $ 38 */ 39 40 #include <stdio.h> 41 #include <stdlib.h> 42 #include <unistd.h> 43 44 #include "shell.h" 45 #include "parser.h" 46 #include "nodes.h" 47 #include "expand.h" /* defines rmescapes() */ 48 #include "syntax.h" 49 #include "options.h" 50 #include "input.h" 51 #include "output.h" 52 #include "var.h" 53 #include "error.h" 54 #include "memalloc.h" 55 #include "mystring.h" 56 #include "alias.h" 57 #include "show.h" 58 #include "eval.h" 59 #include "exec.h" /* to check for special builtins */ 60 #ifndef NO_HISTORY 61 #include "myhistedit.h" 62 #endif 63 64 /* 65 * Shell command parser. 66 */ 67 68 #define EOFMARKLEN 79 69 #define PROMPTLEN 128 70 71 /* values of checkkwd variable */ 72 #define CHKALIAS 0x1 73 #define CHKKWD 0x2 74 #define CHKNL 0x4 75 76 /* values returned by readtoken */ 77 #include "token.h" 78 79 80 81 struct heredoc { 82 struct heredoc *next; /* next here document in list */ 83 union node *here; /* redirection node */ 84 char *eofmark; /* string indicating end of input */ 85 int striptabs; /* if set, strip leading tabs */ 86 }; 87 88 struct parser_temp { 89 struct parser_temp *next; 90 void *data; 91 }; 92 93 94 static struct heredoc *heredoclist; /* list of here documents to read */ 95 static int doprompt; /* if set, prompt the user */ 96 static int needprompt; /* true if interactive and at start of line */ 97 static int lasttoken; /* last token read */ 98 MKINIT int tokpushback; /* last token pushed back */ 99 static char *wordtext; /* text of last word returned by readtoken */ 100 MKINIT int checkkwd; /* 1 == check for kwds, 2 == also eat newlines */ 101 static struct nodelist *backquotelist; 102 static union node *redirnode; 103 static struct heredoc *heredoc; 104 static int quoteflag; /* set if (part of) last token was quoted */ 105 static int startlinno; /* line # where last token started */ 106 static int funclinno; /* line # where the current function started */ 107 static struct parser_temp *parser_temp; 108 109 110 static union node *list(int, int); 111 static union node *andor(void); 112 static union node *pipeline(void); 113 static union node *command(void); 114 static union node *simplecmd(union node **, union node *); 115 static union node *makename(void); 116 static void parsefname(void); 117 static void parseheredoc(void); 118 static int peektoken(void); 119 static int readtoken(void); 120 static int xxreadtoken(void); 121 static int readtoken1(int, char const *, char *, int); 122 static int noexpand(char *); 123 static void synexpect(int) __dead2; 124 static void synerror(const char *) __dead2; 125 static void setprompt(int); 126 127 128 static void * 129 parser_temp_alloc(size_t len) 130 { 131 struct parser_temp *t; 132 133 INTOFF; 134 t = ckmalloc(sizeof(*t)); 135 t->data = NULL; 136 t->next = parser_temp; 137 parser_temp = t; 138 t->data = ckmalloc(len); 139 INTON; 140 return t->data; 141 } 142 143 144 static void * 145 parser_temp_realloc(void *ptr, size_t len) 146 { 147 struct parser_temp *t; 148 149 INTOFF; 150 t = parser_temp; 151 if (ptr != t->data) 152 error("bug: parser_temp_realloc misused"); 153 t->data = ckrealloc(t->data, len); 154 INTON; 155 return t->data; 156 } 157 158 159 static void 160 parser_temp_free_upto(void *ptr) 161 { 162 struct parser_temp *t; 163 int done = 0; 164 165 INTOFF; 166 while (parser_temp != NULL && !done) { 167 t = parser_temp; 168 parser_temp = t->next; 169 done = t->data == ptr; 170 ckfree(t->data); 171 ckfree(t); 172 } 173 INTON; 174 if (!done) 175 error("bug: parser_temp_free_upto misused"); 176 } 177 178 179 static void 180 parser_temp_free_all(void) 181 { 182 struct parser_temp *t; 183 184 INTOFF; 185 while (parser_temp != NULL) { 186 t = parser_temp; 187 parser_temp = t->next; 188 ckfree(t->data); 189 ckfree(t); 190 } 191 INTON; 192 } 193 194 195 /* 196 * Read and parse a command. Returns NEOF on end of file. (NULL is a 197 * valid parse tree indicating a blank line.) 198 */ 199 200 union node * 201 parsecmd(int interact) 202 { 203 int t; 204 205 /* This assumes the parser is not re-entered, 206 * which could happen if we add command substitution on PS1/PS2. 207 */ 208 parser_temp_free_all(); 209 heredoclist = NULL; 210 211 tokpushback = 0; 212 doprompt = interact; 213 if (doprompt) 214 setprompt(1); 215 else 216 setprompt(0); 217 needprompt = 0; 218 t = readtoken(); 219 if (t == TEOF) 220 return NEOF; 221 if (t == TNL) 222 return NULL; 223 tokpushback++; 224 return list(1, 1); 225 } 226 227 228 static union node * 229 list(int nlflag, int erflag) 230 { 231 union node *ntop, *n1, *n2, *n3; 232 int tok; 233 234 checkkwd = CHKNL | CHKKWD | CHKALIAS; 235 if (!nlflag && !erflag && tokendlist[peektoken()]) 236 return NULL; 237 ntop = n1 = NULL; 238 for (;;) { 239 n2 = andor(); 240 tok = readtoken(); 241 if (tok == TBACKGND) { 242 if (n2->type == NCMD || n2->type == NPIPE) { 243 n2->ncmd.backgnd = 1; 244 } else if (n2->type == NREDIR) { 245 n2->type = NBACKGND; 246 } else { 247 n3 = (union node *)stalloc(sizeof (struct nredir)); 248 n3->type = NBACKGND; 249 n3->nredir.n = n2; 250 n3->nredir.redirect = NULL; 251 n2 = n3; 252 } 253 } 254 if (ntop == NULL) 255 ntop = n2; 256 else if (n1 == NULL) { 257 n1 = (union node *)stalloc(sizeof (struct nbinary)); 258 n1->type = NSEMI; 259 n1->nbinary.ch1 = ntop; 260 n1->nbinary.ch2 = n2; 261 ntop = n1; 262 } 263 else { 264 n3 = (union node *)stalloc(sizeof (struct nbinary)); 265 n3->type = NSEMI; 266 n3->nbinary.ch1 = n1->nbinary.ch2; 267 n3->nbinary.ch2 = n2; 268 n1->nbinary.ch2 = n3; 269 n1 = n3; 270 } 271 switch (tok) { 272 case TBACKGND: 273 case TSEMI: 274 tok = readtoken(); 275 /* FALLTHROUGH */ 276 case TNL: 277 if (tok == TNL) { 278 parseheredoc(); 279 if (nlflag) 280 return ntop; 281 } else if (tok == TEOF && nlflag) { 282 parseheredoc(); 283 return ntop; 284 } else { 285 tokpushback++; 286 } 287 checkkwd = CHKNL | CHKKWD | CHKALIAS; 288 if (!nlflag && !erflag && tokendlist[peektoken()]) 289 return ntop; 290 break; 291 case TEOF: 292 if (heredoclist) 293 parseheredoc(); 294 else 295 pungetc(); /* push back EOF on input */ 296 return ntop; 297 default: 298 if (nlflag || erflag) 299 synexpect(-1); 300 tokpushback++; 301 return ntop; 302 } 303 } 304 } 305 306 307 308 static union node * 309 andor(void) 310 { 311 union node *n1, *n2, *n3; 312 int t; 313 314 n1 = pipeline(); 315 for (;;) { 316 if ((t = readtoken()) == TAND) { 317 t = NAND; 318 } else if (t == TOR) { 319 t = NOR; 320 } else { 321 tokpushback++; 322 return n1; 323 } 324 n2 = pipeline(); 325 n3 = (union node *)stalloc(sizeof (struct nbinary)); 326 n3->type = t; 327 n3->nbinary.ch1 = n1; 328 n3->nbinary.ch2 = n2; 329 n1 = n3; 330 } 331 } 332 333 334 335 static union node * 336 pipeline(void) 337 { 338 union node *n1, *n2, *pipenode; 339 struct nodelist *lp, *prev; 340 int negate, t; 341 342 negate = 0; 343 checkkwd = CHKNL | CHKKWD | CHKALIAS; 344 TRACE(("pipeline: entered\n")); 345 while (readtoken() == TNOT) 346 negate = !negate; 347 tokpushback++; 348 n1 = command(); 349 if (readtoken() == TPIPE) { 350 pipenode = (union node *)stalloc(sizeof (struct npipe)); 351 pipenode->type = NPIPE; 352 pipenode->npipe.backgnd = 0; 353 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 354 pipenode->npipe.cmdlist = lp; 355 lp->n = n1; 356 do { 357 prev = lp; 358 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 359 checkkwd = CHKNL | CHKKWD | CHKALIAS; 360 t = readtoken(); 361 tokpushback++; 362 if (t == TNOT) 363 lp->n = pipeline(); 364 else 365 lp->n = command(); 366 prev->next = lp; 367 } while (readtoken() == TPIPE); 368 lp->next = NULL; 369 n1 = pipenode; 370 } 371 tokpushback++; 372 if (negate) { 373 n2 = (union node *)stalloc(sizeof (struct nnot)); 374 n2->type = NNOT; 375 n2->nnot.com = n1; 376 return n2; 377 } else 378 return n1; 379 } 380 381 382 383 static union node * 384 command(void) 385 { 386 union node *n1, *n2; 387 union node *ap, **app; 388 union node *cp, **cpp; 389 union node *redir, **rpp; 390 int t; 391 int is_subshell; 392 393 checkkwd = CHKNL | CHKKWD | CHKALIAS; 394 is_subshell = 0; 395 redir = NULL; 396 n1 = NULL; 397 rpp = &redir; 398 399 /* Check for redirection which may precede command */ 400 while (readtoken() == TREDIR) { 401 *rpp = n2 = redirnode; 402 rpp = &n2->nfile.next; 403 parsefname(); 404 } 405 tokpushback++; 406 407 switch (readtoken()) { 408 case TIF: 409 n1 = (union node *)stalloc(sizeof (struct nif)); 410 n1->type = NIF; 411 if ((n1->nif.test = list(0, 0)) == NULL) 412 synexpect(-1); 413 if (readtoken() != TTHEN) 414 synexpect(TTHEN); 415 n1->nif.ifpart = list(0, 0); 416 n2 = n1; 417 while (readtoken() == TELIF) { 418 n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif)); 419 n2 = n2->nif.elsepart; 420 n2->type = NIF; 421 if ((n2->nif.test = list(0, 0)) == NULL) 422 synexpect(-1); 423 if (readtoken() != TTHEN) 424 synexpect(TTHEN); 425 n2->nif.ifpart = list(0, 0); 426 } 427 if (lasttoken == TELSE) 428 n2->nif.elsepart = list(0, 0); 429 else { 430 n2->nif.elsepart = NULL; 431 tokpushback++; 432 } 433 if (readtoken() != TFI) 434 synexpect(TFI); 435 checkkwd = CHKKWD | CHKALIAS; 436 break; 437 case TWHILE: 438 case TUNTIL: { 439 int got; 440 n1 = (union node *)stalloc(sizeof (struct nbinary)); 441 n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL; 442 if ((n1->nbinary.ch1 = list(0, 0)) == NULL) 443 synexpect(-1); 444 if ((got=readtoken()) != TDO) { 445 TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : "")); 446 synexpect(TDO); 447 } 448 n1->nbinary.ch2 = list(0, 0); 449 if (readtoken() != TDONE) 450 synexpect(TDONE); 451 checkkwd = CHKKWD | CHKALIAS; 452 break; 453 } 454 case TFOR: 455 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext)) 456 synerror("Bad for loop variable"); 457 n1 = (union node *)stalloc(sizeof (struct nfor)); 458 n1->type = NFOR; 459 n1->nfor.var = wordtext; 460 while (readtoken() == TNL) 461 ; 462 if (lasttoken == TWORD && ! quoteflag && equal(wordtext, "in")) { 463 app = ≈ 464 while (readtoken() == TWORD) { 465 n2 = (union node *)stalloc(sizeof (struct narg)); 466 n2->type = NARG; 467 n2->narg.text = wordtext; 468 n2->narg.backquote = backquotelist; 469 *app = n2; 470 app = &n2->narg.next; 471 } 472 *app = NULL; 473 n1->nfor.args = ap; 474 if (lasttoken != TNL && lasttoken != TSEMI) 475 synexpect(-1); 476 } else { 477 static char argvars[5] = { 478 CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0' 479 }; 480 n2 = (union node *)stalloc(sizeof (struct narg)); 481 n2->type = NARG; 482 n2->narg.text = argvars; 483 n2->narg.backquote = NULL; 484 n2->narg.next = NULL; 485 n1->nfor.args = n2; 486 /* 487 * Newline or semicolon here is optional (but note 488 * that the original Bourne shell only allowed NL). 489 */ 490 if (lasttoken != TNL && lasttoken != TSEMI) 491 tokpushback++; 492 } 493 checkkwd = CHKNL | CHKKWD | CHKALIAS; 494 if ((t = readtoken()) == TDO) 495 t = TDONE; 496 else if (t == TBEGIN) 497 t = TEND; 498 else 499 synexpect(-1); 500 n1->nfor.body = list(0, 0); 501 if (readtoken() != t) 502 synexpect(t); 503 checkkwd = CHKKWD | CHKALIAS; 504 break; 505 case TCASE: 506 n1 = (union node *)stalloc(sizeof (struct ncase)); 507 n1->type = NCASE; 508 if (readtoken() != TWORD) 509 synexpect(TWORD); 510 n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg)); 511 n2->type = NARG; 512 n2->narg.text = wordtext; 513 n2->narg.backquote = backquotelist; 514 n2->narg.next = NULL; 515 while (readtoken() == TNL); 516 if (lasttoken != TWORD || ! equal(wordtext, "in")) 517 synerror("expecting \"in\""); 518 cpp = &n1->ncase.cases; 519 checkkwd = CHKNL | CHKKWD, readtoken(); 520 while (lasttoken != TESAC) { 521 *cpp = cp = (union node *)stalloc(sizeof (struct nclist)); 522 cp->type = NCLIST; 523 app = &cp->nclist.pattern; 524 if (lasttoken == TLP) 525 readtoken(); 526 for (;;) { 527 *app = ap = (union node *)stalloc(sizeof (struct narg)); 528 ap->type = NARG; 529 ap->narg.text = wordtext; 530 ap->narg.backquote = backquotelist; 531 checkkwd = CHKNL | CHKKWD; 532 if (readtoken() != TPIPE) 533 break; 534 app = &ap->narg.next; 535 readtoken(); 536 } 537 ap->narg.next = NULL; 538 if (lasttoken != TRP) 539 synexpect(TRP); 540 cp->nclist.body = list(0, 0); 541 542 checkkwd = CHKNL | CHKKWD | CHKALIAS; 543 if ((t = readtoken()) != TESAC) { 544 if (t != TENDCASE) 545 synexpect(TENDCASE); 546 else 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 == 0) 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.backgnd = 0; 689 n->ncmd.args = args; 690 n->ncmd.redirect = redir; 691 return n; 692 } 693 694 static union node * 695 makename(void) 696 { 697 union node *n; 698 699 n = (union node *)stalloc(sizeof (struct narg)); 700 n->type = NARG; 701 n->narg.next = NULL; 702 n->narg.text = wordtext; 703 n->narg.backquote = backquotelist; 704 return n; 705 } 706 707 void 708 fixredir(union node *n, const char *text, int err) 709 { 710 TRACE(("Fix redir %s %d\n", text, err)); 711 if (!err) 712 n->ndup.vname = NULL; 713 714 if (is_digit(text[0]) && text[1] == '\0') 715 n->ndup.dupfd = digit_val(text[0]); 716 else if (text[0] == '-' && text[1] == '\0') 717 n->ndup.dupfd = -1; 718 else { 719 720 if (err) 721 synerror("Bad fd number"); 722 else 723 n->ndup.vname = makename(); 724 } 725 } 726 727 728 static void 729 parsefname(void) 730 { 731 union node *n = redirnode; 732 733 if (readtoken() != TWORD) 734 synexpect(-1); 735 if (n->type == NHERE) { 736 struct heredoc *here = heredoc; 737 struct heredoc *p; 738 int i; 739 740 if (quoteflag == 0) 741 n->type = NXHERE; 742 TRACE(("Here document %d\n", n->type)); 743 if (here->striptabs) { 744 while (*wordtext == '\t') 745 wordtext++; 746 } 747 if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN) 748 synerror("Illegal eof marker for << redirection"); 749 rmescapes(wordtext); 750 here->eofmark = wordtext; 751 here->next = NULL; 752 if (heredoclist == NULL) 753 heredoclist = here; 754 else { 755 for (p = heredoclist ; p->next ; p = p->next); 756 p->next = here; 757 } 758 } else if (n->type == NTOFD || n->type == NFROMFD) { 759 fixredir(n, wordtext, 0); 760 } else { 761 n->nfile.fname = makename(); 762 } 763 } 764 765 766 /* 767 * Input any here documents. 768 */ 769 770 static void 771 parseheredoc(void) 772 { 773 struct heredoc *here; 774 union node *n; 775 776 while (heredoclist) { 777 here = heredoclist; 778 heredoclist = here->next; 779 if (needprompt) { 780 setprompt(2); 781 needprompt = 0; 782 } 783 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, 784 here->eofmark, here->striptabs); 785 n = (union node *)stalloc(sizeof (struct narg)); 786 n->narg.type = NARG; 787 n->narg.next = NULL; 788 n->narg.text = wordtext; 789 n->narg.backquote = backquotelist; 790 here->here->nhere.doc = n; 791 } 792 } 793 794 static int 795 peektoken(void) 796 { 797 int t; 798 799 t = readtoken(); 800 tokpushback++; 801 return (t); 802 } 803 804 static int 805 readtoken(void) 806 { 807 int t; 808 struct alias *ap; 809 #ifdef DEBUG 810 int alreadyseen = tokpushback; 811 #endif 812 813 top: 814 t = xxreadtoken(); 815 816 /* 817 * eat newlines 818 */ 819 if (checkkwd & CHKNL) { 820 while (t == TNL) { 821 parseheredoc(); 822 t = xxreadtoken(); 823 } 824 } 825 826 /* 827 * check for keywords and aliases 828 */ 829 if (t == TWORD && !quoteflag) 830 { 831 const char * const *pp; 832 833 if (checkkwd & CHKKWD) 834 for (pp = parsekwd; *pp; pp++) { 835 if (**pp == *wordtext && equal(*pp, wordtext)) 836 { 837 lasttoken = t = pp - parsekwd + KWDOFFSET; 838 TRACE(("keyword %s recognized\n", tokname[t])); 839 goto out; 840 } 841 } 842 if (checkkwd & CHKALIAS && 843 (ap = lookupalias(wordtext, 1)) != NULL) { 844 pushstring(ap->val, strlen(ap->val), ap); 845 goto top; 846 } 847 } 848 out: 849 if (t != TNOT) 850 checkkwd = 0; 851 852 #ifdef DEBUG 853 if (!alreadyseen) 854 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 855 else 856 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 857 #endif 858 return (t); 859 } 860 861 862 /* 863 * Read the next input token. 864 * If the token is a word, we set backquotelist to the list of cmds in 865 * backquotes. We set quoteflag to true if any part of the word was 866 * quoted. 867 * If the token is TREDIR, then we set redirnode to a structure containing 868 * the redirection. 869 * In all cases, the variable startlinno is set to the number of the line 870 * on which the token starts. 871 * 872 * [Change comment: here documents and internal procedures] 873 * [Readtoken shouldn't have any arguments. Perhaps we should make the 874 * word parsing code into a separate routine. In this case, readtoken 875 * doesn't need to have any internal procedures, but parseword does. 876 * We could also make parseoperator in essence the main routine, and 877 * have parseword (readtoken1?) handle both words and redirection.] 878 */ 879 880 #define RETURN(token) return lasttoken = token 881 882 static int 883 xxreadtoken(void) 884 { 885 int c; 886 887 if (tokpushback) { 888 tokpushback = 0; 889 return lasttoken; 890 } 891 if (needprompt) { 892 setprompt(2); 893 needprompt = 0; 894 } 895 startlinno = plinno; 896 for (;;) { /* until token or start of word found */ 897 c = pgetc_macro(); 898 switch (c) { 899 case ' ': case '\t': 900 continue; 901 case '#': 902 while ((c = pgetc()) != '\n' && c != PEOF); 903 pungetc(); 904 continue; 905 case '\\': 906 if (pgetc() == '\n') { 907 startlinno = ++plinno; 908 if (doprompt) 909 setprompt(2); 910 else 911 setprompt(0); 912 continue; 913 } 914 pungetc(); 915 goto breakloop; 916 case '\n': 917 plinno++; 918 needprompt = doprompt; 919 RETURN(TNL); 920 case PEOF: 921 RETURN(TEOF); 922 case '&': 923 if (pgetc() == '&') 924 RETURN(TAND); 925 pungetc(); 926 RETURN(TBACKGND); 927 case '|': 928 if (pgetc() == '|') 929 RETURN(TOR); 930 pungetc(); 931 RETURN(TPIPE); 932 case ';': 933 if (pgetc() == ';') 934 RETURN(TENDCASE); 935 pungetc(); 936 RETURN(TSEMI); 937 case '(': 938 RETURN(TLP); 939 case ')': 940 RETURN(TRP); 941 default: 942 goto breakloop; 943 } 944 } 945 breakloop: 946 return readtoken1(c, BASESYNTAX, NULL, 0); 947 #undef RETURN 948 } 949 950 951 #define MAXNEST_STATIC 8 952 struct tokenstate 953 { 954 const char *syntax; /* *SYNTAX */ 955 int parenlevel; /* levels of parentheses in arithmetic */ 956 enum tokenstate_category 957 { 958 TSTATE_TOP, 959 TSTATE_VAR_OLD, /* ${var+-=?}, inherits dquotes */ 960 TSTATE_VAR_NEW, /* other ${var...}, own dquote state */ 961 TSTATE_ARITH 962 } category; 963 }; 964 965 966 /* 967 * Called to parse command substitutions. 968 */ 969 970 static char * 971 parsebackq(char *out, struct nodelist **pbqlist, 972 int oldstyle, int dblquote, int quoted) 973 { 974 struct nodelist **nlpp; 975 union node *n; 976 char *volatile str; 977 struct jmploc jmploc; 978 struct jmploc *const savehandler = handler; 979 int savelen; 980 int saveprompt; 981 const int bq_startlinno = plinno; 982 char *volatile ostr = NULL; 983 struct parsefile *const savetopfile = getcurrentfile(); 984 struct heredoc *const saveheredoclist = heredoclist; 985 struct heredoc *here; 986 987 str = NULL; 988 if (setjmp(jmploc.loc)) { 989 popfilesupto(savetopfile); 990 if (str) 991 ckfree(str); 992 if (ostr) 993 ckfree(ostr); 994 heredoclist = saveheredoclist; 995 handler = savehandler; 996 if (exception == EXERROR) { 997 startlinno = bq_startlinno; 998 synerror("Error in command substitution"); 999 } 1000 longjmp(handler->loc, 1); 1001 } 1002 INTOFF; 1003 savelen = out - stackblock(); 1004 if (savelen > 0) { 1005 str = ckmalloc(savelen); 1006 memcpy(str, stackblock(), savelen); 1007 } 1008 handler = &jmploc; 1009 heredoclist = NULL; 1010 INTON; 1011 if (oldstyle) { 1012 /* 1013 * We must read until the closing backquote, giving special 1014 * treatment to some slashes, and then push the string and 1015 * reread it as input, interpreting it normally. 1016 */ 1017 char *oout; 1018 int c, olen; 1019 1020 STARTSTACKSTR(oout); 1021 for (;;) { 1022 if (needprompt) { 1023 setprompt(2); 1024 needprompt = 0; 1025 } 1026 CHECKSTRSPACE(2, oout); 1027 switch (c = pgetc()) { 1028 case '`': 1029 goto done; 1030 1031 case '\\': 1032 if ((c = pgetc()) == '\n') { 1033 plinno++; 1034 if (doprompt) 1035 setprompt(2); 1036 else 1037 setprompt(0); 1038 /* 1039 * If eating a newline, avoid putting 1040 * the newline into the new character 1041 * stream (via the USTPUTC after the 1042 * switch). 1043 */ 1044 continue; 1045 } 1046 if (c != '\\' && c != '`' && c != '$' 1047 && (!dblquote || c != '"')) 1048 USTPUTC('\\', oout); 1049 break; 1050 1051 case '\n': 1052 plinno++; 1053 needprompt = doprompt; 1054 break; 1055 1056 case PEOF: 1057 startlinno = plinno; 1058 synerror("EOF in backquote substitution"); 1059 break; 1060 1061 default: 1062 break; 1063 } 1064 USTPUTC(c, oout); 1065 } 1066 done: 1067 USTPUTC('\0', oout); 1068 olen = oout - stackblock(); 1069 INTOFF; 1070 ostr = ckmalloc(olen); 1071 memcpy(ostr, stackblock(), olen); 1072 setinputstring(ostr, 1); 1073 INTON; 1074 } 1075 nlpp = pbqlist; 1076 while (*nlpp) 1077 nlpp = &(*nlpp)->next; 1078 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 1079 (*nlpp)->next = NULL; 1080 1081 if (oldstyle) { 1082 saveprompt = doprompt; 1083 doprompt = 0; 1084 } 1085 1086 n = list(0, oldstyle); 1087 1088 if (oldstyle) 1089 doprompt = saveprompt; 1090 else { 1091 if (readtoken() != TRP) 1092 synexpect(TRP); 1093 } 1094 1095 (*nlpp)->n = n; 1096 if (oldstyle) { 1097 /* 1098 * Start reading from old file again, ignoring any pushed back 1099 * tokens left from the backquote parsing 1100 */ 1101 popfile(); 1102 tokpushback = 0; 1103 } 1104 STARTSTACKSTR(out); 1105 CHECKSTRSPACE(savelen + 1, out); 1106 INTOFF; 1107 if (str) { 1108 memcpy(out, str, savelen); 1109 STADJUST(savelen, out); 1110 ckfree(str); 1111 str = NULL; 1112 } 1113 if (ostr) { 1114 ckfree(ostr); 1115 ostr = NULL; 1116 } 1117 here = saveheredoclist; 1118 if (here != NULL) { 1119 while (here->next != NULL) 1120 here = here->next; 1121 here->next = heredoclist; 1122 heredoclist = saveheredoclist; 1123 } 1124 handler = savehandler; 1125 INTON; 1126 if (quoted) 1127 USTPUTC(CTLBACKQ | CTLQUOTE, out); 1128 else 1129 USTPUTC(CTLBACKQ, out); 1130 return out; 1131 } 1132 1133 1134 /* 1135 * Called to parse a backslash escape sequence inside $'...'. 1136 * The backslash has already been read. 1137 */ 1138 static char * 1139 readcstyleesc(char *out) 1140 { 1141 int c, v, i, n; 1142 1143 c = pgetc(); 1144 switch (c) { 1145 case '\0': 1146 synerror("Unterminated quoted string"); 1147 case '\n': 1148 plinno++; 1149 if (doprompt) 1150 setprompt(2); 1151 else 1152 setprompt(0); 1153 return out; 1154 case '\\': 1155 case '\'': 1156 case '"': 1157 v = c; 1158 break; 1159 case 'a': v = '\a'; break; 1160 case 'b': v = '\b'; break; 1161 case 'e': v = '\033'; break; 1162 case 'f': v = '\f'; break; 1163 case 'n': v = '\n'; break; 1164 case 'r': v = '\r'; break; 1165 case 't': v = '\t'; break; 1166 case 'v': v = '\v'; break; 1167 case 'x': 1168 v = 0; 1169 for (;;) { 1170 c = pgetc(); 1171 if (c >= '0' && c <= '9') 1172 v = (v << 4) + c - '0'; 1173 else if (c >= 'A' && c <= 'F') 1174 v = (v << 4) + c - 'A' + 10; 1175 else if (c >= 'a' && c <= 'f') 1176 v = (v << 4) + c - 'a' + 10; 1177 else 1178 break; 1179 } 1180 pungetc(); 1181 break; 1182 case '0': case '1': case '2': case '3': 1183 case '4': case '5': case '6': case '7': 1184 v = c - '0'; 1185 c = pgetc(); 1186 if (c >= '0' && c <= '7') { 1187 v <<= 3; 1188 v += c - '0'; 1189 c = pgetc(); 1190 if (c >= '0' && c <= '7') { 1191 v <<= 3; 1192 v += c - '0'; 1193 } else 1194 pungetc(); 1195 } else 1196 pungetc(); 1197 break; 1198 case 'c': 1199 c = pgetc(); 1200 if (c < 0x3f || c > 0x7a || c == 0x60) 1201 synerror("Bad escape sequence"); 1202 if (c == '\\' && pgetc() != '\\') 1203 synerror("Bad escape sequence"); 1204 if (c == '?') 1205 v = 127; 1206 else 1207 v = c & 0x1f; 1208 break; 1209 case 'u': 1210 case 'U': 1211 n = c == 'U' ? 8 : 4; 1212 v = 0; 1213 for (i = 0; i < n; i++) { 1214 c = pgetc(); 1215 if (c >= '0' && c <= '9') 1216 v = (v << 4) + c - '0'; 1217 else if (c >= 'A' && c <= 'F') 1218 v = (v << 4) + c - 'A' + 10; 1219 else if (c >= 'a' && c <= 'f') 1220 v = (v << 4) + c - 'a' + 10; 1221 else 1222 synerror("Bad escape sequence"); 1223 } 1224 if (v == 0 || (v >= 0xd800 && v <= 0xdfff)) 1225 synerror("Bad escape sequence"); 1226 /* We really need iconv here. */ 1227 if (initial_localeisutf8 && v > 127) { 1228 CHECKSTRSPACE(4, out); 1229 /* 1230 * We cannot use wctomb() as the locale may have 1231 * changed. 1232 */ 1233 if (v <= 0x7ff) { 1234 USTPUTC(0xc0 | v >> 6, out); 1235 USTPUTC(0x80 | (v & 0x3f), out); 1236 return out; 1237 } else if (v <= 0xffff) { 1238 USTPUTC(0xe0 | v >> 12, out); 1239 USTPUTC(0x80 | ((v >> 6) & 0x3f), out); 1240 USTPUTC(0x80 | (v & 0x3f), out); 1241 return out; 1242 } else if (v <= 0x10ffff) { 1243 USTPUTC(0xf0 | v >> 18, out); 1244 USTPUTC(0x80 | ((v >> 12) & 0x3f), out); 1245 USTPUTC(0x80 | ((v >> 6) & 0x3f), out); 1246 USTPUTC(0x80 | (v & 0x3f), out); 1247 return out; 1248 } 1249 } 1250 if (v > 127) 1251 v = '?'; 1252 break; 1253 default: 1254 synerror("Bad escape sequence"); 1255 } 1256 v = (char)v; 1257 /* 1258 * We can't handle NUL bytes. 1259 * POSIX says we should skip till the closing quote. 1260 */ 1261 if (v == '\0') { 1262 while ((c = pgetc()) != '\'') { 1263 if (c == '\\') 1264 c = pgetc(); 1265 if (c == PEOF) 1266 synerror("Unterminated quoted string"); 1267 } 1268 pungetc(); 1269 return out; 1270 } 1271 if (SQSYNTAX[v] == CCTL) 1272 USTPUTC(CTLESC, out); 1273 USTPUTC(v, out); 1274 return out; 1275 } 1276 1277 1278 /* 1279 * If eofmark is NULL, read a word or a redirection symbol. If eofmark 1280 * is not NULL, read a here document. In the latter case, eofmark is the 1281 * word which marks the end of the document and striptabs is true if 1282 * leading tabs should be stripped from the document. The argument firstc 1283 * is the first character of the input token or document. 1284 * 1285 * Because C does not have internal subroutines, I have simulated them 1286 * using goto's to implement the subroutine linkage. The following macros 1287 * will run code that appears at the end of readtoken1. 1288 */ 1289 1290 #define CHECKEND() {goto checkend; checkend_return:;} 1291 #define PARSEREDIR() {goto parseredir; parseredir_return:;} 1292 #define PARSESUB() {goto parsesub; parsesub_return:;} 1293 #define PARSEARITH() {goto parsearith; parsearith_return:;} 1294 1295 static int 1296 readtoken1(int firstc, char const *initialsyntax, char *eofmark, int striptabs) 1297 { 1298 int c = firstc; 1299 char * volatile out; 1300 int len; 1301 char line[EOFMARKLEN + 1]; 1302 struct nodelist *bqlist; 1303 volatile int quotef; 1304 int newvarnest; 1305 int level; 1306 int synentry; 1307 struct tokenstate state_static[MAXNEST_STATIC]; 1308 int maxnest = MAXNEST_STATIC; 1309 struct tokenstate *state = state_static; 1310 int sqiscstyle = 0; 1311 1312 startlinno = plinno; 1313 quotef = 0; 1314 bqlist = NULL; 1315 newvarnest = 0; 1316 level = 0; 1317 state[level].syntax = initialsyntax; 1318 state[level].parenlevel = 0; 1319 state[level].category = TSTATE_TOP; 1320 1321 STARTSTACKSTR(out); 1322 loop: { /* for each line, until end of word */ 1323 CHECKEND(); /* set c to PEOF if at end of here document */ 1324 for (;;) { /* until end of line or end of word */ 1325 CHECKSTRSPACE(4, out); /* permit 4 calls to USTPUTC */ 1326 1327 synentry = state[level].syntax[c]; 1328 1329 switch(synentry) { 1330 case CNL: /* '\n' */ 1331 if (state[level].syntax == BASESYNTAX) 1332 goto endword; /* exit outer loop */ 1333 USTPUTC(c, out); 1334 plinno++; 1335 if (doprompt) 1336 setprompt(2); 1337 else 1338 setprompt(0); 1339 c = pgetc(); 1340 goto loop; /* continue outer loop */ 1341 case CSBACK: 1342 if (sqiscstyle) { 1343 out = readcstyleesc(out); 1344 break; 1345 } 1346 /* FALLTHROUGH */ 1347 case CWORD: 1348 USTPUTC(c, out); 1349 break; 1350 case CCTL: 1351 if (eofmark == NULL || initialsyntax != SQSYNTAX) 1352 USTPUTC(CTLESC, out); 1353 USTPUTC(c, out); 1354 break; 1355 case CBACK: /* backslash */ 1356 c = pgetc(); 1357 if (c == PEOF) { 1358 USTPUTC('\\', out); 1359 pungetc(); 1360 } else if (c == '\n') { 1361 plinno++; 1362 if (doprompt) 1363 setprompt(2); 1364 else 1365 setprompt(0); 1366 } else { 1367 if (state[level].syntax == DQSYNTAX && 1368 c != '\\' && c != '`' && c != '$' && 1369 (c != '"' || (eofmark != NULL && 1370 newvarnest == 0)) && 1371 (c != '}' || state[level].category != TSTATE_VAR_OLD)) 1372 USTPUTC('\\', out); 1373 if ((eofmark == NULL || 1374 newvarnest > 0) && 1375 state[level].syntax == BASESYNTAX) 1376 USTPUTC(CTLQUOTEMARK, out); 1377 if (SQSYNTAX[c] == CCTL) 1378 USTPUTC(CTLESC, out); 1379 USTPUTC(c, out); 1380 if ((eofmark == NULL || 1381 newvarnest > 0) && 1382 state[level].syntax == BASESYNTAX && 1383 state[level].category == TSTATE_VAR_OLD) 1384 USTPUTC(CTLQUOTEEND, out); 1385 quotef++; 1386 } 1387 break; 1388 case CSQUOTE: 1389 USTPUTC(CTLQUOTEMARK, out); 1390 state[level].syntax = SQSYNTAX; 1391 sqiscstyle = 0; 1392 break; 1393 case CDQUOTE: 1394 USTPUTC(CTLQUOTEMARK, out); 1395 state[level].syntax = DQSYNTAX; 1396 break; 1397 case CENDQUOTE: 1398 if (eofmark != NULL && newvarnest == 0) 1399 USTPUTC(c, out); 1400 else { 1401 if (state[level].category == TSTATE_VAR_OLD) 1402 USTPUTC(CTLQUOTEEND, out); 1403 state[level].syntax = BASESYNTAX; 1404 quotef++; 1405 } 1406 break; 1407 case CVAR: /* '$' */ 1408 PARSESUB(); /* parse substitution */ 1409 break; 1410 case CENDVAR: /* '}' */ 1411 if (level > 0 && 1412 ((state[level].category == TSTATE_VAR_OLD && 1413 state[level].syntax == 1414 state[level - 1].syntax) || 1415 (state[level].category == TSTATE_VAR_NEW && 1416 state[level].syntax == BASESYNTAX))) { 1417 if (state[level].category == TSTATE_VAR_NEW) 1418 newvarnest--; 1419 level--; 1420 USTPUTC(CTLENDVAR, out); 1421 } else { 1422 USTPUTC(c, out); 1423 } 1424 break; 1425 case CLP: /* '(' in arithmetic */ 1426 state[level].parenlevel++; 1427 USTPUTC(c, out); 1428 break; 1429 case CRP: /* ')' in arithmetic */ 1430 if (state[level].parenlevel > 0) { 1431 USTPUTC(c, out); 1432 --state[level].parenlevel; 1433 } else { 1434 if (pgetc() == ')') { 1435 if (level > 0 && 1436 state[level].category == TSTATE_ARITH) { 1437 level--; 1438 USTPUTC(CTLENDARI, out); 1439 } else 1440 USTPUTC(')', out); 1441 } else { 1442 /* 1443 * unbalanced parens 1444 * (don't 2nd guess - no error) 1445 */ 1446 pungetc(); 1447 USTPUTC(')', out); 1448 } 1449 } 1450 break; 1451 case CBQUOTE: /* '`' */ 1452 out = parsebackq(out, &bqlist, 1, 1453 state[level].syntax == DQSYNTAX && 1454 (eofmark == NULL || newvarnest > 0), 1455 state[level].syntax == DQSYNTAX || state[level].syntax == ARISYNTAX); 1456 break; 1457 case CEOF: 1458 goto endword; /* exit outer loop */ 1459 case CIGN: 1460 break; 1461 default: 1462 if (level == 0) 1463 goto endword; /* exit outer loop */ 1464 USTPUTC(c, out); 1465 } 1466 c = pgetc_macro(); 1467 } 1468 } 1469 endword: 1470 if (state[level].syntax == ARISYNTAX) 1471 synerror("Missing '))'"); 1472 if (state[level].syntax != BASESYNTAX && eofmark == NULL) 1473 synerror("Unterminated quoted string"); 1474 if (state[level].category == TSTATE_VAR_OLD || 1475 state[level].category == TSTATE_VAR_NEW) { 1476 startlinno = plinno; 1477 synerror("Missing '}'"); 1478 } 1479 if (state != state_static) 1480 parser_temp_free_upto(state); 1481 USTPUTC('\0', out); 1482 len = out - stackblock(); 1483 out = stackblock(); 1484 if (eofmark == NULL) { 1485 if ((c == '>' || c == '<') 1486 && quotef == 0 1487 && len <= 2 1488 && (*out == '\0' || is_digit(*out))) { 1489 PARSEREDIR(); 1490 return lasttoken = TREDIR; 1491 } else { 1492 pungetc(); 1493 } 1494 } 1495 quoteflag = quotef; 1496 backquotelist = bqlist; 1497 grabstackblock(len); 1498 wordtext = out; 1499 return lasttoken = TWORD; 1500 /* end of readtoken routine */ 1501 1502 1503 /* 1504 * Check to see whether we are at the end of the here document. When this 1505 * is called, c is set to the first character of the next input line. If 1506 * we are at the end of the here document, this routine sets the c to PEOF. 1507 */ 1508 1509 checkend: { 1510 if (eofmark) { 1511 if (striptabs) { 1512 while (c == '\t') 1513 c = pgetc(); 1514 } 1515 if (c == *eofmark) { 1516 if (pfgets(line, sizeof line) != NULL) { 1517 char *p, *q; 1518 1519 p = line; 1520 for (q = eofmark + 1 ; *q && *p == *q ; p++, q++); 1521 if ((*p == '\0' || *p == '\n') && *q == '\0') { 1522 c = PEOF; 1523 if (*p == '\n') { 1524 plinno++; 1525 needprompt = doprompt; 1526 } 1527 } else { 1528 pushstring(line, strlen(line), NULL); 1529 } 1530 } 1531 } 1532 } 1533 goto checkend_return; 1534 } 1535 1536 1537 /* 1538 * Parse a redirection operator. The variable "out" points to a string 1539 * specifying the fd to be redirected. The variable "c" contains the 1540 * first character of the redirection operator. 1541 */ 1542 1543 parseredir: { 1544 char fd = *out; 1545 union node *np; 1546 1547 np = (union node *)stalloc(sizeof (struct nfile)); 1548 if (c == '>') { 1549 np->nfile.fd = 1; 1550 c = pgetc(); 1551 if (c == '>') 1552 np->type = NAPPEND; 1553 else if (c == '&') 1554 np->type = NTOFD; 1555 else if (c == '|') 1556 np->type = NCLOBBER; 1557 else { 1558 np->type = NTO; 1559 pungetc(); 1560 } 1561 } else { /* c == '<' */ 1562 np->nfile.fd = 0; 1563 c = pgetc(); 1564 if (c == '<') { 1565 if (sizeof (struct nfile) != sizeof (struct nhere)) { 1566 np = (union node *)stalloc(sizeof (struct nhere)); 1567 np->nfile.fd = 0; 1568 } 1569 np->type = NHERE; 1570 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); 1571 heredoc->here = np; 1572 if ((c = pgetc()) == '-') { 1573 heredoc->striptabs = 1; 1574 } else { 1575 heredoc->striptabs = 0; 1576 pungetc(); 1577 } 1578 } else if (c == '&') 1579 np->type = NFROMFD; 1580 else if (c == '>') 1581 np->type = NFROMTO; 1582 else { 1583 np->type = NFROM; 1584 pungetc(); 1585 } 1586 } 1587 if (fd != '\0') 1588 np->nfile.fd = digit_val(fd); 1589 redirnode = np; 1590 goto parseredir_return; 1591 } 1592 1593 1594 /* 1595 * Parse a substitution. At this point, we have read the dollar sign 1596 * and nothing else. 1597 */ 1598 1599 parsesub: { 1600 char buf[10]; 1601 int subtype; 1602 int typeloc; 1603 int flags; 1604 char *p; 1605 static const char types[] = "}-+?="; 1606 int bracketed_name = 0; /* used to handle ${[0-9]*} variables */ 1607 int linno; 1608 int length; 1609 int c1; 1610 1611 c = pgetc(); 1612 if (c == '(') { /* $(command) or $((arith)) */ 1613 if (pgetc() == '(') { 1614 PARSEARITH(); 1615 } else { 1616 pungetc(); 1617 out = parsebackq(out, &bqlist, 0, 1618 state[level].syntax == DQSYNTAX && 1619 (eofmark == NULL || newvarnest > 0), 1620 state[level].syntax == DQSYNTAX || 1621 state[level].syntax == ARISYNTAX); 1622 } 1623 } else if (c == '{' || is_name(c) || is_special(c)) { 1624 USTPUTC(CTLVAR, out); 1625 typeloc = out - stackblock(); 1626 USTPUTC(VSNORMAL, out); 1627 subtype = VSNORMAL; 1628 flags = 0; 1629 if (c == '{') { 1630 bracketed_name = 1; 1631 c = pgetc(); 1632 subtype = 0; 1633 } 1634 varname: 1635 if (!is_eof(c) && is_name(c)) { 1636 length = 0; 1637 do { 1638 STPUTC(c, out); 1639 c = pgetc(); 1640 length++; 1641 } while (!is_eof(c) && is_in_name(c)); 1642 if (length == 6 && 1643 strncmp(out - length, "LINENO", length) == 0) { 1644 /* Replace the variable name with the 1645 * current line number. */ 1646 linno = plinno; 1647 if (funclinno != 0) 1648 linno -= funclinno - 1; 1649 snprintf(buf, sizeof(buf), "%d", linno); 1650 STADJUST(-6, out); 1651 STPUTS(buf, out); 1652 flags |= VSLINENO; 1653 } 1654 } else if (is_digit(c)) { 1655 if (bracketed_name) { 1656 do { 1657 STPUTC(c, out); 1658 c = pgetc(); 1659 } while (is_digit(c)); 1660 } else { 1661 STPUTC(c, out); 1662 c = pgetc(); 1663 } 1664 } else if (is_special(c)) { 1665 c1 = c; 1666 c = pgetc(); 1667 if (subtype == 0 && c1 == '#') { 1668 subtype = VSLENGTH; 1669 if (strchr(types, c) == NULL && c != ':' && 1670 c != '#' && c != '%') 1671 goto varname; 1672 c1 = c; 1673 c = pgetc(); 1674 if (c1 != '}' && c == '}') { 1675 pungetc(); 1676 c = c1; 1677 goto varname; 1678 } 1679 pungetc(); 1680 c = c1; 1681 c1 = '#'; 1682 subtype = 0; 1683 } 1684 USTPUTC(c1, out); 1685 } else { 1686 subtype = VSERROR; 1687 if (c == '}') 1688 pungetc(); 1689 else if (c == '\n' || c == PEOF) 1690 synerror("Unexpected end of line in substitution"); 1691 else 1692 USTPUTC(c, out); 1693 } 1694 if (subtype == 0) { 1695 switch (c) { 1696 case ':': 1697 flags |= VSNUL; 1698 c = pgetc(); 1699 /*FALLTHROUGH*/ 1700 default: 1701 p = strchr(types, c); 1702 if (p == NULL) { 1703 if (c == '\n' || c == PEOF) 1704 synerror("Unexpected end of line in substitution"); 1705 if (flags == VSNUL) 1706 STPUTC(':', out); 1707 STPUTC(c, out); 1708 subtype = VSERROR; 1709 } else 1710 subtype = p - types + VSNORMAL; 1711 break; 1712 case '%': 1713 case '#': 1714 { 1715 int cc = c; 1716 subtype = c == '#' ? VSTRIMLEFT : 1717 VSTRIMRIGHT; 1718 c = pgetc(); 1719 if (c == cc) 1720 subtype++; 1721 else 1722 pungetc(); 1723 break; 1724 } 1725 } 1726 } else if (subtype != VSERROR) { 1727 if (subtype == VSLENGTH && c != '}') 1728 subtype = VSERROR; 1729 pungetc(); 1730 } 1731 STPUTC('=', out); 1732 if (state[level].syntax == DQSYNTAX || 1733 state[level].syntax == ARISYNTAX) 1734 flags |= VSQUOTE; 1735 *(stackblock() + typeloc) = subtype | flags; 1736 if (subtype != VSNORMAL) { 1737 if (level + 1 >= maxnest) { 1738 maxnest *= 2; 1739 if (state == state_static) { 1740 state = parser_temp_alloc( 1741 maxnest * sizeof(*state)); 1742 memcpy(state, state_static, 1743 MAXNEST_STATIC * sizeof(*state)); 1744 } else 1745 state = parser_temp_realloc(state, 1746 maxnest * sizeof(*state)); 1747 } 1748 level++; 1749 state[level].parenlevel = 0; 1750 if (subtype == VSMINUS || subtype == VSPLUS || 1751 subtype == VSQUESTION || subtype == VSASSIGN) { 1752 /* 1753 * For operators that were in the Bourne shell, 1754 * inherit the double-quote state. 1755 */ 1756 state[level].syntax = state[level - 1].syntax; 1757 state[level].category = TSTATE_VAR_OLD; 1758 } else { 1759 /* 1760 * The other operators take a pattern, 1761 * so go to BASESYNTAX. 1762 * Also, ' and " are now special, even 1763 * in here documents. 1764 */ 1765 state[level].syntax = BASESYNTAX; 1766 state[level].category = TSTATE_VAR_NEW; 1767 newvarnest++; 1768 } 1769 } 1770 } else if (c == '\'' && state[level].syntax == BASESYNTAX) { 1771 /* $'cstylequotes' */ 1772 USTPUTC(CTLQUOTEMARK, out); 1773 state[level].syntax = SQSYNTAX; 1774 sqiscstyle = 1; 1775 } else { 1776 USTPUTC('$', out); 1777 pungetc(); 1778 } 1779 goto parsesub_return; 1780 } 1781 1782 1783 /* 1784 * Parse an arithmetic expansion (indicate start of one and set state) 1785 */ 1786 parsearith: { 1787 1788 if (level + 1 >= maxnest) { 1789 maxnest *= 2; 1790 if (state == state_static) { 1791 state = parser_temp_alloc( 1792 maxnest * sizeof(*state)); 1793 memcpy(state, state_static, 1794 MAXNEST_STATIC * sizeof(*state)); 1795 } else 1796 state = parser_temp_realloc(state, 1797 maxnest * sizeof(*state)); 1798 } 1799 level++; 1800 state[level].syntax = ARISYNTAX; 1801 state[level].parenlevel = 0; 1802 state[level].category = TSTATE_ARITH; 1803 USTPUTC(CTLARI, out); 1804 if (state[level - 1].syntax == DQSYNTAX) 1805 USTPUTC('"',out); 1806 else 1807 USTPUTC(' ',out); 1808 goto parsearith_return; 1809 } 1810 1811 } /* end of readtoken */ 1812 1813 1814 1815 #ifdef mkinit 1816 RESET { 1817 tokpushback = 0; 1818 checkkwd = 0; 1819 } 1820 #endif 1821 1822 /* 1823 * Returns true if the text contains nothing to expand (no dollar signs 1824 * or backquotes). 1825 */ 1826 1827 static int 1828 noexpand(char *text) 1829 { 1830 char *p; 1831 char c; 1832 1833 p = text; 1834 while ((c = *p++) != '\0') { 1835 if ( c == CTLQUOTEMARK) 1836 continue; 1837 if (c == CTLESC) 1838 p++; 1839 else if (BASESYNTAX[(int)c] == CCTL) 1840 return 0; 1841 } 1842 return 1; 1843 } 1844 1845 1846 /* 1847 * Return true if the argument is a legal variable name (a letter or 1848 * underscore followed by zero or more letters, underscores, and digits). 1849 */ 1850 1851 int 1852 goodname(const char *name) 1853 { 1854 const char *p; 1855 1856 p = name; 1857 if (! is_name(*p)) 1858 return 0; 1859 while (*++p) { 1860 if (! is_in_name(*p)) 1861 return 0; 1862 } 1863 return 1; 1864 } 1865 1866 1867 int 1868 isassignment(const char *p) 1869 { 1870 if (!is_name(*p)) 1871 return 0; 1872 p++; 1873 for (;;) { 1874 if (*p == '=') 1875 return 1; 1876 else if (!is_in_name(*p)) 1877 return 0; 1878 p++; 1879 } 1880 } 1881 1882 1883 /* 1884 * Called when an unexpected token is read during the parse. The argument 1885 * is the token that is expected, or -1 if more than one type of token can 1886 * occur at this point. 1887 */ 1888 1889 static void 1890 synexpect(int token) 1891 { 1892 char msg[64]; 1893 1894 if (token >= 0) { 1895 fmtstr(msg, 64, "%s unexpected (expecting %s)", 1896 tokname[lasttoken], tokname[token]); 1897 } else { 1898 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]); 1899 } 1900 synerror(msg); 1901 } 1902 1903 1904 static void 1905 synerror(const char *msg) 1906 { 1907 if (commandname) 1908 outfmt(out2, "%s: %d: ", commandname, startlinno); 1909 outfmt(out2, "Syntax error: %s\n", msg); 1910 error(NULL); 1911 } 1912 1913 static void 1914 setprompt(int which) 1915 { 1916 whichprompt = which; 1917 1918 #ifndef NO_HISTORY 1919 if (!el) 1920 #endif 1921 { 1922 out2str(getprompt(NULL)); 1923 flushout(out2); 1924 } 1925 } 1926 1927 /* 1928 * called by editline -- any expansions to the prompt 1929 * should be added here. 1930 */ 1931 const char * 1932 getprompt(void *unused __unused) 1933 { 1934 static char ps[PROMPTLEN]; 1935 const char *fmt; 1936 const char *pwd; 1937 int i, trim; 1938 1939 /* 1940 * Select prompt format. 1941 */ 1942 switch (whichprompt) { 1943 case 0: 1944 fmt = ""; 1945 break; 1946 case 1: 1947 fmt = ps1val(); 1948 break; 1949 case 2: 1950 fmt = ps2val(); 1951 break; 1952 default: 1953 return "??"; 1954 } 1955 1956 /* 1957 * Format prompt string. 1958 */ 1959 for (i = 0; (i < 127) && (*fmt != '\0'); i++, fmt++) 1960 if (*fmt == '\\') 1961 switch (*++fmt) { 1962 1963 /* 1964 * Hostname. 1965 * 1966 * \h specifies just the local hostname, 1967 * \H specifies fully-qualified hostname. 1968 */ 1969 case 'h': 1970 case 'H': 1971 ps[i] = '\0'; 1972 gethostname(&ps[i], PROMPTLEN - i); 1973 /* Skip to end of hostname. */ 1974 trim = (*fmt == 'h') ? '.' : '\0'; 1975 while ((ps[i+1] != '\0') && (ps[i+1] != trim)) 1976 i++; 1977 break; 1978 1979 /* 1980 * Working directory. 1981 * 1982 * \W specifies just the final component, 1983 * \w specifies the entire path. 1984 */ 1985 case 'W': 1986 case 'w': 1987 pwd = lookupvar("PWD"); 1988 if (pwd == NULL) 1989 pwd = "?"; 1990 if (*fmt == 'W' && 1991 *pwd == '/' && pwd[1] != '\0') 1992 strlcpy(&ps[i], strrchr(pwd, '/') + 1, 1993 PROMPTLEN - i); 1994 else 1995 strlcpy(&ps[i], pwd, PROMPTLEN - i); 1996 /* Skip to end of path. */ 1997 while (ps[i + 1] != '\0') 1998 i++; 1999 break; 2000 2001 /* 2002 * Superuser status. 2003 * 2004 * '$' for normal users, '#' for root. 2005 */ 2006 case '$': 2007 ps[i] = (geteuid() != 0) ? '$' : '#'; 2008 break; 2009 2010 /* 2011 * A literal \. 2012 */ 2013 case '\\': 2014 ps[i] = '\\'; 2015 break; 2016 2017 /* 2018 * Emit unrecognized formats verbatim. 2019 */ 2020 default: 2021 ps[i++] = '\\'; 2022 ps[i] = *fmt; 2023 break; 2024 } 2025 else 2026 ps[i] = *fmt; 2027 ps[i] = '\0'; 2028 return (ps); 2029 } 2030