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 35static 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 82struct 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 89struct parser_temp { 90 struct parser_temp *next; 91 void *data; 92}; 93 94 95static struct heredoc *heredoclist; /* list of here documents to read */ 96static int doprompt; /* if set, prompt the user */ 97static int needprompt; /* true if interactive and at start of line */ 98static int lasttoken; /* last token read */ 99MKINIT int tokpushback; /* last token pushed back */ 100static char *wordtext; /* text of last word returned by readtoken */ 101MKINIT int checkkwd; /* 1 == check for kwds, 2 == also eat newlines */ 102static struct nodelist *backquotelist; 103static union node *redirnode; 104static struct heredoc *heredoc; 105static int quoteflag; /* set if (part of) last token was quoted */ 106static int startlinno; /* line # where last token started */ 107static int funclinno; /* line # where the current function started */ 108static struct parser_temp *parser_temp; 109 110 111static union node *list(int, int); 112static union node *andor(void); 113static union node *pipeline(void); 114static union node *command(void); 115static union node *simplecmd(union node **, union node *); 116static union node *makename(void); 117static void parsefname(void); 118static void parseheredoc(void); 119static int peektoken(void); 120static int readtoken(void); 121static int xxreadtoken(void); 122static int readtoken1(int, char const *, char *, int); 123static int noexpand(char *); 124static void synexpect(int) __dead2; 125static void synerror(const char *) __dead2; 126static void setprompt(int); 127 128 129static void * 130parser_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 145static void * 146parser_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 160static void 161parser_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 180static void 181parser_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 201union node * 202parsecmd(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 229static union node * 230list(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 != NULL && n2->type == NPIPE) { 244 n2->npipe.backgnd = 1; 245 } else if (n2 != NULL && 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 309static union node * 310andor(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 336static union node * 337pipeline(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 384static union node * 385command(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) { 446TRACE(("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 case TPIPE: 580 case TENDCASE: 581 case TFALLTHRU: 582 /* 583 * An empty command before a ; doesn't make much sense, and 584 * should certainly be disallowed in the case of `if ;'. 585 */ 586 if (!redir) 587 synexpect(-1); 588 case TNL: 589 case TEOF: 590 case TWORD: 591 case TRP: 592 tokpushback++; 593 n1 = simplecmd(rpp, redir); 594 return n1; 595 default: 596 synexpect(-1); 597 } 598 599 /* Now check for redirection which may follow command */ 600 while (readtoken() == TREDIR) { 601 *rpp = n2 = redirnode; 602 rpp = &n2->nfile.next; 603 parsefname(); 604 } 605 tokpushback++; 606 *rpp = NULL; 607 if (redir) { 608 if (!is_subshell) { 609 n2 = (union node *)stalloc(sizeof (struct nredir)); 610 n2->type = NREDIR; 611 n2->nredir.n = n1; 612 n1 = n2; 613 } 614 n1->nredir.redirect = redir; 615 } 616 617 return n1; 618} 619 620 621static union node * 622simplecmd(union node **rpp, union node *redir) 623{ 624 union node *args, **app; 625 union node **orig_rpp = rpp; 626 union node *n = NULL; 627 int special; 628 int savecheckkwd; 629 630 /* If we don't have any redirections already, then we must reset */ 631 /* rpp to be the address of the local redir variable. */ 632 if (redir == 0) 633 rpp = &redir; 634 635 args = NULL; 636 app = &args; 637 /* 638 * We save the incoming value, because we need this for shell 639 * functions. There can not be a redirect or an argument between 640 * the function name and the open parenthesis. 641 */ 642 orig_rpp = rpp; 643 644 savecheckkwd = CHKALIAS; 645 646 for (;;) { 647 checkkwd = savecheckkwd; 648 if (readtoken() == TWORD) { 649 n = (union node *)stalloc(sizeof (struct narg)); 650 n->type = NARG; 651 n->narg.text = wordtext; 652 n->narg.backquote = backquotelist; 653 *app = n; 654 app = &n->narg.next; 655 if (savecheckkwd != 0 && !isassignment(wordtext)) 656 savecheckkwd = 0; 657 } else if (lasttoken == TREDIR) { 658 *rpp = n = redirnode; 659 rpp = &n->nfile.next; 660 parsefname(); /* read name of redirection file */ 661 } else if (lasttoken == TLP && app == &args->narg.next 662 && rpp == orig_rpp) { 663 /* We have a function */ 664 if (readtoken() != TRP) 665 synexpect(TRP); 666 funclinno = plinno; 667 /* 668 * - Require plain text. 669 * - Functions with '/' cannot be called. 670 * - Reject name=(). 671 * - Reject ksh extended glob patterns. 672 */ 673 if (!noexpand(n->narg.text) || quoteflag || 674 strchr(n->narg.text, '/') || 675 strchr("!%*+-=?@}~", 676 n->narg.text[strlen(n->narg.text) - 1])) 677 synerror("Bad function name"); 678 rmescapes(n->narg.text); 679 if (find_builtin(n->narg.text, &special) >= 0 && 680 special) 681 synerror("Cannot override a special builtin with a function"); 682 n->type = NDEFUN; 683 n->narg.next = command(); 684 funclinno = 0; 685 return n; 686 } else { 687 tokpushback++; 688 break; 689 } 690 } 691 *app = NULL; 692 *rpp = NULL; 693 n = (union node *)stalloc(sizeof (struct ncmd)); 694 n->type = NCMD; 695 n->ncmd.args = args; 696 n->ncmd.redirect = redir; 697 return n; 698} 699 700static union node * 701makename(void) 702{ 703 union node *n; 704 705 n = (union node *)stalloc(sizeof (struct narg)); 706 n->type = NARG; 707 n->narg.next = NULL; 708 n->narg.text = wordtext; 709 n->narg.backquote = backquotelist; 710 return n; 711} 712 713void 714fixredir(union node *n, const char *text, int err) 715{ 716 TRACE(("Fix redir %s %d\n", text, err)); 717 if (!err) 718 n->ndup.vname = NULL; 719 720 if (is_digit(text[0]) && text[1] == '\0') 721 n->ndup.dupfd = digit_val(text[0]); 722 else if (text[0] == '-' && text[1] == '\0') 723 n->ndup.dupfd = -1; 724 else { 725 726 if (err) 727 synerror("Bad fd number"); 728 else 729 n->ndup.vname = makename(); 730 } 731} 732 733 734static void 735parsefname(void) 736{ 737 union node *n = redirnode; 738 739 if (readtoken() != TWORD) 740 synexpect(-1); 741 if (n->type == NHERE) { 742 struct heredoc *here = heredoc; 743 struct heredoc *p; 744 int i; 745 746 if (quoteflag == 0) 747 n->type = NXHERE; 748 TRACE(("Here document %d\n", n->type)); 749 if (here->striptabs) { 750 while (*wordtext == '\t') 751 wordtext++; 752 } 753 if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN) 754 synerror("Illegal eof marker for << redirection"); 755 rmescapes(wordtext); 756 here->eofmark = wordtext; 757 here->next = NULL; 758 if (heredoclist == NULL) 759 heredoclist = here; 760 else { 761 for (p = heredoclist ; p->next ; p = p->next); 762 p->next = here; 763 } 764 } else if (n->type == NTOFD || n->type == NFROMFD) { 765 fixredir(n, wordtext, 0); 766 } else { 767 n->nfile.fname = makename(); 768 } 769} 770 771 772/* 773 * Input any here documents. 774 */ 775 776static void 777parseheredoc(void) 778{ 779 struct heredoc *here; 780 union node *n; 781 782 while (heredoclist) { 783 here = heredoclist; 784 heredoclist = here->next; 785 if (needprompt) { 786 setprompt(2); 787 needprompt = 0; 788 } 789 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, 790 here->eofmark, here->striptabs); 791 n = (union node *)stalloc(sizeof (struct narg)); 792 n->narg.type = NARG; 793 n->narg.next = NULL; 794 n->narg.text = wordtext; 795 n->narg.backquote = backquotelist; 796 here->here->nhere.doc = n; 797 } 798} 799 800static int 801peektoken(void) 802{ 803 int t; 804 805 t = readtoken(); 806 tokpushback++; 807 return (t); 808} 809 810static int 811readtoken(void) 812{ 813 int t; 814 struct alias *ap; 815#ifdef DEBUG 816 int alreadyseen = tokpushback; 817#endif 818 819 top: 820 t = xxreadtoken(); 821 822 /* 823 * eat newlines 824 */ 825 if (checkkwd & CHKNL) { 826 while (t == TNL) { 827 parseheredoc(); 828 t = xxreadtoken(); 829 } 830 } 831 832 /* 833 * check for keywords and aliases 834 */ 835 if (t == TWORD && !quoteflag) 836 { 837 const char * const *pp; 838 839 if (checkkwd & CHKKWD) 840 for (pp = parsekwd; *pp; pp++) { 841 if (**pp == *wordtext && equal(*pp, wordtext)) 842 { 843 lasttoken = t = pp - parsekwd + KWDOFFSET; 844 TRACE(("keyword %s recognized\n", tokname[t])); 845 goto out; 846 } 847 } 848 if (checkkwd & CHKALIAS && 849 (ap = lookupalias(wordtext, 1)) != NULL) { 850 pushstring(ap->val, strlen(ap->val), ap); 851 goto top; 852 } 853 } 854out: 855 if (t != TNOT) 856 checkkwd = 0; 857 858#ifdef DEBUG 859 if (!alreadyseen) 860 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 861 else 862 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 863#endif 864 return (t); 865} 866 867 868/* 869 * Read the next input token. 870 * If the token is a word, we set backquotelist to the list of cmds in 871 * backquotes. We set quoteflag to true if any part of the word was 872 * quoted. 873 * If the token is TREDIR, then we set redirnode to a structure containing 874 * the redirection. 875 * In all cases, the variable startlinno is set to the number of the line 876 * on which the token starts. 877 * 878 * [Change comment: here documents and internal procedures] 879 * [Readtoken shouldn't have any arguments. Perhaps we should make the 880 * word parsing code into a separate routine. In this case, readtoken 881 * doesn't need to have any internal procedures, but parseword does. 882 * We could also make parseoperator in essence the main routine, and 883 * have parseword (readtoken1?) handle both words and redirection.] 884 */ 885 886#define RETURN(token) return lasttoken = token 887 888static int 889xxreadtoken(void) 890{ 891 int c; 892 893 if (tokpushback) { 894 tokpushback = 0; 895 return lasttoken; 896 } 897 if (needprompt) { 898 setprompt(2); 899 needprompt = 0; 900 } 901 startlinno = plinno; 902 for (;;) { /* until token or start of word found */ 903 c = pgetc_macro(); 904 switch (c) { 905 case ' ': case '\t': 906 continue; 907 case '#': 908 while ((c = pgetc()) != '\n' && c != PEOF); 909 pungetc(); 910 continue; 911 case '\\': 912 if (pgetc() == '\n') { 913 startlinno = ++plinno; 914 if (doprompt) 915 setprompt(2); 916 else 917 setprompt(0); 918 continue; 919 } 920 pungetc(); 921 goto breakloop; 922 case '\n': 923 plinno++; 924 needprompt = doprompt; 925 RETURN(TNL); 926 case PEOF: 927 RETURN(TEOF); 928 case '&': 929 if (pgetc() == '&') 930 RETURN(TAND); 931 pungetc(); 932 RETURN(TBACKGND); 933 case '|': 934 if (pgetc() == '|') 935 RETURN(TOR); 936 pungetc(); 937 RETURN(TPIPE); 938 case ';': 939 c = pgetc(); 940 if (c == ';') 941 RETURN(TENDCASE); 942 else if (c == '&') 943 RETURN(TFALLTHRU); 944 pungetc(); 945 RETURN(TSEMI); 946 case '(': 947 RETURN(TLP); 948 case ')': 949 RETURN(TRP); 950 default: 951 goto breakloop; 952 } 953 } 954breakloop: 955 return readtoken1(c, BASESYNTAX, (char *)NULL, 0); 956#undef RETURN 957} 958 959 960#define MAXNEST_static 8 961struct tokenstate 962{ 963 const char *syntax; /* *SYNTAX */ 964 int parenlevel; /* levels of parentheses in arithmetic */ 965 enum tokenstate_category 966 { 967 TSTATE_TOP, 968 TSTATE_VAR_OLD, /* ${var+-=?}, inherits dquotes */ 969 TSTATE_VAR_NEW, /* other ${var...}, own dquote state */ 970 TSTATE_ARITH 971 } category; 972}; 973 974 975/* 976 * Called to parse command substitutions. 977 */ 978 979static char * 980parsebackq(char *out, struct nodelist **pbqlist, 981 int oldstyle, int dblquote, int quoted) 982{ 983 struct nodelist **nlpp; 984 union node *n; 985 char *volatile str; 986 struct jmploc jmploc; 987 struct jmploc *const savehandler = handler; 988 int savelen; 989 int saveprompt; 990 const int bq_startlinno = plinno; 991 char *volatile ostr = NULL; 992 struct parsefile *const savetopfile = getcurrentfile(); 993 struct heredoc *const saveheredoclist = heredoclist; 994 struct heredoc *here; 995 996 str = NULL; 997 if (setjmp(jmploc.loc)) { 998 popfilesupto(savetopfile); 999 if (str) 1000 ckfree(str); 1001 if (ostr) 1002 ckfree(ostr); 1003 heredoclist = saveheredoclist; 1004 handler = savehandler; 1005 if (exception == EXERROR) { 1006 startlinno = bq_startlinno; 1007 synerror("Error in command substitution"); 1008 } 1009 longjmp(handler->loc, 1); 1010 } 1011 INTOFF; 1012 savelen = out - stackblock(); 1013 if (savelen > 0) { 1014 str = ckmalloc(savelen); 1015 memcpy(str, stackblock(), savelen); 1016 } 1017 handler = &jmploc; 1018 heredoclist = NULL; 1019 INTON; 1020 if (oldstyle) { 1021 /* We must read until the closing backquote, giving special 1022 treatment to some slashes, and then push the string and 1023 reread it as input, interpreting it normally. */ 1024 char *oout; 1025 int c; 1026 int olen; 1027 1028 1029 STARTSTACKSTR(oout); 1030 for (;;) { 1031 if (needprompt) { 1032 setprompt(2); 1033 needprompt = 0; 1034 } 1035 CHECKSTRSPACE(2, oout); 1036 switch (c = pgetc()) { 1037 case '`': 1038 goto done; 1039 1040 case '\\': 1041 if ((c = pgetc()) == '\n') { 1042 plinno++; 1043 if (doprompt) 1044 setprompt(2); 1045 else 1046 setprompt(0); 1047 /* 1048 * If eating a newline, avoid putting 1049 * the newline into the new character 1050 * stream (via the USTPUTC after the 1051 * switch). 1052 */ 1053 continue; 1054 } 1055 if (c != '\\' && c != '`' && c != '$' 1056 && (!dblquote || c != '"')) 1057 USTPUTC('\\', oout); 1058 break; 1059 1060 case '\n': 1061 plinno++; 1062 needprompt = doprompt; 1063 break; 1064 1065 case PEOF: 1066 startlinno = plinno; 1067 synerror("EOF in backquote substitution"); 1068 break; 1069 1070 default: 1071 break; 1072 } 1073 USTPUTC(c, oout); 1074 } 1075done: 1076 USTPUTC('\0', oout); 1077 olen = oout - stackblock(); 1078 INTOFF; 1079 ostr = ckmalloc(olen); 1080 memcpy(ostr, stackblock(), olen); 1081 setinputstring(ostr, 1); 1082 INTON; 1083 } 1084 nlpp = pbqlist; 1085 while (*nlpp) 1086 nlpp = &(*nlpp)->next; 1087 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 1088 (*nlpp)->next = NULL; 1089 1090 if (oldstyle) { 1091 saveprompt = doprompt; 1092 doprompt = 0; 1093 } 1094 1095 n = list(0, oldstyle); 1096 1097 if (oldstyle) 1098 doprompt = saveprompt; 1099 else { 1100 if (readtoken() != TRP) 1101 synexpect(TRP); 1102 } 1103 1104 (*nlpp)->n = n; 1105 if (oldstyle) { 1106 /* 1107 * Start reading from old file again, ignoring any pushed back 1108 * tokens left from the backquote parsing 1109 */ 1110 popfile(); 1111 tokpushback = 0; 1112 } 1113 STARTSTACKSTR(out); 1114 CHECKSTRSPACE(savelen + 1, out); 1115 INTOFF; 1116 if (str) { 1117 memcpy(out, str, savelen); 1118 STADJUST(savelen, out); 1119 ckfree(str); 1120 str = NULL; 1121 } 1122 if (ostr) { 1123 ckfree(ostr); 1124 ostr = NULL; 1125 } 1126 here = saveheredoclist; 1127 if (here != NULL) { 1128 while (here->next != NULL) 1129 here = here->next; 1130 here->next = heredoclist; 1131 heredoclist = saveheredoclist; 1132 } 1133 handler = savehandler; 1134 INTON; 1135 if (quoted) 1136 USTPUTC(CTLBACKQ | CTLQUOTE, out); 1137 else 1138 USTPUTC(CTLBACKQ, out); 1139 return out; 1140} 1141 1142 1143/* 1144 * Called to parse a backslash escape sequence inside $'...'. 1145 * The backslash has already been read. 1146 */ 1147static char * 1148readcstyleesc(char *out) 1149{ 1150 int c, v, i, n; 1151 1152 c = pgetc(); 1153 switch (c) { 1154 case '\0': 1155 synerror("Unterminated quoted string"); 1156 case '\n': 1157 plinno++; 1158 if (doprompt) 1159 setprompt(2); 1160 else 1161 setprompt(0); 1162 return out; 1163 case '\\': 1164 case '\'': 1165 case '"': 1166 v = c; 1167 break; 1168 case 'a': v = '\a'; break; 1169 case 'b': v = '\b'; break; 1170 case 'e': v = '\033'; break; 1171 case 'f': v = '\f'; break; 1172 case 'n': v = '\n'; break; 1173 case 'r': v = '\r'; break; 1174 case 't': v = '\t'; break; 1175 case 'v': v = '\v'; break; 1176 case 'x': 1177 v = 0; 1178 for (;;) { 1179 c = pgetc(); 1180 if (c >= '0' && c <= '9') 1181 v = (v << 4) + c - '0'; 1182 else if (c >= 'A' && c <= 'F') 1183 v = (v << 4) + c - 'A' + 10; 1184 else if (c >= 'a' && c <= 'f') 1185 v = (v << 4) + c - 'a' + 10; 1186 else 1187 break; 1188 } 1189 pungetc(); 1190 break; 1191 case '0': case '1': case '2': case '3': 1192 case '4': case '5': case '6': case '7': 1193 v = c - '0'; 1194 c = pgetc(); 1195 if (c >= '0' && c <= '7') { 1196 v <<= 3; 1197 v += c - '0'; 1198 c = pgetc(); 1199 if (c >= '0' && c <= '7') { 1200 v <<= 3; 1201 v += c - '0'; 1202 } else 1203 pungetc(); 1204 } else 1205 pungetc(); 1206 break; 1207 case 'c': 1208 c = pgetc(); 1209 if (c < 0x3f || c > 0x7a || c == 0x60) 1210 synerror("Bad escape sequence"); 1211 if (c == '\\' && pgetc() != '\\') 1212 synerror("Bad escape sequence"); 1213 if (c == '?') 1214 v = 127; 1215 else 1216 v = c & 0x1f; 1217 break; 1218 case 'u': 1219 case 'U': 1220 n = c == 'U' ? 8 : 4; 1221 v = 0; 1222 for (i = 0; i < n; i++) { 1223 c = pgetc(); 1224 if (c >= '0' && c <= '9') 1225 v = (v << 4) + c - '0'; 1226 else if (c >= 'A' && c <= 'F') 1227 v = (v << 4) + c - 'A' + 10; 1228 else if (c >= 'a' && c <= 'f') 1229 v = (v << 4) + c - 'a' + 10; 1230 else 1231 synerror("Bad escape sequence"); 1232 } 1233 if (v == 0 || (v >= 0xd800 && v <= 0xdfff)) 1234 synerror("Bad escape sequence"); 1235 /* We really need iconv here. */ 1236 if (initial_localeisutf8 && v > 127) { 1237 CHECKSTRSPACE(4, out); 1238 /* 1239 * We cannot use wctomb() as the locale may have 1240 * changed. 1241 */ 1242 if (v <= 0x7ff) { 1243 USTPUTC(0xc0 | v >> 6, out); 1244 USTPUTC(0x80 | (v & 0x3f), out); 1245 return out; 1246 } else if (v <= 0xffff) { 1247 USTPUTC(0xe0 | v >> 12, out); 1248 USTPUTC(0x80 | ((v >> 6) & 0x3f), out); 1249 USTPUTC(0x80 | (v & 0x3f), out); 1250 return out; 1251 } else if (v <= 0x10ffff) { 1252 USTPUTC(0xf0 | v >> 18, out); 1253 USTPUTC(0x80 | ((v >> 12) & 0x3f), out); 1254 USTPUTC(0x80 | ((v >> 6) & 0x3f), out); 1255 USTPUTC(0x80 | (v & 0x3f), out); 1256 return out; 1257 } 1258 } 1259 if (v > 127) 1260 v = '?'; 1261 break; 1262 default: 1263 synerror("Bad escape sequence"); 1264 } 1265 v = (char)v; 1266 /* 1267 * We can't handle NUL bytes. 1268 * POSIX says we should skip till the closing quote. 1269 */ 1270 if (v == '\0') { 1271 while ((c = pgetc()) != '\'') { 1272 if (c == '\\') 1273 c = pgetc(); 1274 if (c == PEOF) 1275 synerror("Unterminated quoted string"); 1276 } 1277 pungetc(); 1278 return out; 1279 } 1280 if (SQSYNTAX[v] == CCTL) 1281 USTPUTC(CTLESC, out); 1282 USTPUTC(v, out); 1283 return out; 1284} 1285 1286 1287/* 1288 * If eofmark is NULL, read a word or a redirection symbol. If eofmark 1289 * is not NULL, read a here document. In the latter case, eofmark is the 1290 * word which marks the end of the document and striptabs is true if 1291 * leading tabs should be stripped from the document. The argument firstc 1292 * is the first character of the input token or document. 1293 * 1294 * Because C does not have internal subroutines, I have simulated them 1295 * using goto's to implement the subroutine linkage. The following macros 1296 * will run code that appears at the end of readtoken1. 1297 */ 1298 1299#define CHECKEND() {goto checkend; checkend_return:;} 1300#define PARSEREDIR() {goto parseredir; parseredir_return:;} 1301#define PARSESUB() {goto parsesub; parsesub_return:;} 1302#define PARSEARITH() {goto parsearith; parsearith_return:;} 1303 1304static int 1305readtoken1(int firstc, char const *initialsyntax, char *eofmark, int striptabs) 1306{ 1307 int c = firstc; 1308 char *out; 1309 int len; 1310 char line[EOFMARKLEN + 1]; 1311 struct nodelist *bqlist; 1312 int quotef; 1313 int newvarnest; 1314 int level; 1315 int synentry; 1316 struct tokenstate state_static[MAXNEST_static]; 1317 int maxnest = MAXNEST_static; 1318 struct tokenstate *state = state_static; 1319 int sqiscstyle = 0; 1320 1321 startlinno = plinno; 1322 quotef = 0; 1323 bqlist = NULL; 1324 newvarnest = 0; 1325 level = 0; 1326 state[level].syntax = initialsyntax; 1327 state[level].parenlevel = 0; 1328 state[level].category = TSTATE_TOP; 1329 1330 STARTSTACKSTR(out); 1331 loop: { /* for each line, until end of word */ 1332 CHECKEND(); /* set c to PEOF if at end of here document */ 1333 for (;;) { /* until end of line or end of word */ 1334 CHECKSTRSPACE(4, out); /* permit 4 calls to USTPUTC */ 1335 1336 synentry = state[level].syntax[c]; 1337 1338 switch(synentry) { 1339 case CNL: /* '\n' */ 1340 if (state[level].syntax == BASESYNTAX) 1341 goto endword; /* exit outer loop */ 1342 USTPUTC(c, out); 1343 plinno++; 1344 if (doprompt) 1345 setprompt(2); 1346 else 1347 setprompt(0); 1348 c = pgetc(); 1349 goto loop; /* continue outer loop */ 1350 case CSBACK: 1351 if (sqiscstyle) { 1352 out = readcstyleesc(out); 1353 break; 1354 } 1355 /* FALLTHROUGH */ 1356 case CWORD: 1357 USTPUTC(c, out); 1358 break; 1359 case CCTL: 1360 if (eofmark == NULL || initialsyntax != SQSYNTAX) 1361 USTPUTC(CTLESC, out); 1362 USTPUTC(c, out); 1363 break; 1364 case CBACK: /* backslash */ 1365 c = pgetc(); 1366 if (c == PEOF) { 1367 USTPUTC('\\', out); 1368 pungetc(); 1369 } else if (c == '\n') { 1370 plinno++; 1371 if (doprompt) 1372 setprompt(2); 1373 else 1374 setprompt(0); 1375 } else { 1376 if (state[level].syntax == DQSYNTAX && 1377 c != '\\' && c != '`' && c != '$' && 1378 (c != '"' || (eofmark != NULL && 1379 newvarnest == 0)) && 1380 (c != '}' || state[level].category != TSTATE_VAR_OLD)) 1381 USTPUTC('\\', out); 1382 if ((eofmark == NULL || 1383 newvarnest > 0) && 1384 state[level].syntax == BASESYNTAX) 1385 USTPUTC(CTLQUOTEMARK, out); 1386 if (SQSYNTAX[c] == CCTL) 1387 USTPUTC(CTLESC, out); 1388 USTPUTC(c, out); 1389 if ((eofmark == NULL || 1390 newvarnest > 0) && 1391 state[level].syntax == BASESYNTAX && 1392 state[level].category == TSTATE_VAR_OLD) 1393 USTPUTC(CTLQUOTEEND, out); 1394 quotef++; 1395 } 1396 break; 1397 case CSQUOTE: 1398 USTPUTC(CTLQUOTEMARK, out); 1399 state[level].syntax = SQSYNTAX; 1400 sqiscstyle = 0; 1401 break; 1402 case CDQUOTE: 1403 USTPUTC(CTLQUOTEMARK, out); 1404 state[level].syntax = DQSYNTAX; 1405 break; 1406 case CENDQUOTE: 1407 if (eofmark != NULL && newvarnest == 0) 1408 USTPUTC(c, out); 1409 else { 1410 if (state[level].category == TSTATE_VAR_OLD) 1411 USTPUTC(CTLQUOTEEND, out); 1412 state[level].syntax = BASESYNTAX; 1413 quotef++; 1414 } 1415 break; 1416 case CVAR: /* '$' */ 1417 PARSESUB(); /* parse substitution */ 1418 break; 1419 case CENDVAR: /* '}' */ 1420 if (level > 0 && 1421 ((state[level].category == TSTATE_VAR_OLD && 1422 state[level].syntax == 1423 state[level - 1].syntax) || 1424 (state[level].category == TSTATE_VAR_NEW && 1425 state[level].syntax == BASESYNTAX))) { 1426 if (state[level].category == TSTATE_VAR_NEW) 1427 newvarnest--; 1428 level--; 1429 USTPUTC(CTLENDVAR, out); 1430 } else { 1431 USTPUTC(c, out); 1432 } 1433 break; 1434 case CLP: /* '(' in arithmetic */ 1435 state[level].parenlevel++; 1436 USTPUTC(c, out); 1437 break; 1438 case CRP: /* ')' in arithmetic */ 1439 if (state[level].parenlevel > 0) { 1440 USTPUTC(c, out); 1441 --state[level].parenlevel; 1442 } else { 1443 if (pgetc() == ')') { 1444 if (level > 0 && 1445 state[level].category == TSTATE_ARITH) { 1446 level--; 1447 USTPUTC(CTLENDARI, out); 1448 } else 1449 USTPUTC(')', out); 1450 } else { 1451 /* 1452 * unbalanced parens 1453 * (don't 2nd guess - no error) 1454 */ 1455 pungetc(); 1456 USTPUTC(')', out); 1457 } 1458 } 1459 break; 1460 case CBQUOTE: /* '`' */ 1461 out = parsebackq(out, &bqlist, 1, 1462 state[level].syntax == DQSYNTAX && 1463 (eofmark == NULL || newvarnest > 0), 1464 state[level].syntax == DQSYNTAX || state[level].syntax == ARISYNTAX); 1465 break; 1466 case CEOF: 1467 goto endword; /* exit outer loop */ 1468 case CIGN: 1469 break; 1470 default: 1471 if (level == 0) 1472 goto endword; /* exit outer loop */ 1473 USTPUTC(c, out); 1474 } 1475 c = pgetc_macro(); 1476 } 1477 } 1478endword: 1479 if (state[level].syntax == ARISYNTAX) 1480 synerror("Missing '))'"); 1481 if (state[level].syntax != BASESYNTAX && eofmark == NULL) 1482 synerror("Unterminated quoted string"); 1483 if (state[level].category == TSTATE_VAR_OLD || 1484 state[level].category == TSTATE_VAR_NEW) { 1485 startlinno = plinno; 1486 synerror("Missing '}'"); 1487 } 1488 if (state != state_static) 1489 parser_temp_free_upto(state); 1490 USTPUTC('\0', out); 1491 len = out - stackblock(); 1492 out = stackblock(); 1493 if (eofmark == NULL) { 1494 if ((c == '>' || c == '<') 1495 && quotef == 0 1496 && len <= 2 1497 && (*out == '\0' || is_digit(*out))) { 1498 PARSEREDIR(); 1499 return lasttoken = TREDIR; 1500 } else { 1501 pungetc(); 1502 } 1503 } 1504 quoteflag = quotef; 1505 backquotelist = bqlist; 1506 grabstackblock(len); 1507 wordtext = out; 1508 return lasttoken = TWORD; 1509/* end of readtoken routine */ 1510 1511 1512/* 1513 * Check to see whether we are at the end of the here document. When this 1514 * is called, c is set to the first character of the next input line. If 1515 * we are at the end of the here document, this routine sets the c to PEOF. 1516 */ 1517 1518checkend: { 1519 if (eofmark) { 1520 if (striptabs) { 1521 while (c == '\t') 1522 c = pgetc(); 1523 } 1524 if (c == *eofmark) { 1525 if (pfgets(line, sizeof line) != NULL) { 1526 char *p, *q; 1527 1528 p = line; 1529 for (q = eofmark + 1 ; *q && *p == *q ; p++, q++); 1530 if ((*p == '\0' || *p == '\n') && *q == '\0') { 1531 c = PEOF; 1532 if (*p == '\n') { 1533 plinno++; 1534 needprompt = doprompt; 1535 } 1536 } else { 1537 pushstring(line, strlen(line), NULL); 1538 } 1539 } 1540 } 1541 } 1542 goto checkend_return; 1543} 1544 1545 1546/* 1547 * Parse a redirection operator. The variable "out" points to a string 1548 * specifying the fd to be redirected. The variable "c" contains the 1549 * first character of the redirection operator. 1550 */ 1551 1552parseredir: { 1553 char fd = *out; 1554 union node *np; 1555 1556 np = (union node *)stalloc(sizeof (struct nfile)); 1557 if (c == '>') { 1558 np->nfile.fd = 1; 1559 c = pgetc(); 1560 if (c == '>') 1561 np->type = NAPPEND; 1562 else if (c == '&') 1563 np->type = NTOFD; 1564 else if (c == '|') 1565 np->type = NCLOBBER; 1566 else { 1567 np->type = NTO; 1568 pungetc(); 1569 } 1570 } else { /* c == '<' */ 1571 np->nfile.fd = 0; 1572 c = pgetc(); 1573 if (c == '<') { 1574 if (sizeof (struct nfile) != sizeof (struct nhere)) { 1575 np = (union node *)stalloc(sizeof (struct nhere)); 1576 np->nfile.fd = 0; 1577 } 1578 np->type = NHERE; 1579 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); 1580 heredoc->here = np; 1581 if ((c = pgetc()) == '-') { 1582 heredoc->striptabs = 1; 1583 } else { 1584 heredoc->striptabs = 0; 1585 pungetc(); 1586 } 1587 } else if (c == '&') 1588 np->type = NFROMFD; 1589 else if (c == '>') 1590 np->type = NFROMTO; 1591 else { 1592 np->type = NFROM; 1593 pungetc(); 1594 } 1595 } 1596 if (fd != '\0') 1597 np->nfile.fd = digit_val(fd); 1598 redirnode = np; 1599 goto parseredir_return; 1600} 1601 1602 1603/* 1604 * Parse a substitution. At this point, we have read the dollar sign 1605 * and nothing else. 1606 */ 1607 1608parsesub: { 1609 char buf[10]; 1610 int subtype; 1611 int typeloc; 1612 int flags; 1613 char *p; 1614 static const char types[] = "}-+?="; 1615 int bracketed_name = 0; /* used to handle ${[0-9]*} variables */ 1616 int linno; 1617 int length; 1618 int c1; 1619 1620 c = pgetc(); 1621 if (c == '(') { /* $(command) or $((arith)) */ 1622 if (pgetc() == '(') { 1623 PARSEARITH(); 1624 } else { 1625 pungetc(); 1626 out = parsebackq(out, &bqlist, 0, 1627 state[level].syntax == DQSYNTAX && 1628 (eofmark == NULL || newvarnest > 0), 1629 state[level].syntax == DQSYNTAX || 1630 state[level].syntax == ARISYNTAX); 1631 } 1632 } else if (c == '{' || is_name(c) || is_special(c)) { 1633 USTPUTC(CTLVAR, out); 1634 typeloc = out - stackblock(); 1635 USTPUTC(VSNORMAL, out); 1636 subtype = VSNORMAL; 1637 flags = 0; 1638 if (c == '{') { 1639 bracketed_name = 1; 1640 c = pgetc(); 1641 subtype = 0; 1642 } 1643varname: 1644 if (!is_eof(c) && is_name(c)) { 1645 length = 0; 1646 do { 1647 STPUTC(c, out); 1648 c = pgetc(); 1649 length++; 1650 } while (!is_eof(c) && is_in_name(c)); 1651 if (length == 6 && 1652 strncmp(out - length, "LINENO", length) == 0) { 1653 /* Replace the variable name with the 1654 * current line number. */ 1655 linno = plinno; 1656 if (funclinno != 0) 1657 linno -= funclinno - 1; 1658 snprintf(buf, sizeof(buf), "%d", linno); 1659 STADJUST(-6, out); 1660 STPUTS(buf, out); 1661 flags |= VSLINENO; 1662 } 1663 } else if (is_digit(c)) { 1664 if (bracketed_name) { 1665 do { 1666 STPUTC(c, out); 1667 c = pgetc(); 1668 } while (is_digit(c)); 1669 } else { 1670 STPUTC(c, out); 1671 c = pgetc(); 1672 } 1673 } else if (is_special(c)) { 1674 c1 = c; 1675 c = pgetc(); 1676 if (subtype == 0 && c1 == '#') { 1677 subtype = VSLENGTH; 1678 if (strchr(types, c) == NULL && c != ':' && 1679 c != '#' && c != '%') 1680 goto varname; 1681 c1 = c; 1682 c = pgetc(); 1683 if (c1 != '}' && c == '}') { 1684 pungetc(); 1685 c = c1; 1686 goto varname; 1687 } 1688 pungetc(); 1689 c = c1; 1690 c1 = '#'; 1691 subtype = 0; 1692 } 1693 USTPUTC(c1, out); 1694 } else { 1695 subtype = VSERROR; 1696 if (c == '}') 1697 pungetc(); 1698 else if (c == '\n' || c == PEOF) 1699 synerror("Unexpected end of line in substitution"); 1700 else 1701 USTPUTC(c, out); 1702 } 1703 if (subtype == 0) { 1704 switch (c) { 1705 case ':': 1706 flags |= VSNUL; 1707 c = pgetc(); 1708 /*FALLTHROUGH*/ 1709 default: 1710 p = strchr(types, c); 1711 if (p == NULL) { 1712 if (c == '\n' || c == PEOF) 1713 synerror("Unexpected end of line in substitution"); 1714 if (flags == VSNUL) 1715 STPUTC(':', out); 1716 STPUTC(c, out); 1717 subtype = VSERROR; 1718 } else 1719 subtype = p - types + VSNORMAL; 1720 break; 1721 case '%': 1722 case '#': 1723 { 1724 int cc = c; 1725 subtype = c == '#' ? VSTRIMLEFT : 1726 VSTRIMRIGHT; 1727 c = pgetc(); 1728 if (c == cc) 1729 subtype++; 1730 else 1731 pungetc(); 1732 break; 1733 } 1734 } 1735 } else if (subtype != VSERROR) { 1736 if (subtype == VSLENGTH && c != '}') 1737 subtype = VSERROR; 1738 pungetc(); 1739 } 1740 STPUTC('=', out); 1741 if (state[level].syntax == DQSYNTAX || 1742 state[level].syntax == ARISYNTAX) 1743 flags |= VSQUOTE; 1744 *(stackblock() + typeloc) = subtype | flags; 1745 if (subtype != VSNORMAL) { 1746 if (level + 1 >= maxnest) { 1747 maxnest *= 2; 1748 if (state == state_static) { 1749 state = parser_temp_alloc( 1750 maxnest * sizeof(*state)); 1751 memcpy(state, state_static, 1752 MAXNEST_static * sizeof(*state)); 1753 } else 1754 state = parser_temp_realloc(state, 1755 maxnest * sizeof(*state)); 1756 } 1757 level++; 1758 state[level].parenlevel = 0; 1759 if (subtype == VSMINUS || subtype == VSPLUS || 1760 subtype == VSQUESTION || subtype == VSASSIGN) { 1761 /* 1762 * For operators that were in the Bourne shell, 1763 * inherit the double-quote state. 1764 */ 1765 state[level].syntax = state[level - 1].syntax; 1766 state[level].category = TSTATE_VAR_OLD; 1767 } else { 1768 /* 1769 * The other operators take a pattern, 1770 * so go to BASESYNTAX. 1771 * Also, ' and " are now special, even 1772 * in here documents. 1773 */ 1774 state[level].syntax = BASESYNTAX; 1775 state[level].category = TSTATE_VAR_NEW; 1776 newvarnest++; 1777 } 1778 } 1779 } else if (c == '\'' && state[level].syntax == BASESYNTAX) { 1780 /* $'cstylequotes' */ 1781 USTPUTC(CTLQUOTEMARK, out); 1782 state[level].syntax = SQSYNTAX; 1783 sqiscstyle = 1; 1784 } else { 1785 USTPUTC('$', out); 1786 pungetc(); 1787 } 1788 goto parsesub_return; 1789} 1790 1791 1792/* 1793 * Parse an arithmetic expansion (indicate start of one and set state) 1794 */ 1795parsearith: { 1796 1797 if (level + 1 >= maxnest) { 1798 maxnest *= 2; 1799 if (state == state_static) { 1800 state = parser_temp_alloc( 1801 maxnest * sizeof(*state)); 1802 memcpy(state, state_static, 1803 MAXNEST_static * sizeof(*state)); 1804 } else 1805 state = parser_temp_realloc(state, 1806 maxnest * sizeof(*state)); 1807 } 1808 level++; 1809 state[level].syntax = ARISYNTAX; 1810 state[level].parenlevel = 0; 1811 state[level].category = TSTATE_ARITH; 1812 USTPUTC(CTLARI, out); 1813 if (state[level - 1].syntax == DQSYNTAX) 1814 USTPUTC('"',out); 1815 else 1816 USTPUTC(' ',out); 1817 goto parsearith_return; 1818} 1819 1820} /* end of readtoken */ 1821 1822 1823 1824#ifdef mkinit 1825RESET { 1826 tokpushback = 0; 1827 checkkwd = 0; 1828} 1829#endif 1830 1831/* 1832 * Returns true if the text contains nothing to expand (no dollar signs 1833 * or backquotes). 1834 */ 1835 1836static int 1837noexpand(char *text) 1838{ 1839 char *p; 1840 char c; 1841 1842 p = text; 1843 while ((c = *p++) != '\0') { 1844 if ( c == CTLQUOTEMARK) 1845 continue; 1846 if (c == CTLESC) 1847 p++; 1848 else if (BASESYNTAX[(int)c] == CCTL) 1849 return 0; 1850 } 1851 return 1; 1852} 1853 1854 1855/* 1856 * Return true if the argument is a legal variable name (a letter or 1857 * underscore followed by zero or more letters, underscores, and digits). 1858 */ 1859 1860int 1861goodname(const char *name) 1862{ 1863 const char *p; 1864 1865 p = name; 1866 if (! is_name(*p)) 1867 return 0; 1868 while (*++p) { 1869 if (! is_in_name(*p)) 1870 return 0; 1871 } 1872 return 1; 1873} 1874 1875 1876int 1877isassignment(const char *p) 1878{ 1879 if (!is_name(*p)) 1880 return 0; 1881 p++; 1882 for (;;) { 1883 if (*p == '=') 1884 return 1; 1885 else if (!is_in_name(*p)) 1886 return 0; 1887 p++; 1888 } 1889} 1890 1891 1892/* 1893 * Called when an unexpected token is read during the parse. The argument 1894 * is the token that is expected, or -1 if more than one type of token can 1895 * occur at this point. 1896 */ 1897 1898static void 1899synexpect(int token) 1900{ 1901 char msg[64]; 1902 1903 if (token >= 0) { 1904 fmtstr(msg, 64, "%s unexpected (expecting %s)", 1905 tokname[lasttoken], tokname[token]); 1906 } else { 1907 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]); 1908 } 1909 synerror(msg); 1910} 1911 1912 1913static void 1914synerror(const char *msg) 1915{ 1916 if (commandname) 1917 outfmt(out2, "%s: %d: ", commandname, startlinno); 1918 outfmt(out2, "Syntax error: %s\n", msg); 1919 error((char *)NULL); 1920} 1921 1922static void 1923setprompt(int which) 1924{ 1925 whichprompt = which; 1926 1927#ifndef NO_HISTORY 1928 if (!el) 1929#endif 1930 { 1931 out2str(getprompt(NULL)); 1932 flushout(out2); 1933 } 1934} 1935 1936/* 1937 * called by editline -- any expansions to the prompt 1938 * should be added here. 1939 */ 1940char * 1941getprompt(void *unused __unused) 1942{ 1943 static char ps[PROMPTLEN]; 1944 char *fmt; 1945 const char *pwd; 1946 int i, trim; 1947 static char internal_error[] = "??"; 1948 1949 /* 1950 * Select prompt format. 1951 */ 1952 switch (whichprompt) { 1953 case 0: 1954 fmt = nullstr; 1955 break; 1956 case 1: 1957 fmt = ps1val(); 1958 break; 1959 case 2: 1960 fmt = ps2val(); 1961 break; 1962 default: 1963 return internal_error; 1964 } 1965 1966 /* 1967 * Format prompt string. 1968 */ 1969 for (i = 0; (i < 127) && (*fmt != '\0'); i++, fmt++) 1970 if (*fmt == '\\') 1971 switch (*++fmt) { 1972 1973 /* 1974 * Hostname. 1975 * 1976 * \h specifies just the local hostname, 1977 * \H specifies fully-qualified hostname. 1978 */ 1979 case 'h': 1980 case 'H': 1981 ps[i] = '\0'; 1982 gethostname(&ps[i], PROMPTLEN - i); 1983 /* Skip to end of hostname. */ 1984 trim = (*fmt == 'h') ? '.' : '\0'; 1985 while ((ps[i+1] != '\0') && (ps[i+1] != trim)) 1986 i++; 1987 break; 1988 1989 /* 1990 * Working directory. 1991 * 1992 * \W specifies just the final component, 1993 * \w specifies the entire path. 1994 */ 1995 case 'W': 1996 case 'w': 1997 pwd = lookupvar("PWD"); 1998 if (pwd == NULL) 1999 pwd = "?"; 2000 if (*fmt == 'W' && 2001 *pwd == '/' && pwd[1] != '\0') 2002 strlcpy(&ps[i], strrchr(pwd, '/') + 1, 2003 PROMPTLEN - i); 2004 else 2005 strlcpy(&ps[i], pwd, PROMPTLEN - i); 2006 /* Skip to end of path. */ 2007 while (ps[i + 1] != '\0') 2008 i++; 2009 break; 2010 2011 /* 2012 * Superuser status. 2013 * 2014 * '$' for normal users, '#' for root. 2015 */ 2016 case '$': 2017 ps[i] = (geteuid() != 0) ? '$' : '#'; 2018 break; 2019 2020 /* 2021 * A literal \. 2022 */ 2023 case '\\': 2024 ps[i] = '\\'; 2025 break; 2026 2027 /* 2028 * Emit unrecognized formats verbatim. 2029 */ 2030 default: 2031 ps[i++] = '\\'; 2032 ps[i] = *fmt; 2033 break; 2034 } 2035 else 2036 ps[i] = *fmt; 2037 ps[i] = '\0'; 2038 return (ps); 2039} 2040 2041 2042const char * 2043expandstr(char *ps) 2044{ 2045 union node n; 2046 struct jmploc jmploc; 2047 struct jmploc *const savehandler = handler; 2048 const int saveprompt = doprompt; 2049 struct parsefile *const savetopfile = getcurrentfile(); 2050 struct parser_temp *const saveparser_temp = parser_temp; 2051 const char *result = NULL; 2052 2053 if (!setjmp(jmploc.loc)) { 2054 handler = &jmploc; 2055 parser_temp = NULL; 2056 setinputstring(ps, 1); 2057 doprompt = 0; 2058 readtoken1(pgetc(), DQSYNTAX, "\n\n", 0); 2059 if (backquotelist != NULL) 2060 error("Command substitution not allowed here"); 2061 2062 n.narg.type = NARG; 2063 n.narg.next = NULL; 2064 n.narg.text = wordtext; 2065 n.narg.backquote = backquotelist; 2066 2067 expandarg(&n, NULL, 0); 2068 result = stackblock(); 2069 INTOFF; 2070 } 2071 handler = savehandler; 2072 doprompt = saveprompt; 2073 popfilesupto(savetopfile); 2074 if (parser_temp != saveparser_temp) { 2075 parser_temp_free_all(); 2076 parser_temp = saveparser_temp; 2077 } 2078 if (result != NULL) { 2079 INTON; 2080 } else if (exception == EXINT) 2081 raise(SIGINT); 2082 return result; 2083} 2084