40 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#ifndef NO_HISTORY 60#include "myhistedit.h" 61#endif 62 63/* 64 * Shell command parser. 65 */ 66 67#define EOFMARKLEN 79 68#define PROMPTLEN 128 69 70/* values returned by readtoken */ 71#include "token.h" 72 73 74 75struct heredoc { 76 struct heredoc *next; /* next here document in list */ 77 union node *here; /* redirection node */ 78 char *eofmark; /* string indicating end of input */ 79 int striptabs; /* if set, strip leading tabs */ 80}; 81 82 83 84STATIC struct heredoc *heredoclist; /* list of here documents to read */ 85STATIC int doprompt; /* if set, prompt the user */ 86STATIC int needprompt; /* true if interactive and at start of line */ 87STATIC int lasttoken; /* last token read */ 88MKINIT int tokpushback; /* last token pushed back */ 89STATIC char *wordtext; /* text of last word returned by readtoken */ 90MKINIT int checkkwd; /* 1 == check for kwds, 2 == also eat newlines */ 91STATIC struct nodelist *backquotelist; 92STATIC union node *redirnode; 93STATIC struct heredoc *heredoc; 94STATIC int quoteflag; /* set if (part of) last token was quoted */ 95STATIC int startlinno; /* line # where last token started */ 96STATIC int funclinno; /* line # where the current function started */ 97 98/* XXX When 'noaliases' is set to one, no alias expansion takes place. */ 99static int noaliases = 0; 100 101 102STATIC union node *list(int); 103STATIC union node *andor(void); 104STATIC union node *pipeline(void); 105STATIC union node *command(void); 106STATIC union node *simplecmd(union node **, union node *); 107STATIC union node *makename(void); 108STATIC void parsefname(void); 109STATIC void parseheredoc(void); 110STATIC int peektoken(void); 111STATIC int readtoken(void); 112STATIC int xxreadtoken(void); 113STATIC int readtoken1(int, char const *, char *, int); 114STATIC int noexpand(char *); 115STATIC void synexpect(int); 116STATIC void synerror(char *); 117STATIC void setprompt(int); 118 119 120/* 121 * Read and parse a command. Returns NEOF on end of file. (NULL is a 122 * valid parse tree indicating a blank line.) 123 */ 124 125union node * 126parsecmd(int interact) 127{ 128 int t; 129 130 tokpushback = 0; 131 doprompt = interact; 132 if (doprompt) 133 setprompt(1); 134 else 135 setprompt(0); 136 needprompt = 0; 137 t = readtoken(); 138 if (t == TEOF) 139 return NEOF; 140 if (t == TNL) 141 return NULL; 142 tokpushback++; 143 return list(1); 144} 145 146 147STATIC union node * 148list(int nlflag) 149{ 150 union node *n1, *n2, *n3; 151 int tok; 152 153 checkkwd = 2; 154 if (nlflag == 0 && tokendlist[peektoken()]) 155 return NULL; 156 n1 = NULL; 157 for (;;) { 158 n2 = andor(); 159 tok = readtoken(); 160 if (tok == TBACKGND) { 161 if (n2->type == NCMD || n2->type == NPIPE) { 162 n2->ncmd.backgnd = 1; 163 } else if (n2->type == NREDIR) { 164 n2->type = NBACKGND; 165 } else { 166 n3 = (union node *)stalloc(sizeof (struct nredir)); 167 n3->type = NBACKGND; 168 n3->nredir.n = n2; 169 n3->nredir.redirect = NULL; 170 n2 = n3; 171 } 172 } 173 if (n1 == NULL) { 174 n1 = n2; 175 } 176 else { 177 n3 = (union node *)stalloc(sizeof (struct nbinary)); 178 n3->type = NSEMI; 179 n3->nbinary.ch1 = n1; 180 n3->nbinary.ch2 = n2; 181 n1 = n3; 182 } 183 switch (tok) { 184 case TBACKGND: 185 case TSEMI: 186 tok = readtoken(); 187 /* FALLTHROUGH */ 188 case TNL: 189 if (tok == TNL) { 190 parseheredoc(); 191 if (nlflag) 192 return n1; 193 } else { 194 tokpushback++; 195 } 196 checkkwd = 2; 197 if (tokendlist[peektoken()]) 198 return n1; 199 break; 200 case TEOF: 201 if (heredoclist) 202 parseheredoc(); 203 else 204 pungetc(); /* push back EOF on input */ 205 return n1; 206 default: 207 if (nlflag) 208 synexpect(-1); 209 tokpushback++; 210 return n1; 211 } 212 } 213} 214 215 216 217STATIC union node * 218andor(void) 219{ 220 union node *n1, *n2, *n3; 221 int t; 222 223 n1 = pipeline(); 224 for (;;) { 225 if ((t = readtoken()) == TAND) { 226 t = NAND; 227 } else if (t == TOR) { 228 t = NOR; 229 } else { 230 tokpushback++; 231 return n1; 232 } 233 n2 = pipeline(); 234 n3 = (union node *)stalloc(sizeof (struct nbinary)); 235 n3->type = t; 236 n3->nbinary.ch1 = n1; 237 n3->nbinary.ch2 = n2; 238 n1 = n3; 239 } 240} 241 242 243 244STATIC union node * 245pipeline(void) 246{ 247 union node *n1, *n2, *pipenode; 248 struct nodelist *lp, *prev; 249 int negate; 250 251 negate = 0; 252 checkkwd = 2; 253 TRACE(("pipeline: entered\n")); 254 while (readtoken() == TNOT) 255 negate = !negate; 256 tokpushback++; 257 n1 = command(); 258 if (readtoken() == TPIPE) { 259 pipenode = (union node *)stalloc(sizeof (struct npipe)); 260 pipenode->type = NPIPE; 261 pipenode->npipe.backgnd = 0; 262 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 263 pipenode->npipe.cmdlist = lp; 264 lp->n = n1; 265 do { 266 prev = lp; 267 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 268 lp->n = command(); 269 prev->next = lp; 270 } while (readtoken() == TPIPE); 271 lp->next = NULL; 272 n1 = pipenode; 273 } 274 tokpushback++; 275 if (negate) { 276 n2 = (union node *)stalloc(sizeof (struct nnot)); 277 n2->type = NNOT; 278 n2->nnot.com = n1; 279 return n2; 280 } else 281 return n1; 282} 283 284 285 286STATIC union node * 287command(void) 288{ 289 union node *n1, *n2; 290 union node *ap, **app; 291 union node *cp, **cpp; 292 union node *redir, **rpp; 293 int t, negate = 0; 294 295 checkkwd = 2; 296 redir = NULL; 297 n1 = NULL; 298 rpp = &redir; 299 300 /* Check for redirection which may precede command */ 301 while (readtoken() == TREDIR) { 302 *rpp = n2 = redirnode; 303 rpp = &n2->nfile.next; 304 parsefname(); 305 } 306 tokpushback++; 307 308 while (readtoken() == TNOT) { 309 TRACE(("command: TNOT recognized\n")); 310 negate = !negate; 311 } 312 tokpushback++; 313 314 switch (readtoken()) { 315 case TIF: 316 n1 = (union node *)stalloc(sizeof (struct nif)); 317 n1->type = NIF; 318 if ((n1->nif.test = list(0)) == NULL) 319 synexpect(-1); 320 if (readtoken() != TTHEN) 321 synexpect(TTHEN); 322 n1->nif.ifpart = list(0); 323 n2 = n1; 324 while (readtoken() == TELIF) { 325 n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif)); 326 n2 = n2->nif.elsepart; 327 n2->type = NIF; 328 if ((n2->nif.test = list(0)) == NULL) 329 synexpect(-1); 330 if (readtoken() != TTHEN) 331 synexpect(TTHEN); 332 n2->nif.ifpart = list(0); 333 } 334 if (lasttoken == TELSE) 335 n2->nif.elsepart = list(0); 336 else { 337 n2->nif.elsepart = NULL; 338 tokpushback++; 339 } 340 if (readtoken() != TFI) 341 synexpect(TFI); 342 checkkwd = 1; 343 break; 344 case TWHILE: 345 case TUNTIL: { 346 int got; 347 n1 = (union node *)stalloc(sizeof (struct nbinary)); 348 n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL; 349 if ((n1->nbinary.ch1 = list(0)) == NULL) 350 synexpect(-1); 351 if ((got=readtoken()) != TDO) { 352TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : "")); 353 synexpect(TDO); 354 } 355 n1->nbinary.ch2 = list(0); 356 if (readtoken() != TDONE) 357 synexpect(TDONE); 358 checkkwd = 1; 359 break; 360 } 361 case TFOR: 362 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext)) 363 synerror("Bad for loop variable"); 364 n1 = (union node *)stalloc(sizeof (struct nfor)); 365 n1->type = NFOR; 366 n1->nfor.var = wordtext; 367 while (readtoken() == TNL) 368 ; 369 if (lasttoken == TWORD && ! quoteflag && equal(wordtext, "in")) { 370 app = ≈ 371 while (readtoken() == TWORD) { 372 n2 = (union node *)stalloc(sizeof (struct narg)); 373 n2->type = NARG; 374 n2->narg.text = wordtext; 375 n2->narg.backquote = backquotelist; 376 *app = n2; 377 app = &n2->narg.next; 378 } 379 *app = NULL; 380 n1->nfor.args = ap; 381 if (lasttoken != TNL && lasttoken != TSEMI) 382 synexpect(-1); 383 } else { 384 static char argvars[5] = { 385 CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0' 386 }; 387 n2 = (union node *)stalloc(sizeof (struct narg)); 388 n2->type = NARG; 389 n2->narg.text = argvars; 390 n2->narg.backquote = NULL; 391 n2->narg.next = NULL; 392 n1->nfor.args = n2; 393 /* 394 * Newline or semicolon here is optional (but note 395 * that the original Bourne shell only allowed NL). 396 */ 397 if (lasttoken != TNL && lasttoken != TSEMI) 398 tokpushback++; 399 } 400 checkkwd = 2; 401 if ((t = readtoken()) == TDO) 402 t = TDONE; 403 else if (t == TBEGIN) 404 t = TEND; 405 else 406 synexpect(-1); 407 n1->nfor.body = list(0); 408 if (readtoken() != t) 409 synexpect(t); 410 checkkwd = 1; 411 break; 412 case TCASE: 413 n1 = (union node *)stalloc(sizeof (struct ncase)); 414 n1->type = NCASE; 415 if (readtoken() != TWORD) 416 synexpect(TWORD); 417 n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg)); 418 n2->type = NARG; 419 n2->narg.text = wordtext; 420 n2->narg.backquote = backquotelist; 421 n2->narg.next = NULL; 422 while (readtoken() == TNL); 423 if (lasttoken != TWORD || ! equal(wordtext, "in")) 424 synerror("expecting \"in\""); 425 cpp = &n1->ncase.cases; 426 noaliases = 1; /* turn off alias expansion */ 427 checkkwd = 2, readtoken(); 428 while (lasttoken != TESAC) { 429 *cpp = cp = (union node *)stalloc(sizeof (struct nclist)); 430 cp->type = NCLIST; 431 app = &cp->nclist.pattern; 432 if (lasttoken == TLP) 433 readtoken(); 434 for (;;) { 435 *app = ap = (union node *)stalloc(sizeof (struct narg)); 436 ap->type = NARG; 437 ap->narg.text = wordtext; 438 ap->narg.backquote = backquotelist; 439 if (checkkwd = 2, readtoken() != TPIPE) 440 break; 441 app = &ap->narg.next; 442 readtoken(); 443 } 444 ap->narg.next = NULL; 445 if (lasttoken != TRP) 446 noaliases = 0, synexpect(TRP); 447 cp->nclist.body = list(0); 448 449 checkkwd = 2; 450 if ((t = readtoken()) != TESAC) { 451 if (t != TENDCASE) 452 noaliases = 0, synexpect(TENDCASE); 453 else 454 checkkwd = 2, readtoken(); 455 } 456 cpp = &cp->nclist.next; 457 } 458 noaliases = 0; /* reset alias expansion */ 459 *cpp = NULL; 460 checkkwd = 1; 461 break; 462 case TLP: 463 n1 = (union node *)stalloc(sizeof (struct nredir)); 464 n1->type = NSUBSHELL; 465 n1->nredir.n = list(0); 466 n1->nredir.redirect = NULL; 467 if (readtoken() != TRP) 468 synexpect(TRP); 469 checkkwd = 1; 470 break; 471 case TBEGIN: 472 n1 = list(0); 473 if (readtoken() != TEND) 474 synexpect(TEND); 475 checkkwd = 1; 476 break; 477 /* Handle an empty command like other simple commands. */ 478 case TSEMI: 479 case TAND: 480 case TOR: 481 /* 482 * An empty command before a ; doesn't make much sense, and 483 * should certainly be disallowed in the case of `if ;'. 484 */ 485 if (!redir) 486 synexpect(-1); 487 case TNL: 488 case TEOF: 489 case TWORD: 490 case TRP: 491 tokpushback++; 492 n1 = simplecmd(rpp, redir); 493 goto checkneg; 494 default: 495 synexpect(-1); 496 } 497 498 /* Now check for redirection which may follow command */ 499 while (readtoken() == TREDIR) { 500 *rpp = n2 = redirnode; 501 rpp = &n2->nfile.next; 502 parsefname(); 503 } 504 tokpushback++; 505 *rpp = NULL; 506 if (redir) { 507 if (n1->type != NSUBSHELL) { 508 n2 = (union node *)stalloc(sizeof (struct nredir)); 509 n2->type = NREDIR; 510 n2->nredir.n = n1; 511 n1 = n2; 512 } 513 n1->nredir.redirect = redir; 514 } 515 516checkneg: 517 if (negate) { 518 n2 = (union node *)stalloc(sizeof (struct nnot)); 519 n2->type = NNOT; 520 n2->nnot.com = n1; 521 return n2; 522 } 523 else 524 return n1; 525} 526 527 528STATIC union node * 529simplecmd(union node **rpp, union node *redir) 530{ 531 union node *args, **app; 532 union node **orig_rpp = rpp; 533 union node *n = NULL, *n2; 534 int negate = 0; 535 536 /* If we don't have any redirections already, then we must reset */ 537 /* rpp to be the address of the local redir variable. */ 538 if (redir == 0) 539 rpp = &redir; 540 541 args = NULL; 542 app = &args; 543 /* 544 * We save the incoming value, because we need this for shell 545 * functions. There can not be a redirect or an argument between 546 * the function name and the open parenthesis. 547 */ 548 orig_rpp = rpp; 549 550 while (readtoken() == TNOT) { 551 TRACE(("command: TNOT recognized\n")); 552 negate = !negate; 553 } 554 tokpushback++; 555 556 for (;;) { 557 if (readtoken() == TWORD) { 558 n = (union node *)stalloc(sizeof (struct narg)); 559 n->type = NARG; 560 n->narg.text = wordtext; 561 n->narg.backquote = backquotelist; 562 *app = n; 563 app = &n->narg.next; 564 } else if (lasttoken == TREDIR) { 565 *rpp = n = redirnode; 566 rpp = &n->nfile.next; 567 parsefname(); /* read name of redirection file */ 568 } else if (lasttoken == TLP && app == &args->narg.next 569 && rpp == orig_rpp) { 570 /* We have a function */ 571 if (readtoken() != TRP) 572 synexpect(TRP); 573 funclinno = plinno; 574#ifdef notdef 575 if (! goodname(n->narg.text)) 576 synerror("Bad function name"); 577#endif 578 n->type = NDEFUN; 579 n->narg.next = command(); 580 funclinno = 0; 581 goto checkneg; 582 } else { 583 tokpushback++; 584 break; 585 } 586 } 587 *app = NULL; 588 *rpp = NULL; 589 n = (union node *)stalloc(sizeof (struct ncmd)); 590 n->type = NCMD; 591 n->ncmd.backgnd = 0; 592 n->ncmd.args = args; 593 n->ncmd.redirect = redir; 594 595checkneg: 596 if (negate) { 597 n2 = (union node *)stalloc(sizeof (struct nnot)); 598 n2->type = NNOT; 599 n2->nnot.com = n; 600 return n2; 601 } 602 else 603 return n; 604} 605 606STATIC union node * 607makename(void) 608{ 609 union node *n; 610 611 n = (union node *)stalloc(sizeof (struct narg)); 612 n->type = NARG; 613 n->narg.next = NULL; 614 n->narg.text = wordtext; 615 n->narg.backquote = backquotelist; 616 return n; 617} 618 619void fixredir(union node *n, const char *text, int err) 620{ 621 TRACE(("Fix redir %s %d\n", text, err)); 622 if (!err) 623 n->ndup.vname = NULL; 624 625 if (is_digit(text[0]) && text[1] == '\0') 626 n->ndup.dupfd = digit_val(text[0]); 627 else if (text[0] == '-' && text[1] == '\0') 628 n->ndup.dupfd = -1; 629 else { 630 631 if (err) 632 synerror("Bad fd number"); 633 else 634 n->ndup.vname = makename(); 635 } 636} 637 638 639STATIC void 640parsefname(void) 641{ 642 union node *n = redirnode; 643 644 if (readtoken() != TWORD) 645 synexpect(-1); 646 if (n->type == NHERE) { 647 struct heredoc *here = heredoc; 648 struct heredoc *p; 649 int i; 650 651 if (quoteflag == 0) 652 n->type = NXHERE; 653 TRACE(("Here document %d\n", n->type)); 654 if (here->striptabs) { 655 while (*wordtext == '\t') 656 wordtext++; 657 } 658 if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN) 659 synerror("Illegal eof marker for << redirection"); 660 rmescapes(wordtext); 661 here->eofmark = wordtext; 662 here->next = NULL; 663 if (heredoclist == NULL) 664 heredoclist = here; 665 else { 666 for (p = heredoclist ; p->next ; p = p->next); 667 p->next = here; 668 } 669 } else if (n->type == NTOFD || n->type == NFROMFD) { 670 fixredir(n, wordtext, 0); 671 } else { 672 n->nfile.fname = makename(); 673 } 674} 675 676 677/* 678 * Input any here documents. 679 */ 680 681STATIC void 682parseheredoc(void) 683{ 684 struct heredoc *here; 685 union node *n; 686 687 while (heredoclist) { 688 here = heredoclist; 689 heredoclist = here->next; 690 if (needprompt) { 691 setprompt(2); 692 needprompt = 0; 693 } 694 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, 695 here->eofmark, here->striptabs); 696 n = (union node *)stalloc(sizeof (struct narg)); 697 n->narg.type = NARG; 698 n->narg.next = NULL; 699 n->narg.text = wordtext; 700 n->narg.backquote = backquotelist; 701 here->here->nhere.doc = n; 702 } 703} 704 705STATIC int 706peektoken(void) 707{ 708 int t; 709 710 t = readtoken(); 711 tokpushback++; 712 return (t); 713} 714 715STATIC int 716readtoken(void) 717{ 718 int t; 719 int savecheckkwd = checkkwd; 720 struct alias *ap; 721#ifdef DEBUG 722 int alreadyseen = tokpushback; 723#endif 724 725 top: 726 t = xxreadtoken(); 727 728 if (checkkwd) { 729 /* 730 * eat newlines 731 */ 732 if (checkkwd == 2) { 733 checkkwd = 0; 734 while (t == TNL) { 735 parseheredoc(); 736 t = xxreadtoken(); 737 } 738 } else 739 checkkwd = 0; 740 /* 741 * check for keywords and aliases 742 */ 743 if (t == TWORD && !quoteflag) 744 { 745 const char * const *pp; 746 747 for (pp = parsekwd; *pp; pp++) { 748 if (**pp == *wordtext && equal(*pp, wordtext)) 749 { 750 lasttoken = t = pp - parsekwd + KWDOFFSET; 751 TRACE(("keyword %s recognized\n", tokname[t])); 752 goto out; 753 } 754 } 755 if (noaliases == 0 && 756 (ap = lookupalias(wordtext, 1)) != NULL) { 757 pushstring(ap->val, strlen(ap->val), ap); 758 checkkwd = savecheckkwd; 759 goto top; 760 } 761 } 762out: 763 checkkwd = (t == TNOT) ? savecheckkwd : 0; 764 } 765#ifdef DEBUG 766 if (!alreadyseen) 767 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 768 else 769 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 770#endif 771 return (t); 772} 773 774 775/* 776 * Read the next input token. 777 * If the token is a word, we set backquotelist to the list of cmds in 778 * backquotes. We set quoteflag to true if any part of the word was 779 * quoted. 780 * If the token is TREDIR, then we set redirnode to a structure containing 781 * the redirection. 782 * In all cases, the variable startlinno is set to the number of the line 783 * on which the token starts. 784 * 785 * [Change comment: here documents and internal procedures] 786 * [Readtoken shouldn't have any arguments. Perhaps we should make the 787 * word parsing code into a separate routine. In this case, readtoken 788 * doesn't need to have any internal procedures, but parseword does. 789 * We could also make parseoperator in essence the main routine, and 790 * have parseword (readtoken1?) handle both words and redirection.] 791 */ 792 793#define RETURN(token) return lasttoken = token 794 795STATIC int 796xxreadtoken(void) 797{ 798 int c; 799 800 if (tokpushback) { 801 tokpushback = 0; 802 return lasttoken; 803 } 804 if (needprompt) { 805 setprompt(2); 806 needprompt = 0; 807 } 808 startlinno = plinno; 809 for (;;) { /* until token or start of word found */ 810 c = pgetc_macro(); 811 if (c == ' ' || c == '\t') 812 continue; /* quick check for white space first */ 813 switch (c) { 814 case ' ': case '\t': 815 continue; 816 case '#': 817 while ((c = pgetc()) != '\n' && c != PEOF); 818 pungetc(); 819 continue; 820 case '\\': 821 if (pgetc() == '\n') { 822 startlinno = ++plinno; 823 if (doprompt) 824 setprompt(2); 825 else 826 setprompt(0); 827 continue; 828 } 829 pungetc(); 830 goto breakloop; 831 case '\n': 832 plinno++; 833 needprompt = doprompt; 834 RETURN(TNL); 835 case PEOF: 836 RETURN(TEOF); 837 case '&': 838 if (pgetc() == '&') 839 RETURN(TAND); 840 pungetc(); 841 RETURN(TBACKGND); 842 case '|': 843 if (pgetc() == '|') 844 RETURN(TOR); 845 pungetc(); 846 RETURN(TPIPE); 847 case ';': 848 if (pgetc() == ';') 849 RETURN(TENDCASE); 850 pungetc(); 851 RETURN(TSEMI); 852 case '(': 853 RETURN(TLP); 854 case ')': 855 RETURN(TRP); 856 default: 857 goto breakloop; 858 } 859 } 860breakloop: 861 return readtoken1(c, BASESYNTAX, (char *)NULL, 0); 862#undef RETURN 863} 864 865 866 867/* 868 * If eofmark is NULL, read a word or a redirection symbol. If eofmark 869 * is not NULL, read a here document. In the latter case, eofmark is the 870 * word which marks the end of the document and striptabs is true if 871 * leading tabs should be stripped from the document. The argument firstc 872 * is the first character of the input token or document. 873 * 874 * Because C does not have internal subroutines, I have simulated them 875 * using goto's to implement the subroutine linkage. The following macros 876 * will run code that appears at the end of readtoken1. 877 */ 878 879#define CHECKEND() {goto checkend; checkend_return:;} 880#define PARSEREDIR() {goto parseredir; parseredir_return:;} 881#define PARSESUB() {goto parsesub; parsesub_return:;} 882#define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;} 883#define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;} 884#define PARSEARITH() {goto parsearith; parsearith_return:;} 885 886STATIC int 887readtoken1(int firstc, char const *syntax, char *eofmark, int striptabs) 888{ 889 int c = firstc; 890 char *out; 891 int len; 892 char line[EOFMARKLEN + 1]; 893 struct nodelist *bqlist; 894 int quotef; 895 int dblquote; 896 int varnest; /* levels of variables expansion */ 897 int arinest; /* levels of arithmetic expansion */ 898 int parenlevel; /* levels of parens in arithmetic */ 899 int oldstyle; 900 char const *prevsyntax; /* syntax before arithmetic */ 901 int synentry; 902 903 startlinno = plinno; 904 dblquote = 0; 905 if (syntax == DQSYNTAX) 906 dblquote = 1; 907 quotef = 0; 908 bqlist = NULL; 909 varnest = 0; 910 arinest = 0; 911 parenlevel = 0; 912 913 STARTSTACKSTR(out); 914 loop: { /* for each line, until end of word */ 915 CHECKEND(); /* set c to PEOF if at end of here document */ 916 for (;;) { /* until end of line or end of word */ 917 CHECKSTRSPACE(3, out); /* permit 3 calls to USTPUTC */ 918 919 synentry = syntax[c]; 920 921 switch(synentry) { 922 case CNL: /* '\n' */ 923 if (syntax == BASESYNTAX) 924 goto endword; /* exit outer loop */ 925 USTPUTC(c, out); 926 plinno++; 927 if (doprompt) 928 setprompt(2); 929 else 930 setprompt(0); 931 c = pgetc(); 932 goto loop; /* continue outer loop */ 933 case CWORD: 934 USTPUTC(c, out); 935 break; 936 case CCTL: 937 if (eofmark == NULL || dblquote) 938 USTPUTC(CTLESC, out); 939 USTPUTC(c, out); 940 break; 941 case CBACK: /* backslash */ 942 c = pgetc(); 943 if (c == PEOF) { 944 USTPUTC('\\', out); 945 pungetc(); 946 } else if (c == '\n') { 947 plinno++; 948 if (doprompt) 949 setprompt(2); 950 else 951 setprompt(0); 952 } else { 953 if (dblquote && c != '\\' && 954 c != '`' && c != '$' && 955 (c != '"' || eofmark != NULL)) 956 USTPUTC('\\', out); 957 if (SQSYNTAX[c] == CCTL) 958 USTPUTC(CTLESC, out); 959 else if (eofmark == NULL) 960 USTPUTC(CTLQUOTEMARK, out); 961 USTPUTC(c, out); 962 quotef++; 963 } 964 break; 965 case CSQUOTE: 966 if (eofmark == NULL) 967 USTPUTC(CTLQUOTEMARK, out); 968 syntax = SQSYNTAX; 969 break; 970 case CDQUOTE: 971 if (eofmark == NULL) 972 USTPUTC(CTLQUOTEMARK, out); 973 syntax = DQSYNTAX; 974 dblquote = 1; 975 break; 976 case CENDQUOTE: 977 if (eofmark != NULL && arinest == 0 && 978 varnest == 0) { 979 USTPUTC(c, out); 980 } else { 981 if (arinest) { 982 syntax = ARISYNTAX; 983 dblquote = 0; 984 } else if (eofmark == NULL) { 985 syntax = BASESYNTAX; 986 dblquote = 0; 987 } 988 quotef++; 989 } 990 break; 991 case CVAR: /* '$' */ 992 PARSESUB(); /* parse substitution */ 993 break; 994 case CENDVAR: /* '}' */ 995 if (varnest > 0) { 996 varnest--; 997 USTPUTC(CTLENDVAR, out); 998 } else { 999 USTPUTC(c, out); 1000 } 1001 break; 1002 case CLP: /* '(' in arithmetic */ 1003 parenlevel++; 1004 USTPUTC(c, out); 1005 break; 1006 case CRP: /* ')' in arithmetic */ 1007 if (parenlevel > 0) { 1008 USTPUTC(c, out); 1009 --parenlevel; 1010 } else { 1011 if (pgetc() == ')') { 1012 if (--arinest == 0) { 1013 USTPUTC(CTLENDARI, out); 1014 syntax = prevsyntax; 1015 if (syntax == DQSYNTAX) 1016 dblquote = 1; 1017 else 1018 dblquote = 0; 1019 } else 1020 USTPUTC(')', out); 1021 } else { 1022 /* 1023 * unbalanced parens 1024 * (don't 2nd guess - no error) 1025 */ 1026 pungetc(); 1027 USTPUTC(')', out); 1028 } 1029 } 1030 break; 1031 case CBQUOTE: /* '`' */ 1032 PARSEBACKQOLD(); 1033 break; 1034 case CEOF: 1035 goto endword; /* exit outer loop */ 1036 default: 1037 if (varnest == 0) 1038 goto endword; /* exit outer loop */ 1039 USTPUTC(c, out); 1040 } 1041 c = pgetc_macro(); 1042 } 1043 } 1044endword: 1045 if (syntax == ARISYNTAX) 1046 synerror("Missing '))'"); 1047 if (syntax != BASESYNTAX && eofmark == NULL) 1048 synerror("Unterminated quoted string"); 1049 if (varnest != 0) { 1050 startlinno = plinno; 1051 synerror("Missing '}'"); 1052 } 1053 USTPUTC('\0', out); 1054 len = out - stackblock(); 1055 out = stackblock(); 1056 if (eofmark == NULL) { 1057 if ((c == '>' || c == '<') 1058 && quotef == 0 1059 && len <= 2 1060 && (*out == '\0' || is_digit(*out))) { 1061 PARSEREDIR(); 1062 return lasttoken = TREDIR; 1063 } else { 1064 pungetc(); 1065 } 1066 } 1067 quoteflag = quotef; 1068 backquotelist = bqlist; 1069 grabstackblock(len); 1070 wordtext = out; 1071 return lasttoken = TWORD; 1072/* end of readtoken routine */ 1073 1074 1075 1076/* 1077 * Check to see whether we are at the end of the here document. When this 1078 * is called, c is set to the first character of the next input line. If 1079 * we are at the end of the here document, this routine sets the c to PEOF. 1080 */ 1081 1082checkend: { 1083 if (eofmark) { 1084 if (striptabs) { 1085 while (c == '\t') 1086 c = pgetc(); 1087 } 1088 if (c == *eofmark) { 1089 if (pfgets(line, sizeof line) != NULL) { 1090 char *p, *q; 1091 1092 p = line; 1093 for (q = eofmark + 1 ; *q && *p == *q ; p++, q++); 1094 if (*p == '\n' && *q == '\0') { 1095 c = PEOF; 1096 plinno++; 1097 needprompt = doprompt; 1098 } else { 1099 pushstring(line, strlen(line), NULL); 1100 } 1101 } 1102 } 1103 } 1104 goto checkend_return; 1105} 1106 1107 1108/* 1109 * Parse a redirection operator. The variable "out" points to a string 1110 * specifying the fd to be redirected. The variable "c" contains the 1111 * first character of the redirection operator. 1112 */ 1113 1114parseredir: { 1115 char fd = *out; 1116 union node *np; 1117 1118 np = (union node *)stalloc(sizeof (struct nfile)); 1119 if (c == '>') { 1120 np->nfile.fd = 1; 1121 c = pgetc(); 1122 if (c == '>') 1123 np->type = NAPPEND; 1124 else if (c == '&') 1125 np->type = NTOFD; 1126 else if (c == '|') 1127 np->type = NCLOBBER; 1128 else { 1129 np->type = NTO; 1130 pungetc(); 1131 } 1132 } else { /* c == '<' */ 1133 np->nfile.fd = 0; 1134 c = pgetc(); 1135 if (c == '<') { 1136 if (sizeof (struct nfile) != sizeof (struct nhere)) { 1137 np = (union node *)stalloc(sizeof (struct nhere)); 1138 np->nfile.fd = 0; 1139 } 1140 np->type = NHERE; 1141 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); 1142 heredoc->here = np; 1143 if ((c = pgetc()) == '-') { 1144 heredoc->striptabs = 1; 1145 } else { 1146 heredoc->striptabs = 0; 1147 pungetc(); 1148 } 1149 } else if (c == '&') 1150 np->type = NFROMFD; 1151 else if (c == '>') 1152 np->type = NFROMTO; 1153 else { 1154 np->type = NFROM; 1155 pungetc(); 1156 } 1157 } 1158 if (fd != '\0') 1159 np->nfile.fd = digit_val(fd); 1160 redirnode = np; 1161 goto parseredir_return; 1162} 1163 1164 1165/* 1166 * Parse a substitution. At this point, we have read the dollar sign 1167 * and nothing else. 1168 */ 1169 1170parsesub: { 1171 char buf[10]; 1172 int subtype; 1173 int typeloc; 1174 int flags; 1175 char *p; 1176 static const char types[] = "}-+?="; 1177 int bracketed_name = 0; /* used to handle ${[0-9]*} variables */ 1178 int i; 1179 int linno; 1180 int length; 1181 1182 c = pgetc(); 1183 if (c != '(' && c != '{' && (is_eof(c) || !is_name(c)) && 1184 !is_special(c)) { 1185 USTPUTC('$', out); 1186 pungetc(); 1187 } else if (c == '(') { /* $(command) or $((arith)) */ 1188 if (pgetc() == '(') { 1189 PARSEARITH(); 1190 } else { 1191 pungetc(); 1192 PARSEBACKQNEW(); 1193 } 1194 } else { 1195 USTPUTC(CTLVAR, out); 1196 typeloc = out - stackblock(); 1197 USTPUTC(VSNORMAL, out); 1198 subtype = VSNORMAL; 1199 flags = 0; 1200 if (c == '{') { 1201 bracketed_name = 1; 1202 c = pgetc(); 1203 if (c == '#') { 1204 if ((c = pgetc()) == '}') 1205 c = '#'; 1206 else 1207 subtype = VSLENGTH; 1208 } 1209 else 1210 subtype = 0; 1211 } 1212 if (!is_eof(c) && is_name(c)) { 1213 length = 0; 1214 do { 1215 STPUTC(c, out); 1216 c = pgetc(); 1217 length++; 1218 } while (!is_eof(c) && is_in_name(c)); 1219 if (length == 6 && 1220 strncmp(out - length, "LINENO", length) == 0) { 1221 /* Replace the variable name with the 1222 * current line number. */ 1223 linno = plinno; 1224 if (funclinno != 0) 1225 linno -= funclinno - 1; 1226 snprintf(buf, sizeof(buf), "%d", linno); 1227 STADJUST(-6, out); 1228 for (i = 0; buf[i] != '\0'; i++) 1229 STPUTC(buf[i], out); 1230 flags |= VSLINENO; 1231 } 1232 } else if (is_digit(c)) { 1233 if (bracketed_name) { 1234 do { 1235 STPUTC(c, out); 1236 c = pgetc(); 1237 } while (is_digit(c)); 1238 } else { 1239 STPUTC(c, out); 1240 c = pgetc(); 1241 } 1242 } else { 1243 if (! is_special(c)) { 1244 subtype = VSERROR; 1245 if (c == '}') 1246 pungetc(); 1247 else 1248 USTPUTC(c, out); 1249 } else { 1250 USTPUTC(c, out); 1251 c = pgetc(); 1252 } 1253 } 1254 if (subtype == 0) { 1255 switch (c) { 1256 case ':': 1257 flags |= VSNUL; 1258 c = pgetc(); 1259 /*FALLTHROUGH*/ 1260 default: 1261 p = strchr(types, c); 1262 if (p == NULL) { 1263 if (flags == VSNUL) 1264 STPUTC(':', out); 1265 STPUTC(c, out); 1266 subtype = VSERROR; 1267 } else 1268 subtype = p - types + VSNORMAL; 1269 break; 1270 case '%': 1271 case '#': 1272 { 1273 int cc = c; 1274 subtype = c == '#' ? VSTRIMLEFT : 1275 VSTRIMRIGHT; 1276 c = pgetc(); 1277 if (c == cc) 1278 subtype++; 1279 else 1280 pungetc(); 1281 break; 1282 } 1283 } 1284 } else if (subtype != VSERROR) { 1285 pungetc(); 1286 } 1287 STPUTC('=', out); 1288 if (subtype != VSLENGTH && (dblquote || arinest)) 1289 flags |= VSQUOTE; 1290 *(stackblock() + typeloc) = subtype | flags; 1291 if (subtype != VSNORMAL) 1292 varnest++; 1293 } 1294 goto parsesub_return; 1295} 1296 1297 1298/* 1299 * Called to parse command substitutions. Newstyle is set if the command 1300 * is enclosed inside $(...); nlpp is a pointer to the head of the linked 1301 * list of commands (passed by reference), and savelen is the number of 1302 * characters on the top of the stack which must be preserved. 1303 */ 1304 1305parsebackq: { 1306 struct nodelist **nlpp; 1307 union node *n; 1308 char *volatile str; 1309 struct jmploc jmploc; 1310 struct jmploc *const savehandler = handler; 1311 int savelen; 1312 int saveprompt; 1313 const int bq_startlinno = plinno; 1314 1315 str = NULL; 1316 if (setjmp(jmploc.loc)) { 1317 if (str) 1318 ckfree(str); 1319 handler = savehandler; 1320 if (exception == EXERROR) { 1321 startlinno = bq_startlinno; 1322 synerror("Error in command substitution"); 1323 } 1324 longjmp(handler->loc, 1); 1325 } 1326 INTOFF; 1327 savelen = out - stackblock(); 1328 if (savelen > 0) { 1329 str = ckmalloc(savelen); 1330 memcpy(str, stackblock(), savelen); 1331 } 1332 handler = &jmploc; 1333 INTON; 1334 if (oldstyle) { 1335 /* We must read until the closing backquote, giving special 1336 treatment to some slashes, and then push the string and 1337 reread it as input, interpreting it normally. */ 1338 char *out; 1339 int c; 1340 int savelen; 1341 char *str; 1342 1343 1344 STARTSTACKSTR(out); 1345 for (;;) { 1346 if (needprompt) { 1347 setprompt(2); 1348 needprompt = 0; 1349 } 1350 switch (c = pgetc()) { 1351 case '`': 1352 goto done; 1353 1354 case '\\': 1355 if ((c = pgetc()) == '\n') { 1356 plinno++; 1357 if (doprompt) 1358 setprompt(2); 1359 else 1360 setprompt(0); 1361 /* 1362 * If eating a newline, avoid putting 1363 * the newline into the new character 1364 * stream (via the STPUTC after the 1365 * switch). 1366 */ 1367 continue; 1368 } 1369 if (c != '\\' && c != '`' && c != '$' 1370 && (!dblquote || c != '"')) 1371 STPUTC('\\', out); 1372 break; 1373 1374 case '\n': 1375 plinno++; 1376 needprompt = doprompt; 1377 break; 1378 1379 case PEOF: 1380 startlinno = plinno; 1381 synerror("EOF in backquote substitution"); 1382 break; 1383 1384 default: 1385 break; 1386 } 1387 STPUTC(c, out); 1388 } 1389done: 1390 STPUTC('\0', out); 1391 savelen = out - stackblock(); 1392 if (savelen > 0) { 1393 str = ckmalloc(savelen); 1394 memcpy(str, stackblock(), savelen); 1395 setinputstring(str, 1); 1396 } 1397 } 1398 nlpp = &bqlist; 1399 while (*nlpp) 1400 nlpp = &(*nlpp)->next; 1401 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 1402 (*nlpp)->next = NULL; 1403 1404 if (oldstyle) { 1405 saveprompt = doprompt; 1406 doprompt = 0; 1407 } 1408 1409 n = list(0); 1410 1411 if (oldstyle) 1412 doprompt = saveprompt; 1413 else { 1414 if (readtoken() != TRP) 1415 synexpect(TRP); 1416 } 1417 1418 (*nlpp)->n = n; 1419 if (oldstyle) { 1420 /* 1421 * Start reading from old file again, ignoring any pushed back 1422 * tokens left from the backquote parsing 1423 */ 1424 popfile(); 1425 tokpushback = 0; 1426 } 1427 while (stackblocksize() <= savelen) 1428 growstackblock(); 1429 STARTSTACKSTR(out); 1430 if (str) { 1431 memcpy(out, str, savelen); 1432 STADJUST(savelen, out); 1433 INTOFF; 1434 ckfree(str); 1435 str = NULL; 1436 INTON; 1437 } 1438 handler = savehandler; 1439 if (arinest || dblquote) 1440 USTPUTC(CTLBACKQ | CTLQUOTE, out); 1441 else 1442 USTPUTC(CTLBACKQ, out); 1443 if (oldstyle) 1444 goto parsebackq_oldreturn; 1445 else 1446 goto parsebackq_newreturn; 1447} 1448 1449/* 1450 * Parse an arithmetic expansion (indicate start of one and set state) 1451 */ 1452parsearith: { 1453 1454 if (++arinest == 1) { 1455 prevsyntax = syntax; 1456 syntax = ARISYNTAX; 1457 USTPUTC(CTLARI, out); 1458 if (dblquote) 1459 USTPUTC('"',out); 1460 else 1461 USTPUTC(' ',out); 1462 } else { 1463 /* 1464 * we collapse embedded arithmetic expansion to 1465 * parenthesis, which should be equivalent 1466 */ 1467 USTPUTC('(', out); 1468 } 1469 goto parsearith_return; 1470} 1471 1472} /* end of readtoken */ 1473 1474 1475 1476#ifdef mkinit 1477RESET { 1478 tokpushback = 0; 1479 checkkwd = 0; 1480} 1481#endif 1482 1483/* 1484 * Returns true if the text contains nothing to expand (no dollar signs 1485 * or backquotes). 1486 */ 1487 1488STATIC int 1489noexpand(char *text) 1490{ 1491 char *p; 1492 char c; 1493 1494 p = text; 1495 while ((c = *p++) != '\0') { 1496 if ( c == CTLQUOTEMARK) 1497 continue; 1498 if (c == CTLESC) 1499 p++; 1500 else if (BASESYNTAX[(int)c] == CCTL) 1501 return 0; 1502 } 1503 return 1; 1504} 1505 1506 1507/* 1508 * Return true if the argument is a legal variable name (a letter or 1509 * underscore followed by zero or more letters, underscores, and digits). 1510 */ 1511 1512int
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