1 /*- 2 * Copyright (c) 1991 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kenneth Almquist. 7 * 8 * %sccs.include.redist.c% 9 */ 10 11 #ifndef lint 12 static char sccsid[] = "@(#)parser.c 5.3 (Berkeley) 04/12/91"; 13 #endif /* not lint */ 14 15 #include "shell.h" 16 #include "parser.h" 17 #include "nodes.h" 18 #include "expand.h" /* defines rmescapes() */ 19 #include "redir.h" /* defines copyfd() */ 20 #include "syntax.h" 21 #include "options.h" 22 #include "input.h" 23 #include "output.h" 24 #include "var.h" 25 #include "error.h" 26 #include "memalloc.h" 27 #include "mystring.h" 28 29 30 /* 31 * Shell command parser. 32 */ 33 34 #define EOFMARKLEN 79 35 36 /* values returned by readtoken */ 37 #include "token.def" 38 39 40 41 struct heredoc { 42 struct heredoc *next; /* next here document in list */ 43 union node *here; /* redirection node */ 44 char *eofmark; /* string indicating end of input */ 45 int striptabs; /* if set, strip leading tabs */ 46 }; 47 48 49 50 struct heredoc *heredoclist; /* list of here documents to read */ 51 int parsebackquote; /* nonzero if we are inside backquotes */ 52 int doprompt; /* if set, prompt the user */ 53 int needprompt; /* true if interactive and at start of line */ 54 int lasttoken; /* last token read */ 55 MKINIT int tokpushback; /* last token pushed back */ 56 char *wordtext; /* text of last word returned by readtoken */ 57 int checkkwd; /* 1 == check for kwds, 2 == also eat newlines */ 58 struct nodelist *backquotelist; 59 union node *redirnode; 60 struct heredoc *heredoc; 61 int quoteflag; /* set if (part of) last token was quoted */ 62 int startlinno; /* line # where last token started */ 63 64 65 #define GDB_HACK 1 /* avoid local declarations which gdb can't handle */ 66 #ifdef GDB_HACK 67 static const char argvars[5] = {CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0'}; 68 static const char types[] = "}-+?="; 69 #endif 70 71 72 STATIC union node *list __P((int)); 73 STATIC union node *andor __P((void)); 74 STATIC union node *pipeline __P((void)); 75 STATIC union node *command __P((void)); 76 STATIC union node *simplecmd __P((void)); 77 STATIC void parsefname __P((void)); 78 STATIC void parseheredoc __P((void)); 79 STATIC int readtoken __P((void)); 80 STATIC int readtoken1 __P((int, char const *, char *, int)); 81 STATIC void attyline __P((void)); 82 STATIC int noexpand __P((char *)); 83 STATIC void synexpect __P((int)); 84 STATIC void synerror __P((char *)); 85 86 #if ATTY 87 STATIC void putprompt __P((char *)); 88 #else /* not ATTY */ 89 #define putprompt(s) out2str(s) 90 #endif 91 92 93 94 95 /* 96 * Read and parse a command. Returns NEOF on end of file. (NULL is a 97 * valid parse tree indicating a blank line.) 98 */ 99 100 union node * 101 parsecmd(interact) { 102 int t; 103 104 doprompt = interact; 105 if (doprompt) 106 putprompt(ps1val()); 107 needprompt = 0; 108 if ((t = readtoken()) == TEOF) 109 return NEOF; 110 if (t == TNL) 111 return NULL; 112 tokpushback++; 113 return list(1); 114 } 115 116 117 STATIC union node * 118 list(nlflag) { 119 union node *n1, *n2, *n3; 120 121 checkkwd = 2; 122 if (nlflag == 0 && tokendlist[peektoken()]) 123 return NULL; 124 n1 = andor(); 125 for (;;) { 126 switch (readtoken()) { 127 case TBACKGND: 128 if (n1->type == NCMD || n1->type == NPIPE) { 129 n1->ncmd.backgnd = 1; 130 } else if (n1->type == NREDIR) { 131 n1->type = NBACKGND; 132 } else { 133 n3 = (union node *)stalloc(sizeof (struct nredir)); 134 n3->type = NBACKGND; 135 n3->nredir.n = n1; 136 n3->nredir.redirect = NULL; 137 n1 = n3; 138 } 139 goto tsemi; 140 case TNL: 141 tokpushback++; 142 /* fall through */ 143 tsemi: case TSEMI: 144 if (readtoken() == TNL) { 145 parseheredoc(); 146 if (nlflag) 147 return n1; 148 } else { 149 tokpushback++; 150 } 151 checkkwd = 2; 152 if (tokendlist[peektoken()]) 153 return n1; 154 n2 = andor(); 155 n3 = (union node *)stalloc(sizeof (struct nbinary)); 156 n3->type = NSEMI; 157 n3->nbinary.ch1 = n1; 158 n3->nbinary.ch2 = n2; 159 n1 = n3; 160 break; 161 case TEOF: 162 if (heredoclist) 163 parseheredoc(); 164 else 165 pungetc(); /* push back EOF on input */ 166 return n1; 167 default: 168 if (nlflag) 169 synexpect(-1); 170 tokpushback++; 171 return n1; 172 } 173 } 174 } 175 176 177 178 STATIC union node * 179 andor() { 180 union node *n1, *n2, *n3; 181 int t; 182 183 n1 = pipeline(); 184 for (;;) { 185 if ((t = readtoken()) == TAND) { 186 t = NAND; 187 } else if (t == TOR) { 188 t = NOR; 189 } else { 190 tokpushback++; 191 return n1; 192 } 193 n2 = pipeline(); 194 n3 = (union node *)stalloc(sizeof (struct nbinary)); 195 n3->type = t; 196 n3->nbinary.ch1 = n1; 197 n3->nbinary.ch2 = n2; 198 n1 = n3; 199 } 200 } 201 202 203 204 STATIC union node * 205 pipeline() { 206 union node *n1, *pipenode; 207 struct nodelist *lp, *prev; 208 209 n1 = command(); 210 if (readtoken() == TPIPE) { 211 pipenode = (union node *)stalloc(sizeof (struct npipe)); 212 pipenode->type = NPIPE; 213 pipenode->npipe.backgnd = 0; 214 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 215 pipenode->npipe.cmdlist = lp; 216 lp->n = n1; 217 do { 218 prev = lp; 219 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 220 lp->n = command(); 221 prev->next = lp; 222 } while (readtoken() == TPIPE); 223 lp->next = NULL; 224 n1 = pipenode; 225 } 226 tokpushback++; 227 return n1; 228 } 229 230 231 232 STATIC union node * 233 command() { 234 union node *n1, *n2; 235 union node *ap, **app; 236 union node *cp, **cpp; 237 union node *redir, **rpp; 238 int t; 239 240 checkkwd = 2; 241 switch (readtoken()) { 242 case TIF: 243 n1 = (union node *)stalloc(sizeof (struct nif)); 244 n1->type = NIF; 245 n1->nif.test = list(0); 246 if (readtoken() != TTHEN) 247 synexpect(TTHEN); 248 n1->nif.ifpart = list(0); 249 n2 = n1; 250 while (readtoken() == TELIF) { 251 n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif)); 252 n2 = n2->nif.elsepart; 253 n2->type = NIF; 254 n2->nif.test = list(0); 255 if (readtoken() != TTHEN) 256 synexpect(TTHEN); 257 n2->nif.ifpart = list(0); 258 } 259 if (lasttoken == TELSE) 260 n2->nif.elsepart = list(0); 261 else { 262 n2->nif.elsepart = NULL; 263 tokpushback++; 264 } 265 if (readtoken() != TFI) 266 synexpect(TFI); 267 checkkwd = 1; 268 break; 269 case TWHILE: 270 case TUNTIL: { 271 int got; 272 n1 = (union node *)stalloc(sizeof (struct nbinary)); 273 n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL; 274 n1->nbinary.ch1 = list(0); 275 if ((got=readtoken()) != TDO) { 276 TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : "")); 277 synexpect(TDO); 278 } 279 n1->nbinary.ch2 = list(0); 280 if (readtoken() != TDONE) 281 synexpect(TDONE); 282 checkkwd = 1; 283 break; 284 } 285 case TFOR: 286 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext)) 287 synerror("Bad for loop variable"); 288 n1 = (union node *)stalloc(sizeof (struct nfor)); 289 n1->type = NFOR; 290 n1->nfor.var = wordtext; 291 if (readtoken() == TWORD && ! quoteflag && equal(wordtext, "in")) { 292 app = ≈ 293 while (readtoken() == TWORD) { 294 n2 = (union node *)stalloc(sizeof (struct narg)); 295 n2->type = NARG; 296 n2->narg.text = wordtext; 297 n2->narg.backquote = backquotelist; 298 *app = n2; 299 app = &n2->narg.next; 300 } 301 *app = NULL; 302 n1->nfor.args = ap; 303 } else { 304 #ifndef GDB_HACK 305 static const char argvars[5] = {CTLVAR, VSNORMAL|VSQUOTE, 306 '@', '=', '\0'}; 307 #endif 308 n2 = (union node *)stalloc(sizeof (struct narg)); 309 n2->type = NARG; 310 n2->narg.text = (char *)argvars; 311 n2->narg.backquote = NULL; 312 n2->narg.next = NULL; 313 n1->nfor.args = n2; 314 } 315 if (lasttoken != TNL && lasttoken != TSEMI) 316 synexpect(-1); 317 checkkwd = 2; 318 if ((t = readtoken()) == TDO) 319 t = TDONE; 320 else if (t == TBEGIN) 321 t = TEND; 322 else 323 synexpect(-1); 324 n1->nfor.body = list(0); 325 if (readtoken() != t) 326 synexpect(t); 327 checkkwd = 1; 328 break; 329 case TCASE: 330 n1 = (union node *)stalloc(sizeof (struct ncase)); 331 n1->type = NCASE; 332 if (readtoken() != TWORD) 333 synexpect(TWORD); 334 n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg)); 335 n2->type = NARG; 336 n2->narg.text = wordtext; 337 n2->narg.backquote = backquotelist; 338 n2->narg.next = NULL; 339 while (readtoken() == TNL); 340 if (lasttoken != TWORD || ! equal(wordtext, "in")) 341 synerror("expecting \"in\""); 342 cpp = &n1->ncase.cases; 343 while (checkkwd = 2, readtoken() == TWORD) { 344 *cpp = cp = (union node *)stalloc(sizeof (struct nclist)); 345 cp->type = NCLIST; 346 app = &cp->nclist.pattern; 347 for (;;) { 348 *app = ap = (union node *)stalloc(sizeof (struct narg)); 349 ap->type = NARG; 350 ap->narg.text = wordtext; 351 ap->narg.backquote = backquotelist; 352 if (readtoken() != TPIPE) 353 break; 354 app = &ap->narg.next; 355 if (readtoken() != TWORD) 356 synexpect(TWORD); 357 } 358 ap->narg.next = NULL; 359 if (lasttoken != TRP) 360 synexpect(TRP); 361 cp->nclist.body = list(0); 362 if ((t = readtoken()) == TESAC) 363 tokpushback++; 364 else if (t != TENDCASE) 365 synexpect(TENDCASE); 366 cpp = &cp->nclist.next; 367 } 368 *cpp = NULL; 369 if (lasttoken != TESAC) 370 synexpect(TESAC); 371 checkkwd = 1; 372 break; 373 case TLP: 374 n1 = (union node *)stalloc(sizeof (struct nredir)); 375 n1->type = NSUBSHELL; 376 n1->nredir.n = list(0); 377 n1->nredir.redirect = NULL; 378 if (readtoken() != TRP) 379 synexpect(TRP); 380 checkkwd = 1; 381 break; 382 case TBEGIN: 383 n1 = list(0); 384 if (readtoken() != TEND) 385 synexpect(TEND); 386 checkkwd = 1; 387 break; 388 case TWORD: 389 case TREDIR: 390 tokpushback++; 391 return simplecmd(); 392 default: 393 synexpect(-1); 394 } 395 396 /* Now check for redirection which may follow command */ 397 rpp = &redir; 398 while (readtoken() == TREDIR) { 399 *rpp = n2 = redirnode; 400 rpp = &n2->nfile.next; 401 parsefname(); 402 } 403 tokpushback++; 404 *rpp = NULL; 405 if (redir) { 406 if (n1->type != NSUBSHELL) { 407 n2 = (union node *)stalloc(sizeof (struct nredir)); 408 n2->type = NREDIR; 409 n2->nredir.n = n1; 410 n1 = n2; 411 } 412 n1->nredir.redirect = redir; 413 } 414 return n1; 415 } 416 417 418 STATIC union node * 419 simplecmd() { 420 union node *args, **app; 421 union node *redir, **rpp; 422 union node *n; 423 424 args = NULL; 425 app = &args; 426 rpp = &redir; 427 for (;;) { 428 if (readtoken() == TWORD) { 429 n = (union node *)stalloc(sizeof (struct narg)); 430 n->type = NARG; 431 n->narg.text = wordtext; 432 n->narg.backquote = backquotelist; 433 *app = n; 434 app = &n->narg.next; 435 } else if (lasttoken == TREDIR) { 436 *rpp = n = redirnode; 437 rpp = &n->nfile.next; 438 parsefname(); /* read name of redirection file */ 439 } else if (lasttoken == TLP && app == &args->narg.next 440 && rpp == &redir) { 441 /* We have a function */ 442 if (readtoken() != TRP) 443 synexpect(TRP); 444 #ifdef notdef 445 if (! goodname(n->narg.text)) 446 synerror("Bad function name"); 447 #endif 448 n->type = NDEFUN; 449 n->narg.next = command(); 450 return n; 451 } else { 452 tokpushback++; 453 break; 454 } 455 } 456 *app = NULL; 457 *rpp = NULL; 458 n = (union node *)stalloc(sizeof (struct ncmd)); 459 n->type = NCMD; 460 n->ncmd.backgnd = 0; 461 n->ncmd.args = args; 462 n->ncmd.redirect = redir; 463 return n; 464 } 465 466 467 STATIC void 468 parsefname() { 469 union node *n = redirnode; 470 471 if (readtoken() != TWORD) 472 synexpect(-1); 473 if (n->type == NHERE) { 474 struct heredoc *here = heredoc; 475 struct heredoc *p; 476 int i; 477 478 if (quoteflag == 0) 479 n->type = NXHERE; 480 TRACE(("Here document %d\n", n->type)); 481 if (here->striptabs) { 482 while (*wordtext == '\t') 483 wordtext++; 484 } 485 if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN) 486 synerror("Illegal eof marker for << redirection"); 487 rmescapes(wordtext); 488 here->eofmark = wordtext; 489 here->next = NULL; 490 if (heredoclist == NULL) 491 heredoclist = here; 492 else { 493 for (p = heredoclist ; p->next ; p = p->next); 494 p->next = here; 495 } 496 } else if (n->type == NTOFD || n->type == NFROMFD) { 497 if (is_digit(wordtext[0])) 498 n->ndup.dupfd = digit_val(wordtext[0]); 499 else if (wordtext[0] == '-') 500 n->ndup.dupfd = -1; 501 else 502 goto bad; 503 if (wordtext[1] != '\0') { 504 bad: 505 synerror("Bad fd number"); 506 } 507 } else { 508 n->nfile.fname = (union node *)stalloc(sizeof (struct narg)); 509 n = n->nfile.fname; 510 n->type = NARG; 511 n->narg.next = NULL; 512 n->narg.text = wordtext; 513 n->narg.backquote = backquotelist; 514 } 515 } 516 517 518 /* 519 * Input any here documents. 520 */ 521 522 STATIC void 523 parseheredoc() { 524 struct heredoc *here; 525 union node *n; 526 527 while (heredoclist) { 528 here = heredoclist; 529 heredoclist = here->next; 530 if (needprompt) { 531 putprompt(ps2val()); 532 needprompt = 0; 533 } 534 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, 535 here->eofmark, here->striptabs); 536 n = (union node *)stalloc(sizeof (struct narg)); 537 n->narg.type = NARG; 538 n->narg.next = NULL; 539 n->narg.text = wordtext; 540 n->narg.backquote = backquotelist; 541 here->here->nhere.doc = n; 542 } 543 } 544 545 STATIC int 546 peektoken() { 547 int t; 548 549 t = readtoken(); 550 tokpushback++; 551 return (t); 552 } 553 554 STATIC int xxreadtoken(); 555 556 STATIC int 557 readtoken() { 558 int t; 559 #ifdef DEBUG 560 int alreadyseen = tokpushback; 561 #endif 562 563 t = xxreadtoken(); 564 565 if (checkkwd) { 566 /* 567 * eat newlines 568 */ 569 if (checkkwd == 2) { 570 checkkwd = 0; 571 while (t == TNL) { 572 parseheredoc(); 573 t = xxreadtoken(); 574 } 575 } else 576 checkkwd = 0; 577 /* 578 * check for keywords 579 */ 580 if (t == TWORD && !quoteflag) { 581 register char **pp; 582 583 for (pp = parsekwd; *pp; pp++) { 584 if (**pp == *wordtext && equal(*pp, wordtext)) { 585 lasttoken = t = pp - parsekwd + KWDOFFSET; 586 TRACE(("keyword %s recognized\n", tokname[t])); 587 break; 588 } 589 } 590 } 591 } 592 #ifdef DEBUG 593 if (!alreadyseen) 594 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 595 else 596 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 597 #endif 598 return (t); 599 } 600 601 602 /* 603 * Read the next input token. 604 * If the token is a word, we set backquotelist to the list of cmds in 605 * backquotes. We set quoteflag to true if any part of the word was 606 * quoted. 607 * If the token is TREDIR, then we set redirnode to a structure containing 608 * the redirection. 609 * In all cases, the variable startlinno is set to the number of the line 610 * on which the token starts. 611 * 612 * [Change comment: here documents and internal procedures] 613 * [Readtoken shouldn't have any arguments. Perhaps we should make the 614 * word parsing code into a separate routine. In this case, readtoken 615 * doesn't need to have any internal procedures, but parseword does. 616 * We could also make parseoperator in essence the main routine, and 617 * have parseword (readtoken1?) handle both words and redirection.] 618 */ 619 620 #define RETURN(token) return lasttoken = token 621 622 STATIC int 623 xxreadtoken() { 624 register c; 625 626 if (tokpushback) { 627 tokpushback = 0; 628 return lasttoken; 629 } 630 if (needprompt) { 631 putprompt(ps2val()); 632 needprompt = 0; 633 } 634 startlinno = plinno; 635 for (;;) { /* until token or start of word found */ 636 c = pgetc_macro(); 637 if (c == ' ' || c == '\t') 638 continue; /* quick check for white space first */ 639 switch (c) { 640 case ' ': case '\t': 641 continue; 642 case '#': 643 while ((c = pgetc()) != '\n' && c != PEOF); 644 pungetc(); 645 continue; 646 case '\\': 647 if (pgetc() == '\n') { 648 startlinno = ++plinno; 649 if (doprompt) 650 putprompt(ps2val()); 651 continue; 652 } 653 pungetc(); 654 goto breakloop; 655 case '\n': 656 plinno++; 657 needprompt = doprompt; 658 RETURN(TNL); 659 case PEOF: 660 RETURN(TEOF); 661 case '&': 662 if (pgetc() == '&') 663 RETURN(TAND); 664 pungetc(); 665 RETURN(TBACKGND); 666 case '|': 667 if (pgetc() == '|') 668 RETURN(TOR); 669 pungetc(); 670 RETURN(TPIPE); 671 case ';': 672 if (pgetc() == ';') 673 RETURN(TENDCASE); 674 pungetc(); 675 RETURN(TSEMI); 676 case '(': 677 RETURN(TLP); 678 case ')': 679 RETURN(TRP); 680 default: 681 goto breakloop; 682 } 683 } 684 breakloop: 685 return readtoken1(c, BASESYNTAX, (char *)NULL, 0); 686 #undef RETURN 687 } 688 689 690 691 /* 692 * If eofmark is NULL, read a word or a redirection symbol. If eofmark 693 * is not NULL, read a here document. In the latter case, eofmark is the 694 * word which marks the end of the document and striptabs is true if 695 * leading tabs should be stripped from the document. The argument firstc 696 * is the first character of the input token or document. 697 * 698 * Because C does not have internal subroutines, I have simulated them 699 * using goto's to implement the subroutine linkage. The following macros 700 * will run code that appears at the end of readtoken1. 701 */ 702 703 #define CHECKEND() {goto checkend; checkend_return:;} 704 #define PARSEREDIR() {goto parseredir; parseredir_return:;} 705 #define PARSESUB() {goto parsesub; parsesub_return:;} 706 #define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;} 707 #define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;} 708 709 STATIC int 710 readtoken1(firstc, syntax, eofmark, striptabs) 711 int firstc; 712 char const *syntax; 713 char *eofmark; 714 int striptabs; 715 { 716 register c = firstc; 717 register char *out; 718 int len; 719 char line[EOFMARKLEN + 1]; 720 struct nodelist *bqlist; 721 int quotef; 722 int dblquote; 723 int varnest; 724 int oldstyle; 725 726 startlinno = plinno; 727 dblquote = 0; 728 if (syntax == DQSYNTAX) 729 dblquote = 1; 730 quotef = 0; 731 bqlist = NULL; 732 varnest = 0; 733 STARTSTACKSTR(out); 734 loop: { /* for each line, until end of word */ 735 #if ATTY 736 if (c == '\034' && doprompt 737 && attyset() && ! equal(termval(), "emacs")) { 738 attyline(); 739 if (syntax == BASESYNTAX) 740 return readtoken(); 741 c = pgetc(); 742 goto loop; 743 } 744 #endif 745 CHECKEND(); /* set c to PEOF if at end of here document */ 746 for (;;) { /* until end of line or end of word */ 747 CHECKSTRSPACE(3, out); /* permit 3 calls to USTPUTC */ 748 switch(syntax[c]) { 749 case CNL: /* '\n' */ 750 if (syntax == BASESYNTAX) 751 goto endword; /* exit outer loop */ 752 USTPUTC(c, out); 753 plinno++; 754 if (doprompt) { 755 putprompt(ps2val()); 756 } 757 c = pgetc(); 758 goto loop; /* continue outer loop */ 759 case CWORD: 760 USTPUTC(c, out); 761 break; 762 case CCTL: 763 if (eofmark == NULL || dblquote) 764 USTPUTC(CTLESC, out); 765 USTPUTC(c, out); 766 break; 767 case CBACK: /* backslash */ 768 c = pgetc(); 769 if (c == PEOF) { 770 USTPUTC('\\', out); 771 pungetc(); 772 } else if (c == '\n') { 773 if (doprompt) 774 putprompt(ps2val()); 775 } else { 776 if (dblquote && c != '\\' && c != '`' && c != '$' 777 && (c != '"' || eofmark != NULL)) 778 USTPUTC('\\', out); 779 if (SQSYNTAX[c] == CCTL) 780 USTPUTC(CTLESC, out); 781 USTPUTC(c, out); 782 quotef++; 783 } 784 break; 785 case CSQUOTE: 786 syntax = SQSYNTAX; 787 break; 788 case CDQUOTE: 789 syntax = DQSYNTAX; 790 dblquote = 1; 791 break; 792 case CENDQUOTE: 793 if (eofmark) { 794 USTPUTC(c, out); 795 } else { 796 syntax = BASESYNTAX; 797 quotef++; 798 dblquote = 0; 799 } 800 break; 801 case CVAR: /* '$' */ 802 PARSESUB(); /* parse substitution */ 803 break; 804 case CENDVAR: /* '}' */ 805 if (varnest > 0) { 806 varnest--; 807 USTPUTC(CTLENDVAR, out); 808 } else { 809 USTPUTC(c, out); 810 } 811 break; 812 case CBQUOTE: /* '`' */ 813 if (parsebackquote && syntax == BASESYNTAX) { 814 if (out == stackblock()) 815 return lasttoken = TENDBQUOTE; 816 else 817 goto endword; /* exit outer loop */ 818 } 819 PARSEBACKQOLD(); 820 break; 821 case CEOF: 822 goto endword; /* exit outer loop */ 823 default: 824 if (varnest == 0) 825 goto endword; /* exit outer loop */ 826 USTPUTC(c, out); 827 } 828 c = pgetc_macro(); 829 } 830 } 831 endword: 832 if (syntax != BASESYNTAX && eofmark == NULL) 833 synerror("Unterminated quoted string"); 834 if (varnest != 0) { 835 startlinno = plinno; 836 synerror("Missing '}'"); 837 } 838 USTPUTC('\0', out); 839 len = out - stackblock(); 840 out = stackblock(); 841 if (eofmark == NULL) { 842 if ((c == '>' || c == '<') 843 && quotef == 0 844 && len <= 2 845 && (*out == '\0' || is_digit(*out))) { 846 PARSEREDIR(); 847 return lasttoken = TREDIR; 848 } else { 849 pungetc(); 850 } 851 } 852 quoteflag = quotef; 853 backquotelist = bqlist; 854 grabstackblock(len); 855 wordtext = out; 856 return lasttoken = TWORD; 857 /* end of readtoken routine */ 858 859 860 861 /* 862 * Check to see whether we are at the end of the here document. When this 863 * is called, c is set to the first character of the next input line. If 864 * we are at the end of the here document, this routine sets the c to PEOF. 865 */ 866 867 checkend: { 868 if (eofmark) { 869 if (striptabs) { 870 while (c == '\t') 871 c = pgetc(); 872 } 873 if (c == *eofmark) { 874 if (pfgets(line, sizeof line) != NULL) { 875 register char *p, *q; 876 877 p = line; 878 for (q = eofmark + 1 ; *q && *p == *q ; p++, q++); 879 if (*p == '\n' && *q == '\0') { 880 c = PEOF; 881 plinno++; 882 needprompt = doprompt; 883 } else { 884 ppushback(line, strlen(line)); 885 } 886 } 887 } 888 } 889 goto checkend_return; 890 } 891 892 893 /* 894 * Parse a redirection operator. The variable "out" points to a string 895 * specifying the fd to be redirected. The variable "c" contains the 896 * first character of the redirection operator. 897 */ 898 899 parseredir: { 900 char fd = *out; 901 union node *np; 902 903 np = (union node *)stalloc(sizeof (struct nfile)); 904 if (c == '>') { 905 np->nfile.fd = 1; 906 c = pgetc(); 907 if (c == '>') 908 np->type = NAPPEND; 909 else if (c == '&') 910 np->type = NTOFD; 911 else { 912 np->type = NTO; 913 pungetc(); 914 } 915 } else { /* c == '<' */ 916 np->nfile.fd = 0; 917 c = pgetc(); 918 if (c == '<') { 919 if (sizeof (struct nfile) != sizeof (struct nhere)) { 920 np = (union node *)stalloc(sizeof (struct nhere)); 921 np->nfile.fd = 0; 922 } 923 np->type = NHERE; 924 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); 925 heredoc->here = np; 926 if ((c = pgetc()) == '-') { 927 heredoc->striptabs = 1; 928 } else { 929 heredoc->striptabs = 0; 930 pungetc(); 931 } 932 } else if (c == '&') 933 np->type = NFROMFD; 934 else { 935 np->type = NFROM; 936 pungetc(); 937 } 938 } 939 if (fd != '\0') 940 np->nfile.fd = digit_val(fd); 941 redirnode = np; 942 goto parseredir_return; 943 } 944 945 946 /* 947 * Parse a substitution. At this point, we have read the dollar sign 948 * and nothing else. 949 */ 950 951 parsesub: { 952 int subtype; 953 int typeloc; 954 int flags; 955 char *p; 956 #ifndef GDB_HACK 957 static const char types[] = "}-+?="; 958 #endif 959 960 c = pgetc(); 961 if (c != '(' && c != '{' && !is_name(c) && !is_special(c)) { 962 USTPUTC('$', out); 963 pungetc(); 964 } else if (c == '(') { /* $(command) */ 965 PARSEBACKQNEW(); 966 } else { 967 USTPUTC(CTLVAR, out); 968 typeloc = out - stackblock(); 969 USTPUTC(VSNORMAL, out); 970 subtype = VSNORMAL; 971 if (c == '{') { 972 c = pgetc(); 973 subtype = 0; 974 } 975 if (is_name(c)) { 976 do { 977 STPUTC(c, out); 978 c = pgetc(); 979 } while (is_in_name(c)); 980 } else { 981 if (! is_special(c)) 982 badsub: synerror("Bad substitution"); 983 USTPUTC(c, out); 984 c = pgetc(); 985 } 986 STPUTC('=', out); 987 flags = 0; 988 if (subtype == 0) { 989 if (c == ':') { 990 flags = VSNUL; 991 c = pgetc(); 992 } 993 p = strchr(types, c); 994 if (p == NULL) 995 goto badsub; 996 subtype = p - types + VSNORMAL; 997 } else { 998 pungetc(); 999 } 1000 if (dblquote) 1001 flags |= VSQUOTE; 1002 *(stackblock() + typeloc) = subtype | flags; 1003 if (subtype != VSNORMAL) 1004 varnest++; 1005 } 1006 goto parsesub_return; 1007 } 1008 1009 1010 /* 1011 * Called to parse command substitutions. Newstyle is set if the command 1012 * is enclosed inside $(...); nlpp is a pointer to the head of the linked 1013 * list of commands (passed by reference), and savelen is the number of 1014 * characters on the top of the stack which must be preserved. 1015 */ 1016 1017 parsebackq: { 1018 struct nodelist **nlpp; 1019 int savepbq; 1020 union node *n; 1021 char *volatile str; 1022 struct jmploc jmploc; 1023 struct jmploc *volatile savehandler; 1024 int savelen; 1025 int t; 1026 1027 savepbq = parsebackquote; 1028 if (setjmp(jmploc.loc)) { 1029 if (str) 1030 ckfree(str); 1031 parsebackquote = 0; 1032 handler = savehandler; 1033 longjmp(handler, 1); 1034 } 1035 INTOFF; 1036 str = NULL; 1037 savelen = out - stackblock(); 1038 if (savelen > 0) { 1039 str = ckmalloc(savelen); 1040 bcopy(stackblock(), str, savelen); 1041 } 1042 savehandler = handler; 1043 handler = &jmploc; 1044 INTON; 1045 nlpp = &bqlist; 1046 while (*nlpp) 1047 nlpp = &(*nlpp)->next; 1048 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 1049 (*nlpp)->next = NULL; 1050 parsebackquote = oldstyle; 1051 n = list(0); 1052 t = oldstyle? TENDBQUOTE : TRP; 1053 if (readtoken() != t) 1054 synexpect(t); 1055 (*nlpp)->n = n; 1056 while (stackblocksize() <= savelen) 1057 growstackblock(); 1058 STARTSTACKSTR(out); 1059 if (str) { 1060 bcopy(str, out, savelen); 1061 STADJUST(savelen, out); 1062 INTOFF; 1063 ckfree(str); 1064 str = NULL; 1065 INTON; 1066 } 1067 parsebackquote = savepbq; 1068 handler = savehandler; 1069 USTPUTC(CTLBACKQ + dblquote, out); 1070 if (oldstyle) 1071 goto parsebackq_oldreturn; 1072 else 1073 goto parsebackq_newreturn; 1074 } 1075 1076 } /* end of readtoken */ 1077 1078 1079 1080 #ifdef mkinit 1081 RESET { 1082 tokpushback = 0; 1083 } 1084 #endif 1085 1086 1087 #if ATTY 1088 /* 1089 * Called to process a command generated by atty. We execute the line, 1090 * and catch any errors that occur so they don't propagate outside of 1091 * this routine. 1092 */ 1093 1094 STATIC void 1095 attyline() { 1096 char line[256]; 1097 struct stackmark smark; 1098 struct jmploc jmploc; 1099 struct jmploc *volatile savehandler; 1100 1101 if (pfgets(line, sizeof line) == NULL) 1102 return; /* "can't happen" */ 1103 if (setjmp(jmploc.loc)) { 1104 if (exception == EXERROR) 1105 out2str("\033]D\n"); 1106 handler = savehandler; 1107 longjmp(handler, 1); 1108 } 1109 savehandler = handler; 1110 handler = &jmploc; 1111 setstackmark(&smark); 1112 evalstring(line); 1113 popstackmark(&smark); 1114 handler = savehandler; 1115 doprompt = 1; 1116 } 1117 1118 1119 /* 1120 * Output a prompt for atty. We output the prompt as part of the 1121 * appropriate escape sequence. 1122 */ 1123 1124 STATIC void 1125 putprompt(s) 1126 char *s; 1127 { 1128 register char *p; 1129 1130 if (attyset() && ! equal(termval(), "emacs")) { 1131 if (strchr(s, '\7')) 1132 out2c('\7'); 1133 out2str("\033]P1;"); 1134 for (p = s ; *p ; p++) { 1135 if ((unsigned)(*p - ' ') <= '~' - ' ') 1136 out2c(*p); 1137 } 1138 out2c('\n'); 1139 } else { 1140 out2str(s); 1141 } 1142 } 1143 #endif 1144 1145 1146 1147 /* 1148 * Returns true if the text contains nothing to expand (no dollar signs 1149 * or backquotes). 1150 */ 1151 1152 STATIC int 1153 noexpand(text) 1154 char *text; 1155 { 1156 register char *p; 1157 register char c; 1158 1159 p = text; 1160 while ((c = *p++) != '\0') { 1161 if (c == CTLESC) 1162 p++; 1163 else if (BASESYNTAX[c] == CCTL) 1164 return 0; 1165 } 1166 return 1; 1167 } 1168 1169 1170 /* 1171 * Return true if the argument is a legal variable name (a letter or 1172 * underscore followed by zero or more letters, underscores, and digits). 1173 */ 1174 1175 int 1176 goodname(name) 1177 char *name; 1178 { 1179 register char *p; 1180 1181 p = name; 1182 if (! is_name(*p)) 1183 return 0; 1184 while (*++p) { 1185 if (! is_in_name(*p)) 1186 return 0; 1187 } 1188 return 1; 1189 } 1190 1191 1192 /* 1193 * Called when an unexpected token is read during the parse. The argument 1194 * is the token that is expected, or -1 if more than one type of token can 1195 * occur at this point. 1196 */ 1197 1198 STATIC void 1199 synexpect(token) { 1200 char msg[64]; 1201 1202 if (token >= 0) { 1203 fmtstr(msg, 64, "%s unexpected (expecting %s)", 1204 tokname[lasttoken], tokname[token]); 1205 } else { 1206 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]); 1207 } 1208 synerror(msg); 1209 } 1210 1211 1212 STATIC void 1213 synerror(msg) 1214 char *msg; 1215 { 1216 if (commandname) 1217 outfmt(&errout, "%s: %d: ", commandname, startlinno); 1218 outfmt(&errout, "Syntax error: %s\n", msg); 1219 error((char *)NULL); 1220 } 1221