1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Kenneth Almquist. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #ifndef lint 36 #if 0 37 static char sccsid[] = "@(#)parser.c 8.7 (Berkeley) 5/16/95"; 38 #endif 39 #endif /* not lint */ 40 #include <sys/cdefs.h> 41 __FBSDID("$FreeBSD: head/bin/sh/parser.c 343399 2019-01-24 11:59:46Z trasz $"); 42 43 #include <sys/param.h> 44 #include <pwd.h> 45 #include <stdlib.h> 46 #include <unistd.h> 47 #include <stdio.h> 48 49 #include "shell.h" 50 #include "parser.h" 51 #include "nodes.h" 52 #include "expand.h" /* defines rmescapes() */ 53 #include "syntax.h" 54 #include "options.h" 55 #include "input.h" 56 #include "output.h" 57 #include "var.h" 58 #include "error.h" 59 #include "memalloc.h" 60 #include "mystring.h" 61 #include "alias.h" 62 #include "show.h" 63 #include "eval.h" 64 #include "exec.h" /* to check for special builtins */ 65 #ifndef NO_HISTORY 66 #include "myhistedit.h" 67 #endif 68 69 /* 70 * Shell command parser. 71 */ 72 73 #define PROMPTLEN 128 74 75 /* values of checkkwd variable */ 76 #define CHKALIAS 0x1 77 #define CHKKWD 0x2 78 #define CHKNL 0x4 79 80 /* values returned by readtoken */ 81 #include "token.h" 82 83 84 85 struct heredoc { 86 struct heredoc *next; /* next here document in list */ 87 union node *here; /* redirection node */ 88 char *eofmark; /* string indicating end of input */ 89 int striptabs; /* if set, strip leading tabs */ 90 }; 91 92 struct parser_temp { 93 struct parser_temp *next; 94 void *data; 95 }; 96 97 98 static struct heredoc *heredoclist; /* list of here documents to read */ 99 static int doprompt; /* if set, prompt the user */ 100 static int needprompt; /* true if interactive and at start of line */ 101 static int lasttoken; /* last token read */ 102 static int tokpushback; /* last token pushed back */ 103 static char *wordtext; /* text of last word returned by readtoken */ 104 static int checkkwd; 105 static struct nodelist *backquotelist; 106 static union node *redirnode; 107 static struct heredoc *heredoc; 108 static int quoteflag; /* set if (part of) last token was quoted */ 109 static int startlinno; /* line # where last token started */ 110 static int funclinno; /* line # where the current function started */ 111 static struct parser_temp *parser_temp; 112 113 #define NOEOFMARK ((const char *)&heredoclist) 114 115 116 static union node *list(int); 117 static union node *andor(void); 118 static union node *pipeline(void); 119 static union node *command(void); 120 static union node *simplecmd(union node **, union node *); 121 static union node *makename(void); 122 static union node *makebinary(int type, union node *n1, union node *n2); 123 static void parsefname(void); 124 static void parseheredoc(void); 125 static int peektoken(void); 126 static int readtoken(void); 127 static int xxreadtoken(void); 128 static int readtoken1(int, const char *, const char *, int); 129 static int noexpand(char *); 130 static void consumetoken(int); 131 static void synexpect(int) __dead2; 132 static void synerror(const char *) __dead2; 133 static void setprompt(int); 134 static int pgetc_linecont(void); 135 static void getusername(char *, size_t); 136 137 138 static void * 139 parser_temp_alloc(size_t len) 140 { 141 struct parser_temp *t; 142 143 INTOFF; 144 t = ckmalloc(sizeof(*t)); 145 t->data = NULL; 146 t->next = parser_temp; 147 parser_temp = t; 148 t->data = ckmalloc(len); 149 INTON; 150 return t->data; 151 } 152 153 154 static void * 155 parser_temp_realloc(void *ptr, size_t len) 156 { 157 struct parser_temp *t; 158 159 INTOFF; 160 t = parser_temp; 161 if (ptr != t->data) 162 error("bug: parser_temp_realloc misused"); 163 t->data = ckrealloc(t->data, len); 164 INTON; 165 return t->data; 166 } 167 168 169 static void 170 parser_temp_free_upto(void *ptr) 171 { 172 struct parser_temp *t; 173 int done = 0; 174 175 INTOFF; 176 while (parser_temp != NULL && !done) { 177 t = parser_temp; 178 parser_temp = t->next; 179 done = t->data == ptr; 180 ckfree(t->data); 181 ckfree(t); 182 } 183 INTON; 184 if (!done) 185 error("bug: parser_temp_free_upto misused"); 186 } 187 188 189 static void 190 parser_temp_free_all(void) 191 { 192 struct parser_temp *t; 193 194 INTOFF; 195 while (parser_temp != NULL) { 196 t = parser_temp; 197 parser_temp = t->next; 198 ckfree(t->data); 199 ckfree(t); 200 } 201 INTON; 202 } 203 204 205 /* 206 * Read and parse a command. Returns NEOF on end of file. (NULL is a 207 * valid parse tree indicating a blank line.) 208 */ 209 210 union node * 211 parsecmd(int interact) 212 { 213 int t; 214 215 /* This assumes the parser is not re-entered, 216 * which could happen if we add command substitution on PS1/PS2. 217 */ 218 parser_temp_free_all(); 219 heredoclist = NULL; 220 221 tokpushback = 0; 222 checkkwd = 0; 223 doprompt = interact; 224 if (doprompt) 225 setprompt(1); 226 else 227 setprompt(0); 228 needprompt = 0; 229 t = readtoken(); 230 if (t == TEOF) 231 return NEOF; 232 if (t == TNL) 233 return NULL; 234 tokpushback++; 235 return list(1); 236 } 237 238 239 /* 240 * Read and parse words for wordexp. 241 * Returns a list of NARG nodes; NULL if there are no words. 242 */ 243 union node * 244 parsewordexp(void) 245 { 246 union node *n, *first = NULL, **pnext; 247 int t; 248 249 /* This assumes the parser is not re-entered, 250 * which could happen if we add command substitution on PS1/PS2. 251 */ 252 parser_temp_free_all(); 253 heredoclist = NULL; 254 255 tokpushback = 0; 256 checkkwd = 0; 257 doprompt = 0; 258 setprompt(0); 259 needprompt = 0; 260 pnext = &first; 261 while ((t = readtoken()) != TEOF) { 262 if (t != TWORD) 263 synexpect(TWORD); 264 n = makename(); 265 *pnext = n; 266 pnext = &n->narg.next; 267 } 268 return first; 269 } 270 271 272 static union node * 273 list(int nlflag) 274 { 275 union node *ntop, *n1, *n2, *n3; 276 int tok; 277 278 checkkwd = CHKNL | CHKKWD | CHKALIAS; 279 if (!nlflag && tokendlist[peektoken()]) 280 return NULL; 281 ntop = n1 = NULL; 282 for (;;) { 283 n2 = andor(); 284 tok = readtoken(); 285 if (tok == TBACKGND) { 286 if (n2 != NULL && n2->type == NPIPE) { 287 n2->npipe.backgnd = 1; 288 } else if (n2 != NULL && n2->type == NREDIR) { 289 n2->type = NBACKGND; 290 } else { 291 n3 = (union node *)stalloc(sizeof (struct nredir)); 292 n3->type = NBACKGND; 293 n3->nredir.n = n2; 294 n3->nredir.redirect = NULL; 295 n2 = n3; 296 } 297 } 298 if (ntop == NULL) 299 ntop = n2; 300 else if (n1 == NULL) { 301 n1 = makebinary(NSEMI, ntop, n2); 302 ntop = n1; 303 } 304 else { 305 n3 = makebinary(NSEMI, n1->nbinary.ch2, n2); 306 n1->nbinary.ch2 = n3; 307 n1 = n3; 308 } 309 switch (tok) { 310 case TBACKGND: 311 case TSEMI: 312 tok = readtoken(); 313 /* FALLTHROUGH */ 314 case TNL: 315 if (tok == TNL) { 316 parseheredoc(); 317 if (nlflag) 318 return ntop; 319 } else if (tok == TEOF && nlflag) { 320 parseheredoc(); 321 return ntop; 322 } else { 323 tokpushback++; 324 } 325 checkkwd = CHKNL | CHKKWD | CHKALIAS; 326 if (!nlflag && tokendlist[peektoken()]) 327 return ntop; 328 break; 329 case TEOF: 330 if (heredoclist) 331 parseheredoc(); 332 else 333 pungetc(); /* push back EOF on input */ 334 return ntop; 335 default: 336 if (nlflag) 337 synexpect(-1); 338 tokpushback++; 339 return ntop; 340 } 341 } 342 } 343 344 345 346 static union node * 347 andor(void) 348 { 349 union node *n; 350 int t; 351 352 n = pipeline(); 353 for (;;) { 354 if ((t = readtoken()) == TAND) { 355 t = NAND; 356 } else if (t == TOR) { 357 t = NOR; 358 } else { 359 tokpushback++; 360 return n; 361 } 362 n = makebinary(t, n, pipeline()); 363 } 364 } 365 366 367 368 static union node * 369 pipeline(void) 370 { 371 union node *n1, *n2, *pipenode; 372 struct nodelist *lp, *prev; 373 int negate, t; 374 375 negate = 0; 376 checkkwd = CHKNL | CHKKWD | CHKALIAS; 377 TRACE(("pipeline: entered\n")); 378 while (readtoken() == TNOT) 379 negate = !negate; 380 tokpushback++; 381 n1 = command(); 382 if (readtoken() == TPIPE) { 383 pipenode = (union node *)stalloc(sizeof (struct npipe)); 384 pipenode->type = NPIPE; 385 pipenode->npipe.backgnd = 0; 386 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 387 pipenode->npipe.cmdlist = lp; 388 lp->n = n1; 389 do { 390 prev = lp; 391 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 392 checkkwd = CHKNL | CHKKWD | CHKALIAS; 393 t = readtoken(); 394 tokpushback++; 395 if (t == TNOT) 396 lp->n = pipeline(); 397 else 398 lp->n = command(); 399 prev->next = lp; 400 } while (readtoken() == TPIPE); 401 lp->next = NULL; 402 n1 = pipenode; 403 } 404 tokpushback++; 405 if (negate) { 406 n2 = (union node *)stalloc(sizeof (struct nnot)); 407 n2->type = NNOT; 408 n2->nnot.com = n1; 409 return n2; 410 } else 411 return n1; 412 } 413 414 415 416 static union node * 417 command(void) 418 { 419 union node *n1, *n2; 420 union node *ap, **app; 421 union node *cp, **cpp; 422 union node *redir, **rpp; 423 int t; 424 int is_subshell; 425 426 checkkwd = CHKNL | CHKKWD | CHKALIAS; 427 is_subshell = 0; 428 redir = NULL; 429 n1 = NULL; 430 rpp = &redir; 431 432 /* Check for redirection which may precede command */ 433 while (readtoken() == TREDIR) { 434 *rpp = n2 = redirnode; 435 rpp = &n2->nfile.next; 436 parsefname(); 437 } 438 tokpushback++; 439 440 switch (readtoken()) { 441 case TIF: 442 n1 = (union node *)stalloc(sizeof (struct nif)); 443 n1->type = NIF; 444 if ((n1->nif.test = list(0)) == NULL) 445 synexpect(-1); 446 consumetoken(TTHEN); 447 n1->nif.ifpart = list(0); 448 n2 = n1; 449 while (readtoken() == TELIF) { 450 n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif)); 451 n2 = n2->nif.elsepart; 452 n2->type = NIF; 453 if ((n2->nif.test = list(0)) == NULL) 454 synexpect(-1); 455 consumetoken(TTHEN); 456 n2->nif.ifpart = list(0); 457 } 458 if (lasttoken == TELSE) 459 n2->nif.elsepart = list(0); 460 else { 461 n2->nif.elsepart = NULL; 462 tokpushback++; 463 } 464 consumetoken(TFI); 465 checkkwd = CHKKWD | CHKALIAS; 466 break; 467 case TWHILE: 468 case TUNTIL: 469 t = lasttoken; 470 if ((n1 = list(0)) == NULL) 471 synexpect(-1); 472 consumetoken(TDO); 473 n1 = makebinary((t == TWHILE)? NWHILE : NUNTIL, n1, list(0)); 474 consumetoken(TDONE); 475 checkkwd = CHKKWD | CHKALIAS; 476 break; 477 case TFOR: 478 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext)) 479 synerror("Bad for loop variable"); 480 n1 = (union node *)stalloc(sizeof (struct nfor)); 481 n1->type = NFOR; 482 n1->nfor.var = wordtext; 483 while (readtoken() == TNL) 484 ; 485 if (lasttoken == TWORD && ! quoteflag && equal(wordtext, "in")) { 486 app = ≈ 487 while (readtoken() == TWORD) { 488 n2 = makename(); 489 *app = n2; 490 app = &n2->narg.next; 491 } 492 *app = NULL; 493 n1->nfor.args = ap; 494 if (lasttoken != TNL && lasttoken != TSEMI) 495 synexpect(-1); 496 } else { 497 static char argvars[5] = { 498 CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0' 499 }; 500 n2 = (union node *)stalloc(sizeof (struct narg)); 501 n2->type = NARG; 502 n2->narg.text = argvars; 503 n2->narg.backquote = NULL; 504 n2->narg.next = NULL; 505 n1->nfor.args = n2; 506 /* 507 * Newline or semicolon here is optional (but note 508 * that the original Bourne shell only allowed NL). 509 */ 510 if (lasttoken != TNL && lasttoken != TSEMI) 511 tokpushback++; 512 } 513 checkkwd = CHKNL | CHKKWD | CHKALIAS; 514 if ((t = readtoken()) == TDO) 515 t = TDONE; 516 else if (t == TBEGIN) 517 t = TEND; 518 else 519 synexpect(-1); 520 n1->nfor.body = list(0); 521 consumetoken(t); 522 checkkwd = CHKKWD | CHKALIAS; 523 break; 524 case TCASE: 525 n1 = (union node *)stalloc(sizeof (struct ncase)); 526 n1->type = NCASE; 527 consumetoken(TWORD); 528 n1->ncase.expr = makename(); 529 while (readtoken() == TNL); 530 if (lasttoken != TWORD || ! equal(wordtext, "in")) 531 synerror("expecting \"in\""); 532 cpp = &n1->ncase.cases; 533 checkkwd = CHKNL | CHKKWD, readtoken(); 534 while (lasttoken != TESAC) { 535 *cpp = cp = (union node *)stalloc(sizeof (struct nclist)); 536 cp->type = NCLIST; 537 app = &cp->nclist.pattern; 538 if (lasttoken == TLP) 539 readtoken(); 540 for (;;) { 541 *app = ap = makename(); 542 checkkwd = CHKNL | CHKKWD; 543 if (readtoken() != TPIPE) 544 break; 545 app = &ap->narg.next; 546 readtoken(); 547 } 548 ap->narg.next = NULL; 549 if (lasttoken != TRP) 550 synexpect(TRP); 551 cp->nclist.body = list(0); 552 553 checkkwd = CHKNL | CHKKWD | CHKALIAS; 554 if ((t = readtoken()) != TESAC) { 555 if (t == TENDCASE) 556 ; 557 else if (t == TFALLTHRU) 558 cp->type = NCLISTFALLTHRU; 559 else 560 synexpect(TENDCASE); 561 checkkwd = CHKNL | CHKKWD, readtoken(); 562 } 563 cpp = &cp->nclist.next; 564 } 565 *cpp = NULL; 566 checkkwd = CHKKWD | CHKALIAS; 567 break; 568 case TLP: 569 n1 = (union node *)stalloc(sizeof (struct nredir)); 570 n1->type = NSUBSHELL; 571 n1->nredir.n = list(0); 572 n1->nredir.redirect = NULL; 573 consumetoken(TRP); 574 checkkwd = CHKKWD | CHKALIAS; 575 is_subshell = 1; 576 break; 577 case TBEGIN: 578 n1 = list(0); 579 consumetoken(TEND); 580 checkkwd = CHKKWD | CHKALIAS; 581 break; 582 /* A simple command must have at least one redirection or word. */ 583 case TBACKGND: 584 case TSEMI: 585 case TAND: 586 case TOR: 587 case TPIPE: 588 case TENDCASE: 589 case TFALLTHRU: 590 case TEOF: 591 case TNL: 592 case TRP: 593 if (!redir) 594 synexpect(-1); 595 /* FALLTHROUGH */ 596 case TWORD: 597 tokpushback++; 598 n1 = simplecmd(rpp, redir); 599 return n1; 600 default: 601 synexpect(-1); 602 } 603 604 /* Now check for redirection which may follow command */ 605 while (readtoken() == TREDIR) { 606 *rpp = n2 = redirnode; 607 rpp = &n2->nfile.next; 608 parsefname(); 609 } 610 tokpushback++; 611 *rpp = NULL; 612 if (redir) { 613 if (!is_subshell) { 614 n2 = (union node *)stalloc(sizeof (struct nredir)); 615 n2->type = NREDIR; 616 n2->nredir.n = n1; 617 n1 = n2; 618 } 619 n1->nredir.redirect = redir; 620 } 621 622 return n1; 623 } 624 625 626 static union node * 627 simplecmd(union node **rpp, union node *redir) 628 { 629 union node *args, **app; 630 union node **orig_rpp = rpp; 631 union node *n = NULL; 632 int special; 633 int savecheckkwd; 634 635 /* If we don't have any redirections already, then we must reset */ 636 /* rpp to be the address of the local redir variable. */ 637 if (redir == NULL) 638 rpp = &redir; 639 640 args = NULL; 641 app = &args; 642 /* 643 * We save the incoming value, because we need this for shell 644 * functions. There can not be a redirect or an argument between 645 * the function name and the open parenthesis. 646 */ 647 orig_rpp = rpp; 648 649 savecheckkwd = CHKALIAS; 650 651 for (;;) { 652 checkkwd = savecheckkwd; 653 if (readtoken() == TWORD) { 654 n = makename(); 655 *app = n; 656 app = &n->narg.next; 657 if (savecheckkwd != 0 && !isassignment(wordtext)) 658 savecheckkwd = 0; 659 } else if (lasttoken == TREDIR) { 660 *rpp = n = redirnode; 661 rpp = &n->nfile.next; 662 parsefname(); /* read name of redirection file */ 663 } else if (lasttoken == TLP && app == &args->narg.next 664 && rpp == orig_rpp) { 665 /* We have a function */ 666 consumetoken(TRP); 667 funclinno = plinno; 668 /* 669 * - Require plain text. 670 * - Functions with '/' cannot be called. 671 * - Reject name=(). 672 * - Reject ksh extended glob patterns. 673 */ 674 if (!noexpand(n->narg.text) || quoteflag || 675 strchr(n->narg.text, '/') || 676 strchr("!%*+-=?@}~", 677 n->narg.text[strlen(n->narg.text) - 1])) 678 synerror("Bad function name"); 679 rmescapes(n->narg.text); 680 if (find_builtin(n->narg.text, &special) >= 0 && 681 special) 682 synerror("Cannot override a special builtin with a function"); 683 n->type = NDEFUN; 684 n->narg.next = command(); 685 funclinno = 0; 686 return n; 687 } else { 688 tokpushback++; 689 break; 690 } 691 } 692 *app = NULL; 693 *rpp = NULL; 694 n = (union node *)stalloc(sizeof (struct ncmd)); 695 n->type = NCMD; 696 n->ncmd.args = args; 697 n->ncmd.redirect = redir; 698 return n; 699 } 700 701 static union node * 702 makename(void) 703 { 704 union node *n; 705 706 n = (union node *)stalloc(sizeof (struct narg)); 707 n->type = NARG; 708 n->narg.next = NULL; 709 n->narg.text = wordtext; 710 n->narg.backquote = backquotelist; 711 return n; 712 } 713 714 static union node * 715 makebinary(int type, union node *n1, union node *n2) 716 { 717 union node *n; 718 719 n = (union node *)stalloc(sizeof (struct nbinary)); 720 n->type = type; 721 n->nbinary.ch1 = n1; 722 n->nbinary.ch2 = n2; 723 return (n); 724 } 725 726 void 727 forcealias(void) 728 { 729 checkkwd |= CHKALIAS; 730 } 731 732 void 733 fixredir(union node *n, const char *text, int err) 734 { 735 TRACE(("Fix redir %s %d\n", text, err)); 736 if (!err) 737 n->ndup.vname = NULL; 738 739 if (is_digit(text[0]) && text[1] == '\0') 740 n->ndup.dupfd = digit_val(text[0]); 741 else if (text[0] == '-' && text[1] == '\0') 742 n->ndup.dupfd = -1; 743 else { 744 745 if (err) 746 synerror("Bad fd number"); 747 else 748 n->ndup.vname = makename(); 749 } 750 } 751 752 753 static void 754 parsefname(void) 755 { 756 union node *n = redirnode; 757 758 consumetoken(TWORD); 759 if (n->type == NHERE) { 760 struct heredoc *here = heredoc; 761 struct heredoc *p; 762 763 if (quoteflag == 0) 764 n->type = NXHERE; 765 TRACE(("Here document %d\n", n->type)); 766 if (here->striptabs) { 767 while (*wordtext == '\t') 768 wordtext++; 769 } 770 if (! noexpand(wordtext)) 771 synerror("Illegal eof marker for << redirection"); 772 rmescapes(wordtext); 773 here->eofmark = wordtext; 774 here->next = NULL; 775 if (heredoclist == NULL) 776 heredoclist = here; 777 else { 778 for (p = heredoclist ; p->next ; p = p->next); 779 p->next = here; 780 } 781 } else if (n->type == NTOFD || n->type == NFROMFD) { 782 fixredir(n, wordtext, 0); 783 } else { 784 n->nfile.fname = makename(); 785 } 786 } 787 788 789 /* 790 * Input any here documents. 791 */ 792 793 static void 794 parseheredoc(void) 795 { 796 struct heredoc *here; 797 union node *n; 798 799 while (heredoclist) { 800 here = heredoclist; 801 heredoclist = here->next; 802 if (needprompt) { 803 setprompt(2); 804 needprompt = 0; 805 } 806 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, 807 here->eofmark, here->striptabs); 808 n = makename(); 809 here->here->nhere.doc = n; 810 } 811 } 812 813 static int 814 peektoken(void) 815 { 816 int t; 817 818 t = readtoken(); 819 tokpushback++; 820 return (t); 821 } 822 823 static int 824 readtoken(void) 825 { 826 int t; 827 struct alias *ap; 828 #ifdef DEBUG 829 int alreadyseen = tokpushback; 830 #endif 831 832 top: 833 t = xxreadtoken(); 834 835 /* 836 * eat newlines 837 */ 838 if (checkkwd & CHKNL) { 839 while (t == TNL) { 840 parseheredoc(); 841 t = xxreadtoken(); 842 } 843 } 844 845 /* 846 * check for keywords and aliases 847 */ 848 if (t == TWORD && !quoteflag) 849 { 850 const char * const *pp; 851 852 if (checkkwd & CHKKWD) 853 for (pp = parsekwd; *pp; pp++) { 854 if (**pp == *wordtext && equal(*pp, wordtext)) 855 { 856 lasttoken = t = pp - parsekwd + KWDOFFSET; 857 TRACE(("keyword %s recognized\n", tokname[t])); 858 goto out; 859 } 860 } 861 if (checkkwd & CHKALIAS && 862 (ap = lookupalias(wordtext, 1)) != NULL) { 863 pushstring(ap->val, strlen(ap->val), ap); 864 goto top; 865 } 866 } 867 out: 868 if (t != TNOT) 869 checkkwd = 0; 870 871 #ifdef DEBUG 872 if (!alreadyseen) 873 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 874 else 875 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 876 #endif 877 return (t); 878 } 879 880 881 /* 882 * Read the next input token. 883 * If the token is a word, we set backquotelist to the list of cmds in 884 * backquotes. We set quoteflag to true if any part of the word was 885 * quoted. 886 * If the token is TREDIR, then we set redirnode to a structure containing 887 * the redirection. 888 * In all cases, the variable startlinno is set to the number of the line 889 * on which the token starts. 890 * 891 * [Change comment: here documents and internal procedures] 892 * [Readtoken shouldn't have any arguments. Perhaps we should make the 893 * word parsing code into a separate routine. In this case, readtoken 894 * doesn't need to have any internal procedures, but parseword does. 895 * We could also make parseoperator in essence the main routine, and 896 * have parseword (readtoken1?) handle both words and redirection.] 897 */ 898 899 #define RETURN(token) return lasttoken = token 900 901 static int 902 xxreadtoken(void) 903 { 904 int c; 905 906 if (tokpushback) { 907 tokpushback = 0; 908 return lasttoken; 909 } 910 if (needprompt) { 911 setprompt(2); 912 needprompt = 0; 913 } 914 startlinno = plinno; 915 for (;;) { /* until token or start of word found */ 916 c = pgetc_macro(); 917 switch (c) { 918 case ' ': case '\t': 919 continue; 920 case '#': 921 while ((c = pgetc()) != '\n' && c != PEOF); 922 pungetc(); 923 continue; 924 case '\\': 925 if (pgetc() == '\n') { 926 startlinno = ++plinno; 927 if (doprompt) 928 setprompt(2); 929 else 930 setprompt(0); 931 continue; 932 } 933 pungetc(); 934 /* FALLTHROUGH */ 935 default: 936 return readtoken1(c, BASESYNTAX, (char *)NULL, 0); 937 case '\n': 938 plinno++; 939 needprompt = doprompt; 940 RETURN(TNL); 941 case PEOF: 942 RETURN(TEOF); 943 case '&': 944 if (pgetc_linecont() == '&') 945 RETURN(TAND); 946 pungetc(); 947 RETURN(TBACKGND); 948 case '|': 949 if (pgetc_linecont() == '|') 950 RETURN(TOR); 951 pungetc(); 952 RETURN(TPIPE); 953 case ';': 954 c = pgetc_linecont(); 955 if (c == ';') 956 RETURN(TENDCASE); 957 else if (c == '&') 958 RETURN(TFALLTHRU); 959 pungetc(); 960 RETURN(TSEMI); 961 case '(': 962 RETURN(TLP); 963 case ')': 964 RETURN(TRP); 965 } 966 } 967 #undef RETURN 968 } 969 970 971 #define MAXNEST_static 8 972 struct tokenstate 973 { 974 const char *syntax; /* *SYNTAX */ 975 int parenlevel; /* levels of parentheses in arithmetic */ 976 enum tokenstate_category 977 { 978 TSTATE_TOP, 979 TSTATE_VAR_OLD, /* ${var+-=?}, inherits dquotes */ 980 TSTATE_VAR_NEW, /* other ${var...}, own dquote state */ 981 TSTATE_ARITH 982 } category; 983 }; 984 985 986 /* 987 * Check to see whether we are at the end of the here document. When this 988 * is called, c is set to the first character of the next input line. If 989 * we are at the end of the here document, this routine sets the c to PEOF. 990 * The new value of c is returned. 991 */ 992 993 static int 994 checkend(int c, const char *eofmark, int striptabs) 995 { 996 if (striptabs) { 997 while (c == '\t') 998 c = pgetc(); 999 } 1000 if (c == *eofmark) { 1001 int c2; 1002 const char *q; 1003 1004 for (q = eofmark + 1; c2 = pgetc(), *q != '\0' && c2 == *q; q++) 1005 ; 1006 if ((c2 == PEOF || c2 == '\n') && *q == '\0') { 1007 c = PEOF; 1008 if (c2 == '\n') { 1009 plinno++; 1010 needprompt = doprompt; 1011 } 1012 } else { 1013 pungetc(); 1014 pushstring(eofmark + 1, q - (eofmark + 1), NULL); 1015 } 1016 } else if (c == '\n' && *eofmark == '\0') { 1017 c = PEOF; 1018 plinno++; 1019 needprompt = doprompt; 1020 } 1021 return (c); 1022 } 1023 1024 1025 /* 1026 * Parse a redirection operator. The variable "out" points to a string 1027 * specifying the fd to be redirected. The variable "c" contains the 1028 * first character of the redirection operator. 1029 */ 1030 1031 static void 1032 parseredir(char *out, int c) 1033 { 1034 char fd = *out; 1035 union node *np; 1036 1037 np = (union node *)stalloc(sizeof (struct nfile)); 1038 if (c == '>') { 1039 np->nfile.fd = 1; 1040 c = pgetc_linecont(); 1041 if (c == '>') 1042 np->type = NAPPEND; 1043 else if (c == '&') 1044 np->type = NTOFD; 1045 else if (c == '|') 1046 np->type = NCLOBBER; 1047 else { 1048 np->type = NTO; 1049 pungetc(); 1050 } 1051 } else { /* c == '<' */ 1052 np->nfile.fd = 0; 1053 c = pgetc_linecont(); 1054 if (c == '<') { 1055 if (sizeof (struct nfile) != sizeof (struct nhere)) { 1056 np = (union node *)stalloc(sizeof (struct nhere)); 1057 np->nfile.fd = 0; 1058 } 1059 np->type = NHERE; 1060 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); 1061 heredoc->here = np; 1062 if ((c = pgetc_linecont()) == '-') { 1063 heredoc->striptabs = 1; 1064 } else { 1065 heredoc->striptabs = 0; 1066 pungetc(); 1067 } 1068 } else if (c == '&') 1069 np->type = NFROMFD; 1070 else if (c == '>') 1071 np->type = NFROMTO; 1072 else { 1073 np->type = NFROM; 1074 pungetc(); 1075 } 1076 } 1077 if (fd != '\0') 1078 np->nfile.fd = digit_val(fd); 1079 redirnode = np; 1080 } 1081 1082 /* 1083 * Called to parse command substitutions. 1084 */ 1085 1086 static char * 1087 parsebackq(char *out, struct nodelist **pbqlist, 1088 int oldstyle, int dblquote, int quoted) 1089 { 1090 struct nodelist **nlpp; 1091 union node *n; 1092 char *volatile str; 1093 struct jmploc jmploc; 1094 struct jmploc *const savehandler = handler; 1095 size_t savelen; 1096 int saveprompt; 1097 const int bq_startlinno = plinno; 1098 char *volatile ostr = NULL; 1099 struct parsefile *const savetopfile = getcurrentfile(); 1100 struct heredoc *const saveheredoclist = heredoclist; 1101 struct heredoc *here; 1102 1103 str = NULL; 1104 if (setjmp(jmploc.loc)) { 1105 popfilesupto(savetopfile); 1106 if (str) 1107 ckfree(str); 1108 if (ostr) 1109 ckfree(ostr); 1110 heredoclist = saveheredoclist; 1111 handler = savehandler; 1112 if (exception == EXERROR) { 1113 startlinno = bq_startlinno; 1114 synerror("Error in command substitution"); 1115 } 1116 longjmp(handler->loc, 1); 1117 } 1118 INTOFF; 1119 savelen = out - stackblock(); 1120 if (savelen > 0) { 1121 str = ckmalloc(savelen); 1122 memcpy(str, stackblock(), savelen); 1123 } 1124 handler = &jmploc; 1125 heredoclist = NULL; 1126 INTON; 1127 if (oldstyle) { 1128 /* We must read until the closing backquote, giving special 1129 treatment to some slashes, and then push the string and 1130 reread it as input, interpreting it normally. */ 1131 char *oout; 1132 int c; 1133 int olen; 1134 1135 1136 STARTSTACKSTR(oout); 1137 for (;;) { 1138 if (needprompt) { 1139 setprompt(2); 1140 needprompt = 0; 1141 } 1142 CHECKSTRSPACE(2, oout); 1143 c = pgetc_linecont(); 1144 if (c == '`') 1145 break; 1146 switch (c) { 1147 case '\\': 1148 c = pgetc(); 1149 if (c != '\\' && c != '`' && c != '$' 1150 && (!dblquote || c != '"')) 1151 USTPUTC('\\', oout); 1152 break; 1153 1154 case '\n': 1155 plinno++; 1156 needprompt = doprompt; 1157 break; 1158 1159 case PEOF: 1160 startlinno = plinno; 1161 synerror("EOF in backquote substitution"); 1162 break; 1163 1164 default: 1165 break; 1166 } 1167 USTPUTC(c, oout); 1168 } 1169 USTPUTC('\0', oout); 1170 olen = oout - stackblock(); 1171 INTOFF; 1172 ostr = ckmalloc(olen); 1173 memcpy(ostr, stackblock(), olen); 1174 setinputstring(ostr, 1); 1175 INTON; 1176 } 1177 nlpp = pbqlist; 1178 while (*nlpp) 1179 nlpp = &(*nlpp)->next; 1180 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 1181 (*nlpp)->next = NULL; 1182 1183 if (oldstyle) { 1184 saveprompt = doprompt; 1185 doprompt = 0; 1186 } 1187 1188 n = list(0); 1189 1190 if (oldstyle) { 1191 if (peektoken() != TEOF) 1192 synexpect(-1); 1193 doprompt = saveprompt; 1194 } else 1195 consumetoken(TRP); 1196 1197 (*nlpp)->n = n; 1198 if (oldstyle) { 1199 /* 1200 * Start reading from old file again, ignoring any pushed back 1201 * tokens left from the backquote parsing 1202 */ 1203 popfile(); 1204 tokpushback = 0; 1205 } 1206 STARTSTACKSTR(out); 1207 CHECKSTRSPACE(savelen + 1, out); 1208 INTOFF; 1209 if (str) { 1210 memcpy(out, str, savelen); 1211 STADJUST(savelen, out); 1212 ckfree(str); 1213 str = NULL; 1214 } 1215 if (ostr) { 1216 ckfree(ostr); 1217 ostr = NULL; 1218 } 1219 here = saveheredoclist; 1220 if (here != NULL) { 1221 while (here->next != NULL) 1222 here = here->next; 1223 here->next = heredoclist; 1224 heredoclist = saveheredoclist; 1225 } 1226 handler = savehandler; 1227 INTON; 1228 if (quoted) 1229 USTPUTC(CTLBACKQ | CTLQUOTE, out); 1230 else 1231 USTPUTC(CTLBACKQ, out); 1232 return out; 1233 } 1234 1235 1236 /* 1237 * Called to parse a backslash escape sequence inside $'...'. 1238 * The backslash has already been read. 1239 */ 1240 static char * 1241 readcstyleesc(char *out) 1242 { 1243 int c, vc, i, n; 1244 unsigned int v; 1245 1246 c = pgetc(); 1247 switch (c) { 1248 case '\0': 1249 synerror("Unterminated quoted string"); 1250 case '\n': 1251 plinno++; 1252 if (doprompt) 1253 setprompt(2); 1254 else 1255 setprompt(0); 1256 return out; 1257 case '\\': 1258 case '\'': 1259 case '"': 1260 v = c; 1261 break; 1262 case 'a': v = '\a'; break; 1263 case 'b': v = '\b'; break; 1264 case 'e': v = '\033'; break; 1265 case 'f': v = '\f'; break; 1266 case 'n': v = '\n'; break; 1267 case 'r': v = '\r'; break; 1268 case 't': v = '\t'; break; 1269 case 'v': v = '\v'; break; 1270 case 'x': 1271 v = 0; 1272 for (;;) { 1273 c = pgetc(); 1274 if (c >= '0' && c <= '9') 1275 v = (v << 4) + c - '0'; 1276 else if (c >= 'A' && c <= 'F') 1277 v = (v << 4) + c - 'A' + 10; 1278 else if (c >= 'a' && c <= 'f') 1279 v = (v << 4) + c - 'a' + 10; 1280 else 1281 break; 1282 } 1283 pungetc(); 1284 break; 1285 case '0': case '1': case '2': case '3': 1286 case '4': case '5': case '6': case '7': 1287 v = c - '0'; 1288 c = pgetc(); 1289 if (c >= '0' && c <= '7') { 1290 v <<= 3; 1291 v += c - '0'; 1292 c = pgetc(); 1293 if (c >= '0' && c <= '7') { 1294 v <<= 3; 1295 v += c - '0'; 1296 } else 1297 pungetc(); 1298 } else 1299 pungetc(); 1300 break; 1301 case 'c': 1302 c = pgetc(); 1303 if (c < 0x3f || c > 0x7a || c == 0x60) 1304 synerror("Bad escape sequence"); 1305 if (c == '\\' && pgetc() != '\\') 1306 synerror("Bad escape sequence"); 1307 if (c == '?') 1308 v = 127; 1309 else 1310 v = c & 0x1f; 1311 break; 1312 case 'u': 1313 case 'U': 1314 n = c == 'U' ? 8 : 4; 1315 v = 0; 1316 for (i = 0; i < n; i++) { 1317 c = pgetc(); 1318 if (c >= '0' && c <= '9') 1319 v = (v << 4) + c - '0'; 1320 else if (c >= 'A' && c <= 'F') 1321 v = (v << 4) + c - 'A' + 10; 1322 else if (c >= 'a' && c <= 'f') 1323 v = (v << 4) + c - 'a' + 10; 1324 else 1325 synerror("Bad escape sequence"); 1326 } 1327 if (v == 0 || (v >= 0xd800 && v <= 0xdfff)) 1328 synerror("Bad escape sequence"); 1329 /* We really need iconv here. */ 1330 if (initial_localeisutf8 && v > 127) { 1331 CHECKSTRSPACE(4, out); 1332 /* 1333 * We cannot use wctomb() as the locale may have 1334 * changed. 1335 */ 1336 if (v <= 0x7ff) { 1337 USTPUTC(0xc0 | v >> 6, out); 1338 USTPUTC(0x80 | (v & 0x3f), out); 1339 return out; 1340 } else if (v <= 0xffff) { 1341 USTPUTC(0xe0 | v >> 12, out); 1342 USTPUTC(0x80 | ((v >> 6) & 0x3f), out); 1343 USTPUTC(0x80 | (v & 0x3f), out); 1344 return out; 1345 } else if (v <= 0x10ffff) { 1346 USTPUTC(0xf0 | v >> 18, out); 1347 USTPUTC(0x80 | ((v >> 12) & 0x3f), out); 1348 USTPUTC(0x80 | ((v >> 6) & 0x3f), out); 1349 USTPUTC(0x80 | (v & 0x3f), out); 1350 return out; 1351 } 1352 } 1353 if (v > 127) 1354 v = '?'; 1355 break; 1356 default: 1357 synerror("Bad escape sequence"); 1358 } 1359 vc = (char)v; 1360 /* 1361 * We can't handle NUL bytes. 1362 * POSIX says we should skip till the closing quote. 1363 */ 1364 if (vc == '\0') { 1365 while ((c = pgetc()) != '\'') { 1366 if (c == '\\') 1367 c = pgetc(); 1368 if (c == PEOF) 1369 synerror("Unterminated quoted string"); 1370 if (c == '\n') { 1371 plinno++; 1372 if (doprompt) 1373 setprompt(2); 1374 else 1375 setprompt(0); 1376 } 1377 } 1378 pungetc(); 1379 return out; 1380 } 1381 if (SQSYNTAX[vc] == CCTL) 1382 USTPUTC(CTLESC, out); 1383 USTPUTC(vc, out); 1384 return out; 1385 } 1386 1387 1388 /* 1389 * If eofmark is NULL, read a word or a redirection symbol. If eofmark 1390 * is not NULL, read a here document. In the latter case, eofmark is the 1391 * word which marks the end of the document and striptabs is true if 1392 * leading tabs should be stripped from the document. The argument firstc 1393 * is the first character of the input token or document. 1394 * 1395 * Because C does not have internal subroutines, I have simulated them 1396 * using goto's to implement the subroutine linkage. The following macros 1397 * will run code that appears at the end of readtoken1. 1398 */ 1399 1400 #define PARSESUB() {goto parsesub; parsesub_return:;} 1401 #define PARSEARITH() {goto parsearith; parsearith_return:;} 1402 1403 static int 1404 readtoken1(int firstc, char const *initialsyntax, const char *eofmark, 1405 int striptabs) 1406 { 1407 int c = firstc; 1408 char *out; 1409 int len; 1410 struct nodelist *bqlist; 1411 int quotef; 1412 int newvarnest; 1413 int level; 1414 int synentry; 1415 struct tokenstate state_static[MAXNEST_static]; 1416 int maxnest = MAXNEST_static; 1417 struct tokenstate *state = state_static; 1418 int sqiscstyle = 0; 1419 1420 startlinno = plinno; 1421 quotef = 0; 1422 bqlist = NULL; 1423 newvarnest = 0; 1424 level = 0; 1425 state[level].syntax = initialsyntax; 1426 state[level].parenlevel = 0; 1427 state[level].category = TSTATE_TOP; 1428 1429 STARTSTACKSTR(out); 1430 loop: { /* for each line, until end of word */ 1431 if (eofmark && eofmark != NOEOFMARK) 1432 /* set c to PEOF if at end of here document */ 1433 c = checkend(c, eofmark, striptabs); 1434 for (;;) { /* until end of line or end of word */ 1435 CHECKSTRSPACE(4, out); /* permit 4 calls to USTPUTC */ 1436 1437 synentry = state[level].syntax[c]; 1438 1439 switch(synentry) { 1440 case CNL: /* '\n' */ 1441 if (level == 0) 1442 goto endword; /* exit outer loop */ 1443 /* FALLTHROUGH */ 1444 case CQNL: 1445 USTPUTC(c, out); 1446 plinno++; 1447 if (doprompt) 1448 setprompt(2); 1449 else 1450 setprompt(0); 1451 c = pgetc(); 1452 goto loop; /* continue outer loop */ 1453 case CSBACK: 1454 if (sqiscstyle) { 1455 out = readcstyleesc(out); 1456 break; 1457 } 1458 /* FALLTHROUGH */ 1459 case CWORD: 1460 USTPUTC(c, out); 1461 break; 1462 case CCTL: 1463 if (eofmark == NULL || initialsyntax != SQSYNTAX) 1464 USTPUTC(CTLESC, out); 1465 USTPUTC(c, out); 1466 break; 1467 case CBACK: /* backslash */ 1468 c = pgetc(); 1469 if (c == PEOF) { 1470 USTPUTC('\\', out); 1471 pungetc(); 1472 } else if (c == '\n') { 1473 plinno++; 1474 if (doprompt) 1475 setprompt(2); 1476 else 1477 setprompt(0); 1478 } else { 1479 if (state[level].syntax == DQSYNTAX && 1480 c != '\\' && c != '`' && c != '$' && 1481 (c != '"' || (eofmark != NULL && 1482 newvarnest == 0)) && 1483 (c != '}' || state[level].category != TSTATE_VAR_OLD)) 1484 USTPUTC('\\', out); 1485 if ((eofmark == NULL || 1486 newvarnest > 0) && 1487 state[level].syntax == BASESYNTAX) 1488 USTPUTC(CTLQUOTEMARK, out); 1489 if (SQSYNTAX[c] == CCTL) 1490 USTPUTC(CTLESC, out); 1491 USTPUTC(c, out); 1492 if ((eofmark == NULL || 1493 newvarnest > 0) && 1494 state[level].syntax == BASESYNTAX && 1495 state[level].category == TSTATE_VAR_OLD) 1496 USTPUTC(CTLQUOTEEND, out); 1497 quotef++; 1498 } 1499 break; 1500 case CSQUOTE: 1501 USTPUTC(CTLQUOTEMARK, out); 1502 state[level].syntax = SQSYNTAX; 1503 sqiscstyle = 0; 1504 break; 1505 case CDQUOTE: 1506 USTPUTC(CTLQUOTEMARK, out); 1507 state[level].syntax = DQSYNTAX; 1508 break; 1509 case CENDQUOTE: 1510 if (eofmark != NULL && newvarnest == 0) 1511 USTPUTC(c, out); 1512 else { 1513 if (state[level].category == TSTATE_VAR_OLD) 1514 USTPUTC(CTLQUOTEEND, out); 1515 state[level].syntax = BASESYNTAX; 1516 quotef++; 1517 } 1518 break; 1519 case CVAR: /* '$' */ 1520 PARSESUB(); /* parse substitution */ 1521 break; 1522 case CENDVAR: /* '}' */ 1523 if (level > 0 && 1524 ((state[level].category == TSTATE_VAR_OLD && 1525 state[level].syntax == 1526 state[level - 1].syntax) || 1527 (state[level].category == TSTATE_VAR_NEW && 1528 state[level].syntax == BASESYNTAX))) { 1529 if (state[level].category == TSTATE_VAR_NEW) 1530 newvarnest--; 1531 level--; 1532 USTPUTC(CTLENDVAR, out); 1533 } else { 1534 USTPUTC(c, out); 1535 } 1536 break; 1537 case CLP: /* '(' in arithmetic */ 1538 state[level].parenlevel++; 1539 USTPUTC(c, out); 1540 break; 1541 case CRP: /* ')' in arithmetic */ 1542 if (state[level].parenlevel > 0) { 1543 USTPUTC(c, out); 1544 --state[level].parenlevel; 1545 } else { 1546 if (pgetc_linecont() == ')') { 1547 if (level > 0 && 1548 state[level].category == TSTATE_ARITH) { 1549 level--; 1550 USTPUTC(CTLENDARI, out); 1551 } else 1552 USTPUTC(')', out); 1553 } else { 1554 /* 1555 * unbalanced parens 1556 * (don't 2nd guess - no error) 1557 */ 1558 pungetc(); 1559 USTPUTC(')', out); 1560 } 1561 } 1562 break; 1563 case CBQUOTE: /* '`' */ 1564 out = parsebackq(out, &bqlist, 1, 1565 state[level].syntax == DQSYNTAX && 1566 (eofmark == NULL || newvarnest > 0), 1567 state[level].syntax == DQSYNTAX || state[level].syntax == ARISYNTAX); 1568 break; 1569 case CEOF: 1570 goto endword; /* exit outer loop */ 1571 case CIGN: 1572 break; 1573 default: 1574 if (level == 0) 1575 goto endword; /* exit outer loop */ 1576 USTPUTC(c, out); 1577 } 1578 c = pgetc_macro(); 1579 } 1580 } 1581 endword: 1582 if (state[level].syntax == ARISYNTAX) 1583 synerror("Missing '))'"); 1584 if (state[level].syntax != BASESYNTAX && eofmark == NULL) 1585 synerror("Unterminated quoted string"); 1586 if (state[level].category == TSTATE_VAR_OLD || 1587 state[level].category == TSTATE_VAR_NEW) { 1588 startlinno = plinno; 1589 synerror("Missing '}'"); 1590 } 1591 if (state != state_static) 1592 parser_temp_free_upto(state); 1593 USTPUTC('\0', out); 1594 len = out - stackblock(); 1595 out = stackblock(); 1596 if (eofmark == NULL) { 1597 if ((c == '>' || c == '<') 1598 && quotef == 0 1599 && len <= 2 1600 && (*out == '\0' || is_digit(*out))) { 1601 parseredir(out, c); 1602 return lasttoken = TREDIR; 1603 } else { 1604 pungetc(); 1605 } 1606 } 1607 quoteflag = quotef; 1608 backquotelist = bqlist; 1609 grabstackblock(len); 1610 wordtext = out; 1611 return lasttoken = TWORD; 1612 /* end of readtoken routine */ 1613 1614 1615 /* 1616 * Parse a substitution. At this point, we have read the dollar sign 1617 * and nothing else. 1618 */ 1619 1620 parsesub: { 1621 int subtype; 1622 int typeloc; 1623 int flags; 1624 char *p; 1625 static const char types[] = "}-+?="; 1626 int linno; 1627 int length; 1628 int c1; 1629 1630 c = pgetc_linecont(); 1631 if (c == '(') { /* $(command) or $((arith)) */ 1632 if (pgetc_linecont() == '(') { 1633 PARSEARITH(); 1634 } else { 1635 pungetc(); 1636 out = parsebackq(out, &bqlist, 0, 1637 state[level].syntax == DQSYNTAX && 1638 (eofmark == NULL || newvarnest > 0), 1639 state[level].syntax == DQSYNTAX || 1640 state[level].syntax == ARISYNTAX); 1641 } 1642 } else if (c == '{' || is_name(c) || is_special(c)) { 1643 USTPUTC(CTLVAR, out); 1644 typeloc = out - stackblock(); 1645 USTPUTC(VSNORMAL, out); 1646 subtype = VSNORMAL; 1647 flags = 0; 1648 if (c == '{') { 1649 c = pgetc_linecont(); 1650 subtype = 0; 1651 } 1652 varname: 1653 if (!is_eof(c) && is_name(c)) { 1654 length = 0; 1655 do { 1656 STPUTC(c, out); 1657 c = pgetc_linecont(); 1658 length++; 1659 } while (!is_eof(c) && is_in_name(c)); 1660 if (length == 6 && 1661 strncmp(out - length, "LINENO", length) == 0) { 1662 /* Replace the variable name with the 1663 * current line number. */ 1664 STADJUST(-6, out); 1665 CHECKSTRSPACE(11, out); 1666 linno = plinno; 1667 if (funclinno != 0) 1668 linno -= funclinno - 1; 1669 length = snprintf(out, 11, "%d", linno); 1670 if (length > 10) 1671 length = 10; 1672 out += length; 1673 flags |= VSLINENO; 1674 } 1675 } else if (is_digit(c)) { 1676 if (subtype != VSNORMAL) { 1677 do { 1678 STPUTC(c, out); 1679 c = pgetc_linecont(); 1680 } while (is_digit(c)); 1681 } else { 1682 USTPUTC(c, out); 1683 c = pgetc_linecont(); 1684 } 1685 } else if (is_special(c)) { 1686 c1 = c; 1687 c = pgetc_linecont(); 1688 if (subtype == 0 && c1 == '#') { 1689 subtype = VSLENGTH; 1690 if (strchr(types, c) == NULL && c != ':' && 1691 c != '#' && c != '%') 1692 goto varname; 1693 c1 = c; 1694 c = pgetc_linecont(); 1695 if (c1 != '}' && c == '}') { 1696 pungetc(); 1697 c = c1; 1698 goto varname; 1699 } 1700 pungetc(); 1701 c = c1; 1702 c1 = '#'; 1703 subtype = 0; 1704 } 1705 USTPUTC(c1, out); 1706 } else { 1707 subtype = VSERROR; 1708 if (c == '}') 1709 pungetc(); 1710 else if (c == '\n' || c == PEOF) 1711 synerror("Unexpected end of line in substitution"); 1712 else if (BASESYNTAX[c] != CCTL) 1713 USTPUTC(c, out); 1714 } 1715 if (subtype == 0) { 1716 switch (c) { 1717 case ':': 1718 flags |= VSNUL; 1719 c = pgetc_linecont(); 1720 /*FALLTHROUGH*/ 1721 default: 1722 p = strchr(types, c); 1723 if (p == NULL) { 1724 if (c == '\n' || c == PEOF) 1725 synerror("Unexpected end of line in substitution"); 1726 if (flags == VSNUL) 1727 STPUTC(':', out); 1728 if (BASESYNTAX[c] != CCTL) 1729 STPUTC(c, out); 1730 subtype = VSERROR; 1731 } else 1732 subtype = p - types + VSNORMAL; 1733 break; 1734 case '%': 1735 case '#': 1736 { 1737 int cc = c; 1738 subtype = c == '#' ? VSTRIMLEFT : 1739 VSTRIMRIGHT; 1740 c = pgetc_linecont(); 1741 if (c == cc) 1742 subtype++; 1743 else 1744 pungetc(); 1745 break; 1746 } 1747 } 1748 } else if (subtype != VSERROR) { 1749 if (subtype == VSLENGTH && c != '}') 1750 subtype = VSERROR; 1751 pungetc(); 1752 } 1753 STPUTC('=', out); 1754 if (state[level].syntax == DQSYNTAX || 1755 state[level].syntax == ARISYNTAX) 1756 flags |= VSQUOTE; 1757 *(stackblock() + typeloc) = subtype | flags; 1758 if (subtype != VSNORMAL) { 1759 if (level + 1 >= maxnest) { 1760 maxnest *= 2; 1761 if (state == state_static) { 1762 state = parser_temp_alloc( 1763 maxnest * sizeof(*state)); 1764 memcpy(state, state_static, 1765 MAXNEST_static * sizeof(*state)); 1766 } else 1767 state = parser_temp_realloc(state, 1768 maxnest * sizeof(*state)); 1769 } 1770 level++; 1771 state[level].parenlevel = 0; 1772 if (subtype == VSMINUS || subtype == VSPLUS || 1773 subtype == VSQUESTION || subtype == VSASSIGN) { 1774 /* 1775 * For operators that were in the Bourne shell, 1776 * inherit the double-quote state. 1777 */ 1778 state[level].syntax = state[level - 1].syntax; 1779 state[level].category = TSTATE_VAR_OLD; 1780 } else { 1781 /* 1782 * The other operators take a pattern, 1783 * so go to BASESYNTAX. 1784 * Also, ' and " are now special, even 1785 * in here documents. 1786 */ 1787 state[level].syntax = BASESYNTAX; 1788 state[level].category = TSTATE_VAR_NEW; 1789 newvarnest++; 1790 } 1791 } 1792 } else if (c == '\'' && state[level].syntax == BASESYNTAX) { 1793 /* $'cstylequotes' */ 1794 USTPUTC(CTLQUOTEMARK, out); 1795 state[level].syntax = SQSYNTAX; 1796 sqiscstyle = 1; 1797 } else { 1798 USTPUTC('$', out); 1799 pungetc(); 1800 } 1801 goto parsesub_return; 1802 } 1803 1804 1805 /* 1806 * Parse an arithmetic expansion (indicate start of one and set state) 1807 */ 1808 parsearith: { 1809 1810 if (level + 1 >= maxnest) { 1811 maxnest *= 2; 1812 if (state == state_static) { 1813 state = parser_temp_alloc( 1814 maxnest * sizeof(*state)); 1815 memcpy(state, state_static, 1816 MAXNEST_static * sizeof(*state)); 1817 } else 1818 state = parser_temp_realloc(state, 1819 maxnest * sizeof(*state)); 1820 } 1821 level++; 1822 state[level].syntax = ARISYNTAX; 1823 state[level].parenlevel = 0; 1824 state[level].category = TSTATE_ARITH; 1825 USTPUTC(CTLARI, out); 1826 if (state[level - 1].syntax == DQSYNTAX) 1827 USTPUTC('"',out); 1828 else 1829 USTPUTC(' ',out); 1830 goto parsearith_return; 1831 } 1832 1833 } /* end of readtoken */ 1834 1835 1836 /* 1837 * Returns true if the text contains nothing to expand (no dollar signs 1838 * or backquotes). 1839 */ 1840 1841 static int 1842 noexpand(char *text) 1843 { 1844 char *p; 1845 char c; 1846 1847 p = text; 1848 while ((c = *p++) != '\0') { 1849 if ( c == CTLQUOTEMARK) 1850 continue; 1851 if (c == CTLESC) 1852 p++; 1853 else if (BASESYNTAX[(int)c] == CCTL) 1854 return 0; 1855 } 1856 return 1; 1857 } 1858 1859 1860 /* 1861 * Return true if the argument is a legal variable name (a letter or 1862 * underscore followed by zero or more letters, underscores, and digits). 1863 */ 1864 1865 int 1866 goodname(const char *name) 1867 { 1868 const char *p; 1869 1870 p = name; 1871 if (! is_name(*p)) 1872 return 0; 1873 while (*++p) { 1874 if (! is_in_name(*p)) 1875 return 0; 1876 } 1877 return 1; 1878 } 1879 1880 1881 int 1882 isassignment(const char *p) 1883 { 1884 if (!is_name(*p)) 1885 return 0; 1886 p++; 1887 for (;;) { 1888 if (*p == '=') 1889 return 1; 1890 else if (!is_in_name(*p)) 1891 return 0; 1892 p++; 1893 } 1894 } 1895 1896 1897 static void 1898 consumetoken(int token) 1899 { 1900 if (readtoken() != token) 1901 synexpect(token); 1902 } 1903 1904 1905 /* 1906 * Called when an unexpected token is read during the parse. The argument 1907 * is the token that is expected, or -1 if more than one type of token can 1908 * occur at this point. 1909 */ 1910 1911 static void 1912 synexpect(int token) 1913 { 1914 char msg[64]; 1915 1916 if (token >= 0) { 1917 fmtstr(msg, 64, "%s unexpected (expecting %s)", 1918 tokname[lasttoken], tokname[token]); 1919 } else { 1920 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]); 1921 } 1922 synerror(msg); 1923 } 1924 1925 1926 static void 1927 synerror(const char *msg) 1928 { 1929 if (commandname) 1930 outfmt(out2, "%s: %d: ", commandname, startlinno); 1931 else if (arg0) 1932 outfmt(out2, "%s: ", arg0); 1933 outfmt(out2, "Syntax error: %s\n", msg); 1934 error((char *)NULL); 1935 } 1936 1937 static void 1938 setprompt(int which) 1939 { 1940 whichprompt = which; 1941 if (which == 0) 1942 return; 1943 1944 #ifndef NO_HISTORY 1945 if (!el) 1946 #endif 1947 { 1948 out2str(getprompt(NULL)); 1949 flushout(out2); 1950 } 1951 } 1952 1953 static int 1954 pgetc_linecont(void) 1955 { 1956 int c; 1957 1958 while ((c = pgetc_macro()) == '\\') { 1959 c = pgetc(); 1960 if (c == '\n') { 1961 plinno++; 1962 if (doprompt) 1963 setprompt(2); 1964 else 1965 setprompt(0); 1966 } else { 1967 pungetc(); 1968 /* Allow the backslash to be pushed back. */ 1969 pushstring("\\", 1, NULL); 1970 return (pgetc()); 1971 } 1972 } 1973 return (c); 1974 } 1975 1976 1977 static struct passwd * 1978 getpwlogin(void) 1979 { 1980 const char *login; 1981 1982 login = getlogin(); 1983 if (login == NULL) 1984 return (NULL); 1985 1986 return (getpwnam(login)); 1987 } 1988 1989 1990 static void 1991 getusername(char *name, size_t namelen) 1992 { 1993 static char cached_name[MAXLOGNAME]; 1994 struct passwd *pw; 1995 uid_t euid; 1996 1997 if (cached_name[0] == '\0') { 1998 euid = geteuid(); 1999 2000 /* 2001 * Handle the case when there is more than one 2002 * login with the same UID, or when the login 2003 * returned by getlogin(2) does no longer match 2004 * the current UID. 2005 */ 2006 pw = getpwlogin(); 2007 if (pw == NULL || pw->pw_uid != euid) 2008 pw = getpwuid(euid); 2009 2010 if (pw != NULL) { 2011 strlcpy(cached_name, pw->pw_name, 2012 sizeof(cached_name)); 2013 } else { 2014 snprintf(cached_name, sizeof(cached_name), 2015 "%u", euid); 2016 } 2017 } 2018 2019 strlcpy(name, cached_name, namelen); 2020 } 2021 2022 2023 /* 2024 * called by editline -- any expansions to the prompt 2025 * should be added here. 2026 */ 2027 char * 2028 getprompt(void *unused __unused) 2029 { 2030 static char ps[PROMPTLEN]; 2031 const char *fmt; 2032 const char *home; 2033 const char *pwd; 2034 size_t homelen; 2035 int i, trim; 2036 static char internal_error[] = "??"; 2037 2038 /* 2039 * Select prompt format. 2040 */ 2041 switch (whichprompt) { 2042 case 0: 2043 fmt = ""; 2044 break; 2045 case 1: 2046 fmt = ps1val(); 2047 break; 2048 case 2: 2049 fmt = ps2val(); 2050 break; 2051 default: 2052 return internal_error; 2053 } 2054 2055 /* 2056 * Format prompt string. 2057 */ 2058 for (i = 0; (i < PROMPTLEN - 1) && (*fmt != '\0'); i++, fmt++) 2059 if (*fmt == '\\') 2060 switch (*++fmt) { 2061 2062 /* 2063 * Hostname. 2064 * 2065 * \h specifies just the local hostname, 2066 * \H specifies fully-qualified hostname. 2067 */ 2068 case 'h': 2069 case 'H': 2070 ps[i] = '\0'; 2071 gethostname(&ps[i], PROMPTLEN - i - 1); 2072 ps[PROMPTLEN - 1] = '\0'; 2073 /* Skip to end of hostname. */ 2074 trim = (*fmt == 'h') ? '.' : '\0'; 2075 while ((ps[i] != '\0') && (ps[i] != trim)) 2076 i++; 2077 --i; 2078 break; 2079 2080 /* 2081 * User name. 2082 */ 2083 case 'u': 2084 ps[i] = '\0'; 2085 getusername(&ps[i], PROMPTLEN - i); 2086 /* Skip to end of username. */ 2087 while (ps[i + 1] != '\0') 2088 i++; 2089 break; 2090 2091 /* 2092 * Working directory. 2093 * 2094 * \W specifies just the final component, 2095 * \w specifies the entire path. 2096 */ 2097 case 'W': 2098 case 'w': 2099 pwd = lookupvar("PWD"); 2100 if (pwd == NULL || *pwd == '\0') 2101 pwd = "?"; 2102 if (*fmt == 'W' && 2103 *pwd == '/' && pwd[1] != '\0') 2104 strlcpy(&ps[i], strrchr(pwd, '/') + 1, 2105 PROMPTLEN - i); 2106 else { 2107 home = lookupvar("HOME"); 2108 if (home != NULL) 2109 homelen = strlen(home); 2110 if (home != NULL && 2111 strcmp(home, "/") != 0 && 2112 strncmp(pwd, home, homelen) == 0 && 2113 (pwd[homelen] == '/' || 2114 pwd[homelen] == '\0')) { 2115 strlcpy(&ps[i], "~", 2116 PROMPTLEN - i); 2117 strlcpy(&ps[i + 1], 2118 pwd + homelen, 2119 PROMPTLEN - i - 1); 2120 } else { 2121 strlcpy(&ps[i], pwd, PROMPTLEN - i); 2122 } 2123 } 2124 /* Skip to end of path. */ 2125 while (ps[i + 1] != '\0') 2126 i++; 2127 break; 2128 2129 /* 2130 * Superuser status. 2131 * 2132 * '$' for normal users, '#' for root. 2133 */ 2134 case '$': 2135 ps[i] = (geteuid() != 0) ? '$' : '#'; 2136 break; 2137 2138 /* 2139 * A literal \. 2140 */ 2141 case '\\': 2142 ps[i] = '\\'; 2143 break; 2144 2145 /* 2146 * Emit unrecognized formats verbatim. 2147 */ 2148 default: 2149 ps[i] = '\\'; 2150 if (i < PROMPTLEN - 2) 2151 ps[++i] = *fmt; 2152 break; 2153 } 2154 else 2155 ps[i] = *fmt; 2156 ps[i] = '\0'; 2157 return (ps); 2158 } 2159 2160 2161 const char * 2162 expandstr(const char *ps) 2163 { 2164 union node n; 2165 struct jmploc jmploc; 2166 struct jmploc *const savehandler = handler; 2167 const int saveprompt = doprompt; 2168 struct parsefile *const savetopfile = getcurrentfile(); 2169 struct parser_temp *const saveparser_temp = parser_temp; 2170 const char *result = NULL; 2171 2172 if (!setjmp(jmploc.loc)) { 2173 handler = &jmploc; 2174 parser_temp = NULL; 2175 setinputstring(ps, 1); 2176 doprompt = 0; 2177 readtoken1(pgetc(), DQSYNTAX, NOEOFMARK, 0); 2178 if (backquotelist != NULL) 2179 error("Command substitution not allowed here"); 2180 2181 n.narg.type = NARG; 2182 n.narg.next = NULL; 2183 n.narg.text = wordtext; 2184 n.narg.backquote = backquotelist; 2185 2186 expandarg(&n, NULL, 0); 2187 result = stackblock(); 2188 INTOFF; 2189 } 2190 handler = savehandler; 2191 doprompt = saveprompt; 2192 popfilesupto(savetopfile); 2193 if (parser_temp != saveparser_temp) { 2194 parser_temp_free_all(); 2195 parser_temp = saveparser_temp; 2196 } 2197 if (result != NULL) { 2198 INTON; 2199 } else if (exception == EXINT) 2200 raise(SIGINT); 2201 return result; 2202 } 2203