1 /* 2 * sh.parse.c: Interpret a list of tokens 3 */ 4 /*- 5 * Copyright (c) 1980, 1991 The Regents of the University of California. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 #include "sh.h" 33 34 /* 35 * C shell 36 */ 37 static int asyntax (struct wordent *, struct wordent *); 38 static int asyn0 (struct wordent *, struct wordent *); 39 static int asyn3 (struct wordent *, struct wordent *); 40 static struct wordent *freenod (struct wordent *, struct wordent *); 41 static struct command *syn0 (const struct wordent *, const struct wordent *, int); 42 static struct command *syn1 (const struct wordent *, const struct wordent *, int); 43 static struct command *syn1a (const struct wordent *, const struct wordent *, int); 44 static struct command *syn1b (const struct wordent *, const struct wordent *, int); 45 static struct command *syn2 (const struct wordent *, const struct wordent *, int); 46 static struct command *syn3 (const struct wordent *, const struct wordent *, int); 47 48 #define ALEFT 51 /* max of 50 alias expansions */ 49 #define HLEFT 11 /* max of 10 history expansions */ 50 /* 51 * Perform aliasing on the word list lexp 52 * Do a (very rudimentary) parse to separate into commands. 53 * If word 0 of a command has an alias, do it. 54 * Repeat a maximum of 50 times. 55 */ 56 extern int hleft; 57 void 58 alias(struct wordent *lexp) 59 { 60 int aleft; 61 62 aleft = ALEFT; 63 hleft = HLEFT; 64 do { 65 if (--aleft == 0) 66 stderror(ERR_ALIASLOOP); 67 } while (asyntax(lexp->next, lexp) != 0); 68 } 69 70 static int 71 asyntax(struct wordent *p1, struct wordent *p2) 72 { 73 while (p1 != p2) { 74 if (!any(";&\n", p1->word[0])) 75 return asyn0(p1, p2); 76 p1 = p1->next; 77 } 78 return 0; 79 } 80 81 static int 82 asyn0(struct wordent *p1, struct wordent *p2) 83 { 84 struct wordent *p; 85 int l = 0; 86 87 for (p = p1; p != p2; p = p->next) 88 switch (p->word[0]) { 89 90 case '(': 91 l++; 92 continue; 93 94 case ')': 95 l--; 96 if (l < 0) 97 stderror(ERR_TOOMANYRP); 98 continue; 99 100 case '>': 101 if (p->next != p2 && eq(p->next->word, STRand)) 102 p = p->next; 103 continue; 104 105 case '&': 106 case '|': 107 case ';': 108 case '\n': 109 if (l != 0) 110 continue; 111 if (asyn3(p1, p) != 0) 112 return 1; 113 return asyntax(p->next, p2); 114 115 default: 116 break; 117 } 118 if (l == 0) 119 return asyn3(p1, p2); 120 return 0; 121 } 122 123 static void 124 alvec_cleanup(void *dummy) 125 { 126 USE(dummy); 127 alhistp = NULL; 128 alhistt = NULL; 129 alvec = NULL; 130 } 131 132 static int 133 asyn3(struct wordent *p1, struct wordent *p2) 134 { 135 struct varent *ap; 136 struct wordent alout; 137 int redid; 138 139 if (p1 == p2) 140 return 0; 141 if (p1->word[0] == '(') { 142 for (p2 = p2->prev; p2->word[0] != ')'; p2 = p2->prev) 143 if (p2 == p1) 144 return 0; 145 if (p2 == p1->next) 146 return 0; 147 return asyn0(p1->next, p2); 148 } 149 ap = adrof1(p1->word, &aliases); 150 if (ap == 0) 151 return 0; 152 alhistp = p1->prev; 153 alhistt = p2; 154 alvec = ap->vec; 155 cleanup_push(&alvec, alvec_cleanup); 156 redid = lex(&alout); 157 cleanup_until(&alvec); 158 if (seterr) { 159 freelex(&alout); 160 stderror(ERR_OLD); 161 } 162 if (p1->word[0] && eq(p1->word, alout.next->word)) { 163 Char *cp = alout.next->word; 164 165 alout.next->word = Strspl(STRQNULL, cp); 166 xfree(cp); 167 } 168 p1 = freenod(p1, redid ? p2 : p1->next); 169 if (alout.next != &alout) { 170 p1->next->prev = alout.prev->prev; 171 alout.prev->prev->next = p1->next; 172 alout.next->prev = p1; 173 p1->next = alout.next; 174 xfree(alout.prev->word); 175 xfree(alout.prev); 176 } 177 return 1; 178 } 179 180 static struct wordent * 181 freenod(struct wordent *p1, struct wordent *p2) 182 { 183 struct wordent *retp = p1->prev; 184 185 while (p1 != p2) { 186 xfree(p1->word); 187 p1 = p1->next; 188 xfree(p1->prev); 189 } 190 retp->next = p2; 191 p2->prev = retp; 192 return (retp); 193 } 194 195 #define P_HERE 1 196 #define P_IN 2 197 #define P_OUT 4 198 #define P_DIAG 8 199 200 /* 201 * syntax 202 * empty 203 * syn0 204 */ 205 struct command * 206 syntax(const struct wordent *p1, const struct wordent *p2, int flags) 207 { 208 209 while (p1 != p2) 210 if (any(";&\n", p1->word[0])) 211 p1 = p1->next; 212 else 213 return (syn0(p1, p2, flags)); 214 return (0); 215 } 216 217 /* 218 * syn0 219 * syn1 220 * syn1 & syntax 221 */ 222 static struct command * 223 syn0(const struct wordent *p1, const struct wordent *p2, int flags) 224 { 225 const struct wordent *p; 226 struct command *t, *t1; 227 int l; 228 229 l = 0; 230 for (p = p1; p != p2; p = p->next) 231 switch (p->word[0]) { 232 233 case '(': 234 l++; 235 continue; 236 237 case ')': 238 l--; 239 if (l < 0) 240 seterror(ERR_TOOMANYRP); 241 continue; 242 243 case '|': 244 if (p->word[1] == '|') 245 continue; 246 /*FALLTHROUGH*/ 247 248 case '>': 249 if (p->next != p2 && eq(p->next->word, STRand)) 250 p = p->next; 251 continue; 252 253 case '&': 254 if (l != 0) 255 break; 256 if (p->word[1] == '&') 257 continue; 258 t1 = syn1(p1, p, flags); 259 if (t1->t_dtyp == NODE_LIST || 260 t1->t_dtyp == NODE_AND || 261 t1->t_dtyp == NODE_OR) { 262 t = xcalloc(1, sizeof(*t)); 263 t->t_dtyp = NODE_PAREN; 264 t->t_dflg = F_AMPERSAND | F_NOINTERRUPT; 265 t->t_dspr = t1; 266 t1 = t; 267 } 268 else 269 t1->t_dflg |= F_AMPERSAND | F_NOINTERRUPT; 270 t = xcalloc(1, sizeof(*t)); 271 t->t_dtyp = NODE_LIST; 272 t->t_dflg = 0; 273 t->t_dcar = t1; 274 t->t_dcdr = syntax(p, p2, flags); 275 return (t); 276 default: 277 break; 278 } 279 if (l == 0) 280 return (syn1(p1, p2, flags)); 281 seterror(ERR_TOOMANYLP); 282 return (0); 283 } 284 285 /* 286 * syn1 287 * syn1a 288 * syn1a ; syntax 289 */ 290 static struct command * 291 syn1(const struct wordent *p1, const struct wordent *p2, int flags) 292 { 293 const struct wordent *p; 294 struct command *t; 295 int l; 296 297 l = 0; 298 for (p = p1; p != p2; p = p->next) 299 switch (p->word[0]) { 300 301 case '(': 302 l++; 303 continue; 304 305 case ')': 306 l--; 307 continue; 308 309 case ';': 310 case '\n': 311 if (l != 0) 312 break; 313 t = xcalloc(1, sizeof(*t)); 314 t->t_dtyp = NODE_LIST; 315 t->t_dcar = syn1a(p1, p, flags); 316 t->t_dcdr = syntax(p->next, p2, flags); 317 if (t->t_dcdr == 0) 318 t->t_dcdr = t->t_dcar, t->t_dcar = 0; 319 return (t); 320 321 default: 322 break; 323 } 324 return (syn1a(p1, p2, flags)); 325 } 326 327 /* 328 * syn1a 329 * syn1b 330 * syn1b || syn1a 331 */ 332 static struct command * 333 syn1a(const struct wordent *p1, const struct wordent *p2, int flags) 334 { 335 const struct wordent *p; 336 struct command *t; 337 int l = 0; 338 339 for (p = p1; p != p2; p = p->next) 340 switch (p->word[0]) { 341 342 case '(': 343 l++; 344 continue; 345 346 case ')': 347 l--; 348 continue; 349 350 case '|': 351 if (p->word[1] != '|') 352 continue; 353 if (l == 0) { 354 t = xcalloc(1, sizeof(*t)); 355 t->t_dtyp = NODE_OR; 356 t->t_dcar = syn1b(p1, p, flags); 357 t->t_dcdr = syn1a(p->next, p2, flags); 358 t->t_dflg = 0; 359 return (t); 360 } 361 continue; 362 363 default: 364 break; 365 } 366 return (syn1b(p1, p2, flags)); 367 } 368 369 /* 370 * syn1b 371 * syn2 372 * syn2 && syn1b 373 */ 374 static struct command * 375 syn1b(const struct wordent *p1, const struct wordent *p2, int flags) 376 { 377 const struct wordent *p; 378 struct command *t; 379 int l = 0; 380 381 for (p = p1; p != p2; p = p->next) 382 switch (p->word[0]) { 383 384 case '(': 385 l++; 386 continue; 387 388 case ')': 389 l--; 390 continue; 391 392 case '&': 393 if (p->word[1] == '&' && l == 0) { 394 t = xcalloc(1, sizeof(*t)); 395 t->t_dtyp = NODE_AND; 396 t->t_dcar = syn2(p1, p, flags); 397 t->t_dcdr = syn1b(p->next, p2, flags); 398 t->t_dflg = 0; 399 return (t); 400 } 401 continue; 402 403 default: 404 break; 405 } 406 return (syn2(p1, p2, flags)); 407 } 408 409 /* 410 * syn2 411 * syn3 412 * syn3 | syn2 413 * syn3 |& syn2 414 */ 415 static struct command * 416 syn2(const struct wordent *p1, const struct wordent *p2, int flags) 417 { 418 const struct wordent *p, *pn; 419 struct command *t; 420 int l = 0; 421 int f; 422 423 for (p = p1; p != p2; p = p->next) 424 switch (p->word[0]) { 425 426 case '(': 427 l++; 428 continue; 429 430 case ')': 431 l--; 432 continue; 433 434 case '|': 435 if (l != 0) 436 continue; 437 t = xcalloc(1, sizeof(*t)); 438 f = flags | P_OUT; 439 pn = p->next; 440 if (pn != p2 && pn->word[0] == '&') { 441 f |= P_DIAG; 442 t->t_dflg |= F_STDERR; 443 } 444 t->t_dtyp = NODE_PIPE; 445 t->t_dcar = syn3(p1, p, f); 446 if (pn != p2 && pn->word[0] == '&') 447 p = pn; 448 t->t_dcdr = syn2(p->next, p2, flags | P_IN); 449 return (t); 450 451 default: 452 break; 453 } 454 return (syn3(p1, p2, flags)); 455 } 456 457 static const char RELPAR[] = {'<', '>', '(', ')', '\0'}; 458 459 /* 460 * syn3 461 * ( syn0 ) [ < in ] [ > out ] 462 * word word* [ < in ] [ > out ] 463 * KEYWORD ( word* ) word* [ < in ] [ > out ] 464 * 465 * KEYWORD = (@ exit foreach if set switch test while) 466 */ 467 static struct command * 468 syn3(const struct wordent *p1, const struct wordent *p2, int flags) 469 { 470 const struct wordent *p; 471 const struct wordent *lp, *rp; 472 struct command *t; 473 int l; 474 Char **av; 475 int n, c; 476 int specp = 0; 477 478 if (p1 != p2) { 479 p = p1; 480 again: 481 switch (srchx(p->word)) { 482 483 case TC_ELSE: 484 p = p->next; 485 if (p != p2) 486 goto again; 487 break; 488 489 case TC_EXIT: 490 case TC_FOREACH: 491 case TC_IF: 492 case TC_LET: 493 case TC_SET: 494 case TC_SWITCH: 495 case TC_WHILE: 496 specp = 1; 497 break; 498 default: 499 break; 500 } 501 } 502 n = 0; 503 l = 0; 504 for (p = p1; p != p2; p = p->next) 505 switch (p->word[0]) { 506 507 case '(': 508 if (specp) 509 n++; 510 l++; 511 continue; 512 513 case ')': 514 if (specp) 515 n++; 516 l--; 517 continue; 518 519 case '>': 520 case '<': 521 if (l != 0) { 522 if (specp) 523 n++; 524 continue; 525 } 526 if (p->next == p2) 527 continue; 528 if (any(RELPAR, p->next->word[0])) 529 continue; 530 n--; 531 continue; 532 533 default: 534 if (!specp && l != 0) 535 continue; 536 n++; 537 continue; 538 } 539 if (n < 0) 540 n = 0; 541 t = xcalloc(1, sizeof(*t)); 542 av = xcalloc(n + 1, sizeof(Char **)); 543 t->t_dcom = av; 544 n = 0; 545 if (p2->word[0] == ')') 546 t->t_dflg = F_NOFORK; 547 lp = 0; 548 rp = 0; 549 l = 0; 550 for (p = p1; p != p2; p = p->next) { 551 c = p->word[0]; 552 switch (c) { 553 554 case '(': 555 if (l == 0) { 556 if (lp != 0 && !specp) 557 seterror(ERR_BADPLP); 558 lp = p->next; 559 } 560 l++; 561 goto savep; 562 563 case ')': 564 l--; 565 if (l == 0) 566 rp = p; 567 goto savep; 568 569 case '>': 570 if (l != 0) 571 goto savep; 572 if (p->word[1] == '>') 573 t->t_dflg |= F_APPEND; 574 if (p->next != p2 && eq(p->next->word, STRand)) { 575 t->t_dflg |= F_STDERR, p = p->next; 576 if (flags & (P_OUT | P_DIAG)) { 577 seterror(ERR_OUTRED); 578 continue; 579 } 580 } 581 if (p->next != p2 && eq(p->next->word, STRbang)) 582 t->t_dflg |= F_OVERWRITE, p = p->next; 583 if (p->next == p2) { 584 seterror(ERR_MISRED); 585 continue; 586 } 587 p = p->next; 588 if (any(RELPAR, p->word[0])) { 589 seterror(ERR_MISRED); 590 continue; 591 } 592 if (((flags & P_OUT) && (flags & P_DIAG) == 0) || t->t_drit) 593 seterror(ERR_OUTRED); 594 else 595 t->t_drit = Strsave(p->word); 596 continue; 597 598 case '<': 599 if (l != 0) 600 goto savep; 601 if (p->word[1] == '<') 602 t->t_dflg |= F_READ; 603 if (p->next == p2) { 604 seterror(ERR_MISRED); 605 continue; 606 } 607 p = p->next; 608 if (any(RELPAR, p->word[0])) { 609 seterror(ERR_MISRED); 610 continue; 611 } 612 if ((flags & P_HERE) && (t->t_dflg & F_READ)) 613 seterror(ERR_REDPAR); 614 else if ((flags & P_IN) || t->t_dlef) 615 seterror(ERR_INRED); 616 else 617 t->t_dlef = Strsave(p->word); 618 continue; 619 620 savep: 621 if (!specp) 622 continue; 623 /* FALLTHROUGH */ 624 default: 625 if (l != 0 && !specp) 626 continue; 627 if (seterr == 0) 628 av[n] = Strsave(p->word); 629 n++; 630 continue; 631 } 632 } 633 if (lp != 0 && !specp) { 634 if (n != 0) 635 seterror(ERR_BADPLPS); 636 t->t_dtyp = NODE_PAREN; 637 t->t_dspr = syn0(lp, rp, P_HERE); 638 } 639 else { 640 if (n == 0) 641 seterror(ERR_NULLCOM); 642 t->t_dtyp = NODE_COMMAND; 643 } 644 return (t); 645 } 646 647 void 648 freesyn(struct command *t) 649 { 650 Char **v; 651 652 if (t == 0) 653 return; 654 switch (t->t_dtyp) { 655 656 case NODE_COMMAND: 657 for (v = t->t_dcom; *v; v++) 658 xfree(*v); 659 xfree(t->t_dcom); 660 xfree(t->t_dlef); 661 xfree(t->t_drit); 662 break; 663 case NODE_PAREN: 664 freesyn(t->t_dspr); 665 xfree(t->t_dlef); 666 xfree(t->t_drit); 667 break; 668 669 case NODE_AND: 670 case NODE_OR: 671 case NODE_PIPE: 672 case NODE_LIST: 673 freesyn(t->t_dcar), freesyn(t->t_dcdr); 674 break; 675 default: 676 break; 677 } 678 #ifdef DEBUG 679 memset(t, 0, sizeof(*t)); 680 #endif 681 xfree(t); 682 } 683 684 void 685 syntax_cleanup(void *xt) 686 { 687 struct command *t; 688 689 t = xt; 690 freesyn(t); 691 } 692