1 /* $NetBSD: expand.c,v 1.57 2003/08/07 09:05:32 agc Exp $ */ 2 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 #include <sys/cdefs.h> 36 #ifndef lint 37 #if 0 38 static char sccsid[] = "@(#)expand.c 8.5 (Berkeley) 5/15/95"; 39 #else 40 __RCSID("$NetBSD: expand.c,v 1.57 2003/08/07 09:05:32 agc Exp $"); 41 #endif 42 #endif /* not lint */ 43 44 #include <sys/types.h> 45 #include <sys/time.h> 46 #include <sys/stat.h> 47 #include <errno.h> 48 #include <dirent.h> 49 #include <unistd.h> 50 #include <pwd.h> 51 #include <stdlib.h> 52 #include <stdio.h> 53 54 /* 55 * Routines to expand arguments to commands. We have to deal with 56 * backquotes, shell variables, and file metacharacters. 57 */ 58 59 #include "shell.h" 60 #include "main.h" 61 #include "nodes.h" 62 #include "eval.h" 63 #include "expand.h" 64 #include "syntax.h" 65 #include "parser.h" 66 #include "jobs.h" 67 #include "options.h" 68 #include "var.h" 69 #include "input.h" 70 #include "output.h" 71 #include "memalloc.h" 72 #include "error.h" 73 #include "mystring.h" 74 #include "show.h" 75 76 /* 77 * Structure specifying which parts of the string should be searched 78 * for IFS characters. 79 */ 80 81 struct ifsregion { 82 struct ifsregion *next; /* next region in list */ 83 int begoff; /* offset of start of region */ 84 int endoff; /* offset of end of region */ 85 int nulonly; /* search for nul bytes only */ 86 }; 87 88 89 char *expdest; /* output of current string */ 90 struct nodelist *argbackq; /* list of back quote expressions */ 91 struct ifsregion ifsfirst; /* first struct in list of ifs regions */ 92 struct ifsregion *ifslastp; /* last struct in list */ 93 struct arglist exparg; /* holds expanded arg list */ 94 95 STATIC void argstr(char *, int); 96 STATIC char *exptilde(char *, int); 97 STATIC void expbackq(union node *, int, int); 98 STATIC int subevalvar(char *, char *, int, int, int, int); 99 STATIC char *evalvar(char *, int); 100 STATIC int varisset(char *, int); 101 STATIC void varvalue(char *, int, int); 102 STATIC void recordregion(int, int, int); 103 STATIC void removerecordregions(int); 104 STATIC void ifsbreakup(char *, struct arglist *); 105 STATIC void ifsfree(void); 106 STATIC void expandmeta(struct strlist *, int); 107 STATIC void expmeta(char *, char *); 108 STATIC void addfname(char *); 109 STATIC struct strlist *expsort(struct strlist *); 110 STATIC struct strlist *msort(struct strlist *, int); 111 STATIC int pmatch(char *, char *, int); 112 STATIC char *cvtnum(int, char *); 113 114 /* 115 * Expand shell variables and backquotes inside a here document. 116 */ 117 118 void 119 expandhere(union node *arg, int fd) 120 { 121 herefd = fd; 122 expandarg(arg, (struct arglist *)NULL, 0); 123 xwrite(fd, stackblock(), expdest - stackblock()); 124 } 125 126 127 /* 128 * Perform variable substitution and command substitution on an argument, 129 * placing the resulting list of arguments in arglist. If EXP_FULL is true, 130 * perform splitting and file name expansion. When arglist is NULL, perform 131 * here document expansion. 132 */ 133 134 void 135 expandarg(union node *arg, struct arglist *arglist, int flag) 136 { 137 struct strlist *sp; 138 char *p; 139 140 argbackq = arg->narg.backquote; 141 STARTSTACKSTR(expdest); 142 ifsfirst.next = NULL; 143 ifslastp = NULL; 144 argstr(arg->narg.text, flag); 145 if (arglist == NULL) { 146 return; /* here document expanded */ 147 } 148 STPUTC('\0', expdest); 149 p = grabstackstr(expdest); 150 exparg.lastp = &exparg.list; 151 /* 152 * TODO - EXP_REDIR 153 */ 154 if (flag & EXP_FULL) { 155 ifsbreakup(p, &exparg); 156 *exparg.lastp = NULL; 157 exparg.lastp = &exparg.list; 158 expandmeta(exparg.list, flag); 159 } else { 160 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */ 161 rmescapes(p); 162 sp = (struct strlist *)stalloc(sizeof (struct strlist)); 163 sp->text = p; 164 *exparg.lastp = sp; 165 exparg.lastp = &sp->next; 166 } 167 ifsfree(); 168 *exparg.lastp = NULL; 169 if (exparg.list) { 170 *arglist->lastp = exparg.list; 171 arglist->lastp = exparg.lastp; 172 } 173 } 174 175 176 177 /* 178 * Perform variable and command substitution. If EXP_FULL is set, output CTLESC 179 * characters to allow for further processing. Otherwise treat 180 * $@ like $* since no splitting will be performed. 181 */ 182 183 STATIC void 184 argstr(char *p, int flag) 185 { 186 char c; 187 int quotes = flag & (EXP_FULL | EXP_CASE); /* do CTLESC */ 188 int firsteq = 1; 189 190 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE))) 191 p = exptilde(p, flag); 192 for (;;) { 193 switch (c = *p++) { 194 case '\0': 195 case CTLENDVAR: /* ??? */ 196 goto breakloop; 197 case CTLQUOTEMARK: 198 /* "$@" syntax adherence hack */ 199 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=') 200 break; 201 if ((flag & EXP_FULL) != 0) 202 STPUTC(c, expdest); 203 break; 204 case CTLESC: 205 if (quotes) 206 STPUTC(c, expdest); 207 c = *p++; 208 STPUTC(c, expdest); 209 break; 210 case CTLVAR: 211 p = evalvar(p, flag); 212 break; 213 case CTLBACKQ: 214 case CTLBACKQ|CTLQUOTE: 215 expbackq(argbackq->n, c & CTLQUOTE, flag); 216 argbackq = argbackq->next; 217 break; 218 case CTLENDARI: 219 expari(flag); 220 break; 221 case ':': 222 case '=': 223 /* 224 * sort of a hack - expand tildes in variable 225 * assignments (after the first '=' and after ':'s). 226 */ 227 STPUTC(c, expdest); 228 if (flag & EXP_VARTILDE && *p == '~') { 229 if (c == '=') { 230 if (firsteq) 231 firsteq = 0; 232 else 233 break; 234 } 235 p = exptilde(p, flag); 236 } 237 break; 238 default: 239 STPUTC(c, expdest); 240 } 241 } 242 breakloop:; 243 return; 244 } 245 246 STATIC char * 247 exptilde(char *p, int flag) 248 { 249 char c, *startp = p; 250 struct passwd *pw; 251 const char *home; 252 int quotes = flag & (EXP_FULL | EXP_CASE); 253 254 while ((c = *p) != '\0') { 255 switch(c) { 256 case CTLESC: 257 return (startp); 258 case CTLQUOTEMARK: 259 return (startp); 260 case ':': 261 if (flag & EXP_VARTILDE) 262 goto done; 263 break; 264 case '/': 265 goto done; 266 } 267 p++; 268 } 269 done: 270 *p = '\0'; 271 if (*(startp+1) == '\0') { 272 if ((home = lookupvar("HOME")) == NULL) 273 goto lose; 274 } else { 275 if ((pw = getpwnam(startp+1)) == NULL) 276 goto lose; 277 home = pw->pw_dir; 278 } 279 if (*home == '\0') 280 goto lose; 281 *p = c; 282 while ((c = *home++) != '\0') { 283 if (quotes && SQSYNTAX[(int)c] == CCTL) 284 STPUTC(CTLESC, expdest); 285 STPUTC(c, expdest); 286 } 287 return (p); 288 lose: 289 *p = c; 290 return (startp); 291 } 292 293 294 STATIC void 295 removerecordregions(int endoff) 296 { 297 if (ifslastp == NULL) 298 return; 299 300 if (ifsfirst.endoff > endoff) { 301 while (ifsfirst.next != NULL) { 302 struct ifsregion *ifsp; 303 INTOFF; 304 ifsp = ifsfirst.next->next; 305 ckfree(ifsfirst.next); 306 ifsfirst.next = ifsp; 307 INTON; 308 } 309 if (ifsfirst.begoff > endoff) 310 ifslastp = NULL; 311 else { 312 ifslastp = &ifsfirst; 313 ifsfirst.endoff = endoff; 314 } 315 return; 316 } 317 318 ifslastp = &ifsfirst; 319 while (ifslastp->next && ifslastp->next->begoff < endoff) 320 ifslastp=ifslastp->next; 321 while (ifslastp->next != NULL) { 322 struct ifsregion *ifsp; 323 INTOFF; 324 ifsp = ifslastp->next->next; 325 ckfree(ifslastp->next); 326 ifslastp->next = ifsp; 327 INTON; 328 } 329 if (ifslastp->endoff > endoff) 330 ifslastp->endoff = endoff; 331 } 332 333 334 /* 335 * Expand arithmetic expression. Backup to start of expression, 336 * evaluate, place result in (backed up) result, adjust string position. 337 */ 338 void 339 expari(int flag) 340 { 341 char *p, *start; 342 int result; 343 int begoff; 344 int quotes = flag & (EXP_FULL | EXP_CASE); 345 int quoted; 346 347 /* ifsfree(); */ 348 349 /* 350 * This routine is slightly over-complicated for 351 * efficiency. First we make sure there is 352 * enough space for the result, which may be bigger 353 * than the expression if we add exponentation. Next we 354 * scan backwards looking for the start of arithmetic. If the 355 * next previous character is a CTLESC character, then we 356 * have to rescan starting from the beginning since CTLESC 357 * characters have to be processed left to right. 358 */ 359 #if INT_MAX / 1000000000 >= 10 || INT_MIN / 1000000000 <= -10 360 #error "integers with more than 10 digits are not supported" 361 #endif 362 CHECKSTRSPACE(12 - 2, expdest); 363 USTPUTC('\0', expdest); 364 start = stackblock(); 365 p = expdest - 1; 366 while (*p != CTLARI && p >= start) 367 --p; 368 if (*p != CTLARI) 369 error("missing CTLARI (shouldn't happen)"); 370 if (p > start && *(p-1) == CTLESC) 371 for (p = start; *p != CTLARI; p++) 372 if (*p == CTLESC) 373 p++; 374 375 if (p[1] == '"') 376 quoted=1; 377 else 378 quoted=0; 379 begoff = p - start; 380 removerecordregions(begoff); 381 if (quotes) 382 rmescapes(p+2); 383 result = arith(p+2); 384 fmtstr(p, 12, "%d", result); 385 386 while (*p++) 387 ; 388 389 if (quoted == 0) 390 recordregion(begoff, p - 1 - start, 0); 391 result = expdest - p + 1; 392 STADJUST(-result, expdest); 393 } 394 395 396 /* 397 * Expand stuff in backwards quotes. 398 */ 399 400 STATIC void 401 expbackq(union node *cmd, int quoted, int flag) 402 { 403 struct backcmd in; 404 int i; 405 char buf[128]; 406 char *p; 407 char *dest = expdest; 408 struct ifsregion saveifs, *savelastp; 409 struct nodelist *saveargbackq; 410 char lastc; 411 int startloc = dest - stackblock(); 412 char const *syntax = quoted? DQSYNTAX : BASESYNTAX; 413 int saveherefd; 414 int quotes = flag & (EXP_FULL | EXP_CASE); 415 416 INTOFF; 417 saveifs = ifsfirst; 418 savelastp = ifslastp; 419 saveargbackq = argbackq; 420 saveherefd = herefd; 421 herefd = -1; 422 p = grabstackstr(dest); 423 evalbackcmd(cmd, &in); 424 ungrabstackstr(p, dest); 425 ifsfirst = saveifs; 426 ifslastp = savelastp; 427 argbackq = saveargbackq; 428 herefd = saveherefd; 429 430 p = in.buf; 431 lastc = '\0'; 432 for (;;) { 433 if (--in.nleft < 0) { 434 if (in.fd < 0) 435 break; 436 while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR); 437 TRACE(("expbackq: read returns %d\n", i)); 438 if (i <= 0) 439 break; 440 p = buf; 441 in.nleft = i - 1; 442 } 443 lastc = *p++; 444 if (lastc != '\0') { 445 if (quotes && syntax[(int)lastc] == CCTL) 446 STPUTC(CTLESC, dest); 447 STPUTC(lastc, dest); 448 } 449 } 450 451 /* Eat all trailing newlines */ 452 for (p--; lastc == '\n'; lastc = *--p) 453 STUNPUTC(dest); 454 455 if (in.fd >= 0) 456 close(in.fd); 457 if (in.buf) 458 ckfree(in.buf); 459 if (in.jp) 460 back_exitstatus = waitforjob(in.jp); 461 if (quoted == 0) 462 recordregion(startloc, dest - stackblock(), 0); 463 TRACE(("evalbackq: size=%d: \"%.*s\"\n", 464 (dest - stackblock()) - startloc, 465 (dest - stackblock()) - startloc, 466 stackblock() + startloc)); 467 expdest = dest; 468 INTON; 469 } 470 471 472 473 STATIC int 474 subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varflags) 475 { 476 char *startp; 477 char *loc = NULL; 478 char *q; 479 int c = 0; 480 int saveherefd = herefd; 481 struct nodelist *saveargbackq = argbackq; 482 int amount; 483 484 herefd = -1; 485 argstr(p, 0); 486 STACKSTRNUL(expdest); 487 herefd = saveherefd; 488 argbackq = saveargbackq; 489 startp = stackblock() + startloc; 490 if (str == NULL) 491 str = stackblock() + strloc; 492 493 switch (subtype) { 494 case VSASSIGN: 495 setvar(str, startp, 0); 496 amount = startp - expdest; 497 STADJUST(amount, expdest); 498 varflags &= ~VSNUL; 499 if (c != 0) 500 *loc = c; 501 return 1; 502 503 case VSQUESTION: 504 if (*p != CTLENDVAR) { 505 outfmt(&errout, "%s\n", startp); 506 error((char *)NULL); 507 } 508 error("%.*s: parameter %snot set", p - str - 1, 509 str, (varflags & VSNUL) ? "null or " 510 : nullstr); 511 /* NOTREACHED */ 512 513 case VSTRIMLEFT: 514 for (loc = startp; loc < str; loc++) { 515 c = *loc; 516 *loc = '\0'; 517 if (patmatch(str, startp, varflags & VSQUOTE)) 518 goto recordleft; 519 *loc = c; 520 if ((varflags & VSQUOTE) && *loc == CTLESC) 521 loc++; 522 } 523 return 0; 524 525 case VSTRIMLEFTMAX: 526 for (loc = str - 1; loc >= startp;) { 527 c = *loc; 528 *loc = '\0'; 529 if (patmatch(str, startp, varflags & VSQUOTE)) 530 goto recordleft; 531 *loc = c; 532 loc--; 533 if ((varflags & VSQUOTE) && loc > startp && 534 *(loc - 1) == CTLESC) { 535 for (q = startp; q < loc; q++) 536 if (*q == CTLESC) 537 q++; 538 if (q > loc) 539 loc--; 540 } 541 } 542 return 0; 543 544 case VSTRIMRIGHT: 545 for (loc = str - 1; loc >= startp;) { 546 if (patmatch(str, loc, varflags & VSQUOTE)) 547 goto recordright; 548 loc--; 549 if ((varflags & VSQUOTE) && loc > startp && 550 *(loc - 1) == CTLESC) { 551 for (q = startp; q < loc; q++) 552 if (*q == CTLESC) 553 q++; 554 if (q > loc) 555 loc--; 556 } 557 } 558 return 0; 559 560 case VSTRIMRIGHTMAX: 561 for (loc = startp; loc < str - 1; loc++) { 562 if (patmatch(str, loc, varflags & VSQUOTE)) 563 goto recordright; 564 if ((varflags & VSQUOTE) && *loc == CTLESC) 565 loc++; 566 } 567 return 0; 568 569 default: 570 abort(); 571 } 572 573 recordleft: 574 *loc = c; 575 amount = ((str - 1) - (loc - startp)) - expdest; 576 STADJUST(amount, expdest); 577 while (loc != str - 1) 578 *startp++ = *loc++; 579 return 1; 580 581 recordright: 582 amount = loc - expdest; 583 STADJUST(amount, expdest); 584 STPUTC('\0', expdest); 585 STADJUST(-1, expdest); 586 return 1; 587 } 588 589 590 /* 591 * Expand a variable, and return a pointer to the next character in the 592 * input string. 593 */ 594 595 STATIC char * 596 evalvar(char *p, int flag) 597 { 598 int subtype; 599 int varflags; 600 char *var; 601 char *val; 602 int patloc; 603 int c; 604 int set; 605 int special; 606 int startloc; 607 int varlen; 608 int easy; 609 int quotes = flag & (EXP_FULL | EXP_CASE); 610 611 varflags = *p++; 612 subtype = varflags & VSTYPE; 613 var = p; 614 special = 0; 615 if (! is_name(*p)) 616 special = 1; 617 p = strchr(p, '=') + 1; 618 again: /* jump here after setting a variable with ${var=text} */ 619 if (special) { 620 set = varisset(var, varflags & VSNUL); 621 val = NULL; 622 } else { 623 val = lookupvar(var); 624 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) { 625 val = NULL; 626 set = 0; 627 } else 628 set = 1; 629 } 630 varlen = 0; 631 startloc = expdest - stackblock(); 632 if (!set && uflag) 633 switch (subtype) { 634 case VSNORMAL: 635 case VSTRIMLEFT: 636 case VSTRIMLEFTMAX: 637 case VSTRIMRIGHT: 638 case VSTRIMRIGHTMAX: 639 case VSLENGTH: 640 error("%.*s: parameter not set", p - var - 1, var); 641 /* NOTREACHED */ 642 } 643 if (set && subtype != VSPLUS) { 644 /* insert the value of the variable */ 645 if (special) { 646 varvalue(var, varflags & VSQUOTE, flag & EXP_FULL); 647 if (subtype == VSLENGTH) { 648 varlen = expdest - stackblock() - startloc; 649 STADJUST(-varlen, expdest); 650 } 651 } else { 652 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX 653 : BASESYNTAX; 654 655 if (subtype == VSLENGTH) { 656 for (;*val; val++) 657 varlen++; 658 } 659 else { 660 while (*val) { 661 if (quotes && syntax[(int)*val] == CCTL) 662 STPUTC(CTLESC, expdest); 663 STPUTC(*val++, expdest); 664 } 665 666 } 667 } 668 } 669 670 if (subtype == VSPLUS) 671 set = ! set; 672 673 easy = ((varflags & VSQUOTE) == 0 || 674 (*var == '@' && shellparam.nparam != 1)); 675 676 677 switch (subtype) { 678 case VSLENGTH: 679 expdest = cvtnum(varlen, expdest); 680 goto record; 681 682 case VSNORMAL: 683 if (!easy) 684 break; 685 record: 686 recordregion(startloc, expdest - stackblock(), 687 varflags & VSQUOTE); 688 break; 689 690 case VSPLUS: 691 case VSMINUS: 692 if (!set) { 693 argstr(p, flag); 694 break; 695 } 696 if (easy) 697 goto record; 698 break; 699 700 case VSTRIMLEFT: 701 case VSTRIMLEFTMAX: 702 case VSTRIMRIGHT: 703 case VSTRIMRIGHTMAX: 704 if (!set) 705 break; 706 /* 707 * Terminate the string and start recording the pattern 708 * right after it 709 */ 710 STPUTC('\0', expdest); 711 patloc = expdest - stackblock(); 712 if (subevalvar(p, NULL, patloc, subtype, 713 startloc, varflags) == 0) { 714 int amount = (expdest - stackblock() - patloc) + 1; 715 STADJUST(-amount, expdest); 716 } 717 /* Remove any recorded regions beyond start of variable */ 718 removerecordregions(startloc); 719 goto record; 720 721 case VSASSIGN: 722 case VSQUESTION: 723 if (!set) { 724 if (subevalvar(p, var, 0, subtype, startloc, 725 varflags)) { 726 varflags &= ~VSNUL; 727 /* 728 * Remove any recorded regions beyond 729 * start of variable 730 */ 731 removerecordregions(startloc); 732 goto again; 733 } 734 break; 735 } 736 if (easy) 737 goto record; 738 break; 739 740 default: 741 abort(); 742 } 743 744 if (subtype != VSNORMAL) { /* skip to end of alternative */ 745 int nesting = 1; 746 for (;;) { 747 if ((c = *p++) == CTLESC) 748 p++; 749 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) { 750 if (set) 751 argbackq = argbackq->next; 752 } else if (c == CTLVAR) { 753 if ((*p++ & VSTYPE) != VSNORMAL) 754 nesting++; 755 } else if (c == CTLENDVAR) { 756 if (--nesting == 0) 757 break; 758 } 759 } 760 } 761 return p; 762 } 763 764 765 766 /* 767 * Test whether a specialized variable is set. 768 */ 769 770 STATIC int 771 varisset(char *name, int nulok) 772 { 773 if (*name == '!') 774 return backgndpid != -1; 775 else if (*name == '@' || *name == '*') { 776 if (*shellparam.p == NULL) 777 return 0; 778 779 if (nulok) { 780 char **av; 781 782 for (av = shellparam.p; *av; av++) 783 if (**av != '\0') 784 return 1; 785 return 0; 786 } 787 } else if (is_digit(*name)) { 788 char *ap; 789 int num = atoi(name); 790 791 if (num > shellparam.nparam) 792 return 0; 793 794 if (num == 0) 795 ap = arg0; 796 else 797 ap = shellparam.p[num - 1]; 798 799 if (nulok && (ap == NULL || *ap == '\0')) 800 return 0; 801 } 802 return 1; 803 } 804 805 806 807 /* 808 * Add the value of a specialized variable to the stack string. 809 */ 810 811 STATIC void 812 varvalue(char *name, int quoted, int allow_split) 813 { 814 int num; 815 char *p; 816 int i; 817 char sep; 818 char **ap; 819 char const *syntax; 820 821 #define STRTODEST(p) \ 822 do {\ 823 if (allow_split) { \ 824 syntax = quoted? DQSYNTAX : BASESYNTAX; \ 825 while (*p) { \ 826 if (syntax[(int)*p] == CCTL) \ 827 STPUTC(CTLESC, expdest); \ 828 STPUTC(*p++, expdest); \ 829 } \ 830 } else \ 831 while (*p) \ 832 STPUTC(*p++, expdest); \ 833 } while (0) 834 835 836 switch (*name) { 837 case '$': 838 num = rootpid; 839 goto numvar; 840 case '?': 841 num = exitstatus; 842 goto numvar; 843 case '#': 844 num = shellparam.nparam; 845 goto numvar; 846 case '!': 847 num = backgndpid; 848 numvar: 849 expdest = cvtnum(num, expdest); 850 break; 851 case '-': 852 for (i = 0; optlist[i].name; i++) { 853 if (optlist[i].val) 854 STPUTC(optlist[i].letter, expdest); 855 } 856 break; 857 case '@': 858 if (allow_split && quoted) { 859 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 860 STRTODEST(p); 861 if (*ap) 862 STPUTC('\0', expdest); 863 } 864 break; 865 } 866 /* fall through */ 867 case '*': 868 if (ifsset() != 0) 869 sep = ifsval()[0]; 870 else 871 sep = ' '; 872 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 873 STRTODEST(p); 874 if (*ap && sep) 875 STPUTC(sep, expdest); 876 } 877 break; 878 case '0': 879 p = arg0; 880 STRTODEST(p); 881 break; 882 default: 883 if (is_digit(*name)) { 884 num = atoi(name); 885 if (num > 0 && num <= shellparam.nparam) { 886 p = shellparam.p[num - 1]; 887 STRTODEST(p); 888 } 889 } 890 break; 891 } 892 } 893 894 895 896 /* 897 * Record the fact that we have to scan this region of the 898 * string for IFS characters. 899 */ 900 901 STATIC void 902 recordregion(int start, int end, int nulonly) 903 { 904 struct ifsregion *ifsp; 905 906 if (ifslastp == NULL) { 907 ifsp = &ifsfirst; 908 } else { 909 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion)); 910 ifslastp->next = ifsp; 911 } 912 ifslastp = ifsp; 913 ifslastp->next = NULL; 914 ifslastp->begoff = start; 915 ifslastp->endoff = end; 916 ifslastp->nulonly = nulonly; 917 } 918 919 920 921 /* 922 * Break the argument string into pieces based upon IFS and add the 923 * strings to the argument list. The regions of the string to be 924 * searched for IFS characters have been stored by recordregion. 925 */ 926 STATIC void 927 ifsbreakup(char *string, struct arglist *arglist) 928 { 929 struct ifsregion *ifsp; 930 struct strlist *sp; 931 char *start; 932 char *p; 933 char *q; 934 const char *ifs; 935 int ifsspc; 936 int nulonly; 937 938 939 start = string; 940 ifsspc = 0; 941 nulonly = 0; 942 if (ifslastp != NULL) { 943 ifsp = &ifsfirst; 944 do { 945 p = string + ifsp->begoff; 946 nulonly = ifsp->nulonly; 947 ifs = nulonly ? nullstr : 948 ( ifsset() ? ifsval() : " \t\n" ); 949 ifsspc = 0; 950 while (p < string + ifsp->endoff) { 951 q = p; 952 if (*p == CTLESC) 953 p++; 954 if (strchr(ifs, *p)) { 955 if (!nulonly) 956 ifsspc = (strchr(" \t\n", *p) != NULL); 957 /* Ignore IFS whitespace at start */ 958 if (q == start && ifsspc) { 959 p++; 960 start = p; 961 continue; 962 } 963 *q = '\0'; 964 sp = (struct strlist *)stalloc(sizeof *sp); 965 sp->text = start; 966 *arglist->lastp = sp; 967 arglist->lastp = &sp->next; 968 p++; 969 if (!nulonly) { 970 for (;;) { 971 if (p >= string + ifsp->endoff) { 972 break; 973 } 974 q = p; 975 if (*p == CTLESC) 976 p++; 977 if (strchr(ifs, *p) == NULL ) { 978 p = q; 979 break; 980 } else if (strchr(" \t\n",*p) == NULL) { 981 if (ifsspc) { 982 p++; 983 ifsspc = 0; 984 } else { 985 p = q; 986 break; 987 } 988 } else 989 p++; 990 } 991 } 992 start = p; 993 } else 994 p++; 995 } 996 } while ((ifsp = ifsp->next) != NULL); 997 if (*start || (!ifsspc && start > string && 998 (nulonly || 1))) { 999 sp = (struct strlist *)stalloc(sizeof *sp); 1000 sp->text = start; 1001 *arglist->lastp = sp; 1002 arglist->lastp = &sp->next; 1003 } 1004 } else { 1005 sp = (struct strlist *)stalloc(sizeof *sp); 1006 sp->text = start; 1007 *arglist->lastp = sp; 1008 arglist->lastp = &sp->next; 1009 } 1010 } 1011 1012 STATIC void 1013 ifsfree(void) 1014 { 1015 while (ifsfirst.next != NULL) { 1016 struct ifsregion *ifsp; 1017 INTOFF; 1018 ifsp = ifsfirst.next->next; 1019 ckfree(ifsfirst.next); 1020 ifsfirst.next = ifsp; 1021 INTON; 1022 } 1023 ifslastp = NULL; 1024 ifsfirst.next = NULL; 1025 } 1026 1027 1028 1029 /* 1030 * Expand shell metacharacters. At this point, the only control characters 1031 * should be escapes. The results are stored in the list exparg. 1032 */ 1033 1034 char *expdir; 1035 1036 1037 STATIC void 1038 expandmeta(struct strlist *str, int flag) 1039 { 1040 char *p; 1041 struct strlist **savelastp; 1042 struct strlist *sp; 1043 char c; 1044 /* TODO - EXP_REDIR */ 1045 1046 while (str) { 1047 if (fflag) 1048 goto nometa; 1049 p = str->text; 1050 for (;;) { /* fast check for meta chars */ 1051 if ((c = *p++) == '\0') 1052 goto nometa; 1053 if (c == '*' || c == '?' || c == '[' || c == '!') 1054 break; 1055 } 1056 savelastp = exparg.lastp; 1057 INTOFF; 1058 if (expdir == NULL) { 1059 int i = strlen(str->text); 1060 expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */ 1061 } 1062 1063 expmeta(expdir, str->text); 1064 ckfree(expdir); 1065 expdir = NULL; 1066 INTON; 1067 if (exparg.lastp == savelastp) { 1068 /* 1069 * no matches 1070 */ 1071 nometa: 1072 *exparg.lastp = str; 1073 rmescapes(str->text); 1074 exparg.lastp = &str->next; 1075 } else { 1076 *exparg.lastp = NULL; 1077 *savelastp = sp = expsort(*savelastp); 1078 while (sp->next != NULL) 1079 sp = sp->next; 1080 exparg.lastp = &sp->next; 1081 } 1082 str = str->next; 1083 } 1084 } 1085 1086 1087 /* 1088 * Do metacharacter (i.e. *, ?, [...]) expansion. 1089 */ 1090 1091 STATIC void 1092 expmeta(char *enddir, char *name) 1093 { 1094 char *p; 1095 const char *cp; 1096 char *q; 1097 char *start; 1098 char *endname; 1099 int metaflag; 1100 struct stat statb; 1101 DIR *dirp; 1102 struct dirent *dp; 1103 int atend; 1104 int matchdot; 1105 1106 metaflag = 0; 1107 start = name; 1108 for (p = name ; ; p++) { 1109 if (*p == '*' || *p == '?') 1110 metaflag = 1; 1111 else if (*p == '[') { 1112 q = p + 1; 1113 if (*q == '!') 1114 q++; 1115 for (;;) { 1116 while (*q == CTLQUOTEMARK) 1117 q++; 1118 if (*q == CTLESC) 1119 q++; 1120 if (*q == '/' || *q == '\0') 1121 break; 1122 if (*++q == ']') { 1123 metaflag = 1; 1124 break; 1125 } 1126 } 1127 } else if (*p == '!' && p[1] == '!' && (p == name || p[-1] == '/')) { 1128 metaflag = 1; 1129 } else if (*p == '\0') 1130 break; 1131 else if (*p == CTLQUOTEMARK) 1132 continue; 1133 else if (*p == CTLESC) 1134 p++; 1135 if (*p == '/') { 1136 if (metaflag) 1137 break; 1138 start = p + 1; 1139 } 1140 } 1141 if (metaflag == 0) { /* we've reached the end of the file name */ 1142 if (enddir != expdir) 1143 metaflag++; 1144 for (p = name ; ; p++) { 1145 if (*p == CTLQUOTEMARK) 1146 continue; 1147 if (*p == CTLESC) 1148 p++; 1149 *enddir++ = *p; 1150 if (*p == '\0') 1151 break; 1152 } 1153 if (metaflag == 0 || lstat(expdir, &statb) >= 0) 1154 addfname(expdir); 1155 return; 1156 } 1157 endname = p; 1158 if (start != name) { 1159 p = name; 1160 while (p < start) { 1161 while (*p == CTLQUOTEMARK) 1162 p++; 1163 if (*p == CTLESC) 1164 p++; 1165 *enddir++ = *p++; 1166 } 1167 } 1168 if (enddir == expdir) { 1169 cp = "."; 1170 } else if (enddir == expdir + 1 && *expdir == '/') { 1171 cp = "/"; 1172 } else { 1173 cp = expdir; 1174 enddir[-1] = '\0'; 1175 } 1176 if ((dirp = opendir(cp)) == NULL) 1177 return; 1178 if (enddir != expdir) 1179 enddir[-1] = '/'; 1180 if (*endname == 0) { 1181 atend = 1; 1182 } else { 1183 atend = 0; 1184 *endname++ = '\0'; 1185 } 1186 matchdot = 0; 1187 p = start; 1188 while (*p == CTLQUOTEMARK) 1189 p++; 1190 if (*p == CTLESC) 1191 p++; 1192 if (*p == '.') 1193 matchdot++; 1194 while (! int_pending() && (dp = readdir(dirp)) != NULL) { 1195 if (dp->d_name[0] == '.' && ! matchdot) 1196 continue; 1197 if (patmatch(start, dp->d_name, 0)) { 1198 if (atend) { 1199 scopy(dp->d_name, enddir); 1200 addfname(expdir); 1201 } else { 1202 for (p = enddir, cp = dp->d_name; 1203 (*p++ = *cp++) != '\0';) 1204 continue; 1205 p[-1] = '/'; 1206 expmeta(p, endname); 1207 } 1208 } 1209 } 1210 closedir(dirp); 1211 if (! atend) 1212 endname[-1] = '/'; 1213 } 1214 1215 1216 /* 1217 * Add a file name to the list. 1218 */ 1219 1220 STATIC void 1221 addfname(char *name) 1222 { 1223 char *p; 1224 struct strlist *sp; 1225 1226 p = stalloc(strlen(name) + 1); 1227 scopy(name, p); 1228 sp = (struct strlist *)stalloc(sizeof *sp); 1229 sp->text = p; 1230 *exparg.lastp = sp; 1231 exparg.lastp = &sp->next; 1232 } 1233 1234 1235 /* 1236 * Sort the results of file name expansion. It calculates the number of 1237 * strings to sort and then calls msort (short for merge sort) to do the 1238 * work. 1239 */ 1240 1241 STATIC struct strlist * 1242 expsort(struct strlist *str) 1243 { 1244 int len; 1245 struct strlist *sp; 1246 1247 len = 0; 1248 for (sp = str ; sp ; sp = sp->next) 1249 len++; 1250 return msort(str, len); 1251 } 1252 1253 1254 STATIC struct strlist * 1255 msort(struct strlist *list, int len) 1256 { 1257 struct strlist *p, *q = NULL; 1258 struct strlist **lpp; 1259 int half; 1260 int n; 1261 1262 if (len <= 1) 1263 return list; 1264 half = len >> 1; 1265 p = list; 1266 for (n = half ; --n >= 0 ; ) { 1267 q = p; 1268 p = p->next; 1269 } 1270 q->next = NULL; /* terminate first half of list */ 1271 q = msort(list, half); /* sort first half of list */ 1272 p = msort(p, len - half); /* sort second half */ 1273 lpp = &list; 1274 for (;;) { 1275 if (strcmp(p->text, q->text) < 0) { 1276 *lpp = p; 1277 lpp = &p->next; 1278 if ((p = *lpp) == NULL) { 1279 *lpp = q; 1280 break; 1281 } 1282 } else { 1283 *lpp = q; 1284 lpp = &q->next; 1285 if ((q = *lpp) == NULL) { 1286 *lpp = p; 1287 break; 1288 } 1289 } 1290 } 1291 return list; 1292 } 1293 1294 1295 1296 /* 1297 * Returns true if the pattern matches the string. 1298 */ 1299 1300 int 1301 patmatch(char *pattern, char *string, int squoted) 1302 { 1303 #ifdef notdef 1304 if (pattern[0] == '!' && pattern[1] == '!') 1305 return 1 - pmatch(pattern + 2, string); 1306 else 1307 #endif 1308 return pmatch(pattern, string, squoted); 1309 } 1310 1311 1312 STATIC int 1313 pmatch(char *pattern, char *string, int squoted) 1314 { 1315 char *p, *q; 1316 char c; 1317 1318 p = pattern; 1319 q = string; 1320 for (;;) { 1321 switch (c = *p++) { 1322 case '\0': 1323 goto breakloop; 1324 case CTLESC: 1325 if (squoted && *q == CTLESC) 1326 q++; 1327 if (*q++ != *p++) 1328 return 0; 1329 break; 1330 case CTLQUOTEMARK: 1331 continue; 1332 case '?': 1333 if (squoted && *q == CTLESC) 1334 q++; 1335 if (*q++ == '\0') 1336 return 0; 1337 break; 1338 case '*': 1339 c = *p; 1340 while (c == CTLQUOTEMARK || c == '*') 1341 c = *++p; 1342 if (c != CTLESC && c != CTLQUOTEMARK && 1343 c != '?' && c != '*' && c != '[') { 1344 while (*q != c) { 1345 if (squoted && *q == CTLESC && 1346 q[1] == c) 1347 break; 1348 if (*q == '\0') 1349 return 0; 1350 if (squoted && *q == CTLESC) 1351 q++; 1352 q++; 1353 } 1354 } 1355 do { 1356 if (pmatch(p, q, squoted)) 1357 return 1; 1358 if (squoted && *q == CTLESC) 1359 q++; 1360 } while (*q++ != '\0'); 1361 return 0; 1362 case '[': { 1363 char *endp; 1364 int invert, found; 1365 char chr; 1366 1367 endp = p; 1368 if (*endp == '!') 1369 endp++; 1370 for (;;) { 1371 while (*endp == CTLQUOTEMARK) 1372 endp++; 1373 if (*endp == '\0') 1374 goto dft; /* no matching ] */ 1375 if (*endp == CTLESC) 1376 endp++; 1377 if (*++endp == ']') 1378 break; 1379 } 1380 invert = 0; 1381 if (*p == '!') { 1382 invert++; 1383 p++; 1384 } 1385 found = 0; 1386 chr = *q++; 1387 if (squoted && chr == CTLESC) 1388 chr = *q++; 1389 if (chr == '\0') 1390 return 0; 1391 c = *p++; 1392 do { 1393 if (c == CTLQUOTEMARK) 1394 continue; 1395 if (c == CTLESC) 1396 c = *p++; 1397 if (*p == '-' && p[1] != ']') { 1398 p++; 1399 while (*p == CTLQUOTEMARK) 1400 p++; 1401 if (*p == CTLESC) 1402 p++; 1403 if (chr >= c && chr <= *p) 1404 found = 1; 1405 p++; 1406 } else { 1407 if (chr == c) 1408 found = 1; 1409 } 1410 } while ((c = *p++) != ']'); 1411 if (found == invert) 1412 return 0; 1413 break; 1414 } 1415 dft: default: 1416 if (squoted && *q == CTLESC) 1417 q++; 1418 if (*q++ != c) 1419 return 0; 1420 break; 1421 } 1422 } 1423 breakloop: 1424 if (*q != '\0') 1425 return 0; 1426 return 1; 1427 } 1428 1429 1430 1431 /* 1432 * Remove any CTLESC characters from a string. 1433 */ 1434 1435 void 1436 rmescapes(char *str) 1437 { 1438 char *p, *q; 1439 1440 p = str; 1441 while (*p != CTLESC && *p != CTLQUOTEMARK) { 1442 if (*p++ == '\0') 1443 return; 1444 } 1445 q = p; 1446 while (*p) { 1447 if (*p == CTLQUOTEMARK) { 1448 p++; 1449 continue; 1450 } 1451 if (*p == CTLESC) 1452 p++; 1453 *q++ = *p++; 1454 } 1455 *q = '\0'; 1456 } 1457 1458 1459 1460 /* 1461 * See if a pattern matches in a case statement. 1462 */ 1463 1464 int 1465 casematch(union node *pattern, char *val) 1466 { 1467 struct stackmark smark; 1468 int result; 1469 char *p; 1470 1471 setstackmark(&smark); 1472 argbackq = pattern->narg.backquote; 1473 STARTSTACKSTR(expdest); 1474 ifslastp = NULL; 1475 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE); 1476 STPUTC('\0', expdest); 1477 p = grabstackstr(expdest); 1478 result = patmatch(p, val, 0); 1479 popstackmark(&smark); 1480 return result; 1481 } 1482 1483 /* 1484 * Our own itoa(). 1485 */ 1486 1487 STATIC char * 1488 cvtnum(int num, char *buf) 1489 { 1490 char temp[32]; 1491 int neg = num < 0; 1492 char *p = temp + 31; 1493 1494 temp[31] = '\0'; 1495 1496 do { 1497 *--p = num % 10 + '0'; 1498 } while ((num /= 10) != 0); 1499 1500 if (neg) 1501 *--p = '-'; 1502 1503 while (*p) 1504 STPUTC(*p++, buf); 1505 return buf; 1506 } 1507