1 /*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kenneth Almquist. 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. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #ifndef lint 38 #if 0 39 static char sccsid[] = "@(#)expand.c 8.5 (Berkeley) 5/15/95"; 40 #endif 41 static const char rcsid[] = 42 "$FreeBSD$"; 43 #endif /* not lint */ 44 45 #include <sys/types.h> 46 #include <sys/time.h> 47 #include <sys/stat.h> 48 #include <errno.h> 49 #include <dirent.h> 50 #include <unistd.h> 51 #include <pwd.h> 52 #include <stdlib.h> 53 #include <limits.h> 54 #include <stdio.h> 55 56 /* 57 * Routines to expand arguments to commands. We have to deal with 58 * backquotes, shell variables, and file metacharacters. 59 */ 60 61 #include "shell.h" 62 #include "main.h" 63 #include "nodes.h" 64 #include "eval.h" 65 #include "expand.h" 66 #include "syntax.h" 67 #include "parser.h" 68 #include "jobs.h" 69 #include "options.h" 70 #include "var.h" 71 #include "input.h" 72 #include "output.h" 73 #include "memalloc.h" 74 #include "error.h" 75 #include "mystring.h" 76 #include "arith.h" 77 #include "show.h" 78 79 /* 80 * Structure specifying which parts of the string should be searched 81 * for IFS characters. 82 */ 83 84 struct ifsregion { 85 struct ifsregion *next; /* next region in list */ 86 int begoff; /* offset of start of region */ 87 int endoff; /* offset of end of region */ 88 int nulonly; /* search for nul bytes only */ 89 }; 90 91 92 char *expdest; /* output of current string */ 93 struct nodelist *argbackq; /* list of back quote expressions */ 94 struct ifsregion ifsfirst; /* first struct in list of ifs regions */ 95 struct ifsregion *ifslastp; /* last struct in list */ 96 struct arglist exparg; /* holds expanded arg list */ 97 98 STATIC void argstr(char *, int); 99 STATIC char *exptilde(char *, int); 100 STATIC void expbackq(union node *, int, int); 101 STATIC int subevalvar(char *, char *, int, int, int, int); 102 STATIC char *evalvar(char *, int); 103 STATIC int varisset(char *, int); 104 STATIC void varvalue(char *, int, int); 105 STATIC void recordregion(int, int, int); 106 STATIC void removerecordregions(int); 107 STATIC void ifsbreakup(char *, struct arglist *); 108 STATIC void expandmeta(struct strlist *, int); 109 STATIC void expmeta(char *, char *); 110 STATIC void addfname(char *); 111 STATIC struct strlist *expsort(struct strlist *); 112 STATIC struct strlist *msort(struct strlist *, int); 113 STATIC int pmatch(char *, char *, int); 114 STATIC char *cvtnum(int, char *); 115 STATIC int collate_range_cmp(int, int); 116 117 STATIC int 118 collate_range_cmp (int c1, int c2) 119 { 120 static char s1[2], s2[2]; 121 int ret; 122 123 c1 &= UCHAR_MAX; 124 c2 &= UCHAR_MAX; 125 if (c1 == c2) 126 return (0); 127 s1[0] = c1; 128 s2[0] = c2; 129 if ((ret = strcoll(s1, s2)) != 0) 130 return (ret); 131 return (c1 - c2); 132 } 133 134 /* 135 * Expand shell variables and backquotes inside a here document. 136 * union node *arg the document 137 * int fd; where to write the expanded version 138 */ 139 140 void 141 expandhere(union node *arg, int fd) 142 { 143 herefd = fd; 144 expandarg(arg, (struct arglist *)NULL, 0); 145 xwrite(fd, stackblock(), expdest - stackblock()); 146 } 147 148 149 /* 150 * Perform variable substitution and command substitution on an argument, 151 * placing the resulting list of arguments in arglist. If EXP_FULL is true, 152 * perform splitting and file name expansion. When arglist is NULL, perform 153 * here document expansion. 154 */ 155 156 void 157 expandarg(union node *arg, struct arglist *arglist, int flag) 158 { 159 struct strlist *sp; 160 char *p; 161 162 argbackq = arg->narg.backquote; 163 STARTSTACKSTR(expdest); 164 ifsfirst.next = NULL; 165 ifslastp = NULL; 166 argstr(arg->narg.text, flag); 167 if (arglist == NULL) { 168 return; /* here document expanded */ 169 } 170 STPUTC('\0', expdest); 171 p = grabstackstr(expdest); 172 exparg.lastp = &exparg.list; 173 /* 174 * TODO - EXP_REDIR 175 */ 176 if (flag & EXP_FULL) { 177 ifsbreakup(p, &exparg); 178 *exparg.lastp = NULL; 179 exparg.lastp = &exparg.list; 180 expandmeta(exparg.list, flag); 181 } else { 182 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */ 183 rmescapes(p); 184 sp = (struct strlist *)stalloc(sizeof (struct strlist)); 185 sp->text = p; 186 *exparg.lastp = sp; 187 exparg.lastp = &sp->next; 188 } 189 while (ifsfirst.next != NULL) { 190 struct ifsregion *ifsp; 191 INTOFF; 192 ifsp = ifsfirst.next->next; 193 ckfree(ifsfirst.next); 194 ifsfirst.next = ifsp; 195 INTON; 196 } 197 *exparg.lastp = NULL; 198 if (exparg.list) { 199 *arglist->lastp = exparg.list; 200 arglist->lastp = exparg.lastp; 201 } 202 } 203 204 205 206 /* 207 * Perform variable and command substitution. If EXP_FULL is set, output CTLESC 208 * characters to allow for further processing. Otherwise treat 209 * $@ like $* since no splitting will be performed. 210 */ 211 212 STATIC void 213 argstr(char *p, int flag) 214 { 215 char c; 216 int quotes = flag & (EXP_FULL | EXP_CASE); /* do CTLESC */ 217 int firsteq = 1; 218 219 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE))) 220 p = exptilde(p, flag); 221 for (;;) { 222 switch (c = *p++) { 223 case '\0': 224 case CTLENDVAR: /* ??? */ 225 goto breakloop; 226 case CTLQUOTEMARK: 227 /* "$@" syntax adherence hack */ 228 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=') 229 break; 230 if ((flag & EXP_FULL) != 0) 231 STPUTC(c, expdest); 232 break; 233 case CTLESC: 234 if (quotes) 235 STPUTC(c, expdest); 236 c = *p++; 237 STPUTC(c, expdest); 238 break; 239 case CTLVAR: 240 p = evalvar(p, flag); 241 break; 242 case CTLBACKQ: 243 case CTLBACKQ|CTLQUOTE: 244 expbackq(argbackq->n, c & CTLQUOTE, flag); 245 argbackq = argbackq->next; 246 break; 247 case CTLENDARI: 248 expari(flag); 249 break; 250 case ':': 251 case '=': 252 /* 253 * sort of a hack - expand tildes in variable 254 * assignments (after the first '=' and after ':'s). 255 */ 256 STPUTC(c, expdest); 257 if (flag & EXP_VARTILDE && *p == '~') { 258 if (c == '=') { 259 if (firsteq) 260 firsteq = 0; 261 else 262 break; 263 } 264 p = exptilde(p, flag); 265 } 266 break; 267 default: 268 STPUTC(c, expdest); 269 } 270 } 271 breakloop:; 272 } 273 274 STATIC char * 275 exptilde(char *p, int flag) 276 { 277 char c, *startp = p; 278 struct passwd *pw; 279 char *home; 280 int quotes = flag & (EXP_FULL | EXP_CASE); 281 282 while ((c = *p) != '\0') { 283 switch(c) { 284 case CTLESC: 285 return (startp); 286 case CTLQUOTEMARK: 287 return (startp); 288 case ':': 289 if (flag & EXP_VARTILDE) 290 goto done; 291 break; 292 case '/': 293 goto done; 294 } 295 p++; 296 } 297 done: 298 *p = '\0'; 299 if (*(startp+1) == '\0') { 300 if ((home = lookupvar("HOME")) == NULL) 301 goto lose; 302 } else { 303 if ((pw = getpwnam(startp+1)) == NULL) 304 goto lose; 305 home = pw->pw_dir; 306 } 307 if (*home == '\0') 308 goto lose; 309 *p = c; 310 while ((c = *home++) != '\0') { 311 if (quotes && SQSYNTAX[(int)c] == CCTL) 312 STPUTC(CTLESC, expdest); 313 STPUTC(c, expdest); 314 } 315 return (p); 316 lose: 317 *p = c; 318 return (startp); 319 } 320 321 322 STATIC void 323 removerecordregions(int endoff) 324 { 325 if (ifslastp == NULL) 326 return; 327 328 if (ifsfirst.endoff > endoff) { 329 while (ifsfirst.next != NULL) { 330 struct ifsregion *ifsp; 331 INTOFF; 332 ifsp = ifsfirst.next->next; 333 ckfree(ifsfirst.next); 334 ifsfirst.next = ifsp; 335 INTON; 336 } 337 if (ifsfirst.begoff > endoff) 338 ifslastp = NULL; 339 else { 340 ifslastp = &ifsfirst; 341 ifsfirst.endoff = endoff; 342 } 343 return; 344 } 345 346 ifslastp = &ifsfirst; 347 while (ifslastp->next && ifslastp->next->begoff < endoff) 348 ifslastp=ifslastp->next; 349 while (ifslastp->next != NULL) { 350 struct ifsregion *ifsp; 351 INTOFF; 352 ifsp = ifslastp->next->next; 353 ckfree(ifslastp->next); 354 ifslastp->next = ifsp; 355 INTON; 356 } 357 if (ifslastp->endoff > endoff) 358 ifslastp->endoff = endoff; 359 } 360 361 /* 362 * Expand arithmetic expression. Backup to start of expression, 363 * evaluate, place result in (backed up) result, adjust string position. 364 */ 365 void 366 expari(int flag) 367 { 368 char *p, *start; 369 int result; 370 int begoff; 371 int quotes = flag & (EXP_FULL | EXP_CASE); 372 int quoted; 373 374 375 /* 376 * This routine is slightly over-complicated for 377 * efficiency. First we make sure there is 378 * enough space for the result, which may be bigger 379 * than the expression if we add exponentiation. Next we 380 * scan backwards looking for the start of arithmetic. If the 381 * next previous character is a CTLESC character, then we 382 * have to rescan starting from the beginning since CTLESC 383 * characters have to be processed left to right. 384 */ 385 #if INT_MAX / 1000000000 >= 10 || INT_MIN / 1000000000 <= -10 386 #error "integers with more than 10 digits are not supported" 387 #endif 388 CHECKSTRSPACE(12 - 2, expdest); 389 USTPUTC('\0', expdest); 390 start = stackblock(); 391 p = expdest - 2; 392 while (p >= start && *p != CTLARI) 393 --p; 394 if (p < start || *p != CTLARI) 395 error("missing CTLARI (shouldn't happen)"); 396 if (p > start && *(p - 1) == CTLESC) 397 for (p = start; *p != CTLARI; p++) 398 if (*p == CTLESC) 399 p++; 400 401 if (p[1] == '"') 402 quoted=1; 403 else 404 quoted=0; 405 begoff = p - start; 406 removerecordregions(begoff); 407 if (quotes) 408 rmescapes(p+2); 409 result = arith(p+2); 410 fmtstr(p, 12, "%d", result); 411 while (*p++) 412 ; 413 if (quoted == 0) 414 recordregion(begoff, p - 1 - start, 0); 415 result = expdest - p + 1; 416 STADJUST(-result, expdest); 417 } 418 419 420 /* 421 * Expand stuff in backwards quotes. 422 */ 423 424 STATIC void 425 expbackq(union node *cmd, int quoted, int flag) 426 { 427 struct backcmd in; 428 int i; 429 char buf[128]; 430 char *p; 431 char *dest = expdest; 432 struct ifsregion saveifs, *savelastp; 433 struct nodelist *saveargbackq; 434 char lastc; 435 int startloc = dest - stackblock(); 436 char const *syntax = quoted? DQSYNTAX : BASESYNTAX; 437 int saveherefd; 438 int quotes = flag & (EXP_FULL | EXP_CASE); 439 440 INTOFF; 441 saveifs = ifsfirst; 442 savelastp = ifslastp; 443 saveargbackq = argbackq; 444 saveherefd = herefd; 445 herefd = -1; 446 p = grabstackstr(dest); 447 evalbackcmd(cmd, &in); 448 ungrabstackstr(p, dest); 449 ifsfirst = saveifs; 450 ifslastp = savelastp; 451 argbackq = saveargbackq; 452 herefd = saveherefd; 453 454 p = in.buf; 455 lastc = '\0'; 456 for (;;) { 457 if (--in.nleft < 0) { 458 if (in.fd < 0) 459 break; 460 while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR); 461 TRACE(("expbackq: read returns %d\n", i)); 462 if (i <= 0) 463 break; 464 p = buf; 465 in.nleft = i - 1; 466 } 467 lastc = *p++; 468 if (lastc != '\0') { 469 if (quotes && syntax[(int)lastc] == CCTL) 470 STPUTC(CTLESC, dest); 471 STPUTC(lastc, dest); 472 } 473 } 474 475 /* Eat all trailing newlines */ 476 for (p--; lastc == '\n'; lastc = *--p) 477 STUNPUTC(dest); 478 479 if (in.fd >= 0) 480 close(in.fd); 481 if (in.buf) 482 ckfree(in.buf); 483 if (in.jp) 484 exitstatus = waitforjob(in.jp, (int *)NULL); 485 if (quoted == 0) 486 recordregion(startloc, dest - stackblock(), 0); 487 TRACE(("evalbackq: size=%d: \"%.*s\"\n", 488 (dest - stackblock()) - startloc, 489 (dest - stackblock()) - startloc, 490 stackblock() + startloc)); 491 expdest = dest; 492 INTON; 493 } 494 495 496 497 STATIC int 498 subevalvar(char *p, char *str, int strloc, int subtype, int startloc, 499 int varflags) 500 { 501 char *startp; 502 char *loc = NULL; 503 char *q; 504 int c = 0; 505 int saveherefd = herefd; 506 struct nodelist *saveargbackq = argbackq; 507 int amount; 508 509 herefd = -1; 510 argstr(p, 0); 511 STACKSTRNUL(expdest); 512 herefd = saveherefd; 513 argbackq = saveargbackq; 514 startp = stackblock() + startloc; 515 if (str == NULL) 516 str = stackblock() + strloc; 517 518 switch (subtype) { 519 case VSASSIGN: 520 setvar(str, startp, 0); 521 amount = startp - expdest; 522 STADJUST(amount, expdest); 523 varflags &= ~VSNUL; 524 if (c != 0) 525 *loc = c; 526 return 1; 527 528 case VSQUESTION: 529 if (*p != CTLENDVAR) { 530 outfmt(&errout, "%s\n", startp); 531 error((char *)NULL); 532 } 533 error("%.*s: parameter %snot set", p - str - 1, 534 str, (varflags & VSNUL) ? "null or " 535 : nullstr); 536 return 0; 537 538 case VSTRIMLEFT: 539 for (loc = startp; loc < str; loc++) { 540 c = *loc; 541 *loc = '\0'; 542 if (patmatch(str, startp, varflags & VSQUOTE)) { 543 *loc = c; 544 goto recordleft; 545 } 546 *loc = c; 547 if ((varflags & VSQUOTE) && *loc == CTLESC) 548 loc++; 549 } 550 return 0; 551 552 case VSTRIMLEFTMAX: 553 for (loc = str - 1; loc >= startp;) { 554 c = *loc; 555 *loc = '\0'; 556 if (patmatch(str, startp, varflags & VSQUOTE)) { 557 *loc = c; 558 goto recordleft; 559 } 560 *loc = c; 561 loc--; 562 if ((varflags & VSQUOTE) && loc > startp && 563 *(loc - 1) == CTLESC) { 564 for (q = startp; q < loc; q++) 565 if (*q == CTLESC) 566 q++; 567 if (q > loc) 568 loc--; 569 } 570 } 571 return 0; 572 573 case VSTRIMRIGHT: 574 for (loc = str - 1; loc >= startp;) { 575 if (patmatch(str, loc, varflags & VSQUOTE)) { 576 amount = loc - expdest; 577 STADJUST(amount, expdest); 578 return 1; 579 } 580 loc--; 581 if ((varflags & VSQUOTE) && loc > startp && 582 *(loc - 1) == CTLESC) { 583 for (q = startp; q < loc; q++) 584 if (*q == CTLESC) 585 q++; 586 if (q > loc) 587 loc--; 588 } 589 } 590 return 0; 591 592 case VSTRIMRIGHTMAX: 593 for (loc = startp; loc < str - 1; loc++) { 594 if (patmatch(str, loc, varflags & VSQUOTE)) { 595 amount = loc - expdest; 596 STADJUST(amount, expdest); 597 return 1; 598 } 599 if ((varflags & VSQUOTE) && *loc == CTLESC) 600 loc++; 601 } 602 return 0; 603 604 605 default: 606 abort(); 607 } 608 609 recordleft: 610 amount = ((str - 1) - (loc - startp)) - expdest; 611 STADJUST(amount, expdest); 612 while (loc != str - 1) 613 *startp++ = *loc++; 614 return 1; 615 } 616 617 618 /* 619 * Expand a variable, and return a pointer to the next character in the 620 * input string. 621 */ 622 623 STATIC char * 624 evalvar(char *p, int flag) 625 { 626 int subtype; 627 int varflags; 628 char *var; 629 char *val; 630 int patloc; 631 int c; 632 int set; 633 int special; 634 int startloc; 635 int varlen; 636 int easy; 637 int quotes = flag & (EXP_FULL | EXP_CASE); 638 639 varflags = *p++; 640 subtype = varflags & VSTYPE; 641 var = p; 642 special = 0; 643 if (! is_name(*p)) 644 special = 1; 645 p = strchr(p, '=') + 1; 646 again: /* jump here after setting a variable with ${var=text} */ 647 if (special) { 648 set = varisset(var, varflags & VSNUL); 649 val = NULL; 650 } else { 651 val = bltinlookup(var, 1); 652 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) { 653 val = NULL; 654 set = 0; 655 } else 656 set = 1; 657 } 658 varlen = 0; 659 startloc = expdest - stackblock(); 660 if (set && subtype != VSPLUS) { 661 /* insert the value of the variable */ 662 if (special) { 663 varvalue(var, varflags & VSQUOTE, flag & EXP_FULL); 664 if (subtype == VSLENGTH) { 665 varlen = expdest - stackblock() - startloc; 666 STADJUST(-varlen, expdest); 667 } 668 } else { 669 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX 670 : BASESYNTAX; 671 672 if (subtype == VSLENGTH) { 673 for (;*val; val++) 674 varlen++; 675 } 676 else { 677 while (*val) { 678 if (quotes && 679 syntax[(int)*val] == CCTL) 680 STPUTC(CTLESC, expdest); 681 STPUTC(*val++, expdest); 682 } 683 684 } 685 } 686 } 687 688 if (subtype == VSPLUS) 689 set = ! set; 690 691 easy = ((varflags & VSQUOTE) == 0 || 692 (*var == '@' && shellparam.nparam != 1)); 693 694 695 switch (subtype) { 696 case VSLENGTH: 697 expdest = cvtnum(varlen, expdest); 698 goto record; 699 700 case VSNORMAL: 701 if (!easy) 702 break; 703 record: 704 recordregion(startloc, expdest - stackblock(), 705 varflags & VSQUOTE); 706 break; 707 708 case VSPLUS: 709 case VSMINUS: 710 if (!set) { 711 argstr(p, flag); 712 break; 713 } 714 if (easy) 715 goto record; 716 break; 717 718 case VSTRIMLEFT: 719 case VSTRIMLEFTMAX: 720 case VSTRIMRIGHT: 721 case VSTRIMRIGHTMAX: 722 if (!set) 723 break; 724 /* 725 * Terminate the string and start recording the pattern 726 * right after it 727 */ 728 STPUTC('\0', expdest); 729 patloc = expdest - stackblock(); 730 if (subevalvar(p, NULL, patloc, subtype, 731 startloc, varflags) == 0) { 732 int amount = (expdest - stackblock() - patloc) + 1; 733 STADJUST(-amount, expdest); 734 } 735 /* Remove any recorded regions beyond start of variable */ 736 removerecordregions(startloc); 737 goto record; 738 739 case VSASSIGN: 740 case VSQUESTION: 741 if (!set) { 742 if (subevalvar(p, var, 0, subtype, startloc, varflags)) { 743 varflags &= ~VSNUL; 744 /* 745 * Remove any recorded regions beyond 746 * start of variable 747 */ 748 removerecordregions(startloc); 749 goto again; 750 } 751 break; 752 } 753 if (easy) 754 goto record; 755 break; 756 757 default: 758 abort(); 759 } 760 761 if (subtype != VSNORMAL) { /* skip to end of alternative */ 762 int nesting = 1; 763 for (;;) { 764 if ((c = *p++) == CTLESC) 765 p++; 766 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) { 767 if (set) 768 argbackq = argbackq->next; 769 } else if (c == CTLVAR) { 770 if ((*p++ & VSTYPE) != VSNORMAL) 771 nesting++; 772 } else if (c == CTLENDVAR) { 773 if (--nesting == 0) 774 break; 775 } 776 } 777 } 778 return p; 779 } 780 781 782 783 /* 784 * Test whether a specialized variable is set. 785 */ 786 787 STATIC int 788 varisset(char *name, int nulok) 789 { 790 791 if (*name == '!') 792 return backgndpid != -1; 793 else if (*name == '@' || *name == '*') { 794 if (*shellparam.p == NULL) 795 return 0; 796 797 if (nulok) { 798 char **av; 799 800 for (av = shellparam.p; *av; av++) 801 if (**av != '\0') 802 return 1; 803 return 0; 804 } 805 } else if (is_digit(*name)) { 806 char *ap; 807 int num = atoi(name); 808 809 if (num > shellparam.nparam) 810 return 0; 811 812 if (num == 0) 813 ap = arg0; 814 else 815 ap = shellparam.p[num - 1]; 816 817 if (nulok && (ap == NULL || *ap == '\0')) 818 return 0; 819 } 820 return 1; 821 } 822 823 824 825 /* 826 * Add the value of a specialized variable to the stack string. 827 */ 828 829 STATIC void 830 varvalue(char *name, int quoted, int allow_split) 831 { 832 int num; 833 char *p; 834 int i; 835 extern int oexitstatus; 836 char sep; 837 char **ap; 838 char const *syntax; 839 840 #define STRTODEST(p) \ 841 do {\ 842 if (allow_split) { \ 843 syntax = quoted? DQSYNTAX : BASESYNTAX; \ 844 while (*p) { \ 845 if (syntax[(int)*p] == CCTL) \ 846 STPUTC(CTLESC, expdest); \ 847 STPUTC(*p++, expdest); \ 848 } \ 849 } else \ 850 while (*p) \ 851 STPUTC(*p++, expdest); \ 852 } while (0) 853 854 855 switch (*name) { 856 case '$': 857 num = rootpid; 858 goto numvar; 859 case '?': 860 num = oexitstatus; 861 goto numvar; 862 case '#': 863 num = shellparam.nparam; 864 goto numvar; 865 case '!': 866 num = backgndpid; 867 numvar: 868 expdest = cvtnum(num, expdest); 869 break; 870 case '-': 871 for (i = 0 ; i < NOPTS ; i++) { 872 if (optlist[i].val) 873 STPUTC(optlist[i].letter, expdest); 874 } 875 break; 876 case '@': 877 if (allow_split && quoted) { 878 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 879 STRTODEST(p); 880 if (*ap) 881 STPUTC('\0', expdest); 882 } 883 break; 884 } 885 /* fall through */ 886 case '*': 887 if (ifsset() != 0) 888 sep = ifsval()[0]; 889 else 890 sep = ' '; 891 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 892 STRTODEST(p); 893 if (*ap && sep) 894 STPUTC(sep, expdest); 895 } 896 break; 897 case '0': 898 p = arg0; 899 STRTODEST(p); 900 break; 901 default: 902 if (is_digit(*name)) { 903 num = atoi(name); 904 if (num > 0 && num <= shellparam.nparam) { 905 p = shellparam.p[num - 1]; 906 STRTODEST(p); 907 } 908 } 909 break; 910 } 911 } 912 913 914 915 /* 916 * Record the the fact that we have to scan this region of the 917 * string for IFS characters. 918 */ 919 920 STATIC void 921 recordregion(int start, int end, int nulonly) 922 { 923 struct ifsregion *ifsp; 924 925 if (ifslastp == NULL) { 926 ifsp = &ifsfirst; 927 } else { 928 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion)); 929 ifslastp->next = ifsp; 930 } 931 ifslastp = ifsp; 932 ifslastp->next = NULL; 933 ifslastp->begoff = start; 934 ifslastp->endoff = end; 935 ifslastp->nulonly = nulonly; 936 } 937 938 939 940 /* 941 * Break the argument string into pieces based upon IFS and add the 942 * strings to the argument list. The regions of the string to be 943 * searched for IFS characters have been stored by recordregion. 944 */ 945 STATIC void 946 ifsbreakup(char *string, struct arglist *arglist) 947 { 948 struct ifsregion *ifsp; 949 struct strlist *sp; 950 char *start; 951 char *p; 952 char *q; 953 char *ifs; 954 int ifsspc; 955 int nulonly; 956 957 958 start = string; 959 ifsspc = 0; 960 nulonly = 0; 961 if (ifslastp != NULL) { 962 ifsp = &ifsfirst; 963 do { 964 p = string + ifsp->begoff; 965 nulonly = ifsp->nulonly; 966 ifs = nulonly ? nullstr : 967 ( ifsset() ? ifsval() : " \t\n" ); 968 ifsspc = 0; 969 while (p < string + ifsp->endoff) { 970 q = p; 971 if (*p == CTLESC) 972 p++; 973 if (strchr(ifs, *p)) { 974 if (!nulonly) 975 ifsspc = (strchr(" \t\n", *p) != NULL); 976 /* Ignore IFS whitespace at start */ 977 if (q == start && ifsspc) { 978 p++; 979 start = p; 980 continue; 981 } 982 *q = '\0'; 983 sp = (struct strlist *)stalloc(sizeof *sp); 984 sp->text = start; 985 *arglist->lastp = sp; 986 arglist->lastp = &sp->next; 987 p++; 988 if (!nulonly) { 989 for (;;) { 990 if (p >= string + ifsp->endoff) { 991 break; 992 } 993 q = p; 994 if (*p == CTLESC) 995 p++; 996 if (strchr(ifs, *p) == NULL ) { 997 p = q; 998 break; 999 } else if (strchr(" \t\n",*p) == NULL) { 1000 if (ifsspc) { 1001 p++; 1002 ifsspc = 0; 1003 } else { 1004 p = q; 1005 break; 1006 } 1007 } else 1008 p++; 1009 } 1010 } 1011 start = p; 1012 } else 1013 p++; 1014 } 1015 } while ((ifsp = ifsp->next) != NULL); 1016 if (*start || (!ifsspc && start > string && 1017 (nulonly || 1))) { 1018 sp = (struct strlist *)stalloc(sizeof *sp); 1019 sp->text = start; 1020 *arglist->lastp = sp; 1021 arglist->lastp = &sp->next; 1022 } 1023 } else { 1024 sp = (struct strlist *)stalloc(sizeof *sp); 1025 sp->text = start; 1026 *arglist->lastp = sp; 1027 arglist->lastp = &sp->next; 1028 } 1029 } 1030 1031 1032 1033 /* 1034 * Expand shell metacharacters. At this point, the only control characters 1035 * should be escapes. The results are stored in the list exparg. 1036 */ 1037 1038 char *expdir; 1039 1040 1041 STATIC void 1042 expandmeta(struct strlist *str, int flag __unused) 1043 { 1044 char *p; 1045 struct strlist **savelastp; 1046 struct strlist *sp; 1047 char c; 1048 /* TODO - EXP_REDIR */ 1049 1050 while (str) { 1051 if (fflag) 1052 goto nometa; 1053 p = str->text; 1054 for (;;) { /* fast check for meta chars */ 1055 if ((c = *p++) == '\0') 1056 goto nometa; 1057 if (c == '*' || c == '?' || c == '[' || c == '!') 1058 break; 1059 } 1060 savelastp = exparg.lastp; 1061 INTOFF; 1062 if (expdir == NULL) { 1063 int i = strlen(str->text); 1064 expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */ 1065 } 1066 1067 expmeta(expdir, str->text); 1068 ckfree(expdir); 1069 expdir = NULL; 1070 INTON; 1071 if (exparg.lastp == savelastp) { 1072 /* 1073 * no matches 1074 */ 1075 nometa: 1076 *exparg.lastp = str; 1077 rmescapes(str->text); 1078 exparg.lastp = &str->next; 1079 } else { 1080 *exparg.lastp = NULL; 1081 *savelastp = sp = expsort(*savelastp); 1082 while (sp->next != NULL) 1083 sp = sp->next; 1084 exparg.lastp = &sp->next; 1085 } 1086 str = str->next; 1087 } 1088 } 1089 1090 1091 /* 1092 * Do metacharacter (i.e. *, ?, [...]) expansion. 1093 */ 1094 1095 STATIC void 1096 expmeta(char *enddir, char *name) 1097 { 1098 char *p; 1099 char *q; 1100 char *start; 1101 char *endname; 1102 int metaflag; 1103 struct stat statb; 1104 DIR *dirp; 1105 struct dirent *dp; 1106 int atend; 1107 int matchdot; 1108 1109 metaflag = 0; 1110 start = name; 1111 for (p = name ; ; p++) { 1112 if (*p == '*' || *p == '?') 1113 metaflag = 1; 1114 else if (*p == '[') { 1115 q = p + 1; 1116 if (*q == '!' || *q == '^') 1117 q++; 1118 for (;;) { 1119 while (*q == CTLQUOTEMARK) 1120 q++; 1121 if (*q == CTLESC) 1122 q++; 1123 if (*q == '/' || *q == '\0') 1124 break; 1125 if (*++q == ']') { 1126 metaflag = 1; 1127 break; 1128 } 1129 } 1130 } else if (*p == '!' && p[1] == '!' && (p == name || p[-1] == '/')) { 1131 metaflag = 1; 1132 } else if (*p == '\0') 1133 break; 1134 else if (*p == CTLQUOTEMARK) 1135 continue; 1136 else if (*p == CTLESC) 1137 p++; 1138 if (*p == '/') { 1139 if (metaflag) 1140 break; 1141 start = p + 1; 1142 } 1143 } 1144 if (metaflag == 0) { /* we've reached the end of the file name */ 1145 if (enddir != expdir) 1146 metaflag++; 1147 for (p = name ; ; p++) { 1148 if (*p == CTLQUOTEMARK) 1149 continue; 1150 if (*p == CTLESC) 1151 p++; 1152 *enddir++ = *p; 1153 if (*p == '\0') 1154 break; 1155 } 1156 if (metaflag == 0 || stat(expdir, &statb) >= 0) 1157 addfname(expdir); 1158 return; 1159 } 1160 endname = p; 1161 if (start != name) { 1162 p = name; 1163 while (p < start) { 1164 while (*p == CTLQUOTEMARK) 1165 p++; 1166 if (*p == CTLESC) 1167 p++; 1168 *enddir++ = *p++; 1169 } 1170 } 1171 if (enddir == expdir) { 1172 p = "."; 1173 } else if (enddir == expdir + 1 && *expdir == '/') { 1174 p = "/"; 1175 } else { 1176 p = expdir; 1177 enddir[-1] = '\0'; 1178 } 1179 if ((dirp = opendir(p)) == NULL) 1180 return; 1181 if (enddir != expdir) 1182 enddir[-1] = '/'; 1183 if (*endname == 0) { 1184 atend = 1; 1185 } else { 1186 atend = 0; 1187 *endname++ = '\0'; 1188 } 1189 matchdot = 0; 1190 p = start; 1191 while (*p == CTLQUOTEMARK) 1192 p++; 1193 if (*p == CTLESC) 1194 p++; 1195 if (*p == '.') 1196 matchdot++; 1197 while (! int_pending() && (dp = readdir(dirp)) != NULL) { 1198 if (dp->d_name[0] == '.' && ! matchdot) 1199 continue; 1200 if (patmatch(start, dp->d_name, 0)) { 1201 if (atend) { 1202 scopy(dp->d_name, enddir); 1203 addfname(expdir); 1204 } else { 1205 char *q; 1206 for (p = enddir, q = dp->d_name; 1207 (*p++ = *q++) != '\0';) 1208 continue; 1209 p[-1] = '/'; 1210 expmeta(p, endname); 1211 } 1212 } 1213 } 1214 closedir(dirp); 1215 if (! atend) 1216 endname[-1] = '/'; 1217 } 1218 1219 1220 /* 1221 * Add a file name to the list. 1222 */ 1223 1224 STATIC void 1225 addfname(char *name) 1226 { 1227 char *p; 1228 struct strlist *sp; 1229 1230 p = stalloc(strlen(name) + 1); 1231 scopy(name, p); 1232 sp = (struct strlist *)stalloc(sizeof *sp); 1233 sp->text = p; 1234 *exparg.lastp = sp; 1235 exparg.lastp = &sp->next; 1236 } 1237 1238 1239 /* 1240 * Sort the results of file name expansion. It calculates the number of 1241 * strings to sort and then calls msort (short for merge sort) to do the 1242 * work. 1243 */ 1244 1245 STATIC struct strlist * 1246 expsort(struct strlist *str) 1247 { 1248 int len; 1249 struct strlist *sp; 1250 1251 len = 0; 1252 for (sp = str ; sp ; sp = sp->next) 1253 len++; 1254 return msort(str, len); 1255 } 1256 1257 1258 STATIC struct strlist * 1259 msort(struct strlist *list, int len) 1260 { 1261 struct strlist *p, *q = NULL; 1262 struct strlist **lpp; 1263 int half; 1264 int n; 1265 1266 if (len <= 1) 1267 return list; 1268 half = len >> 1; 1269 p = list; 1270 for (n = half ; --n >= 0 ; ) { 1271 q = p; 1272 p = p->next; 1273 } 1274 q->next = NULL; /* terminate first half of list */ 1275 q = msort(list, half); /* sort first half of list */ 1276 p = msort(p, len - half); /* sort second half */ 1277 lpp = &list; 1278 for (;;) { 1279 if (strcmp(p->text, q->text) < 0) { 1280 *lpp = p; 1281 lpp = &p->next; 1282 if ((p = *lpp) == NULL) { 1283 *lpp = q; 1284 break; 1285 } 1286 } else { 1287 *lpp = q; 1288 lpp = &q->next; 1289 if ((q = *lpp) == NULL) { 1290 *lpp = p; 1291 break; 1292 } 1293 } 1294 } 1295 return list; 1296 } 1297 1298 1299 1300 /* 1301 * Returns true if the pattern matches the string. 1302 */ 1303 1304 int 1305 patmatch(char *pattern, char *string, int squoted) 1306 { 1307 #ifdef notdef 1308 if (pattern[0] == '!' && pattern[1] == '!') 1309 return 1 - pmatch(pattern + 2, string); 1310 else 1311 #endif 1312 return pmatch(pattern, string, squoted); 1313 } 1314 1315 1316 STATIC int 1317 pmatch(char *pattern, char *string, int squoted) 1318 { 1319 char *p, *q; 1320 char c; 1321 1322 p = pattern; 1323 q = string; 1324 for (;;) { 1325 switch (c = *p++) { 1326 case '\0': 1327 goto breakloop; 1328 case CTLESC: 1329 if (squoted && *q == CTLESC) 1330 q++; 1331 if (*q++ != *p++) 1332 return 0; 1333 break; 1334 case CTLQUOTEMARK: 1335 continue; 1336 case '?': 1337 if (squoted && *q == CTLESC) 1338 q++; 1339 if (*q++ == '\0') 1340 return 0; 1341 break; 1342 case '*': 1343 c = *p; 1344 while (c == CTLQUOTEMARK || c == '*') 1345 c = *++p; 1346 if (c != CTLESC && c != CTLQUOTEMARK && 1347 c != '?' && c != '*' && c != '[') { 1348 while (*q != c) { 1349 if (squoted && *q == CTLESC && 1350 q[1] == c) 1351 break; 1352 if (*q == '\0') 1353 return 0; 1354 if (squoted && *q == CTLESC) 1355 q++; 1356 q++; 1357 } 1358 } 1359 do { 1360 if (pmatch(p, q, squoted)) 1361 return 1; 1362 if (squoted && *q == CTLESC) 1363 q++; 1364 } while (*q++ != '\0'); 1365 return 0; 1366 case '[': { 1367 char *endp; 1368 int invert, found; 1369 char chr; 1370 1371 endp = p; 1372 if (*endp == '!' || *endp == '^') 1373 endp++; 1374 for (;;) { 1375 while (*endp == CTLQUOTEMARK) 1376 endp++; 1377 if (*endp == '\0') 1378 goto dft; /* no matching ] */ 1379 if (*endp == CTLESC) 1380 endp++; 1381 if (*++endp == ']') 1382 break; 1383 } 1384 invert = 0; 1385 if (*p == '!' || *p == '^') { 1386 invert++; 1387 p++; 1388 } 1389 found = 0; 1390 chr = *q++; 1391 if (squoted && chr == CTLESC) 1392 chr = *q++; 1393 if (chr == '\0') 1394 return 0; 1395 c = *p++; 1396 do { 1397 if (c == CTLQUOTEMARK) 1398 continue; 1399 if (c == CTLESC) 1400 c = *p++; 1401 if (*p == '-' && p[1] != ']') { 1402 p++; 1403 while (*p == CTLQUOTEMARK) 1404 p++; 1405 if (*p == CTLESC) 1406 p++; 1407 if ( collate_range_cmp(chr, c) >= 0 1408 && collate_range_cmp(chr, *p) <= 0 1409 ) 1410 found = 1; 1411 p++; 1412 } else { 1413 if (chr == c) 1414 found = 1; 1415 } 1416 } while ((c = *p++) != ']'); 1417 if (found == invert) 1418 return 0; 1419 break; 1420 } 1421 dft: default: 1422 if (squoted && *q == CTLESC) 1423 q++; 1424 if (*q++ != c) 1425 return 0; 1426 break; 1427 } 1428 } 1429 breakloop: 1430 if (*q != '\0') 1431 return 0; 1432 return 1; 1433 } 1434 1435 1436 1437 /* 1438 * Remove any CTLESC characters from a string. 1439 */ 1440 1441 void 1442 rmescapes(char *str) 1443 { 1444 char *p, *q; 1445 1446 p = str; 1447 while (*p != CTLESC && *p != CTLQUOTEMARK) { 1448 if (*p++ == '\0') 1449 return; 1450 } 1451 q = p; 1452 while (*p) { 1453 if (*p == CTLQUOTEMARK) { 1454 p++; 1455 continue; 1456 } 1457 if (*p == CTLESC) 1458 p++; 1459 *q++ = *p++; 1460 } 1461 *q = '\0'; 1462 } 1463 1464 1465 1466 /* 1467 * See if a pattern matches in a case statement. 1468 */ 1469 1470 int 1471 casematch(union node *pattern, char *val) 1472 { 1473 struct stackmark smark; 1474 int result; 1475 char *p; 1476 1477 setstackmark(&smark); 1478 argbackq = pattern->narg.backquote; 1479 STARTSTACKSTR(expdest); 1480 ifslastp = NULL; 1481 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE); 1482 STPUTC('\0', expdest); 1483 p = grabstackstr(expdest); 1484 result = patmatch(p, val, 0); 1485 popstackmark(&smark); 1486 return result; 1487 } 1488 1489 /* 1490 * Our own itoa(). 1491 */ 1492 1493 STATIC char * 1494 cvtnum(int num, char *buf) 1495 { 1496 char temp[32]; 1497 int neg = num < 0; 1498 char *p = temp + 31; 1499 1500 temp[31] = '\0'; 1501 1502 do { 1503 *--p = num % 10 + '0'; 1504 } while ((num /= 10) != 0); 1505 1506 if (neg) 1507 *--p = '-'; 1508 1509 while (*p) 1510 STPUTC(*p++, buf); 1511 return buf; 1512 } 1513