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 * @(#)expand.c 8.5 (Berkeley) 5/15/95 37 * $FreeBSD: src/bin/sh/expand.c,v 1.31.2.5 2003/01/17 07:44:01 tjr Exp $ 38 * $DragonFly: src/bin/sh/expand.c,v 1.3 2003/08/24 16:26:00 drhodus Exp $ 39 */ 40 41 #include <sys/types.h> 42 #include <sys/time.h> 43 #include <sys/stat.h> 44 #include <errno.h> 45 #include <dirent.h> 46 #include <unistd.h> 47 #include <pwd.h> 48 #include <stdlib.h> 49 #include <limits.h> 50 #include <stdio.h> 51 52 /* 53 * Routines to expand arguments to commands. We have to deal with 54 * backquotes, shell variables, and file metacharacters. 55 */ 56 57 #include "shell.h" 58 #include "main.h" 59 #include "nodes.h" 60 #include "eval.h" 61 #include "expand.h" 62 #include "syntax.h" 63 #include "parser.h" 64 #include "jobs.h" 65 #include "options.h" 66 #include "var.h" 67 #include "input.h" 68 #include "output.h" 69 #include "memalloc.h" 70 #include "error.h" 71 #include "mystring.h" 72 #include "arith.h" 73 #include "show.h" 74 75 /* 76 * Structure specifying which parts of the string should be searched 77 * for IFS characters. 78 */ 79 80 struct ifsregion { 81 struct ifsregion *next; /* next region in list */ 82 int begoff; /* offset of start of region */ 83 int endoff; /* offset of end of region */ 84 int nulonly; /* search for nul bytes only */ 85 }; 86 87 88 STATIC char *expdest; /* output of current string */ 89 STATIC struct nodelist *argbackq; /* list of back quote expressions */ 90 STATIC struct ifsregion ifsfirst; /* first struct in list of ifs regions */ 91 STATIC struct ifsregion *ifslastp; /* last struct in list */ 92 STATIC struct arglist exparg; /* holds expanded arg list */ 93 94 STATIC void argstr(char *, int); 95 STATIC char *exptilde(char *, int); 96 STATIC void expbackq(union node *, int, int); 97 STATIC int subevalvar(char *, char *, int, int, int, int); 98 STATIC char *evalvar(char *, int); 99 STATIC int varisset(char *, int); 100 STATIC void varvalue(char *, int, int); 101 STATIC void recordregion(int, int, int); 102 STATIC void removerecordregions(int); 103 STATIC void ifsbreakup(char *, struct arglist *); 104 STATIC void expandmeta(struct strlist *, int); 105 STATIC void expmeta(char *, char *); 106 STATIC void addfname(char *); 107 STATIC struct strlist *expsort(struct strlist *); 108 STATIC struct strlist *msort(struct strlist *, int); 109 STATIC int pmatch(char *, char *, int); 110 STATIC char *cvtnum(int, char *); 111 STATIC int collate_range_cmp(int, int); 112 113 STATIC int 114 collate_range_cmp (int c1, int c2) 115 { 116 static char s1[2], s2[2]; 117 int ret; 118 119 c1 &= UCHAR_MAX; 120 c2 &= UCHAR_MAX; 121 if (c1 == c2) 122 return (0); 123 s1[0] = c1; 124 s2[0] = c2; 125 if ((ret = strcoll(s1, s2)) != 0) 126 return (ret); 127 return (c1 - c2); 128 } 129 130 /* 131 * Expand shell variables and backquotes inside a here document. 132 * union node *arg the document 133 * int fd; where to write the expanded version 134 */ 135 136 void 137 expandhere(union node *arg, int fd) 138 { 139 herefd = fd; 140 expandarg(arg, (struct arglist *)NULL, 0); 141 xwrite(fd, stackblock(), expdest - stackblock()); 142 } 143 144 145 /* 146 * Perform variable substitution and command substitution on an argument, 147 * placing the resulting list of arguments in arglist. If EXP_FULL is true, 148 * perform splitting and file name expansion. When arglist is NULL, perform 149 * here document expansion. 150 */ 151 152 void 153 expandarg(union node *arg, struct arglist *arglist, int flag) 154 { 155 struct strlist *sp; 156 char *p; 157 158 argbackq = arg->narg.backquote; 159 STARTSTACKSTR(expdest); 160 ifsfirst.next = NULL; 161 ifslastp = NULL; 162 argstr(arg->narg.text, flag); 163 if (arglist == NULL) { 164 return; /* here document expanded */ 165 } 166 STPUTC('\0', expdest); 167 p = grabstackstr(expdest); 168 exparg.lastp = &exparg.list; 169 /* 170 * TODO - EXP_REDIR 171 */ 172 if (flag & EXP_FULL) { 173 ifsbreakup(p, &exparg); 174 *exparg.lastp = NULL; 175 exparg.lastp = &exparg.list; 176 expandmeta(exparg.list, flag); 177 } else { 178 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */ 179 rmescapes(p); 180 sp = (struct strlist *)stalloc(sizeof (struct strlist)); 181 sp->text = p; 182 *exparg.lastp = sp; 183 exparg.lastp = &sp->next; 184 } 185 while (ifsfirst.next != NULL) { 186 struct ifsregion *ifsp; 187 INTOFF; 188 ifsp = ifsfirst.next->next; 189 ckfree(ifsfirst.next); 190 ifsfirst.next = ifsp; 191 INTON; 192 } 193 *exparg.lastp = NULL; 194 if (exparg.list) { 195 *arglist->lastp = exparg.list; 196 arglist->lastp = exparg.lastp; 197 } 198 } 199 200 201 202 /* 203 * Perform variable and command substitution. If EXP_FULL is set, output CTLESC 204 * characters to allow for further processing. Otherwise treat 205 * $@ like $* since no splitting will be performed. 206 */ 207 208 STATIC void 209 argstr(char *p, int flag) 210 { 211 char c; 212 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); /* do CTLESC */ 213 int firsteq = 1; 214 215 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE))) 216 p = exptilde(p, flag); 217 for (;;) { 218 switch (c = *p++) { 219 case '\0': 220 case CTLENDVAR: /* ??? */ 221 goto breakloop; 222 case CTLQUOTEMARK: 223 /* "$@" syntax adherence hack */ 224 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=') 225 break; 226 if ((flag & EXP_FULL) != 0) 227 STPUTC(c, expdest); 228 break; 229 case CTLESC: 230 if (quotes) 231 STPUTC(c, expdest); 232 c = *p++; 233 STPUTC(c, expdest); 234 break; 235 case CTLVAR: 236 p = evalvar(p, flag); 237 break; 238 case CTLBACKQ: 239 case CTLBACKQ|CTLQUOTE: 240 expbackq(argbackq->n, c & CTLQUOTE, flag); 241 argbackq = argbackq->next; 242 break; 243 case CTLENDARI: 244 expari(flag); 245 break; 246 case ':': 247 case '=': 248 /* 249 * sort of a hack - expand tildes in variable 250 * assignments (after the first '=' and after ':'s). 251 */ 252 STPUTC(c, expdest); 253 if (flag & EXP_VARTILDE && *p == '~') { 254 if (c == '=') { 255 if (firsteq) 256 firsteq = 0; 257 else 258 break; 259 } 260 p = exptilde(p, flag); 261 } 262 break; 263 default: 264 STPUTC(c, expdest); 265 } 266 } 267 breakloop:; 268 } 269 270 STATIC char * 271 exptilde(char *p, int flag) 272 { 273 char c, *startp = p; 274 struct passwd *pw; 275 char *home; 276 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 277 278 while ((c = *p) != '\0') { 279 switch(c) { 280 case CTLESC: 281 return (startp); 282 case CTLQUOTEMARK: 283 return (startp); 284 case ':': 285 if (flag & EXP_VARTILDE) 286 goto done; 287 break; 288 case '/': 289 goto done; 290 } 291 p++; 292 } 293 done: 294 *p = '\0'; 295 if (*(startp+1) == '\0') { 296 if ((home = lookupvar("HOME")) == NULL) 297 goto lose; 298 } else { 299 if ((pw = getpwnam(startp+1)) == NULL) 300 goto lose; 301 home = pw->pw_dir; 302 } 303 if (*home == '\0') 304 goto lose; 305 *p = c; 306 while ((c = *home++) != '\0') { 307 if (quotes && SQSYNTAX[(int)c] == CCTL) 308 STPUTC(CTLESC, expdest); 309 STPUTC(c, expdest); 310 } 311 return (p); 312 lose: 313 *p = c; 314 return (startp); 315 } 316 317 318 STATIC void 319 removerecordregions(int endoff) 320 { 321 if (ifslastp == NULL) 322 return; 323 324 if (ifsfirst.endoff > endoff) { 325 while (ifsfirst.next != NULL) { 326 struct ifsregion *ifsp; 327 INTOFF; 328 ifsp = ifsfirst.next->next; 329 ckfree(ifsfirst.next); 330 ifsfirst.next = ifsp; 331 INTON; 332 } 333 if (ifsfirst.begoff > endoff) 334 ifslastp = NULL; 335 else { 336 ifslastp = &ifsfirst; 337 ifsfirst.endoff = endoff; 338 } 339 return; 340 } 341 342 ifslastp = &ifsfirst; 343 while (ifslastp->next && ifslastp->next->begoff < endoff) 344 ifslastp=ifslastp->next; 345 while (ifslastp->next != NULL) { 346 struct ifsregion *ifsp; 347 INTOFF; 348 ifsp = ifslastp->next->next; 349 ckfree(ifslastp->next); 350 ifslastp->next = ifsp; 351 INTON; 352 } 353 if (ifslastp->endoff > endoff) 354 ifslastp->endoff = endoff; 355 } 356 357 /* 358 * Expand arithmetic expression. Backup to start of expression, 359 * evaluate, place result in (backed up) result, adjust string position. 360 */ 361 void 362 expari(int flag) 363 { 364 char *p, *start; 365 int result; 366 int begoff; 367 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 368 int quoted; 369 370 371 /* 372 * This routine is slightly over-complicated for 373 * efficiency. First we make sure there is 374 * enough space for the result, which may be bigger 375 * than the expression if we add exponentiation. Next we 376 * scan backwards looking for the start of arithmetic. If the 377 * next previous character is a CTLESC character, then we 378 * have to rescan starting from the beginning since CTLESC 379 * characters have to be processed left to right. 380 */ 381 #if INT_MAX / 1000000000 >= 10 || INT_MIN / 1000000000 <= -10 382 #error "integers with more than 10 digits are not supported" 383 #endif 384 CHECKSTRSPACE(12 - 2, expdest); 385 USTPUTC('\0', expdest); 386 start = stackblock(); 387 p = expdest - 2; 388 while (p >= start && *p != CTLARI) 389 --p; 390 if (p < start || *p != CTLARI) 391 error("missing CTLARI (shouldn't happen)"); 392 if (p > start && *(p - 1) == CTLESC) 393 for (p = start; *p != CTLARI; p++) 394 if (*p == CTLESC) 395 p++; 396 397 if (p[1] == '"') 398 quoted=1; 399 else 400 quoted=0; 401 begoff = p - start; 402 removerecordregions(begoff); 403 if (quotes) 404 rmescapes(p+2); 405 result = arith(p+2); 406 fmtstr(p, 12, "%d", result); 407 while (*p++) 408 ; 409 if (quoted == 0) 410 recordregion(begoff, p - 1 - start, 0); 411 result = expdest - p + 1; 412 STADJUST(-result, expdest); 413 } 414 415 416 /* 417 * Expand stuff in backwards quotes. 418 */ 419 420 STATIC void 421 expbackq(union node *cmd, int quoted, int flag) 422 { 423 struct backcmd in; 424 int i; 425 char buf[128]; 426 char *p; 427 char *dest = expdest; 428 struct ifsregion saveifs, *savelastp; 429 struct nodelist *saveargbackq; 430 char lastc; 431 int startloc = dest - stackblock(); 432 char const *syntax = quoted? DQSYNTAX : BASESYNTAX; 433 int saveherefd; 434 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 435 436 INTOFF; 437 saveifs = ifsfirst; 438 savelastp = ifslastp; 439 saveargbackq = argbackq; 440 saveherefd = herefd; 441 herefd = -1; 442 p = grabstackstr(dest); 443 evalbackcmd(cmd, &in); 444 ungrabstackstr(p, dest); 445 ifsfirst = saveifs; 446 ifslastp = savelastp; 447 argbackq = saveargbackq; 448 herefd = saveherefd; 449 450 p = in.buf; 451 lastc = '\0'; 452 for (;;) { 453 if (--in.nleft < 0) { 454 if (in.fd < 0) 455 break; 456 while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR); 457 TRACE(("expbackq: read returns %d\n", i)); 458 if (i <= 0) 459 break; 460 p = buf; 461 in.nleft = i - 1; 462 } 463 lastc = *p++; 464 if (lastc != '\0') { 465 if (quotes && syntax[(int)lastc] == CCTL) 466 STPUTC(CTLESC, dest); 467 STPUTC(lastc, dest); 468 } 469 } 470 471 /* Eat all trailing newlines */ 472 for (p--; lastc == '\n'; lastc = *--p) 473 STUNPUTC(dest); 474 475 if (in.fd >= 0) 476 close(in.fd); 477 if (in.buf) 478 ckfree(in.buf); 479 if (in.jp) 480 exitstatus = waitforjob(in.jp, (int *)NULL); 481 if (quoted == 0) 482 recordregion(startloc, dest - stackblock(), 0); 483 TRACE(("evalbackq: size=%d: \"%.*s\"\n", 484 (dest - stackblock()) - startloc, 485 (dest - stackblock()) - startloc, 486 stackblock() + startloc)); 487 expdest = dest; 488 INTON; 489 } 490 491 492 493 STATIC int 494 subevalvar(char *p, char *str, int strloc, int subtype, int startloc, 495 int varflags) 496 { 497 char *startp; 498 char *loc = NULL; 499 char *q; 500 int c = 0; 501 int saveherefd = herefd; 502 struct nodelist *saveargbackq = argbackq; 503 int amount; 504 505 herefd = -1; 506 argstr(p, 0); 507 STACKSTRNUL(expdest); 508 herefd = saveherefd; 509 argbackq = saveargbackq; 510 startp = stackblock() + startloc; 511 if (str == NULL) 512 str = stackblock() + strloc; 513 514 switch (subtype) { 515 case VSASSIGN: 516 setvar(str, startp, 0); 517 amount = startp - expdest; 518 STADJUST(amount, expdest); 519 varflags &= ~VSNUL; 520 if (c != 0) 521 *loc = c; 522 return 1; 523 524 case VSQUESTION: 525 if (*p != CTLENDVAR) { 526 outfmt(&errout, "%s\n", startp); 527 error((char *)NULL); 528 } 529 error("%.*s: parameter %snot set", p - str - 1, 530 str, (varflags & VSNUL) ? "null or " 531 : nullstr); 532 return 0; 533 534 case VSTRIMLEFT: 535 for (loc = startp; loc < str; loc++) { 536 c = *loc; 537 *loc = '\0'; 538 if (patmatch(str, startp, varflags & VSQUOTE)) { 539 *loc = c; 540 goto recordleft; 541 } 542 *loc = c; 543 if ((varflags & VSQUOTE) && *loc == CTLESC) 544 loc++; 545 } 546 return 0; 547 548 case VSTRIMLEFTMAX: 549 for (loc = str - 1; loc >= startp;) { 550 c = *loc; 551 *loc = '\0'; 552 if (patmatch(str, startp, varflags & VSQUOTE)) { 553 *loc = c; 554 goto recordleft; 555 } 556 *loc = c; 557 loc--; 558 if ((varflags & VSQUOTE) && loc > startp && 559 *(loc - 1) == CTLESC) { 560 for (q = startp; q < loc; q++) 561 if (*q == CTLESC) 562 q++; 563 if (q > loc) 564 loc--; 565 } 566 } 567 return 0; 568 569 case VSTRIMRIGHT: 570 for (loc = str - 1; loc >= startp;) { 571 if (patmatch(str, loc, varflags & VSQUOTE)) { 572 amount = loc - expdest; 573 STADJUST(amount, expdest); 574 return 1; 575 } 576 loc--; 577 if ((varflags & VSQUOTE) && loc > startp && 578 *(loc - 1) == CTLESC) { 579 for (q = startp; q < loc; q++) 580 if (*q == CTLESC) 581 q++; 582 if (q > loc) 583 loc--; 584 } 585 } 586 return 0; 587 588 case VSTRIMRIGHTMAX: 589 for (loc = startp; loc < str - 1; loc++) { 590 if (patmatch(str, loc, varflags & VSQUOTE)) { 591 amount = loc - expdest; 592 STADJUST(amount, expdest); 593 return 1; 594 } 595 if ((varflags & VSQUOTE) && *loc == CTLESC) 596 loc++; 597 } 598 return 0; 599 600 601 default: 602 abort(); 603 } 604 605 recordleft: 606 amount = ((str - 1) - (loc - startp)) - expdest; 607 STADJUST(amount, expdest); 608 while (loc != str - 1) 609 *startp++ = *loc++; 610 return 1; 611 } 612 613 614 /* 615 * Expand a variable, and return a pointer to the next character in the 616 * input string. 617 */ 618 619 STATIC char * 620 evalvar(char *p, int flag) 621 { 622 int subtype; 623 int varflags; 624 char *var; 625 char *val; 626 int patloc; 627 int c; 628 int set; 629 int special; 630 int startloc; 631 int varlen; 632 int easy; 633 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 634 635 varflags = *p++; 636 subtype = varflags & VSTYPE; 637 var = p; 638 special = 0; 639 if (! is_name(*p)) 640 special = 1; 641 p = strchr(p, '=') + 1; 642 again: /* jump here after setting a variable with ${var=text} */ 643 if (special) { 644 set = varisset(var, varflags & VSNUL); 645 val = NULL; 646 } else { 647 val = bltinlookup(var, 1); 648 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) { 649 val = NULL; 650 set = 0; 651 } else 652 set = 1; 653 } 654 varlen = 0; 655 startloc = expdest - stackblock(); 656 if (!set && uflag) { 657 switch (subtype) { 658 case VSNORMAL: 659 case VSTRIMLEFT: 660 case VSTRIMLEFTMAX: 661 case VSTRIMRIGHT: 662 case VSTRIMRIGHTMAX: 663 case VSLENGTH: 664 error("%.*s: parameter not set", p - var - 1, var); 665 } 666 } 667 if (set && subtype != VSPLUS) { 668 /* insert the value of the variable */ 669 if (special) { 670 varvalue(var, varflags & VSQUOTE, flag & EXP_FULL); 671 if (subtype == VSLENGTH) { 672 varlen = expdest - stackblock() - startloc; 673 STADJUST(-varlen, expdest); 674 } 675 } else { 676 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX 677 : BASESYNTAX; 678 679 if (subtype == VSLENGTH) { 680 for (;*val; val++) 681 varlen++; 682 } 683 else { 684 while (*val) { 685 if (quotes && 686 syntax[(int)*val] == CCTL) 687 STPUTC(CTLESC, expdest); 688 STPUTC(*val++, expdest); 689 } 690 691 } 692 } 693 } 694 695 if (subtype == VSPLUS) 696 set = ! set; 697 698 easy = ((varflags & VSQUOTE) == 0 || 699 (*var == '@' && shellparam.nparam != 1)); 700 701 702 switch (subtype) { 703 case VSLENGTH: 704 expdest = cvtnum(varlen, expdest); 705 goto record; 706 707 case VSNORMAL: 708 if (!easy) 709 break; 710 record: 711 recordregion(startloc, expdest - stackblock(), 712 varflags & VSQUOTE); 713 break; 714 715 case VSPLUS: 716 case VSMINUS: 717 if (!set) { 718 argstr(p, flag); 719 break; 720 } 721 if (easy) 722 goto record; 723 break; 724 725 case VSTRIMLEFT: 726 case VSTRIMLEFTMAX: 727 case VSTRIMRIGHT: 728 case VSTRIMRIGHTMAX: 729 if (!set) 730 break; 731 /* 732 * Terminate the string and start recording the pattern 733 * right after it 734 */ 735 STPUTC('\0', expdest); 736 patloc = expdest - stackblock(); 737 if (subevalvar(p, NULL, patloc, subtype, 738 startloc, varflags) == 0) { 739 int amount = (expdest - stackblock() - patloc) + 1; 740 STADJUST(-amount, expdest); 741 } 742 /* Remove any recorded regions beyond start of variable */ 743 removerecordregions(startloc); 744 goto record; 745 746 case VSASSIGN: 747 case VSQUESTION: 748 if (!set) { 749 if (subevalvar(p, var, 0, subtype, startloc, varflags)) { 750 varflags &= ~VSNUL; 751 /* 752 * Remove any recorded regions beyond 753 * start of variable 754 */ 755 removerecordregions(startloc); 756 goto again; 757 } 758 break; 759 } 760 if (easy) 761 goto record; 762 break; 763 764 default: 765 abort(); 766 } 767 768 if (subtype != VSNORMAL) { /* skip to end of alternative */ 769 int nesting = 1; 770 for (;;) { 771 if ((c = *p++) == CTLESC) 772 p++; 773 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) { 774 if (set) 775 argbackq = argbackq->next; 776 } else if (c == CTLVAR) { 777 if ((*p++ & VSTYPE) != VSNORMAL) 778 nesting++; 779 } else if (c == CTLENDVAR) { 780 if (--nesting == 0) 781 break; 782 } 783 } 784 } 785 return p; 786 } 787 788 789 790 /* 791 * Test whether a specialized variable is set. 792 */ 793 794 STATIC int 795 varisset(char *name, int nulok) 796 { 797 798 if (*name == '!') 799 return backgndpid != -1; 800 else if (*name == '@' || *name == '*') { 801 if (*shellparam.p == NULL) 802 return 0; 803 804 if (nulok) { 805 char **av; 806 807 for (av = shellparam.p; *av; av++) 808 if (**av != '\0') 809 return 1; 810 return 0; 811 } 812 } else if (is_digit(*name)) { 813 char *ap; 814 int num = atoi(name); 815 816 if (num > shellparam.nparam) 817 return 0; 818 819 if (num == 0) 820 ap = arg0; 821 else 822 ap = shellparam.p[num - 1]; 823 824 if (nulok && (ap == NULL || *ap == '\0')) 825 return 0; 826 } 827 return 1; 828 } 829 830 831 832 /* 833 * Add the value of a specialized variable to the stack string. 834 */ 835 836 STATIC void 837 varvalue(char *name, int quoted, int allow_split) 838 { 839 int num; 840 char *p; 841 int i; 842 extern int oexitstatus; 843 char sep; 844 char **ap; 845 char const *syntax; 846 847 #define STRTODEST(p) \ 848 do {\ 849 if (allow_split) { \ 850 syntax = quoted? DQSYNTAX : BASESYNTAX; \ 851 while (*p) { \ 852 if (syntax[(int)*p] == CCTL) \ 853 STPUTC(CTLESC, expdest); \ 854 STPUTC(*p++, expdest); \ 855 } \ 856 } else \ 857 while (*p) \ 858 STPUTC(*p++, expdest); \ 859 } while (0) 860 861 862 switch (*name) { 863 case '$': 864 num = rootpid; 865 goto numvar; 866 case '?': 867 num = oexitstatus; 868 goto numvar; 869 case '#': 870 num = shellparam.nparam; 871 goto numvar; 872 case '!': 873 num = backgndpid; 874 numvar: 875 expdest = cvtnum(num, expdest); 876 break; 877 case '-': 878 for (i = 0 ; i < NOPTS ; i++) { 879 if (optlist[i].val) 880 STPUTC(optlist[i].letter, expdest); 881 } 882 break; 883 case '@': 884 if (allow_split && quoted) { 885 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 886 STRTODEST(p); 887 if (*ap) 888 STPUTC('\0', expdest); 889 } 890 break; 891 } 892 /* fall through */ 893 case '*': 894 if (ifsset() != 0) 895 sep = ifsval()[0]; 896 else 897 sep = ' '; 898 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 899 STRTODEST(p); 900 if (*ap && sep) 901 STPUTC(sep, expdest); 902 } 903 break; 904 case '0': 905 p = arg0; 906 STRTODEST(p); 907 break; 908 default: 909 if (is_digit(*name)) { 910 num = atoi(name); 911 if (num > 0 && num <= shellparam.nparam) { 912 p = shellparam.p[num - 1]; 913 STRTODEST(p); 914 } 915 } 916 break; 917 } 918 } 919 920 921 922 /* 923 * Record the the fact that we have to scan this region of the 924 * string for IFS characters. 925 */ 926 927 STATIC void 928 recordregion(int start, int end, int nulonly) 929 { 930 struct ifsregion *ifsp; 931 932 if (ifslastp == NULL) { 933 ifsp = &ifsfirst; 934 } else { 935 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion)); 936 ifslastp->next = ifsp; 937 } 938 ifslastp = ifsp; 939 ifslastp->next = NULL; 940 ifslastp->begoff = start; 941 ifslastp->endoff = end; 942 ifslastp->nulonly = nulonly; 943 } 944 945 946 947 /* 948 * Break the argument string into pieces based upon IFS and add the 949 * strings to the argument list. The regions of the string to be 950 * searched for IFS characters have been stored by recordregion. 951 */ 952 STATIC void 953 ifsbreakup(char *string, struct arglist *arglist) 954 { 955 struct ifsregion *ifsp; 956 struct strlist *sp; 957 char *start; 958 char *p; 959 char *q; 960 char *ifs; 961 int ifsspc; 962 int nulonly; 963 964 965 start = string; 966 ifsspc = 0; 967 nulonly = 0; 968 if (ifslastp != NULL) { 969 ifsp = &ifsfirst; 970 do { 971 p = string + ifsp->begoff; 972 nulonly = ifsp->nulonly; 973 ifs = nulonly ? nullstr : 974 ( ifsset() ? ifsval() : " \t\n" ); 975 ifsspc = 0; 976 while (p < string + ifsp->endoff) { 977 q = p; 978 if (*p == CTLESC) 979 p++; 980 if (strchr(ifs, *p)) { 981 if (!nulonly) 982 ifsspc = (strchr(" \t\n", *p) != NULL); 983 /* Ignore IFS whitespace at start */ 984 if (q == start && ifsspc) { 985 p++; 986 start = p; 987 continue; 988 } 989 *q = '\0'; 990 sp = (struct strlist *)stalloc(sizeof *sp); 991 sp->text = start; 992 *arglist->lastp = sp; 993 arglist->lastp = &sp->next; 994 p++; 995 if (!nulonly) { 996 for (;;) { 997 if (p >= string + ifsp->endoff) { 998 break; 999 } 1000 q = p; 1001 if (*p == CTLESC) 1002 p++; 1003 if (strchr(ifs, *p) == NULL ) { 1004 p = q; 1005 break; 1006 } else if (strchr(" \t\n",*p) == NULL) { 1007 if (ifsspc) { 1008 p++; 1009 ifsspc = 0; 1010 } else { 1011 p = q; 1012 break; 1013 } 1014 } else 1015 p++; 1016 } 1017 } 1018 start = p; 1019 } else 1020 p++; 1021 } 1022 } while ((ifsp = ifsp->next) != NULL); 1023 if (*start || (!ifsspc && start > string && 1024 (nulonly || 1))) { 1025 sp = (struct strlist *)stalloc(sizeof *sp); 1026 sp->text = start; 1027 *arglist->lastp = sp; 1028 arglist->lastp = &sp->next; 1029 } 1030 } else { 1031 sp = (struct strlist *)stalloc(sizeof *sp); 1032 sp->text = start; 1033 *arglist->lastp = sp; 1034 arglist->lastp = &sp->next; 1035 } 1036 } 1037 1038 1039 1040 /* 1041 * Expand shell metacharacters. At this point, the only control characters 1042 * should be escapes. The results are stored in the list exparg. 1043 */ 1044 1045 STATIC char *expdir; 1046 1047 1048 STATIC void 1049 expandmeta(struct strlist *str, int flag __unused) 1050 { 1051 char *p; 1052 struct strlist **savelastp; 1053 struct strlist *sp; 1054 char c; 1055 /* TODO - EXP_REDIR */ 1056 1057 while (str) { 1058 if (fflag) 1059 goto nometa; 1060 p = str->text; 1061 for (;;) { /* fast check for meta chars */ 1062 if ((c = *p++) == '\0') 1063 goto nometa; 1064 if (c == '*' || c == '?' || c == '[' || c == '!') 1065 break; 1066 } 1067 savelastp = exparg.lastp; 1068 INTOFF; 1069 if (expdir == NULL) { 1070 int i = strlen(str->text); 1071 expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */ 1072 } 1073 1074 expmeta(expdir, str->text); 1075 ckfree(expdir); 1076 expdir = NULL; 1077 INTON; 1078 if (exparg.lastp == savelastp) { 1079 /* 1080 * no matches 1081 */ 1082 nometa: 1083 *exparg.lastp = str; 1084 rmescapes(str->text); 1085 exparg.lastp = &str->next; 1086 } else { 1087 *exparg.lastp = NULL; 1088 *savelastp = sp = expsort(*savelastp); 1089 while (sp->next != NULL) 1090 sp = sp->next; 1091 exparg.lastp = &sp->next; 1092 } 1093 str = str->next; 1094 } 1095 } 1096 1097 1098 /* 1099 * Do metacharacter (i.e. *, ?, [...]) expansion. 1100 */ 1101 1102 STATIC void 1103 expmeta(char *enddir, char *name) 1104 { 1105 char *p; 1106 char *q; 1107 char *start; 1108 char *endname; 1109 int metaflag; 1110 struct stat statb; 1111 DIR *dirp; 1112 struct dirent *dp; 1113 int atend; 1114 int matchdot; 1115 1116 metaflag = 0; 1117 start = name; 1118 for (p = name ; ; p++) { 1119 if (*p == '*' || *p == '?') 1120 metaflag = 1; 1121 else if (*p == '[') { 1122 q = p + 1; 1123 if (*q == '!' || *q == '^') 1124 q++; 1125 for (;;) { 1126 while (*q == CTLQUOTEMARK) 1127 q++; 1128 if (*q == CTLESC) 1129 q++; 1130 if (*q == '/' || *q == '\0') 1131 break; 1132 if (*++q == ']') { 1133 metaflag = 1; 1134 break; 1135 } 1136 } 1137 } else if (*p == '!' && p[1] == '!' && (p == name || p[-1] == '/')) { 1138 metaflag = 1; 1139 } else if (*p == '\0') 1140 break; 1141 else if (*p == CTLQUOTEMARK) 1142 continue; 1143 else if (*p == CTLESC) 1144 p++; 1145 if (*p == '/') { 1146 if (metaflag) 1147 break; 1148 start = p + 1; 1149 } 1150 } 1151 if (metaflag == 0) { /* we've reached the end of the file name */ 1152 if (enddir != expdir) 1153 metaflag++; 1154 for (p = name ; ; p++) { 1155 if (*p == CTLQUOTEMARK) 1156 continue; 1157 if (*p == CTLESC) 1158 p++; 1159 *enddir++ = *p; 1160 if (*p == '\0') 1161 break; 1162 } 1163 if (metaflag == 0 || stat(expdir, &statb) >= 0) 1164 addfname(expdir); 1165 return; 1166 } 1167 endname = p; 1168 if (start != name) { 1169 p = name; 1170 while (p < start) { 1171 while (*p == CTLQUOTEMARK) 1172 p++; 1173 if (*p == CTLESC) 1174 p++; 1175 *enddir++ = *p++; 1176 } 1177 } 1178 if (enddir == expdir) { 1179 p = "."; 1180 } else if (enddir == expdir + 1 && *expdir == '/') { 1181 p = "/"; 1182 } else { 1183 p = expdir; 1184 enddir[-1] = '\0'; 1185 } 1186 if ((dirp = opendir(p)) == NULL) 1187 return; 1188 if (enddir != expdir) 1189 enddir[-1] = '/'; 1190 if (*endname == 0) { 1191 atend = 1; 1192 } else { 1193 atend = 0; 1194 *endname++ = '\0'; 1195 } 1196 matchdot = 0; 1197 p = start; 1198 while (*p == CTLQUOTEMARK) 1199 p++; 1200 if (*p == CTLESC) 1201 p++; 1202 if (*p == '.') 1203 matchdot++; 1204 while (! int_pending() && (dp = readdir(dirp)) != NULL) { 1205 if (dp->d_name[0] == '.' && ! matchdot) 1206 continue; 1207 if (patmatch(start, dp->d_name, 0)) { 1208 if (atend) { 1209 scopy(dp->d_name, enddir); 1210 addfname(expdir); 1211 } else { 1212 char *q; 1213 for (p = enddir, q = dp->d_name; 1214 (*p++ = *q++) != '\0';) 1215 continue; 1216 p[-1] = '/'; 1217 expmeta(p, endname); 1218 } 1219 } 1220 } 1221 closedir(dirp); 1222 if (! atend) 1223 endname[-1] = '/'; 1224 } 1225 1226 1227 /* 1228 * Add a file name to the list. 1229 */ 1230 1231 STATIC void 1232 addfname(char *name) 1233 { 1234 char *p; 1235 struct strlist *sp; 1236 1237 p = stalloc(strlen(name) + 1); 1238 scopy(name, p); 1239 sp = (struct strlist *)stalloc(sizeof *sp); 1240 sp->text = p; 1241 *exparg.lastp = sp; 1242 exparg.lastp = &sp->next; 1243 } 1244 1245 1246 /* 1247 * Sort the results of file name expansion. It calculates the number of 1248 * strings to sort and then calls msort (short for merge sort) to do the 1249 * work. 1250 */ 1251 1252 STATIC struct strlist * 1253 expsort(struct strlist *str) 1254 { 1255 int len; 1256 struct strlist *sp; 1257 1258 len = 0; 1259 for (sp = str ; sp ; sp = sp->next) 1260 len++; 1261 return msort(str, len); 1262 } 1263 1264 1265 STATIC struct strlist * 1266 msort(struct strlist *list, int len) 1267 { 1268 struct strlist *p, *q = NULL; 1269 struct strlist **lpp; 1270 int half; 1271 int n; 1272 1273 if (len <= 1) 1274 return list; 1275 half = len >> 1; 1276 p = list; 1277 for (n = half ; --n >= 0 ; ) { 1278 q = p; 1279 p = p->next; 1280 } 1281 q->next = NULL; /* terminate first half of list */ 1282 q = msort(list, half); /* sort first half of list */ 1283 p = msort(p, len - half); /* sort second half */ 1284 lpp = &list; 1285 for (;;) { 1286 if (strcmp(p->text, q->text) < 0) { 1287 *lpp = p; 1288 lpp = &p->next; 1289 if ((p = *lpp) == NULL) { 1290 *lpp = q; 1291 break; 1292 } 1293 } else { 1294 *lpp = q; 1295 lpp = &q->next; 1296 if ((q = *lpp) == NULL) { 1297 *lpp = p; 1298 break; 1299 } 1300 } 1301 } 1302 return list; 1303 } 1304 1305 1306 1307 /* 1308 * Returns true if the pattern matches the string. 1309 */ 1310 1311 int 1312 patmatch(char *pattern, char *string, int squoted) 1313 { 1314 #ifdef notdef 1315 if (pattern[0] == '!' && pattern[1] == '!') 1316 return 1 - pmatch(pattern + 2, string); 1317 else 1318 #endif 1319 return pmatch(pattern, string, squoted); 1320 } 1321 1322 1323 STATIC int 1324 pmatch(char *pattern, char *string, int squoted) 1325 { 1326 char *p, *q; 1327 char c; 1328 1329 p = pattern; 1330 q = string; 1331 for (;;) { 1332 switch (c = *p++) { 1333 case '\0': 1334 goto breakloop; 1335 case CTLESC: 1336 if (squoted && *q == CTLESC) 1337 q++; 1338 if (*q++ != *p++) 1339 return 0; 1340 break; 1341 case CTLQUOTEMARK: 1342 continue; 1343 case '?': 1344 if (squoted && *q == CTLESC) 1345 q++; 1346 if (*q++ == '\0') 1347 return 0; 1348 break; 1349 case '*': 1350 c = *p; 1351 while (c == CTLQUOTEMARK || c == '*') 1352 c = *++p; 1353 if (c != CTLESC && c != CTLQUOTEMARK && 1354 c != '?' && c != '*' && c != '[') { 1355 while (*q != c) { 1356 if (squoted && *q == CTLESC && 1357 q[1] == c) 1358 break; 1359 if (*q == '\0') 1360 return 0; 1361 if (squoted && *q == CTLESC) 1362 q++; 1363 q++; 1364 } 1365 } 1366 do { 1367 if (pmatch(p, q, squoted)) 1368 return 1; 1369 if (squoted && *q == CTLESC) 1370 q++; 1371 } while (*q++ != '\0'); 1372 return 0; 1373 case '[': { 1374 char *endp; 1375 int invert, found; 1376 char chr; 1377 1378 endp = p; 1379 if (*endp == '!' || *endp == '^') 1380 endp++; 1381 for (;;) { 1382 while (*endp == CTLQUOTEMARK) 1383 endp++; 1384 if (*endp == '\0') 1385 goto dft; /* no matching ] */ 1386 if (*endp == CTLESC) 1387 endp++; 1388 if (*++endp == ']') 1389 break; 1390 } 1391 invert = 0; 1392 if (*p == '!' || *p == '^') { 1393 invert++; 1394 p++; 1395 } 1396 found = 0; 1397 chr = *q++; 1398 if (squoted && chr == CTLESC) 1399 chr = *q++; 1400 if (chr == '\0') 1401 return 0; 1402 c = *p++; 1403 do { 1404 if (c == CTLQUOTEMARK) 1405 continue; 1406 if (c == CTLESC) 1407 c = *p++; 1408 if (*p == '-' && p[1] != ']') { 1409 p++; 1410 while (*p == CTLQUOTEMARK) 1411 p++; 1412 if (*p == CTLESC) 1413 p++; 1414 if ( collate_range_cmp(chr, c) >= 0 1415 && collate_range_cmp(chr, *p) <= 0 1416 ) 1417 found = 1; 1418 p++; 1419 } else { 1420 if (chr == c) 1421 found = 1; 1422 } 1423 } while ((c = *p++) != ']'); 1424 if (found == invert) 1425 return 0; 1426 break; 1427 } 1428 dft: default: 1429 if (squoted && *q == CTLESC) 1430 q++; 1431 if (*q++ != c) 1432 return 0; 1433 break; 1434 } 1435 } 1436 breakloop: 1437 if (*q != '\0') 1438 return 0; 1439 return 1; 1440 } 1441 1442 1443 1444 /* 1445 * Remove any CTLESC characters from a string. 1446 */ 1447 1448 void 1449 rmescapes(char *str) 1450 { 1451 char *p, *q; 1452 1453 p = str; 1454 while (*p != CTLESC && *p != CTLQUOTEMARK) { 1455 if (*p++ == '\0') 1456 return; 1457 } 1458 q = p; 1459 while (*p) { 1460 if (*p == CTLQUOTEMARK) { 1461 p++; 1462 continue; 1463 } 1464 if (*p == CTLESC) 1465 p++; 1466 *q++ = *p++; 1467 } 1468 *q = '\0'; 1469 } 1470 1471 1472 1473 /* 1474 * See if a pattern matches in a case statement. 1475 */ 1476 1477 int 1478 casematch(union node *pattern, char *val) 1479 { 1480 struct stackmark smark; 1481 int result; 1482 char *p; 1483 1484 setstackmark(&smark); 1485 argbackq = pattern->narg.backquote; 1486 STARTSTACKSTR(expdest); 1487 ifslastp = NULL; 1488 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE); 1489 STPUTC('\0', expdest); 1490 p = grabstackstr(expdest); 1491 result = patmatch(p, val, 0); 1492 popstackmark(&smark); 1493 return result; 1494 } 1495 1496 /* 1497 * Our own itoa(). 1498 */ 1499 1500 STATIC char * 1501 cvtnum(int num, char *buf) 1502 { 1503 char temp[32]; 1504 int neg = num < 0; 1505 char *p = temp + 31; 1506 1507 temp[31] = '\0'; 1508 1509 do { 1510 *--p = num % 10 + '0'; 1511 } while ((num /= 10) != 0); 1512 1513 if (neg) 1514 *--p = '-'; 1515 1516 while (*p) 1517 STPUTC(*p++, buf); 1518 return buf; 1519 } 1520