1 /* $NetBSD: expand.c,v 1.74 2006/05/20 13:57:27 dsl 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 1.74 2006/05/20 13:57:27 dsl 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 inquotes; /* 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, 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. 179 * If EXP_FULL is set, output CTLESC characters to allow for further processing. 180 * Otherwise treat $@ 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 const char *ifs = NULL; 190 int ifs_split = EXP_IFS_SPLIT; 191 192 if (flag & EXP_IFS_SPLIT) 193 ifs = ifsset() ? ifsval() : " \t\n"; 194 195 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE))) 196 p = exptilde(p, flag); 197 for (;;) { 198 switch (c = *p++) { 199 case '\0': 200 case CTLENDVAR: /* end of expanding yyy in ${xxx-yyy} */ 201 return; 202 case CTLQUOTEMARK: 203 /* "$@" syntax adherence hack */ 204 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=') 205 break; 206 if ((flag & EXP_FULL) != 0) 207 STPUTC(c, expdest); 208 ifs_split = 0; 209 break; 210 case CTLQUOTEEND: 211 ifs_split = EXP_IFS_SPLIT; 212 break; 213 case CTLESC: 214 if (quotes) 215 STPUTC(c, expdest); 216 c = *p++; 217 STPUTC(c, expdest); 218 break; 219 case CTLVAR: 220 p = evalvar(p, (flag & ~EXP_IFS_SPLIT) | (flag & ifs_split)); 221 break; 222 case CTLBACKQ: 223 case CTLBACKQ|CTLQUOTE: 224 expbackq(argbackq->n, c & CTLQUOTE, flag); 225 argbackq = argbackq->next; 226 break; 227 case CTLENDARI: 228 expari(flag); 229 break; 230 case ':': 231 case '=': 232 /* 233 * sort of a hack - expand tildes in variable 234 * assignments (after the first '=' and after ':'s). 235 */ 236 STPUTC(c, expdest); 237 if (flag & EXP_VARTILDE && *p == '~') { 238 if (c == '=') { 239 if (firsteq) 240 firsteq = 0; 241 else 242 break; 243 } 244 p = exptilde(p, flag); 245 } 246 break; 247 default: 248 STPUTC(c, expdest); 249 if (flag & EXP_IFS_SPLIT & ifs_split && strchr(ifs, c) != NULL) { 250 /* We need to get the output split here... */ 251 recordregion(expdest - stackblock() - 1, 252 expdest - stackblock(), 0); 253 } 254 break; 255 } 256 } 257 } 258 259 STATIC char * 260 exptilde(char *p, int flag) 261 { 262 char c, *startp = p; 263 struct passwd *pw; 264 const char *home; 265 int quotes = flag & (EXP_FULL | EXP_CASE); 266 267 while ((c = *p) != '\0') { 268 switch(c) { 269 case CTLESC: 270 return (startp); 271 case CTLQUOTEMARK: 272 return (startp); 273 case ':': 274 if (flag & EXP_VARTILDE) 275 goto done; 276 break; 277 case '/': 278 goto done; 279 } 280 p++; 281 } 282 done: 283 *p = '\0'; 284 if (*(startp+1) == '\0') { 285 if ((home = lookupvar("HOME")) == NULL) 286 goto lose; 287 } else { 288 if ((pw = getpwnam(startp+1)) == NULL) 289 goto lose; 290 home = pw->pw_dir; 291 } 292 if (*home == '\0') 293 goto lose; 294 *p = c; 295 while ((c = *home++) != '\0') { 296 if (quotes && SQSYNTAX[(int)c] == CCTL) 297 STPUTC(CTLESC, expdest); 298 STPUTC(c, expdest); 299 } 300 return (p); 301 lose: 302 *p = c; 303 return (startp); 304 } 305 306 307 STATIC void 308 removerecordregions(int endoff) 309 { 310 if (ifslastp == NULL) 311 return; 312 313 if (ifsfirst.endoff > endoff) { 314 while (ifsfirst.next != NULL) { 315 struct ifsregion *ifsp; 316 INTOFF; 317 ifsp = ifsfirst.next->next; 318 ckfree(ifsfirst.next); 319 ifsfirst.next = ifsp; 320 INTON; 321 } 322 if (ifsfirst.begoff > endoff) 323 ifslastp = NULL; 324 else { 325 ifslastp = &ifsfirst; 326 ifsfirst.endoff = endoff; 327 } 328 return; 329 } 330 331 ifslastp = &ifsfirst; 332 while (ifslastp->next && ifslastp->next->begoff < endoff) 333 ifslastp=ifslastp->next; 334 while (ifslastp->next != NULL) { 335 struct ifsregion *ifsp; 336 INTOFF; 337 ifsp = ifslastp->next->next; 338 ckfree(ifslastp->next); 339 ifslastp->next = ifsp; 340 INTON; 341 } 342 if (ifslastp->endoff > endoff) 343 ifslastp->endoff = endoff; 344 } 345 346 347 /* 348 * Expand arithmetic expression. Backup to start of expression, 349 * evaluate, place result in (backed up) result, adjust string position. 350 */ 351 void 352 expari(int flag) 353 { 354 char *p, *start; 355 int result; 356 int begoff; 357 int quotes = flag & (EXP_FULL | EXP_CASE); 358 int quoted; 359 360 /* ifsfree(); */ 361 362 /* 363 * This routine is slightly over-complicated for 364 * efficiency. First we make sure there is 365 * enough space for the result, which may be bigger 366 * than the expression if we add exponentation. Next we 367 * scan backwards looking for the start of arithmetic. If the 368 * next previous character is a CTLESC character, then we 369 * have to rescan starting from the beginning since CTLESC 370 * characters have to be processed left to right. 371 */ 372 #if INT_MAX / 1000000000 >= 10 || INT_MIN / 1000000000 <= -10 373 #error "integers with more than 10 digits are not supported" 374 #endif 375 CHECKSTRSPACE(12 - 2, expdest); 376 USTPUTC('\0', expdest); 377 start = stackblock(); 378 p = expdest - 1; 379 while (*p != CTLARI && p >= start) 380 --p; 381 if (*p != CTLARI) 382 error("missing CTLARI (shouldn't happen)"); 383 if (p > start && *(p-1) == CTLESC) 384 for (p = start; *p != CTLARI; p++) 385 if (*p == CTLESC) 386 p++; 387 388 if (p[1] == '"') 389 quoted=1; 390 else 391 quoted=0; 392 begoff = p - start; 393 removerecordregions(begoff); 394 if (quotes) 395 rmescapes(p+2); 396 result = arith(p+2); 397 fmtstr(p, 12, "%d", result); 398 399 while (*p++) 400 ; 401 402 if (quoted == 0) 403 recordregion(begoff, p - 1 - start, 0); 404 result = expdest - p + 1; 405 STADJUST(-result, expdest); 406 } 407 408 409 /* 410 * Expand stuff in backwards quotes. 411 */ 412 413 STATIC void 414 expbackq(union node *cmd, int quoted, int flag) 415 { 416 struct backcmd in; 417 int i; 418 char buf[128]; 419 char *p; 420 char *dest = expdest; 421 struct ifsregion saveifs, *savelastp; 422 struct nodelist *saveargbackq; 423 char lastc; 424 int startloc = dest - stackblock(); 425 char const *syntax = quoted? DQSYNTAX : BASESYNTAX; 426 int saveherefd; 427 int quotes = flag & (EXP_FULL | EXP_CASE); 428 429 INTOFF; 430 saveifs = ifsfirst; 431 savelastp = ifslastp; 432 saveargbackq = argbackq; 433 saveherefd = herefd; 434 herefd = -1; 435 p = grabstackstr(dest); 436 evalbackcmd(cmd, &in); 437 ungrabstackstr(p, dest); 438 ifsfirst = saveifs; 439 ifslastp = savelastp; 440 argbackq = saveargbackq; 441 herefd = saveherefd; 442 443 p = in.buf; 444 lastc = '\0'; 445 for (;;) { 446 if (--in.nleft < 0) { 447 if (in.fd < 0) 448 break; 449 while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR); 450 TRACE(("expbackq: read returns %d\n", i)); 451 if (i <= 0) 452 break; 453 p = buf; 454 in.nleft = i - 1; 455 } 456 lastc = *p++; 457 if (lastc != '\0') { 458 if (quotes && syntax[(int)lastc] == CCTL) 459 STPUTC(CTLESC, dest); 460 STPUTC(lastc, dest); 461 } 462 } 463 464 /* Eat all trailing newlines */ 465 p = stackblock() + startloc; 466 while (dest > p && dest[-1] == '\n') 467 STUNPUTC(dest); 468 469 if (in.fd >= 0) 470 close(in.fd); 471 if (in.buf) 472 ckfree(in.buf); 473 if (in.jp) 474 back_exitstatus = waitforjob(in.jp); 475 if (quoted == 0) 476 recordregion(startloc, dest - stackblock(), 0); 477 TRACE(("evalbackq: size=%d: \"%.*s\"\n", 478 (dest - stackblock()) - startloc, 479 (dest - stackblock()) - startloc, 480 stackblock() + startloc)); 481 expdest = dest; 482 INTON; 483 } 484 485 486 487 STATIC int 488 subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varflags) 489 { 490 char *startp; 491 char *loc = NULL; 492 char *q; 493 int c = 0; 494 int saveherefd = herefd; 495 struct nodelist *saveargbackq = argbackq; 496 int amount; 497 498 herefd = -1; 499 argstr(p, 0); 500 STACKSTRNUL(expdest); 501 herefd = saveherefd; 502 argbackq = saveargbackq; 503 startp = stackblock() + startloc; 504 if (str == NULL) 505 str = stackblock() + strloc; 506 507 switch (subtype) { 508 case VSASSIGN: 509 setvar(str, startp, 0); 510 amount = startp - expdest; 511 STADJUST(amount, expdest); 512 varflags &= ~VSNUL; 513 return 1; 514 515 case VSQUESTION: 516 if (*p != CTLENDVAR) { 517 outfmt(&errout, "%s\n", startp); 518 error((char *)NULL); 519 } 520 error("%.*s: parameter %snot set", p - str - 1, 521 str, (varflags & VSNUL) ? "null or " 522 : nullstr); 523 /* NOTREACHED */ 524 525 case VSTRIMLEFT: 526 for (loc = startp; loc < str; loc++) { 527 c = *loc; 528 *loc = '\0'; 529 if (patmatch(str, startp, varflags & VSQUOTE)) 530 goto recordleft; 531 *loc = c; 532 if ((varflags & VSQUOTE) && *loc == CTLESC) 533 loc++; 534 } 535 return 0; 536 537 case VSTRIMLEFTMAX: 538 for (loc = str - 1; loc >= startp;) { 539 c = *loc; 540 *loc = '\0'; 541 if (patmatch(str, startp, varflags & VSQUOTE)) 542 goto recordleft; 543 *loc = c; 544 loc--; 545 if ((varflags & VSQUOTE) && loc > startp && 546 *(loc - 1) == CTLESC) { 547 for (q = startp; q < loc; q++) 548 if (*q == CTLESC) 549 q++; 550 if (q > loc) 551 loc--; 552 } 553 } 554 return 0; 555 556 case VSTRIMRIGHT: 557 for (loc = str - 1; loc >= startp;) { 558 if (patmatch(str, loc, varflags & VSQUOTE)) 559 goto recordright; 560 loc--; 561 if ((varflags & VSQUOTE) && loc > startp && 562 *(loc - 1) == CTLESC) { 563 for (q = startp; q < loc; q++) 564 if (*q == CTLESC) 565 q++; 566 if (q > loc) 567 loc--; 568 } 569 } 570 return 0; 571 572 case VSTRIMRIGHTMAX: 573 for (loc = startp; loc < str - 1; loc++) { 574 if (patmatch(str, loc, varflags & VSQUOTE)) 575 goto recordright; 576 if ((varflags & VSQUOTE) && *loc == CTLESC) 577 loc++; 578 } 579 return 0; 580 581 default: 582 abort(); 583 } 584 585 recordleft: 586 *loc = c; 587 amount = ((str - 1) - (loc - startp)) - expdest; 588 STADJUST(amount, expdest); 589 while (loc != str - 1) 590 *startp++ = *loc++; 591 return 1; 592 593 recordright: 594 amount = loc - expdest; 595 STADJUST(amount, expdest); 596 STPUTC('\0', expdest); 597 STADJUST(-1, expdest); 598 return 1; 599 } 600 601 602 /* 603 * Expand a variable, and return a pointer to the next character in the 604 * input string. 605 */ 606 607 STATIC char * 608 evalvar(char *p, int flag) 609 { 610 int subtype; 611 int varflags; 612 char *var; 613 char *val; 614 int patloc; 615 int c; 616 int set; 617 int special; 618 int startloc; 619 int varlen; 620 int apply_ifs; 621 int quotes = flag & (EXP_FULL | EXP_CASE); 622 623 varflags = (unsigned char)*p++; 624 subtype = varflags & VSTYPE; 625 var = p; 626 special = !is_name(*p); 627 p = strchr(p, '=') + 1; 628 629 again: /* jump here after setting a variable with ${var=text} */ 630 if (special) { 631 set = varisset(var, varflags & VSNUL); 632 val = NULL; 633 } else { 634 val = lookupvar(var); 635 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) { 636 val = NULL; 637 set = 0; 638 } else 639 set = 1; 640 } 641 642 varlen = 0; 643 startloc = expdest - stackblock(); 644 645 if (!set && uflag) { 646 switch (subtype) { 647 case VSNORMAL: 648 case VSTRIMLEFT: 649 case VSTRIMLEFTMAX: 650 case VSTRIMRIGHT: 651 case VSTRIMRIGHTMAX: 652 case VSLENGTH: 653 error("%.*s: parameter not set", p - var - 1, var); 654 /* NOTREACHED */ 655 } 656 } 657 658 if (set && subtype != VSPLUS) { 659 /* insert the value of the variable */ 660 if (special) { 661 varvalue(var, varflags & VSQUOTE, subtype, flag); 662 if (subtype == VSLENGTH) { 663 varlen = expdest - stackblock() - startloc; 664 STADJUST(-varlen, expdest); 665 } 666 } else { 667 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX 668 : BASESYNTAX; 669 670 if (subtype == VSLENGTH) { 671 for (;*val; val++) 672 varlen++; 673 } else { 674 while (*val) { 675 if (quotes && syntax[(int)*val] == CCTL) 676 STPUTC(CTLESC, expdest); 677 STPUTC(*val++, expdest); 678 } 679 680 } 681 } 682 } 683 684 685 apply_ifs = ((varflags & VSQUOTE) == 0 || 686 (*var == '@' && shellparam.nparam != 1)); 687 688 switch (subtype) { 689 case VSLENGTH: 690 expdest = cvtnum(varlen, expdest); 691 break; 692 693 case VSNORMAL: 694 break; 695 696 case VSPLUS: 697 set = !set; 698 /* FALLTHROUGH */ 699 case VSMINUS: 700 if (!set) { 701 argstr(p, flag | (apply_ifs ? EXP_IFS_SPLIT : 0)); 702 /* 703 * ${x-a b c} doesn't get split, but removing the 704 * 'apply_ifs = 0' apparantly breaks ${1+"$@"}.. 705 * ${x-'a b' c} should generate 2 args. 706 */ 707 /* We should have marked stuff already */ 708 apply_ifs = 0; 709 } 710 break; 711 712 case VSTRIMLEFT: 713 case VSTRIMLEFTMAX: 714 case VSTRIMRIGHT: 715 case VSTRIMRIGHTMAX: 716 if (!set) 717 break; 718 /* 719 * Terminate the string and start recording the pattern 720 * right after it 721 */ 722 STPUTC('\0', expdest); 723 patloc = expdest - stackblock(); 724 if (subevalvar(p, NULL, patloc, subtype, 725 startloc, varflags) == 0) { 726 int amount = (expdest - stackblock() - patloc) + 1; 727 STADJUST(-amount, expdest); 728 } 729 /* Remove any recorded regions beyond start of variable */ 730 removerecordregions(startloc); 731 apply_ifs = 1; 732 break; 733 734 case VSASSIGN: 735 case VSQUESTION: 736 if (set) 737 break; 738 if (subevalvar(p, var, 0, subtype, startloc, varflags)) { 739 varflags &= ~VSNUL; 740 /* 741 * Remove any recorded regions beyond 742 * start of variable 743 */ 744 removerecordregions(startloc); 745 goto again; 746 } 747 apply_ifs = 0; 748 break; 749 750 default: 751 abort(); 752 } 753 754 if (apply_ifs) 755 recordregion(startloc, expdest - stackblock(), 756 varflags & VSQUOTE); 757 758 if (subtype != VSNORMAL) { /* skip to end of alternative */ 759 int nesting = 1; 760 for (;;) { 761 if ((c = *p++) == CTLESC) 762 p++; 763 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) { 764 if (set) 765 argbackq = argbackq->next; 766 } else if (c == CTLVAR) { 767 if ((*p++ & VSTYPE) != VSNORMAL) 768 nesting++; 769 } else if (c == CTLENDVAR) { 770 if (--nesting == 0) 771 break; 772 } 773 } 774 } 775 return p; 776 } 777 778 779 780 /* 781 * Test whether a specialized variable is set. 782 */ 783 784 STATIC int 785 varisset(char *name, int nulok) 786 { 787 if (*name == '!') 788 return backgndpid != -1; 789 else if (*name == '@' || *name == '*') { 790 if (*shellparam.p == NULL) 791 return 0; 792 793 if (nulok) { 794 char **av; 795 796 for (av = shellparam.p; *av; av++) 797 if (**av != '\0') 798 return 1; 799 return 0; 800 } 801 } else if (is_digit(*name)) { 802 char *ap; 803 int num = atoi(name); 804 805 if (num > shellparam.nparam) 806 return 0; 807 808 if (num == 0) 809 ap = arg0; 810 else 811 ap = shellparam.p[num - 1]; 812 813 if (nulok && (ap == NULL || *ap == '\0')) 814 return 0; 815 } 816 return 1; 817 } 818 819 820 821 /* 822 * Add the value of a specialized variable to the stack string. 823 */ 824 825 STATIC void 826 varvalue(char *name, int quoted, int subtype, int flag) 827 { 828 int num; 829 char *p; 830 int i; 831 char sep; 832 char **ap; 833 char const *syntax; 834 835 #define STRTODEST(p) \ 836 do {\ 837 if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) { \ 838 syntax = quoted? DQSYNTAX : BASESYNTAX; \ 839 while (*p) { \ 840 if (syntax[(int)*p] == CCTL) \ 841 STPUTC(CTLESC, expdest); \ 842 STPUTC(*p++, expdest); \ 843 } \ 844 } else \ 845 while (*p) \ 846 STPUTC(*p++, expdest); \ 847 } while (0) 848 849 850 switch (*name) { 851 case '$': 852 num = rootpid; 853 goto numvar; 854 case '?': 855 num = exitstatus; 856 goto numvar; 857 case '#': 858 num = shellparam.nparam; 859 goto numvar; 860 case '!': 861 num = backgndpid; 862 numvar: 863 expdest = cvtnum(num, expdest); 864 break; 865 case '-': 866 for (i = 0; optlist[i].name; i++) { 867 if (optlist[i].val && optlist[i].letter) 868 STPUTC(optlist[i].letter, expdest); 869 } 870 break; 871 case '@': 872 if (flag & EXP_FULL && quoted) { 873 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 874 STRTODEST(p); 875 /* Nul forces a parameter split inside "" */ 876 STPUTC('\0', expdest); 877 } 878 break; 879 } 880 /* fall through */ 881 case '*': 882 if (ifsset() != 0) 883 sep = ifsval()[0]; 884 else 885 sep = ' '; 886 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 887 STRTODEST(p); 888 if (*ap && sep) 889 STPUTC(sep, expdest); 890 } 891 break; 892 case '0': 893 p = arg0; 894 STRTODEST(p); 895 break; 896 default: 897 if (is_digit(*name)) { 898 num = atoi(name); 899 if (num > 0 && num <= shellparam.nparam) { 900 p = shellparam.p[num - 1]; 901 STRTODEST(p); 902 } 903 } 904 break; 905 } 906 } 907 908 909 910 /* 911 * Record the fact that we have to scan this region of the 912 * string for IFS characters. 913 */ 914 915 STATIC void 916 recordregion(int start, int end, int inquotes) 917 { 918 struct ifsregion *ifsp; 919 920 if (ifslastp == NULL) { 921 ifsp = &ifsfirst; 922 } else { 923 if (ifslastp->endoff == start 924 && ifslastp->inquotes == inquotes) { 925 /* extend previous area */ 926 ifslastp->endoff = end; 927 return; 928 } 929 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion)); 930 ifslastp->next = ifsp; 931 } 932 ifslastp = ifsp; 933 ifslastp->next = NULL; 934 ifslastp->begoff = start; 935 ifslastp->endoff = end; 936 ifslastp->inquotes = inquotes; 937 } 938 939 940 941 /* 942 * Break the argument string into pieces based upon IFS and add the 943 * strings to the argument list. The regions of the string to be 944 * searched for IFS characters have been stored by recordregion. 945 */ 946 STATIC void 947 ifsbreakup(char *string, struct arglist *arglist) 948 { 949 struct ifsregion *ifsp; 950 struct strlist *sp; 951 char *start; 952 char *p; 953 char *q; 954 const char *ifs; 955 const char *ifsspc; 956 int inquotes; 957 958 start = string; 959 ifsspc = NULL; 960 inquotes = 0; 961 962 if (ifslastp == NULL) { 963 /* Return entire argument, IFS doesn't apply to any of it */ 964 sp = (struct strlist *)stalloc(sizeof *sp); 965 sp->text = start; 966 *arglist->lastp = sp; 967 arglist->lastp = &sp->next; 968 return; 969 } 970 971 ifs = ifsset() ? ifsval() : " \t\n"; 972 973 for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) { 974 p = string + ifsp->begoff; 975 inquotes = ifsp->inquotes; 976 ifsspc = NULL; 977 while (p < string + ifsp->endoff) { 978 q = p; 979 if (*p == CTLESC) 980 p++; 981 if (inquotes) { 982 /* Only NULs (probably from "$@") end args */ 983 if (*p != 0) { 984 p++; 985 continue; 986 } 987 } else { 988 if (!strchr(ifs, *p)) { 989 p++; 990 continue; 991 } 992 ifsspc = strchr(" \t\n", *p); 993 994 /* Ignore IFS whitespace at start */ 995 if (q == start && ifsspc != NULL) { 996 p++; 997 start = p; 998 continue; 999 } 1000 } 1001 1002 /* Save this argument... */ 1003 *q = '\0'; 1004 sp = (struct strlist *)stalloc(sizeof *sp); 1005 sp->text = start; 1006 *arglist->lastp = sp; 1007 arglist->lastp = &sp->next; 1008 p++; 1009 1010 if (ifsspc != NULL) { 1011 /* Ignore further trailing IFS whitespace */ 1012 for (; p < string + ifsp->endoff; p++) { 1013 q = p; 1014 if (*p == CTLESC) 1015 p++; 1016 if (strchr(ifs, *p) == NULL) { 1017 p = q; 1018 break; 1019 } 1020 if (strchr(" \t\n", *p) == NULL) { 1021 p++; 1022 break; 1023 } 1024 } 1025 } 1026 start = p; 1027 } 1028 } 1029 1030 /* 1031 * Save anything left as an argument. 1032 * Traditionally we have treated 'IFS=':'; set -- x$IFS' as 1033 * generating 2 arguments, the second of which is empty. 1034 * Some recent clarification of the Posix spec say that it 1035 * should only generate one.... 1036 */ 1037 if (*start) { 1038 sp = (struct strlist *)stalloc(sizeof *sp); 1039 sp->text = start; 1040 *arglist->lastp = sp; 1041 arglist->lastp = &sp->next; 1042 } 1043 } 1044 1045 STATIC void 1046 ifsfree(void) 1047 { 1048 while (ifsfirst.next != NULL) { 1049 struct ifsregion *ifsp; 1050 INTOFF; 1051 ifsp = ifsfirst.next->next; 1052 ckfree(ifsfirst.next); 1053 ifsfirst.next = ifsp; 1054 INTON; 1055 } 1056 ifslastp = NULL; 1057 ifsfirst.next = NULL; 1058 } 1059 1060 1061 1062 /* 1063 * Expand shell metacharacters. At this point, the only control characters 1064 * should be escapes. The results are stored in the list exparg. 1065 */ 1066 1067 char *expdir; 1068 1069 1070 STATIC void 1071 expandmeta(struct strlist *str, int flag) 1072 { 1073 char *p; 1074 struct strlist **savelastp; 1075 struct strlist *sp; 1076 char c; 1077 /* TODO - EXP_REDIR */ 1078 1079 while (str) { 1080 if (fflag) 1081 goto nometa; 1082 p = str->text; 1083 for (;;) { /* fast check for meta chars */ 1084 if ((c = *p++) == '\0') 1085 goto nometa; 1086 if (c == '*' || c == '?' || c == '[' || c == '!') 1087 break; 1088 } 1089 savelastp = exparg.lastp; 1090 INTOFF; 1091 if (expdir == NULL) { 1092 int i = strlen(str->text); 1093 expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */ 1094 } 1095 1096 expmeta(expdir, str->text); 1097 ckfree(expdir); 1098 expdir = NULL; 1099 INTON; 1100 if (exparg.lastp == savelastp) { 1101 /* 1102 * no matches 1103 */ 1104 nometa: 1105 *exparg.lastp = str; 1106 rmescapes(str->text); 1107 exparg.lastp = &str->next; 1108 } else { 1109 *exparg.lastp = NULL; 1110 *savelastp = sp = expsort(*savelastp); 1111 while (sp->next != NULL) 1112 sp = sp->next; 1113 exparg.lastp = &sp->next; 1114 } 1115 str = str->next; 1116 } 1117 } 1118 1119 1120 /* 1121 * Do metacharacter (i.e. *, ?, [...]) expansion. 1122 */ 1123 1124 STATIC void 1125 expmeta(char *enddir, char *name) 1126 { 1127 char *p; 1128 const char *cp; 1129 char *q; 1130 char *start; 1131 char *endname; 1132 int metaflag; 1133 struct stat statb; 1134 DIR *dirp; 1135 struct dirent *dp; 1136 int atend; 1137 int matchdot; 1138 1139 metaflag = 0; 1140 start = name; 1141 for (p = name ; ; p++) { 1142 if (*p == '*' || *p == '?') 1143 metaflag = 1; 1144 else if (*p == '[') { 1145 q = p + 1; 1146 if (*q == '!') 1147 q++; 1148 for (;;) { 1149 while (*q == CTLQUOTEMARK) 1150 q++; 1151 if (*q == CTLESC) 1152 q++; 1153 if (*q == '/' || *q == '\0') 1154 break; 1155 if (*++q == ']') { 1156 metaflag = 1; 1157 break; 1158 } 1159 } 1160 } else if (*p == '!' && p[1] == '!' && (p == name || p[-1] == '/')) { 1161 metaflag = 1; 1162 } else if (*p == '\0') 1163 break; 1164 else if (*p == CTLQUOTEMARK) 1165 continue; 1166 else if (*p == CTLESC) 1167 p++; 1168 if (*p == '/') { 1169 if (metaflag) 1170 break; 1171 start = p + 1; 1172 } 1173 } 1174 if (metaflag == 0) { /* we've reached the end of the file name */ 1175 if (enddir != expdir) 1176 metaflag++; 1177 for (p = name ; ; p++) { 1178 if (*p == CTLQUOTEMARK) 1179 continue; 1180 if (*p == CTLESC) 1181 p++; 1182 *enddir++ = *p; 1183 if (*p == '\0') 1184 break; 1185 } 1186 if (metaflag == 0 || lstat(expdir, &statb) >= 0) 1187 addfname(expdir); 1188 return; 1189 } 1190 endname = p; 1191 if (start != name) { 1192 p = name; 1193 while (p < start) { 1194 while (*p == CTLQUOTEMARK) 1195 p++; 1196 if (*p == CTLESC) 1197 p++; 1198 *enddir++ = *p++; 1199 } 1200 } 1201 if (enddir == expdir) { 1202 cp = "."; 1203 } else if (enddir == expdir + 1 && *expdir == '/') { 1204 cp = "/"; 1205 } else { 1206 cp = expdir; 1207 enddir[-1] = '\0'; 1208 } 1209 if ((dirp = opendir(cp)) == NULL) 1210 return; 1211 if (enddir != expdir) 1212 enddir[-1] = '/'; 1213 if (*endname == 0) { 1214 atend = 1; 1215 } else { 1216 atend = 0; 1217 *endname++ = '\0'; 1218 } 1219 matchdot = 0; 1220 p = start; 1221 while (*p == CTLQUOTEMARK) 1222 p++; 1223 if (*p == CTLESC) 1224 p++; 1225 if (*p == '.') 1226 matchdot++; 1227 while (! int_pending() && (dp = readdir(dirp)) != NULL) { 1228 if (dp->d_name[0] == '.' && ! matchdot) 1229 continue; 1230 if (patmatch(start, dp->d_name, 0)) { 1231 if (atend) { 1232 scopy(dp->d_name, enddir); 1233 addfname(expdir); 1234 } else { 1235 for (p = enddir, cp = dp->d_name; 1236 (*p++ = *cp++) != '\0';) 1237 continue; 1238 p[-1] = '/'; 1239 expmeta(p, endname); 1240 } 1241 } 1242 } 1243 closedir(dirp); 1244 if (! atend) 1245 endname[-1] = '/'; 1246 } 1247 1248 1249 /* 1250 * Add a file name to the list. 1251 */ 1252 1253 STATIC void 1254 addfname(char *name) 1255 { 1256 char *p; 1257 struct strlist *sp; 1258 1259 p = stalloc(strlen(name) + 1); 1260 scopy(name, p); 1261 sp = (struct strlist *)stalloc(sizeof *sp); 1262 sp->text = p; 1263 *exparg.lastp = sp; 1264 exparg.lastp = &sp->next; 1265 } 1266 1267 1268 /* 1269 * Sort the results of file name expansion. It calculates the number of 1270 * strings to sort and then calls msort (short for merge sort) to do the 1271 * work. 1272 */ 1273 1274 STATIC struct strlist * 1275 expsort(struct strlist *str) 1276 { 1277 int len; 1278 struct strlist *sp; 1279 1280 len = 0; 1281 for (sp = str ; sp ; sp = sp->next) 1282 len++; 1283 return msort(str, len); 1284 } 1285 1286 1287 STATIC struct strlist * 1288 msort(struct strlist *list, int len) 1289 { 1290 struct strlist *p, *q = NULL; 1291 struct strlist **lpp; 1292 int half; 1293 int n; 1294 1295 if (len <= 1) 1296 return list; 1297 half = len >> 1; 1298 p = list; 1299 for (n = half ; --n >= 0 ; ) { 1300 q = p; 1301 p = p->next; 1302 } 1303 q->next = NULL; /* terminate first half of list */ 1304 q = msort(list, half); /* sort first half of list */ 1305 p = msort(p, len - half); /* sort second half */ 1306 lpp = &list; 1307 for (;;) { 1308 if (strcmp(p->text, q->text) < 0) { 1309 *lpp = p; 1310 lpp = &p->next; 1311 if ((p = *lpp) == NULL) { 1312 *lpp = q; 1313 break; 1314 } 1315 } else { 1316 *lpp = q; 1317 lpp = &q->next; 1318 if ((q = *lpp) == NULL) { 1319 *lpp = p; 1320 break; 1321 } 1322 } 1323 } 1324 return list; 1325 } 1326 1327 1328 1329 /* 1330 * Returns true if the pattern matches the string. 1331 */ 1332 1333 int 1334 patmatch(char *pattern, char *string, int squoted) 1335 { 1336 #ifdef notdef 1337 if (pattern[0] == '!' && pattern[1] == '!') 1338 return 1 - pmatch(pattern + 2, string); 1339 else 1340 #endif 1341 return pmatch(pattern, string, squoted); 1342 } 1343 1344 1345 STATIC int 1346 pmatch(char *pattern, char *string, int squoted) 1347 { 1348 char *p, *q; 1349 char c; 1350 1351 p = pattern; 1352 q = string; 1353 for (;;) { 1354 switch (c = *p++) { 1355 case '\0': 1356 goto breakloop; 1357 case CTLESC: 1358 if (squoted && *q == CTLESC) 1359 q++; 1360 if (*q++ != *p++) 1361 return 0; 1362 break; 1363 case CTLQUOTEMARK: 1364 continue; 1365 case '?': 1366 if (squoted && *q == CTLESC) 1367 q++; 1368 if (*q++ == '\0') 1369 return 0; 1370 break; 1371 case '*': 1372 c = *p; 1373 while (c == CTLQUOTEMARK || c == '*') 1374 c = *++p; 1375 if (c != CTLESC && c != CTLQUOTEMARK && 1376 c != '?' && c != '*' && c != '[') { 1377 while (*q != c) { 1378 if (squoted && *q == CTLESC && 1379 q[1] == c) 1380 break; 1381 if (*q == '\0') 1382 return 0; 1383 if (squoted && *q == CTLESC) 1384 q++; 1385 q++; 1386 } 1387 } 1388 do { 1389 if (pmatch(p, q, squoted)) 1390 return 1; 1391 if (squoted && *q == CTLESC) 1392 q++; 1393 } while (*q++ != '\0'); 1394 return 0; 1395 case '[': { 1396 char *endp; 1397 int invert, found; 1398 char chr; 1399 1400 endp = p; 1401 if (*endp == '!') 1402 endp++; 1403 for (;;) { 1404 while (*endp == CTLQUOTEMARK) 1405 endp++; 1406 if (*endp == '\0') 1407 goto dft; /* no matching ] */ 1408 if (*endp == CTLESC) 1409 endp++; 1410 if (*++endp == ']') 1411 break; 1412 } 1413 invert = 0; 1414 if (*p == '!') { 1415 invert++; 1416 p++; 1417 } 1418 found = 0; 1419 chr = *q++; 1420 if (squoted && chr == CTLESC) 1421 chr = *q++; 1422 if (chr == '\0') 1423 return 0; 1424 c = *p++; 1425 do { 1426 if (c == CTLQUOTEMARK) 1427 continue; 1428 if (c == CTLESC) 1429 c = *p++; 1430 if (*p == '-' && p[1] != ']') { 1431 p++; 1432 while (*p == CTLQUOTEMARK) 1433 p++; 1434 if (*p == CTLESC) 1435 p++; 1436 if (chr >= c && chr <= *p) 1437 found = 1; 1438 p++; 1439 } else { 1440 if (chr == c) 1441 found = 1; 1442 } 1443 } while ((c = *p++) != ']'); 1444 if (found == invert) 1445 return 0; 1446 break; 1447 } 1448 dft: default: 1449 if (squoted && *q == CTLESC) 1450 q++; 1451 if (*q++ != c) 1452 return 0; 1453 break; 1454 } 1455 } 1456 breakloop: 1457 if (*q != '\0') 1458 return 0; 1459 return 1; 1460 } 1461 1462 1463 1464 /* 1465 * Remove any CTLESC characters from a string. 1466 */ 1467 1468 void 1469 rmescapes(char *str) 1470 { 1471 char *p, *q; 1472 1473 p = str; 1474 while (*p != CTLESC && *p != CTLQUOTEMARK) { 1475 if (*p++ == '\0') 1476 return; 1477 } 1478 q = p; 1479 while (*p) { 1480 if (*p == CTLQUOTEMARK) { 1481 p++; 1482 continue; 1483 } 1484 if (*p == CTLESC) 1485 p++; 1486 *q++ = *p++; 1487 } 1488 *q = '\0'; 1489 } 1490 1491 1492 1493 /* 1494 * See if a pattern matches in a case statement. 1495 */ 1496 1497 int 1498 casematch(union node *pattern, char *val) 1499 { 1500 struct stackmark smark; 1501 int result; 1502 char *p; 1503 1504 setstackmark(&smark); 1505 argbackq = pattern->narg.backquote; 1506 STARTSTACKSTR(expdest); 1507 ifslastp = NULL; 1508 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE); 1509 STPUTC('\0', expdest); 1510 p = grabstackstr(expdest); 1511 result = patmatch(p, val, 0); 1512 popstackmark(&smark); 1513 return result; 1514 } 1515 1516 /* 1517 * Our own itoa(). 1518 */ 1519 1520 STATIC char * 1521 cvtnum(int num, char *buf) 1522 { 1523 char temp[32]; 1524 int neg = num < 0; 1525 char *p = temp + 31; 1526 1527 temp[31] = '\0'; 1528 1529 do { 1530 *--p = num % 10 + '0'; 1531 } while ((num /= 10) != 0); 1532 1533 if (neg) 1534 *--p = '-'; 1535 1536 while (*p) 1537 STPUTC(*p++, buf); 1538 return buf; 1539 } 1540 1541 /* 1542 * Do most of the work for wordexp(3). 1543 */ 1544 1545 int 1546 wordexpcmd(int argc, char **argv) 1547 { 1548 size_t len; 1549 int i; 1550 1551 out1fmt("%d", argc - 1); 1552 out1c('\0'); 1553 for (i = 1, len = 0; i < argc; i++) 1554 len += strlen(argv[i]); 1555 out1fmt("%zd", len); 1556 out1c('\0'); 1557 for (i = 1; i < argc; i++) { 1558 out1str(argv[i]); 1559 out1c('\0'); 1560 } 1561 return (0); 1562 } 1563