1 /* $NetBSD: expand.c,v 1.67 2004/07/13 15:05:59 seb 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 1.67 2004/07/13 15:05:59 seb 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; 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 for (p--; lastc == '\n'; lastc = *--p) 466 STUNPUTC(dest); 467 468 if (in.fd >= 0) 469 close(in.fd); 470 if (in.buf) 471 ckfree(in.buf); 472 if (in.jp) 473 back_exitstatus = waitforjob(in.jp); 474 if (quoted == 0) 475 recordregion(startloc, dest - stackblock(), 0); 476 TRACE(("evalbackq: size=%d: \"%.*s\"\n", 477 (dest - stackblock()) - startloc, 478 (dest - stackblock()) - startloc, 479 stackblock() + startloc)); 480 expdest = dest; 481 INTON; 482 } 483 484 485 486 STATIC int 487 subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varflags) 488 { 489 char *startp; 490 char *loc = NULL; 491 char *q; 492 int c = 0; 493 int saveherefd = herefd; 494 struct nodelist *saveargbackq = argbackq; 495 int amount; 496 497 herefd = -1; 498 argstr(p, 0); 499 STACKSTRNUL(expdest); 500 herefd = saveherefd; 501 argbackq = saveargbackq; 502 startp = stackblock() + startloc; 503 if (str == NULL) 504 str = stackblock() + strloc; 505 506 switch (subtype) { 507 case VSASSIGN: 508 setvar(str, startp, 0); 509 amount = startp - expdest; 510 STADJUST(amount, expdest); 511 varflags &= ~VSNUL; 512 if (c != 0) 513 *loc = c; 514 return 1; 515 516 case VSQUESTION: 517 if (*p != CTLENDVAR) { 518 outfmt(&errout, "%s\n", startp); 519 error((char *)NULL); 520 } 521 error("%.*s: parameter %snot set", p - str - 1, 522 str, (varflags & VSNUL) ? "null or " 523 : nullstr); 524 /* NOTREACHED */ 525 526 case VSTRIMLEFT: 527 for (loc = startp; loc < str; loc++) { 528 c = *loc; 529 *loc = '\0'; 530 if (patmatch(str, startp, varflags & VSQUOTE)) 531 goto recordleft; 532 *loc = c; 533 if ((varflags & VSQUOTE) && *loc == CTLESC) 534 loc++; 535 } 536 return 0; 537 538 case VSTRIMLEFTMAX: 539 for (loc = str - 1; loc >= startp;) { 540 c = *loc; 541 *loc = '\0'; 542 if (patmatch(str, startp, varflags & VSQUOTE)) 543 goto recordleft; 544 *loc = c; 545 loc--; 546 if ((varflags & VSQUOTE) && loc > startp && 547 *(loc - 1) == CTLESC) { 548 for (q = startp; q < loc; q++) 549 if (*q == CTLESC) 550 q++; 551 if (q > loc) 552 loc--; 553 } 554 } 555 return 0; 556 557 case VSTRIMRIGHT: 558 for (loc = str - 1; loc >= startp;) { 559 if (patmatch(str, loc, varflags & VSQUOTE)) 560 goto recordright; 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 VSTRIMRIGHTMAX: 574 for (loc = startp; loc < str - 1; loc++) { 575 if (patmatch(str, loc, varflags & VSQUOTE)) 576 goto recordright; 577 if ((varflags & VSQUOTE) && *loc == CTLESC) 578 loc++; 579 } 580 return 0; 581 582 default: 583 abort(); 584 } 585 586 recordleft: 587 *loc = c; 588 amount = ((str - 1) - (loc - startp)) - expdest; 589 STADJUST(amount, expdest); 590 while (loc != str - 1) 591 *startp++ = *loc++; 592 return 1; 593 594 recordright: 595 amount = loc - expdest; 596 STADJUST(amount, expdest); 597 STPUTC('\0', expdest); 598 STADJUST(-1, expdest); 599 return 1; 600 } 601 602 603 /* 604 * Expand a variable, and return a pointer to the next character in the 605 * input string. 606 */ 607 608 STATIC char * 609 evalvar(char *p, int flag) 610 { 611 int subtype; 612 int varflags; 613 char *var; 614 char *val; 615 int patloc; 616 int c; 617 int set; 618 int special; 619 int startloc; 620 int varlen; 621 int apply_ifs; 622 int quotes = flag & (EXP_FULL | EXP_CASE); 623 624 varflags = (unsigned char)*p++; 625 subtype = varflags & VSTYPE; 626 var = p; 627 special = !is_name(*p); 628 p = strchr(p, '=') + 1; 629 630 again: /* jump here after setting a variable with ${var=text} */ 631 if (special) { 632 set = varisset(var, varflags & VSNUL); 633 val = NULL; 634 } else { 635 val = lookupvar(var); 636 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) { 637 val = NULL; 638 set = 0; 639 } else 640 set = 1; 641 } 642 643 varlen = 0; 644 startloc = expdest - stackblock(); 645 646 if (!set && uflag) { 647 switch (subtype) { 648 case VSNORMAL: 649 case VSTRIMLEFT: 650 case VSTRIMLEFTMAX: 651 case VSTRIMRIGHT: 652 case VSTRIMRIGHTMAX: 653 case VSLENGTH: 654 error("%.*s: parameter not set", p - var - 1, var); 655 /* NOTREACHED */ 656 } 657 } 658 659 if (set && subtype != VSPLUS) { 660 /* insert the value of the variable */ 661 if (special) { 662 varvalue(var, varflags & VSQUOTE, subtype, flag); 663 if (subtype == VSLENGTH) { 664 varlen = expdest - stackblock() - startloc; 665 STADJUST(-varlen, expdest); 666 } 667 } else { 668 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX 669 : BASESYNTAX; 670 671 if (subtype == VSLENGTH) { 672 for (;*val; val++) 673 varlen++; 674 } else { 675 while (*val) { 676 if (quotes && syntax[(int)*val] == CCTL) 677 STPUTC(CTLESC, expdest); 678 STPUTC(*val++, expdest); 679 } 680 681 } 682 } 683 } 684 685 686 apply_ifs = ((varflags & VSQUOTE) == 0 || 687 (*var == '@' && shellparam.nparam != 1)); 688 689 switch (subtype) { 690 case VSLENGTH: 691 expdest = cvtnum(varlen, expdest); 692 break; 693 694 case VSNORMAL: 695 break; 696 697 case VSPLUS: 698 set = !set; 699 /* FALLTHROUGH */ 700 case VSMINUS: 701 if (!set) { 702 argstr(p, flag | (apply_ifs ? EXP_IFS_SPLIT : 0)); 703 /* 704 * ${x-a b c} doesn't get split, but removing the 705 * 'apply_ifs = 0' apparantly breaks ${1+"$@"}.. 706 * ${x-'a b' c} should generate 2 args. 707 */ 708 /* We should have marked stuff already */ 709 apply_ifs = 0; 710 } 711 break; 712 713 case VSTRIMLEFT: 714 case VSTRIMLEFTMAX: 715 case VSTRIMRIGHT: 716 case VSTRIMRIGHTMAX: 717 if (!set) 718 break; 719 /* 720 * Terminate the string and start recording the pattern 721 * right after it 722 */ 723 STPUTC('\0', expdest); 724 patloc = expdest - stackblock(); 725 if (subevalvar(p, NULL, patloc, subtype, 726 startloc, varflags) == 0) { 727 int amount = (expdest - stackblock() - patloc) + 1; 728 STADJUST(-amount, expdest); 729 } 730 /* Remove any recorded regions beyond start of variable */ 731 removerecordregions(startloc); 732 apply_ifs = 1; 733 break; 734 735 case VSASSIGN: 736 case VSQUESTION: 737 if (set) 738 break; 739 if (subevalvar(p, var, 0, subtype, startloc, varflags)) { 740 varflags &= ~VSNUL; 741 /* 742 * Remove any recorded regions beyond 743 * start of variable 744 */ 745 removerecordregions(startloc); 746 goto again; 747 } 748 apply_ifs = 0; 749 break; 750 751 default: 752 abort(); 753 } 754 755 if (apply_ifs) 756 recordregion(startloc, expdest - stackblock(), 757 varflags & VSQUOTE); 758 759 if (subtype != VSNORMAL) { /* skip to end of alternative */ 760 int nesting = 1; 761 for (;;) { 762 if ((c = *p++) == CTLESC) 763 p++; 764 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) { 765 if (set) 766 argbackq = argbackq->next; 767 } else if (c == CTLVAR) { 768 if ((*p++ & VSTYPE) != VSNORMAL) 769 nesting++; 770 } else if (c == CTLENDVAR) { 771 if (--nesting == 0) 772 break; 773 } 774 } 775 } 776 return p; 777 } 778 779 780 781 /* 782 * Test whether a specialized variable is set. 783 */ 784 785 STATIC int 786 varisset(char *name, int nulok) 787 { 788 if (*name == '!') 789 return backgndpid != -1; 790 else if (*name == '@' || *name == '*') { 791 if (*shellparam.p == NULL) 792 return 0; 793 794 if (nulok) { 795 char **av; 796 797 for (av = shellparam.p; *av; av++) 798 if (**av != '\0') 799 return 1; 800 return 0; 801 } 802 } else if (is_digit(*name)) { 803 char *ap; 804 int num = atoi(name); 805 806 if (num > shellparam.nparam) 807 return 0; 808 809 if (num == 0) 810 ap = arg0; 811 else 812 ap = shellparam.p[num - 1]; 813 814 if (nulok && (ap == NULL || *ap == '\0')) 815 return 0; 816 } 817 return 1; 818 } 819 820 821 822 /* 823 * Add the value of a specialized variable to the stack string. 824 */ 825 826 STATIC void 827 varvalue(char *name, int quoted, int subtype, int flag) 828 { 829 int num; 830 char *p; 831 int i; 832 char sep; 833 char **ap; 834 char const *syntax; 835 836 #define STRTODEST(p) \ 837 do {\ 838 if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) { \ 839 syntax = quoted? DQSYNTAX : BASESYNTAX; \ 840 while (*p) { \ 841 if (syntax[(int)*p] == CCTL) \ 842 STPUTC(CTLESC, expdest); \ 843 STPUTC(*p++, expdest); \ 844 } \ 845 } else \ 846 while (*p) \ 847 STPUTC(*p++, expdest); \ 848 } while (0) 849 850 851 switch (*name) { 852 case '$': 853 num = rootpid; 854 goto numvar; 855 case '?': 856 num = exitstatus; 857 goto numvar; 858 case '#': 859 num = shellparam.nparam; 860 goto numvar; 861 case '!': 862 num = backgndpid; 863 numvar: 864 expdest = cvtnum(num, expdest); 865 break; 866 case '-': 867 for (i = 0; optlist[i].name; i++) { 868 if (optlist[i].val) 869 STPUTC(optlist[i].letter, expdest); 870 } 871 break; 872 case '@': 873 if (flag & EXP_FULL && quoted) { 874 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 875 STRTODEST(p); 876 if (*ap) 877 STPUTC('\0', expdest); 878 } 879 break; 880 } 881 /* fall through */ 882 case '*': 883 if (ifsset() != 0) 884 sep = ifsval()[0]; 885 else 886 sep = ' '; 887 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 888 STRTODEST(p); 889 if (*ap && sep) 890 STPUTC(sep, expdest); 891 } 892 break; 893 case '0': 894 p = arg0; 895 STRTODEST(p); 896 break; 897 default: 898 if (is_digit(*name)) { 899 num = atoi(name); 900 if (num > 0 && num <= shellparam.nparam) { 901 p = shellparam.p[num - 1]; 902 STRTODEST(p); 903 } 904 } 905 break; 906 } 907 } 908 909 910 911 /* 912 * Record the fact that we have to scan this region of the 913 * string for IFS characters. 914 */ 915 916 STATIC void 917 recordregion(int start, int end, int inquotes) 918 { 919 struct ifsregion *ifsp; 920 921 if (ifslastp == NULL) { 922 ifsp = &ifsfirst; 923 } else { 924 if (ifslastp->endoff == start) { 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 (!inquotes) { 1011 /* Ignore trailing IFS writespace */ 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 if (ifsspc == NULL) { 1022 p = q; 1023 break; 1024 } 1025 ifsspc = NULL; 1026 } 1027 } 1028 } 1029 start = p; 1030 } 1031 } 1032 1033 /* Save anything left as an argument */ 1034 if (*start || (!ifsspc && start > string)) { 1035 sp = (struct strlist *)stalloc(sizeof *sp); 1036 sp->text = start; 1037 *arglist->lastp = sp; 1038 arglist->lastp = &sp->next; 1039 } 1040 } 1041 1042 STATIC void 1043 ifsfree(void) 1044 { 1045 while (ifsfirst.next != NULL) { 1046 struct ifsregion *ifsp; 1047 INTOFF; 1048 ifsp = ifsfirst.next->next; 1049 ckfree(ifsfirst.next); 1050 ifsfirst.next = ifsp; 1051 INTON; 1052 } 1053 ifslastp = NULL; 1054 ifsfirst.next = NULL; 1055 } 1056 1057 1058 1059 /* 1060 * Expand shell metacharacters. At this point, the only control characters 1061 * should be escapes. The results are stored in the list exparg. 1062 */ 1063 1064 char *expdir; 1065 1066 1067 STATIC void 1068 expandmeta(struct strlist *str, int flag) 1069 { 1070 char *p; 1071 struct strlist **savelastp; 1072 struct strlist *sp; 1073 char c; 1074 /* TODO - EXP_REDIR */ 1075 1076 while (str) { 1077 if (fflag) 1078 goto nometa; 1079 p = str->text; 1080 for (;;) { /* fast check for meta chars */ 1081 if ((c = *p++) == '\0') 1082 goto nometa; 1083 if (c == '*' || c == '?' || c == '[' || c == '!') 1084 break; 1085 } 1086 savelastp = exparg.lastp; 1087 INTOFF; 1088 if (expdir == NULL) { 1089 int i = strlen(str->text); 1090 expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */ 1091 } 1092 1093 expmeta(expdir, str->text); 1094 ckfree(expdir); 1095 expdir = NULL; 1096 INTON; 1097 if (exparg.lastp == savelastp) { 1098 /* 1099 * no matches 1100 */ 1101 nometa: 1102 *exparg.lastp = str; 1103 rmescapes(str->text); 1104 exparg.lastp = &str->next; 1105 } else { 1106 *exparg.lastp = NULL; 1107 *savelastp = sp = expsort(*savelastp); 1108 while (sp->next != NULL) 1109 sp = sp->next; 1110 exparg.lastp = &sp->next; 1111 } 1112 str = str->next; 1113 } 1114 } 1115 1116 1117 /* 1118 * Do metacharacter (i.e. *, ?, [...]) expansion. 1119 */ 1120 1121 STATIC void 1122 expmeta(char *enddir, char *name) 1123 { 1124 char *p; 1125 const char *cp; 1126 char *q; 1127 char *start; 1128 char *endname; 1129 int metaflag; 1130 struct stat statb; 1131 DIR *dirp; 1132 struct dirent *dp; 1133 int atend; 1134 int matchdot; 1135 1136 metaflag = 0; 1137 start = name; 1138 for (p = name ; ; p++) { 1139 if (*p == '*' || *p == '?') 1140 metaflag = 1; 1141 else if (*p == '[') { 1142 q = p + 1; 1143 if (*q == '!') 1144 q++; 1145 for (;;) { 1146 while (*q == CTLQUOTEMARK) 1147 q++; 1148 if (*q == CTLESC) 1149 q++; 1150 if (*q == '/' || *q == '\0') 1151 break; 1152 if (*++q == ']') { 1153 metaflag = 1; 1154 break; 1155 } 1156 } 1157 } else if (*p == '!' && p[1] == '!' && (p == name || p[-1] == '/')) { 1158 metaflag = 1; 1159 } else if (*p == '\0') 1160 break; 1161 else if (*p == CTLQUOTEMARK) 1162 continue; 1163 else if (*p == CTLESC) 1164 p++; 1165 if (*p == '/') { 1166 if (metaflag) 1167 break; 1168 start = p + 1; 1169 } 1170 } 1171 if (metaflag == 0) { /* we've reached the end of the file name */ 1172 if (enddir != expdir) 1173 metaflag++; 1174 for (p = name ; ; p++) { 1175 if (*p == CTLQUOTEMARK) 1176 continue; 1177 if (*p == CTLESC) 1178 p++; 1179 *enddir++ = *p; 1180 if (*p == '\0') 1181 break; 1182 } 1183 if (metaflag == 0 || lstat(expdir, &statb) >= 0) 1184 addfname(expdir); 1185 return; 1186 } 1187 endname = p; 1188 if (start != name) { 1189 p = name; 1190 while (p < start) { 1191 while (*p == CTLQUOTEMARK) 1192 p++; 1193 if (*p == CTLESC) 1194 p++; 1195 *enddir++ = *p++; 1196 } 1197 } 1198 if (enddir == expdir) { 1199 cp = "."; 1200 } else if (enddir == expdir + 1 && *expdir == '/') { 1201 cp = "/"; 1202 } else { 1203 cp = expdir; 1204 enddir[-1] = '\0'; 1205 } 1206 if ((dirp = opendir(cp)) == NULL) 1207 return; 1208 if (enddir != expdir) 1209 enddir[-1] = '/'; 1210 if (*endname == 0) { 1211 atend = 1; 1212 } else { 1213 atend = 0; 1214 *endname++ = '\0'; 1215 } 1216 matchdot = 0; 1217 p = start; 1218 while (*p == CTLQUOTEMARK) 1219 p++; 1220 if (*p == CTLESC) 1221 p++; 1222 if (*p == '.') 1223 matchdot++; 1224 while (! int_pending() && (dp = readdir(dirp)) != NULL) { 1225 if (dp->d_name[0] == '.' && ! matchdot) 1226 continue; 1227 if (patmatch(start, dp->d_name, 0)) { 1228 if (atend) { 1229 scopy(dp->d_name, enddir); 1230 addfname(expdir); 1231 } else { 1232 for (p = enddir, cp = dp->d_name; 1233 (*p++ = *cp++) != '\0';) 1234 continue; 1235 p[-1] = '/'; 1236 expmeta(p, endname); 1237 } 1238 } 1239 } 1240 closedir(dirp); 1241 if (! atend) 1242 endname[-1] = '/'; 1243 } 1244 1245 1246 /* 1247 * Add a file name to the list. 1248 */ 1249 1250 STATIC void 1251 addfname(char *name) 1252 { 1253 char *p; 1254 struct strlist *sp; 1255 1256 p = stalloc(strlen(name) + 1); 1257 scopy(name, p); 1258 sp = (struct strlist *)stalloc(sizeof *sp); 1259 sp->text = p; 1260 *exparg.lastp = sp; 1261 exparg.lastp = &sp->next; 1262 } 1263 1264 1265 /* 1266 * Sort the results of file name expansion. It calculates the number of 1267 * strings to sort and then calls msort (short for merge sort) to do the 1268 * work. 1269 */ 1270 1271 STATIC struct strlist * 1272 expsort(struct strlist *str) 1273 { 1274 int len; 1275 struct strlist *sp; 1276 1277 len = 0; 1278 for (sp = str ; sp ; sp = sp->next) 1279 len++; 1280 return msort(str, len); 1281 } 1282 1283 1284 STATIC struct strlist * 1285 msort(struct strlist *list, int len) 1286 { 1287 struct strlist *p, *q = NULL; 1288 struct strlist **lpp; 1289 int half; 1290 int n; 1291 1292 if (len <= 1) 1293 return list; 1294 half = len >> 1; 1295 p = list; 1296 for (n = half ; --n >= 0 ; ) { 1297 q = p; 1298 p = p->next; 1299 } 1300 q->next = NULL; /* terminate first half of list */ 1301 q = msort(list, half); /* sort first half of list */ 1302 p = msort(p, len - half); /* sort second half */ 1303 lpp = &list; 1304 for (;;) { 1305 if (strcmp(p->text, q->text) < 0) { 1306 *lpp = p; 1307 lpp = &p->next; 1308 if ((p = *lpp) == NULL) { 1309 *lpp = q; 1310 break; 1311 } 1312 } else { 1313 *lpp = q; 1314 lpp = &q->next; 1315 if ((q = *lpp) == NULL) { 1316 *lpp = p; 1317 break; 1318 } 1319 } 1320 } 1321 return list; 1322 } 1323 1324 1325 1326 /* 1327 * Returns true if the pattern matches the string. 1328 */ 1329 1330 int 1331 patmatch(char *pattern, char *string, int squoted) 1332 { 1333 #ifdef notdef 1334 if (pattern[0] == '!' && pattern[1] == '!') 1335 return 1 - pmatch(pattern + 2, string); 1336 else 1337 #endif 1338 return pmatch(pattern, string, squoted); 1339 } 1340 1341 1342 STATIC int 1343 pmatch(char *pattern, char *string, int squoted) 1344 { 1345 char *p, *q; 1346 char c; 1347 1348 p = pattern; 1349 q = string; 1350 for (;;) { 1351 switch (c = *p++) { 1352 case '\0': 1353 goto breakloop; 1354 case CTLESC: 1355 if (squoted && *q == CTLESC) 1356 q++; 1357 if (*q++ != *p++) 1358 return 0; 1359 break; 1360 case CTLQUOTEMARK: 1361 continue; 1362 case '?': 1363 if (squoted && *q == CTLESC) 1364 q++; 1365 if (*q++ == '\0') 1366 return 0; 1367 break; 1368 case '*': 1369 c = *p; 1370 while (c == CTLQUOTEMARK || c == '*') 1371 c = *++p; 1372 if (c != CTLESC && c != CTLQUOTEMARK && 1373 c != '?' && c != '*' && c != '[') { 1374 while (*q != c) { 1375 if (squoted && *q == CTLESC && 1376 q[1] == c) 1377 break; 1378 if (*q == '\0') 1379 return 0; 1380 if (squoted && *q == CTLESC) 1381 q++; 1382 q++; 1383 } 1384 } 1385 do { 1386 if (pmatch(p, q, squoted)) 1387 return 1; 1388 if (squoted && *q == CTLESC) 1389 q++; 1390 } while (*q++ != '\0'); 1391 return 0; 1392 case '[': { 1393 char *endp; 1394 int invert, found; 1395 char chr; 1396 1397 endp = p; 1398 if (*endp == '!') 1399 endp++; 1400 for (;;) { 1401 while (*endp == CTLQUOTEMARK) 1402 endp++; 1403 if (*endp == '\0') 1404 goto dft; /* no matching ] */ 1405 if (*endp == CTLESC) 1406 endp++; 1407 if (*++endp == ']') 1408 break; 1409 } 1410 invert = 0; 1411 if (*p == '!') { 1412 invert++; 1413 p++; 1414 } 1415 found = 0; 1416 chr = *q++; 1417 if (squoted && chr == CTLESC) 1418 chr = *q++; 1419 if (chr == '\0') 1420 return 0; 1421 c = *p++; 1422 do { 1423 if (c == CTLQUOTEMARK) 1424 continue; 1425 if (c == CTLESC) 1426 c = *p++; 1427 if (*p == '-' && p[1] != ']') { 1428 p++; 1429 while (*p == CTLQUOTEMARK) 1430 p++; 1431 if (*p == CTLESC) 1432 p++; 1433 if (chr >= c && chr <= *p) 1434 found = 1; 1435 p++; 1436 } else { 1437 if (chr == c) 1438 found = 1; 1439 } 1440 } while ((c = *p++) != ']'); 1441 if (found == invert) 1442 return 0; 1443 break; 1444 } 1445 dft: default: 1446 if (squoted && *q == CTLESC) 1447 q++; 1448 if (*q++ != c) 1449 return 0; 1450 break; 1451 } 1452 } 1453 breakloop: 1454 if (*q != '\0') 1455 return 0; 1456 return 1; 1457 } 1458 1459 1460 1461 /* 1462 * Remove any CTLESC characters from a string. 1463 */ 1464 1465 void 1466 rmescapes(char *str) 1467 { 1468 char *p, *q; 1469 1470 p = str; 1471 while (*p != CTLESC && *p != CTLQUOTEMARK) { 1472 if (*p++ == '\0') 1473 return; 1474 } 1475 q = p; 1476 while (*p) { 1477 if (*p == CTLQUOTEMARK) { 1478 p++; 1479 continue; 1480 } 1481 if (*p == CTLESC) 1482 p++; 1483 *q++ = *p++; 1484 } 1485 *q = '\0'; 1486 } 1487 1488 1489 1490 /* 1491 * See if a pattern matches in a case statement. 1492 */ 1493 1494 int 1495 casematch(union node *pattern, char *val) 1496 { 1497 struct stackmark smark; 1498 int result; 1499 char *p; 1500 1501 setstackmark(&smark); 1502 argbackq = pattern->narg.backquote; 1503 STARTSTACKSTR(expdest); 1504 ifslastp = NULL; 1505 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE); 1506 STPUTC('\0', expdest); 1507 p = grabstackstr(expdest); 1508 result = patmatch(p, val, 0); 1509 popstackmark(&smark); 1510 return result; 1511 } 1512 1513 /* 1514 * Our own itoa(). 1515 */ 1516 1517 STATIC char * 1518 cvtnum(int num, char *buf) 1519 { 1520 char temp[32]; 1521 int neg = num < 0; 1522 char *p = temp + 31; 1523 1524 temp[31] = '\0'; 1525 1526 do { 1527 *--p = num % 10 + '0'; 1528 } while ((num /= 10) != 0); 1529 1530 if (neg) 1531 *--p = '-'; 1532 1533 while (*p) 1534 STPUTC(*p++, buf); 1535 return buf; 1536 } 1537 1538 /* 1539 * Do most of the work for wordexp(3). 1540 */ 1541 1542 int 1543 wordexpcmd(int argc, char **argv) 1544 { 1545 size_t len; 1546 int i; 1547 1548 out1fmt("%d", argc - 1); 1549 out1c('\0'); 1550 for (i = 1, len = 0; i < argc; i++) 1551 len += strlen(argv[i]); 1552 out1fmt("%zd", len); 1553 out1c('\0'); 1554 for (i = 1; i < argc; i++) { 1555 out1str(argv[i]); 1556 out1c('\0'); 1557 } 1558 return (0); 1559 } 1560