1 /* $NetBSD: expand.c,v 1.72 2005/12/13 17:44:18 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 1.72 2005/12/13 17:44:18 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 if (c != 0) 514 *loc = c; 515 return 1; 516 517 case VSQUESTION: 518 if (*p != CTLENDVAR) { 519 outfmt(&errout, "%s\n", startp); 520 error((char *)NULL); 521 } 522 error("%.*s: parameter %snot set", p - str - 1, 523 str, (varflags & VSNUL) ? "null or " 524 : nullstr); 525 /* NOTREACHED */ 526 527 case VSTRIMLEFT: 528 for (loc = startp; loc < str; loc++) { 529 c = *loc; 530 *loc = '\0'; 531 if (patmatch(str, startp, varflags & VSQUOTE)) 532 goto recordleft; 533 *loc = c; 534 if ((varflags & VSQUOTE) && *loc == CTLESC) 535 loc++; 536 } 537 return 0; 538 539 case VSTRIMLEFTMAX: 540 for (loc = str - 1; loc >= startp;) { 541 c = *loc; 542 *loc = '\0'; 543 if (patmatch(str, startp, varflags & VSQUOTE)) 544 goto recordleft; 545 *loc = c; 546 loc--; 547 if ((varflags & VSQUOTE) && loc > startp && 548 *(loc - 1) == CTLESC) { 549 for (q = startp; q < loc; q++) 550 if (*q == CTLESC) 551 q++; 552 if (q > loc) 553 loc--; 554 } 555 } 556 return 0; 557 558 case VSTRIMRIGHT: 559 for (loc = str - 1; loc >= startp;) { 560 if (patmatch(str, loc, varflags & VSQUOTE)) 561 goto recordright; 562 loc--; 563 if ((varflags & VSQUOTE) && loc > startp && 564 *(loc - 1) == CTLESC) { 565 for (q = startp; q < loc; q++) 566 if (*q == CTLESC) 567 q++; 568 if (q > loc) 569 loc--; 570 } 571 } 572 return 0; 573 574 case VSTRIMRIGHTMAX: 575 for (loc = startp; loc < str - 1; loc++) { 576 if (patmatch(str, loc, varflags & VSQUOTE)) 577 goto recordright; 578 if ((varflags & VSQUOTE) && *loc == CTLESC) 579 loc++; 580 } 581 return 0; 582 583 default: 584 abort(); 585 } 586 587 recordleft: 588 *loc = c; 589 amount = ((str - 1) - (loc - startp)) - expdest; 590 STADJUST(amount, expdest); 591 while (loc != str - 1) 592 *startp++ = *loc++; 593 return 1; 594 595 recordright: 596 amount = loc - expdest; 597 STADJUST(amount, expdest); 598 STPUTC('\0', expdest); 599 STADJUST(-1, expdest); 600 return 1; 601 } 602 603 604 /* 605 * Expand a variable, and return a pointer to the next character in the 606 * input string. 607 */ 608 609 STATIC char * 610 evalvar(char *p, int flag) 611 { 612 int subtype; 613 int varflags; 614 char *var; 615 char *val; 616 int patloc; 617 int c; 618 int set; 619 int special; 620 int startloc; 621 int varlen; 622 int apply_ifs; 623 int quotes = flag & (EXP_FULL | EXP_CASE); 624 625 varflags = (unsigned char)*p++; 626 subtype = varflags & VSTYPE; 627 var = p; 628 special = !is_name(*p); 629 p = strchr(p, '=') + 1; 630 631 again: /* jump here after setting a variable with ${var=text} */ 632 if (special) { 633 set = varisset(var, varflags & VSNUL); 634 val = NULL; 635 } else { 636 val = lookupvar(var); 637 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) { 638 val = NULL; 639 set = 0; 640 } else 641 set = 1; 642 } 643 644 varlen = 0; 645 startloc = expdest - stackblock(); 646 647 if (!set && uflag) { 648 switch (subtype) { 649 case VSNORMAL: 650 case VSTRIMLEFT: 651 case VSTRIMLEFTMAX: 652 case VSTRIMRIGHT: 653 case VSTRIMRIGHTMAX: 654 case VSLENGTH: 655 error("%.*s: parameter not set", p - var - 1, var); 656 /* NOTREACHED */ 657 } 658 } 659 660 if (set && subtype != VSPLUS) { 661 /* insert the value of the variable */ 662 if (special) { 663 varvalue(var, varflags & VSQUOTE, subtype, flag); 664 if (subtype == VSLENGTH) { 665 varlen = expdest - stackblock() - startloc; 666 STADJUST(-varlen, expdest); 667 } 668 } else { 669 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX 670 : BASESYNTAX; 671 672 if (subtype == VSLENGTH) { 673 for (;*val; val++) 674 varlen++; 675 } else { 676 while (*val) { 677 if (quotes && syntax[(int)*val] == CCTL) 678 STPUTC(CTLESC, expdest); 679 STPUTC(*val++, expdest); 680 } 681 682 } 683 } 684 } 685 686 687 apply_ifs = ((varflags & VSQUOTE) == 0 || 688 (*var == '@' && shellparam.nparam != 1)); 689 690 switch (subtype) { 691 case VSLENGTH: 692 expdest = cvtnum(varlen, expdest); 693 break; 694 695 case VSNORMAL: 696 break; 697 698 case VSPLUS: 699 set = !set; 700 /* FALLTHROUGH */ 701 case VSMINUS: 702 if (!set) { 703 argstr(p, flag | (apply_ifs ? EXP_IFS_SPLIT : 0)); 704 /* 705 * ${x-a b c} doesn't get split, but removing the 706 * 'apply_ifs = 0' apparantly breaks ${1+"$@"}.. 707 * ${x-'a b' c} should generate 2 args. 708 */ 709 /* We should have marked stuff already */ 710 apply_ifs = 0; 711 } 712 break; 713 714 case VSTRIMLEFT: 715 case VSTRIMLEFTMAX: 716 case VSTRIMRIGHT: 717 case VSTRIMRIGHTMAX: 718 if (!set) 719 break; 720 /* 721 * Terminate the string and start recording the pattern 722 * right after it 723 */ 724 STPUTC('\0', expdest); 725 patloc = expdest - stackblock(); 726 if (subevalvar(p, NULL, patloc, subtype, 727 startloc, varflags) == 0) { 728 int amount = (expdest - stackblock() - patloc) + 1; 729 STADJUST(-amount, expdest); 730 } 731 /* Remove any recorded regions beyond start of variable */ 732 removerecordregions(startloc); 733 apply_ifs = 1; 734 break; 735 736 case VSASSIGN: 737 case VSQUESTION: 738 if (set) 739 break; 740 if (subevalvar(p, var, 0, subtype, startloc, varflags)) { 741 varflags &= ~VSNUL; 742 /* 743 * Remove any recorded regions beyond 744 * start of variable 745 */ 746 removerecordregions(startloc); 747 goto again; 748 } 749 apply_ifs = 0; 750 break; 751 752 default: 753 abort(); 754 } 755 756 if (apply_ifs) 757 recordregion(startloc, expdest - stackblock(), 758 varflags & VSQUOTE); 759 760 if (subtype != VSNORMAL) { /* skip to end of alternative */ 761 int nesting = 1; 762 for (;;) { 763 if ((c = *p++) == CTLESC) 764 p++; 765 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) { 766 if (set) 767 argbackq = argbackq->next; 768 } else if (c == CTLVAR) { 769 if ((*p++ & VSTYPE) != VSNORMAL) 770 nesting++; 771 } else if (c == CTLENDVAR) { 772 if (--nesting == 0) 773 break; 774 } 775 } 776 } 777 return p; 778 } 779 780 781 782 /* 783 * Test whether a specialized variable is set. 784 */ 785 786 STATIC int 787 varisset(char *name, int nulok) 788 { 789 if (*name == '!') 790 return backgndpid != -1; 791 else if (*name == '@' || *name == '*') { 792 if (*shellparam.p == NULL) 793 return 0; 794 795 if (nulok) { 796 char **av; 797 798 for (av = shellparam.p; *av; av++) 799 if (**av != '\0') 800 return 1; 801 return 0; 802 } 803 } else if (is_digit(*name)) { 804 char *ap; 805 int num = atoi(name); 806 807 if (num > shellparam.nparam) 808 return 0; 809 810 if (num == 0) 811 ap = arg0; 812 else 813 ap = shellparam.p[num - 1]; 814 815 if (nulok && (ap == NULL || *ap == '\0')) 816 return 0; 817 } 818 return 1; 819 } 820 821 822 823 /* 824 * Add the value of a specialized variable to the stack string. 825 */ 826 827 STATIC void 828 varvalue(char *name, int quoted, int subtype, int flag) 829 { 830 int num; 831 char *p; 832 int i; 833 char sep; 834 char **ap; 835 char const *syntax; 836 837 #define STRTODEST(p) \ 838 do {\ 839 if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) { \ 840 syntax = quoted? DQSYNTAX : BASESYNTAX; \ 841 while (*p) { \ 842 if (syntax[(int)*p] == CCTL) \ 843 STPUTC(CTLESC, expdest); \ 844 STPUTC(*p++, expdest); \ 845 } \ 846 } else \ 847 while (*p) \ 848 STPUTC(*p++, expdest); \ 849 } while (0) 850 851 852 switch (*name) { 853 case '$': 854 num = rootpid; 855 goto numvar; 856 case '?': 857 num = exitstatus; 858 goto numvar; 859 case '#': 860 num = shellparam.nparam; 861 goto numvar; 862 case '!': 863 num = backgndpid; 864 numvar: 865 expdest = cvtnum(num, expdest); 866 break; 867 case '-': 868 for (i = 0; optlist[i].name; i++) { 869 if (optlist[i].val && optlist[i].letter) 870 STPUTC(optlist[i].letter, expdest); 871 } 872 break; 873 case '@': 874 if (flag & EXP_FULL && quoted) { 875 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 876 STRTODEST(p); 877 if (*ap) 878 STPUTC('\0', expdest); 879 } 880 break; 881 } 882 /* fall through */ 883 case '*': 884 if (ifsset() != 0) 885 sep = ifsval()[0]; 886 else 887 sep = ' '; 888 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 889 STRTODEST(p); 890 if (*ap && sep) 891 STPUTC(sep, expdest); 892 } 893 break; 894 case '0': 895 p = arg0; 896 STRTODEST(p); 897 break; 898 default: 899 if (is_digit(*name)) { 900 num = atoi(name); 901 if (num > 0 && num <= shellparam.nparam) { 902 p = shellparam.p[num - 1]; 903 STRTODEST(p); 904 } 905 } 906 break; 907 } 908 } 909 910 911 912 /* 913 * Record the fact that we have to scan this region of the 914 * string for IFS characters. 915 */ 916 917 STATIC void 918 recordregion(int start, int end, int inquotes) 919 { 920 struct ifsregion *ifsp; 921 922 if (ifslastp == NULL) { 923 ifsp = &ifsfirst; 924 } else { 925 if (ifslastp->endoff == start 926 && ifslastp->inquotes == inquotes) { 927 /* extend previous area */ 928 ifslastp->endoff = end; 929 return; 930 } 931 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion)); 932 ifslastp->next = ifsp; 933 } 934 ifslastp = ifsp; 935 ifslastp->next = NULL; 936 ifslastp->begoff = start; 937 ifslastp->endoff = end; 938 ifslastp->inquotes = inquotes; 939 } 940 941 942 943 /* 944 * Break the argument string into pieces based upon IFS and add the 945 * strings to the argument list. The regions of the string to be 946 * searched for IFS characters have been stored by recordregion. 947 */ 948 STATIC void 949 ifsbreakup(char *string, struct arglist *arglist) 950 { 951 struct ifsregion *ifsp; 952 struct strlist *sp; 953 char *start; 954 char *p; 955 char *q; 956 const char *ifs; 957 const char *ifsspc; 958 int inquotes; 959 960 start = string; 961 ifsspc = NULL; 962 inquotes = 0; 963 964 if (ifslastp == NULL) { 965 /* Return entire argument, IFS doesn't apply to any of it */ 966 sp = (struct strlist *)stalloc(sizeof *sp); 967 sp->text = start; 968 *arglist->lastp = sp; 969 arglist->lastp = &sp->next; 970 return; 971 } 972 973 ifs = ifsset() ? ifsval() : " \t\n"; 974 975 for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) { 976 p = string + ifsp->begoff; 977 inquotes = ifsp->inquotes; 978 ifsspc = NULL; 979 while (p < string + ifsp->endoff) { 980 q = p; 981 if (*p == CTLESC) 982 p++; 983 if (inquotes) { 984 /* Only NULs (probably from "$@") end args */ 985 if (*p != 0) { 986 p++; 987 continue; 988 } 989 } else { 990 if (!strchr(ifs, *p)) { 991 p++; 992 continue; 993 } 994 ifsspc = strchr(" \t\n", *p); 995 996 /* Ignore IFS whitespace at start */ 997 if (q == start && ifsspc != NULL) { 998 p++; 999 start = p; 1000 continue; 1001 } 1002 } 1003 1004 /* Save this argument... */ 1005 *q = '\0'; 1006 sp = (struct strlist *)stalloc(sizeof *sp); 1007 sp->text = start; 1008 *arglist->lastp = sp; 1009 arglist->lastp = &sp->next; 1010 p++; 1011 1012 if (ifsspc != NULL) { 1013 /* Ignore further trailing IFS whitespace */ 1014 for (; p < string + ifsp->endoff; p++) { 1015 q = p; 1016 if (*p == CTLESC) 1017 p++; 1018 if (strchr(ifs, *p) == NULL) { 1019 p = q; 1020 break; 1021 } 1022 if (strchr(" \t\n", *p) == NULL) { 1023 p++; 1024 break; 1025 } 1026 } 1027 } 1028 start = p; 1029 } 1030 } 1031 1032 /* 1033 * Save anything left as an argument. 1034 * Traditionally we have treated 'IFS=':'; set -- x$IFS' as 1035 * generating 2 arguments, the second of which is empty. 1036 * Some recent clarification of the Posix spec say that it 1037 * should only generate one.... 1038 */ 1039 if (*start /* || (!ifsspc && start > string) */) { 1040 sp = (struct strlist *)stalloc(sizeof *sp); 1041 sp->text = start; 1042 *arglist->lastp = sp; 1043 arglist->lastp = &sp->next; 1044 } 1045 } 1046 1047 STATIC void 1048 ifsfree(void) 1049 { 1050 while (ifsfirst.next != NULL) { 1051 struct ifsregion *ifsp; 1052 INTOFF; 1053 ifsp = ifsfirst.next->next; 1054 ckfree(ifsfirst.next); 1055 ifsfirst.next = ifsp; 1056 INTON; 1057 } 1058 ifslastp = NULL; 1059 ifsfirst.next = NULL; 1060 } 1061 1062 1063 1064 /* 1065 * Expand shell metacharacters. At this point, the only control characters 1066 * should be escapes. The results are stored in the list exparg. 1067 */ 1068 1069 char *expdir; 1070 1071 1072 STATIC void 1073 expandmeta(struct strlist *str, int flag) 1074 { 1075 char *p; 1076 struct strlist **savelastp; 1077 struct strlist *sp; 1078 char c; 1079 /* TODO - EXP_REDIR */ 1080 1081 while (str) { 1082 if (fflag) 1083 goto nometa; 1084 p = str->text; 1085 for (;;) { /* fast check for meta chars */ 1086 if ((c = *p++) == '\0') 1087 goto nometa; 1088 if (c == '*' || c == '?' || c == '[' || c == '!') 1089 break; 1090 } 1091 savelastp = exparg.lastp; 1092 INTOFF; 1093 if (expdir == NULL) { 1094 int i = strlen(str->text); 1095 expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */ 1096 } 1097 1098 expmeta(expdir, str->text); 1099 ckfree(expdir); 1100 expdir = NULL; 1101 INTON; 1102 if (exparg.lastp == savelastp) { 1103 /* 1104 * no matches 1105 */ 1106 nometa: 1107 *exparg.lastp = str; 1108 rmescapes(str->text); 1109 exparg.lastp = &str->next; 1110 } else { 1111 *exparg.lastp = NULL; 1112 *savelastp = sp = expsort(*savelastp); 1113 while (sp->next != NULL) 1114 sp = sp->next; 1115 exparg.lastp = &sp->next; 1116 } 1117 str = str->next; 1118 } 1119 } 1120 1121 1122 /* 1123 * Do metacharacter (i.e. *, ?, [...]) expansion. 1124 */ 1125 1126 STATIC void 1127 expmeta(char *enddir, char *name) 1128 { 1129 char *p; 1130 const char *cp; 1131 char *q; 1132 char *start; 1133 char *endname; 1134 int metaflag; 1135 struct stat statb; 1136 DIR *dirp; 1137 struct dirent *dp; 1138 int atend; 1139 int matchdot; 1140 1141 metaflag = 0; 1142 start = name; 1143 for (p = name ; ; p++) { 1144 if (*p == '*' || *p == '?') 1145 metaflag = 1; 1146 else if (*p == '[') { 1147 q = p + 1; 1148 if (*q == '!') 1149 q++; 1150 for (;;) { 1151 while (*q == CTLQUOTEMARK) 1152 q++; 1153 if (*q == CTLESC) 1154 q++; 1155 if (*q == '/' || *q == '\0') 1156 break; 1157 if (*++q == ']') { 1158 metaflag = 1; 1159 break; 1160 } 1161 } 1162 } else if (*p == '!' && p[1] == '!' && (p == name || p[-1] == '/')) { 1163 metaflag = 1; 1164 } else if (*p == '\0') 1165 break; 1166 else if (*p == CTLQUOTEMARK) 1167 continue; 1168 else if (*p == CTLESC) 1169 p++; 1170 if (*p == '/') { 1171 if (metaflag) 1172 break; 1173 start = p + 1; 1174 } 1175 } 1176 if (metaflag == 0) { /* we've reached the end of the file name */ 1177 if (enddir != expdir) 1178 metaflag++; 1179 for (p = name ; ; p++) { 1180 if (*p == CTLQUOTEMARK) 1181 continue; 1182 if (*p == CTLESC) 1183 p++; 1184 *enddir++ = *p; 1185 if (*p == '\0') 1186 break; 1187 } 1188 if (metaflag == 0 || lstat(expdir, &statb) >= 0) 1189 addfname(expdir); 1190 return; 1191 } 1192 endname = p; 1193 if (start != name) { 1194 p = name; 1195 while (p < start) { 1196 while (*p == CTLQUOTEMARK) 1197 p++; 1198 if (*p == CTLESC) 1199 p++; 1200 *enddir++ = *p++; 1201 } 1202 } 1203 if (enddir == expdir) { 1204 cp = "."; 1205 } else if (enddir == expdir + 1 && *expdir == '/') { 1206 cp = "/"; 1207 } else { 1208 cp = expdir; 1209 enddir[-1] = '\0'; 1210 } 1211 if ((dirp = opendir(cp)) == NULL) 1212 return; 1213 if (enddir != expdir) 1214 enddir[-1] = '/'; 1215 if (*endname == 0) { 1216 atend = 1; 1217 } else { 1218 atend = 0; 1219 *endname++ = '\0'; 1220 } 1221 matchdot = 0; 1222 p = start; 1223 while (*p == CTLQUOTEMARK) 1224 p++; 1225 if (*p == CTLESC) 1226 p++; 1227 if (*p == '.') 1228 matchdot++; 1229 while (! int_pending() && (dp = readdir(dirp)) != NULL) { 1230 if (dp->d_name[0] == '.' && ! matchdot) 1231 continue; 1232 if (patmatch(start, dp->d_name, 0)) { 1233 if (atend) { 1234 scopy(dp->d_name, enddir); 1235 addfname(expdir); 1236 } else { 1237 for (p = enddir, cp = dp->d_name; 1238 (*p++ = *cp++) != '\0';) 1239 continue; 1240 p[-1] = '/'; 1241 expmeta(p, endname); 1242 } 1243 } 1244 } 1245 closedir(dirp); 1246 if (! atend) 1247 endname[-1] = '/'; 1248 } 1249 1250 1251 /* 1252 * Add a file name to the list. 1253 */ 1254 1255 STATIC void 1256 addfname(char *name) 1257 { 1258 char *p; 1259 struct strlist *sp; 1260 1261 p = stalloc(strlen(name) + 1); 1262 scopy(name, p); 1263 sp = (struct strlist *)stalloc(sizeof *sp); 1264 sp->text = p; 1265 *exparg.lastp = sp; 1266 exparg.lastp = &sp->next; 1267 } 1268 1269 1270 /* 1271 * Sort the results of file name expansion. It calculates the number of 1272 * strings to sort and then calls msort (short for merge sort) to do the 1273 * work. 1274 */ 1275 1276 STATIC struct strlist * 1277 expsort(struct strlist *str) 1278 { 1279 int len; 1280 struct strlist *sp; 1281 1282 len = 0; 1283 for (sp = str ; sp ; sp = sp->next) 1284 len++; 1285 return msort(str, len); 1286 } 1287 1288 1289 STATIC struct strlist * 1290 msort(struct strlist *list, int len) 1291 { 1292 struct strlist *p, *q = NULL; 1293 struct strlist **lpp; 1294 int half; 1295 int n; 1296 1297 if (len <= 1) 1298 return list; 1299 half = len >> 1; 1300 p = list; 1301 for (n = half ; --n >= 0 ; ) { 1302 q = p; 1303 p = p->next; 1304 } 1305 q->next = NULL; /* terminate first half of list */ 1306 q = msort(list, half); /* sort first half of list */ 1307 p = msort(p, len - half); /* sort second half */ 1308 lpp = &list; 1309 for (;;) { 1310 if (strcmp(p->text, q->text) < 0) { 1311 *lpp = p; 1312 lpp = &p->next; 1313 if ((p = *lpp) == NULL) { 1314 *lpp = q; 1315 break; 1316 } 1317 } else { 1318 *lpp = q; 1319 lpp = &q->next; 1320 if ((q = *lpp) == NULL) { 1321 *lpp = p; 1322 break; 1323 } 1324 } 1325 } 1326 return list; 1327 } 1328 1329 1330 1331 /* 1332 * Returns true if the pattern matches the string. 1333 */ 1334 1335 int 1336 patmatch(char *pattern, char *string, int squoted) 1337 { 1338 #ifdef notdef 1339 if (pattern[0] == '!' && pattern[1] == '!') 1340 return 1 - pmatch(pattern + 2, string); 1341 else 1342 #endif 1343 return pmatch(pattern, string, squoted); 1344 } 1345 1346 1347 STATIC int 1348 pmatch(char *pattern, char *string, int squoted) 1349 { 1350 char *p, *q; 1351 char c; 1352 1353 p = pattern; 1354 q = string; 1355 for (;;) { 1356 switch (c = *p++) { 1357 case '\0': 1358 goto breakloop; 1359 case CTLESC: 1360 if (squoted && *q == CTLESC) 1361 q++; 1362 if (*q++ != *p++) 1363 return 0; 1364 break; 1365 case CTLQUOTEMARK: 1366 continue; 1367 case '?': 1368 if (squoted && *q == CTLESC) 1369 q++; 1370 if (*q++ == '\0') 1371 return 0; 1372 break; 1373 case '*': 1374 c = *p; 1375 while (c == CTLQUOTEMARK || c == '*') 1376 c = *++p; 1377 if (c != CTLESC && c != CTLQUOTEMARK && 1378 c != '?' && c != '*' && c != '[') { 1379 while (*q != c) { 1380 if (squoted && *q == CTLESC && 1381 q[1] == c) 1382 break; 1383 if (*q == '\0') 1384 return 0; 1385 if (squoted && *q == CTLESC) 1386 q++; 1387 q++; 1388 } 1389 } 1390 do { 1391 if (pmatch(p, q, squoted)) 1392 return 1; 1393 if (squoted && *q == CTLESC) 1394 q++; 1395 } while (*q++ != '\0'); 1396 return 0; 1397 case '[': { 1398 char *endp; 1399 int invert, found; 1400 char chr; 1401 1402 endp = p; 1403 if (*endp == '!') 1404 endp++; 1405 for (;;) { 1406 while (*endp == CTLQUOTEMARK) 1407 endp++; 1408 if (*endp == '\0') 1409 goto dft; /* no matching ] */ 1410 if (*endp == CTLESC) 1411 endp++; 1412 if (*++endp == ']') 1413 break; 1414 } 1415 invert = 0; 1416 if (*p == '!') { 1417 invert++; 1418 p++; 1419 } 1420 found = 0; 1421 chr = *q++; 1422 if (squoted && chr == CTLESC) 1423 chr = *q++; 1424 if (chr == '\0') 1425 return 0; 1426 c = *p++; 1427 do { 1428 if (c == CTLQUOTEMARK) 1429 continue; 1430 if (c == CTLESC) 1431 c = *p++; 1432 if (*p == '-' && p[1] != ']') { 1433 p++; 1434 while (*p == CTLQUOTEMARK) 1435 p++; 1436 if (*p == CTLESC) 1437 p++; 1438 if (chr >= c && chr <= *p) 1439 found = 1; 1440 p++; 1441 } else { 1442 if (chr == c) 1443 found = 1; 1444 } 1445 } while ((c = *p++) != ']'); 1446 if (found == invert) 1447 return 0; 1448 break; 1449 } 1450 dft: default: 1451 if (squoted && *q == CTLESC) 1452 q++; 1453 if (*q++ != c) 1454 return 0; 1455 break; 1456 } 1457 } 1458 breakloop: 1459 if (*q != '\0') 1460 return 0; 1461 return 1; 1462 } 1463 1464 1465 1466 /* 1467 * Remove any CTLESC characters from a string. 1468 */ 1469 1470 void 1471 rmescapes(char *str) 1472 { 1473 char *p, *q; 1474 1475 p = str; 1476 while (*p != CTLESC && *p != CTLQUOTEMARK) { 1477 if (*p++ == '\0') 1478 return; 1479 } 1480 q = p; 1481 while (*p) { 1482 if (*p == CTLQUOTEMARK) { 1483 p++; 1484 continue; 1485 } 1486 if (*p == CTLESC) 1487 p++; 1488 *q++ = *p++; 1489 } 1490 *q = '\0'; 1491 } 1492 1493 1494 1495 /* 1496 * See if a pattern matches in a case statement. 1497 */ 1498 1499 int 1500 casematch(union node *pattern, char *val) 1501 { 1502 struct stackmark smark; 1503 int result; 1504 char *p; 1505 1506 setstackmark(&smark); 1507 argbackq = pattern->narg.backquote; 1508 STARTSTACKSTR(expdest); 1509 ifslastp = NULL; 1510 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE); 1511 STPUTC('\0', expdest); 1512 p = grabstackstr(expdest); 1513 result = patmatch(p, val, 0); 1514 popstackmark(&smark); 1515 return result; 1516 } 1517 1518 /* 1519 * Our own itoa(). 1520 */ 1521 1522 STATIC char * 1523 cvtnum(int num, char *buf) 1524 { 1525 char temp[32]; 1526 int neg = num < 0; 1527 char *p = temp + 31; 1528 1529 temp[31] = '\0'; 1530 1531 do { 1532 *--p = num % 10 + '0'; 1533 } while ((num /= 10) != 0); 1534 1535 if (neg) 1536 *--p = '-'; 1537 1538 while (*p) 1539 STPUTC(*p++, buf); 1540 return buf; 1541 } 1542 1543 /* 1544 * Do most of the work for wordexp(3). 1545 */ 1546 1547 int 1548 wordexpcmd(int argc, char **argv) 1549 { 1550 size_t len; 1551 int i; 1552 1553 out1fmt("%d", argc - 1); 1554 out1c('\0'); 1555 for (i = 1, len = 0; i < argc; i++) 1556 len += strlen(argv[i]); 1557 out1fmt("%zd", len); 1558 out1c('\0'); 1559 for (i = 1; i < argc; i++) { 1560 out1str(argv[i]); 1561 out1c('\0'); 1562 } 1563 return (0); 1564 } 1565