1 /* $NetBSD: expand.c,v 1.87 2012/03/28 20:11:25 christos 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 1.87 2012/03/28 20:11:25 christos 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 <limits.h> 52 #include <stdlib.h> 53 #include <stdio.h> 54 55 /* 56 * Routines to expand arguments to commands. We have to deal with 57 * backquotes, shell variables, and file metacharacters. 58 */ 59 60 #include "shell.h" 61 #include "main.h" 62 #include "nodes.h" 63 #include "eval.h" 64 #include "expand.h" 65 #include "syntax.h" 66 #include "parser.h" 67 #include "jobs.h" 68 #include "options.h" 69 #include "builtins.h" 70 #include "var.h" 71 #include "input.h" 72 #include "output.h" 73 #include "memalloc.h" 74 #include "error.h" 75 #include "mystring.h" 76 #include "show.h" 77 78 /* 79 * Structure specifying which parts of the string should be searched 80 * for IFS characters. 81 */ 82 83 struct ifsregion { 84 struct ifsregion *next; /* next region in list */ 85 int begoff; /* offset of start of region */ 86 int endoff; /* offset of end of region */ 87 int inquotes; /* search for nul bytes only */ 88 }; 89 90 91 char *expdest; /* output of current string */ 92 struct nodelist *argbackq; /* list of back quote expressions */ 93 struct ifsregion ifsfirst; /* first struct in list of ifs regions */ 94 struct ifsregion *ifslastp; /* last struct in list */ 95 struct arglist exparg; /* holds expanded arg list */ 96 97 STATIC void argstr(char *, int); 98 STATIC char *exptilde(char *, int); 99 STATIC void expbackq(union node *, int, int); 100 STATIC int subevalvar(char *, char *, int, int, int, int); 101 STATIC char *evalvar(char *, int); 102 STATIC int varisset(char *, int); 103 STATIC void varvalue(char *, int, int, int); 104 STATIC void recordregion(int, int, int); 105 STATIC void removerecordregions(int); 106 STATIC void ifsbreakup(char *, struct arglist *); 107 STATIC void ifsfree(void); 108 STATIC void expandmeta(struct strlist *, int); 109 STATIC void expmeta(char *, char *); 110 STATIC void addfname(char *); 111 STATIC struct strlist *expsort(struct strlist *); 112 STATIC struct strlist *msort(struct strlist *, int); 113 STATIC int pmatch(char *, char *, int); 114 STATIC char *cvtnum(int, char *); 115 116 /* 117 * Expand shell variables and backquotes inside a here document. 118 */ 119 120 void 121 expandhere(union node *arg, int fd) 122 { 123 herefd = fd; 124 expandarg(arg, NULL, 0); 125 xwrite(fd, stackblock(), expdest - stackblock()); 126 } 127 128 129 /* 130 * Perform variable substitution and command substitution on an argument, 131 * placing the resulting list of arguments in arglist. If EXP_FULL is true, 132 * perform splitting and file name expansion. When arglist is NULL, perform 133 * here document expansion. 134 */ 135 136 void 137 expandarg(union node *arg, struct arglist *arglist, int flag) 138 { 139 struct strlist *sp; 140 char *p; 141 142 argbackq = arg->narg.backquote; 143 STARTSTACKSTR(expdest); 144 ifsfirst.next = NULL; 145 ifslastp = NULL; 146 argstr(arg->narg.text, flag); 147 if (arglist == NULL) { 148 return; /* here document expanded */ 149 } 150 STPUTC('\0', expdest); 151 p = grabstackstr(expdest); 152 exparg.lastp = &exparg.list; 153 /* 154 * TODO - EXP_REDIR 155 */ 156 if (flag & EXP_FULL) { 157 ifsbreakup(p, &exparg); 158 *exparg.lastp = NULL; 159 exparg.lastp = &exparg.list; 160 expandmeta(exparg.list, flag); 161 } else { 162 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */ 163 rmescapes(p); 164 sp = (struct strlist *)stalloc(sizeof (struct strlist)); 165 sp->text = p; 166 *exparg.lastp = sp; 167 exparg.lastp = &sp->next; 168 } 169 ifsfree(); 170 *exparg.lastp = NULL; 171 if (exparg.list) { 172 *arglist->lastp = exparg.list; 173 arglist->lastp = exparg.lastp; 174 } 175 } 176 177 178 179 /* 180 * Perform variable and command substitution. 181 * If EXP_FULL is set, output CTLESC characters to allow for further processing. 182 * Otherwise treat $@ like $* since no splitting will be performed. 183 */ 184 185 STATIC void 186 argstr(char *p, int flag) 187 { 188 char c; 189 int quotes = flag & (EXP_FULL | EXP_CASE); /* do CTLESC */ 190 int firsteq = 1; 191 const char *ifs = NULL; 192 int ifs_split = EXP_IFS_SPLIT; 193 194 if (flag & EXP_IFS_SPLIT) 195 ifs = ifsset() ? ifsval() : " \t\n"; 196 197 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE))) 198 p = exptilde(p, flag); 199 for (;;) { 200 switch (c = *p++) { 201 case '\0': 202 case CTLENDVAR: /* end of expanding yyy in ${xxx-yyy} */ 203 return; 204 case CTLQUOTEMARK: 205 /* "$@" syntax adherence hack */ 206 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=') 207 break; 208 if ((flag & EXP_FULL) != 0) 209 STPUTC(c, expdest); 210 ifs_split = 0; 211 break; 212 case CTLQUOTEEND: 213 ifs_split = EXP_IFS_SPLIT; 214 break; 215 case CTLESC: 216 if (quotes) 217 STPUTC(c, expdest); 218 c = *p++; 219 STPUTC(c, expdest); 220 break; 221 case CTLVAR: 222 p = evalvar(p, (flag & ~EXP_IFS_SPLIT) | (flag & ifs_split)); 223 break; 224 case CTLBACKQ: 225 case CTLBACKQ|CTLQUOTE: 226 expbackq(argbackq->n, c & CTLQUOTE, flag); 227 argbackq = argbackq->next; 228 break; 229 case CTLENDARI: 230 expari(flag); 231 break; 232 case ':': 233 case '=': 234 /* 235 * sort of a hack - expand tildes in variable 236 * assignments (after the first '=' and after ':'s). 237 */ 238 STPUTC(c, expdest); 239 if (flag & EXP_VARTILDE && *p == '~') { 240 if (c == '=') { 241 if (firsteq) 242 firsteq = 0; 243 else 244 break; 245 } 246 p = exptilde(p, flag); 247 } 248 break; 249 default: 250 STPUTC(c, expdest); 251 if (flag & EXP_IFS_SPLIT & ifs_split && strchr(ifs, c) != NULL) { 252 /* We need to get the output split here... */ 253 recordregion(expdest - stackblock() - 1, 254 expdest - stackblock(), 0); 255 } 256 break; 257 } 258 } 259 } 260 261 STATIC char * 262 exptilde(char *p, int flag) 263 { 264 char c, *startp = p; 265 struct passwd *pw; 266 const char *home; 267 int quotes = flag & (EXP_FULL | EXP_CASE); 268 269 while ((c = *p) != '\0') { 270 switch(c) { 271 case CTLESC: 272 return (startp); 273 case CTLQUOTEMARK: 274 return (startp); 275 case ':': 276 if (flag & EXP_VARTILDE) 277 goto done; 278 break; 279 case '/': 280 goto done; 281 } 282 p++; 283 } 284 done: 285 *p = '\0'; 286 if (*(startp+1) == '\0') { 287 if ((home = lookupvar("HOME")) == NULL) 288 goto lose; 289 } else { 290 if ((pw = getpwnam(startp+1)) == NULL) 291 goto lose; 292 home = pw->pw_dir; 293 } 294 if (*home == '\0') 295 goto lose; 296 *p = c; 297 while ((c = *home++) != '\0') { 298 if (quotes && SQSYNTAX[(int)c] == CCTL) 299 STPUTC(CTLESC, expdest); 300 STPUTC(c, expdest); 301 } 302 return (p); 303 lose: 304 *p = c; 305 return (startp); 306 } 307 308 309 STATIC void 310 removerecordregions(int endoff) 311 { 312 if (ifslastp == NULL) 313 return; 314 315 if (ifsfirst.endoff > endoff) { 316 while (ifsfirst.next != NULL) { 317 struct ifsregion *ifsp; 318 INTOFF; 319 ifsp = ifsfirst.next->next; 320 ckfree(ifsfirst.next); 321 ifsfirst.next = ifsp; 322 INTON; 323 } 324 if (ifsfirst.begoff > endoff) 325 ifslastp = NULL; 326 else { 327 ifslastp = &ifsfirst; 328 ifsfirst.endoff = endoff; 329 } 330 return; 331 } 332 333 ifslastp = &ifsfirst; 334 while (ifslastp->next && ifslastp->next->begoff < endoff) 335 ifslastp=ifslastp->next; 336 while (ifslastp->next != NULL) { 337 struct ifsregion *ifsp; 338 INTOFF; 339 ifsp = ifslastp->next->next; 340 ckfree(ifslastp->next); 341 ifslastp->next = ifsp; 342 INTON; 343 } 344 if (ifslastp->endoff > endoff) 345 ifslastp->endoff = endoff; 346 } 347 348 349 /* 350 * Expand arithmetic expression. Backup to start of expression, 351 * evaluate, place result in (backed up) result, adjust string position. 352 */ 353 void 354 expari(int flag) 355 { 356 char *p, *start; 357 intmax_t result; 358 int adjustment; 359 int begoff; 360 int quotes = flag & (EXP_FULL | EXP_CASE); 361 int quoted; 362 363 /* ifsfree(); */ 364 365 /* 366 * This routine is slightly over-complicated for 367 * efficiency. First we make sure there is 368 * enough space for the result, which may be bigger 369 * than the expression if we add exponentation. Next we 370 * scan backwards looking for the start of arithmetic. If the 371 * next previous character is a CTLESC character, then we 372 * have to rescan starting from the beginning since CTLESC 373 * characters have to be processed left to right. 374 */ 375 /* SPACE_NEEDED is enough for all digits, plus possible "-", plus 2 (why?) */ 376 #define SPACE_NEEDED ((sizeof(intmax_t) * CHAR_BIT + 2) / 3 + 1 + 2) 377 CHECKSTRSPACE((int)(SPACE_NEEDED - 2), expdest); 378 USTPUTC('\0', expdest); 379 start = stackblock(); 380 p = expdest - 1; 381 while (*p != CTLARI && p >= start) 382 --p; 383 if (*p != CTLARI) 384 error("missing CTLARI (shouldn't happen)"); 385 if (p > start && *(p-1) == CTLESC) 386 for (p = start; *p != CTLARI; p++) 387 if (*p == CTLESC) 388 p++; 389 390 if (p[1] == '"') 391 quoted=1; 392 else 393 quoted=0; 394 begoff = p - start; 395 removerecordregions(begoff); 396 if (quotes) 397 rmescapes(p+2); 398 result = arith(p+2); 399 fmtstr(p, SPACE_NEEDED, "%"PRIdMAX, result); 400 401 while (*p++) 402 ; 403 404 if (quoted == 0) 405 recordregion(begoff, p - 1 - start, 0); 406 adjustment = expdest - p + 1; 407 STADJUST(-adjustment, expdest); 408 } 409 410 411 /* 412 * Expand stuff in backwards quotes. 413 */ 414 415 STATIC void 416 expbackq(union node *cmd, int quoted, int flag) 417 { 418 struct backcmd in; 419 int i; 420 char buf[128]; 421 char *p; 422 char *dest = expdest; 423 struct ifsregion saveifs, *savelastp; 424 struct nodelist *saveargbackq; 425 char lastc; 426 int startloc = dest - stackblock(); 427 char const *syntax = quoted? DQSYNTAX : BASESYNTAX; 428 int saveherefd; 429 int quotes = flag & (EXP_FULL | EXP_CASE); 430 int nnl; 431 432 INTOFF; 433 saveifs = ifsfirst; 434 savelastp = ifslastp; 435 saveargbackq = argbackq; 436 saveherefd = herefd; 437 herefd = -1; 438 p = grabstackstr(dest); 439 evalbackcmd(cmd, &in); 440 ungrabstackstr(p, dest); 441 ifsfirst = saveifs; 442 ifslastp = savelastp; 443 argbackq = saveargbackq; 444 herefd = saveherefd; 445 446 p = in.buf; 447 lastc = '\0'; 448 nnl = 0; 449 for (;;) { 450 if (--in.nleft < 0) { 451 if (in.fd < 0) 452 break; 453 while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR); 454 TRACE(("expbackq: read returns %d\n", i)); 455 if (i <= 0) 456 break; 457 p = buf; 458 in.nleft = i - 1; 459 } 460 lastc = *p++; 461 if (lastc != '\0') { 462 if (lastc == '\n') 463 nnl++; 464 else { 465 CHECKSTRSPACE(nnl + 2, dest); 466 while (nnl > 0) { 467 nnl--; 468 USTPUTC('\n', dest); 469 } 470 if (quotes && syntax[(int)lastc] == CCTL) 471 USTPUTC(CTLESC, dest); 472 USTPUTC(lastc, dest); 473 } 474 } 475 } 476 477 if (in.fd >= 0) 478 close(in.fd); 479 if (in.buf) 480 ckfree(in.buf); 481 if (in.jp) 482 back_exitstatus = waitforjob(in.jp); 483 if (quoted == 0) 484 recordregion(startloc, dest - stackblock(), 0); 485 TRACE(("evalbackq: size=%d: \"%.*s\"\n", 486 (int)((dest - stackblock()) - startloc), 487 (int)((dest - stackblock()) - startloc), 488 stackblock() + startloc)); 489 expdest = dest; 490 INTON; 491 } 492 493 494 495 STATIC int 496 subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varflags) 497 { 498 char *startp; 499 char *loc = NULL; 500 char *q; 501 int c = 0; 502 int saveherefd = herefd; 503 struct nodelist *saveargbackq = argbackq; 504 int amount, how; 505 506 herefd = -1; 507 switch (subtype) { 508 case VSTRIMLEFT: 509 case VSTRIMLEFTMAX: 510 case VSTRIMRIGHT: 511 case VSTRIMRIGHTMAX: 512 how = (varflags & VSQUOTE) ? 0 : EXP_CASE; 513 break; 514 default: 515 how = 0; 516 break; 517 } 518 argstr(p, how); 519 STACKSTRNUL(expdest); 520 herefd = saveherefd; 521 argbackq = saveargbackq; 522 startp = stackblock() + startloc; 523 if (str == NULL) 524 str = stackblock() + strloc; 525 526 switch (subtype) { 527 case VSASSIGN: 528 setvar(str, startp, 0); 529 amount = startp - expdest; 530 STADJUST(amount, expdest); 531 varflags &= ~VSNUL; 532 return 1; 533 534 case VSQUESTION: 535 if (*p != CTLENDVAR) { 536 outfmt(&errout, "%s\n", startp); 537 error(NULL); 538 } 539 error("%.*s: parameter %snot set", 540 (int)(p - str - 1), 541 str, (varflags & VSNUL) ? "null or " 542 : nullstr); 543 /* NOTREACHED */ 544 545 case VSTRIMLEFT: 546 for (loc = startp; loc < str; loc++) { 547 c = *loc; 548 *loc = '\0'; 549 if (patmatch(str, startp, varflags & VSQUOTE)) 550 goto recordleft; 551 *loc = c; 552 if ((varflags & VSQUOTE) && *loc == CTLESC) 553 loc++; 554 } 555 return 0; 556 557 case VSTRIMLEFTMAX: 558 for (loc = str - 1; loc >= startp;) { 559 c = *loc; 560 *loc = '\0'; 561 if (patmatch(str, startp, varflags & VSQUOTE)) 562 goto recordleft; 563 *loc = c; 564 loc--; 565 if ((varflags & VSQUOTE) && loc > startp && 566 *(loc - 1) == CTLESC) { 567 for (q = startp; q < loc; q++) 568 if (*q == CTLESC) 569 q++; 570 if (q > loc) 571 loc--; 572 } 573 } 574 return 0; 575 576 case VSTRIMRIGHT: 577 for (loc = str - 1; loc >= startp;) { 578 if (patmatch(str, loc, varflags & VSQUOTE)) 579 goto recordright; 580 loc--; 581 if ((varflags & VSQUOTE) && loc > startp && 582 *(loc - 1) == CTLESC) { 583 for (q = startp; q < loc; q++) 584 if (*q == CTLESC) 585 q++; 586 if (q > loc) 587 loc--; 588 } 589 } 590 return 0; 591 592 case VSTRIMRIGHTMAX: 593 for (loc = startp; loc < str - 1; loc++) { 594 if (patmatch(str, loc, varflags & VSQUOTE)) 595 goto recordright; 596 if ((varflags & VSQUOTE) && *loc == CTLESC) 597 loc++; 598 } 599 return 0; 600 601 default: 602 abort(); 603 } 604 605 recordleft: 606 *loc = c; 607 amount = ((str - 1) - (loc - startp)) - expdest; 608 STADJUST(amount, expdest); 609 while (loc != str - 1) 610 *startp++ = *loc++; 611 return 1; 612 613 recordright: 614 amount = loc - expdest; 615 STADJUST(amount, expdest); 616 STPUTC('\0', expdest); 617 STADJUST(-1, expdest); 618 return 1; 619 } 620 621 622 /* 623 * Expand a variable, and return a pointer to the next character in the 624 * input string. 625 */ 626 627 STATIC char * 628 evalvar(char *p, int flag) 629 { 630 int subtype; 631 int varflags; 632 char *var; 633 char *val; 634 int patloc; 635 int c; 636 int set; 637 int special; 638 int startloc; 639 int varlen; 640 int apply_ifs; 641 int quotes = flag & (EXP_FULL | EXP_CASE); 642 643 varflags = (unsigned char)*p++; 644 subtype = varflags & VSTYPE; 645 var = p; 646 special = !is_name(*p); 647 p = strchr(p, '=') + 1; 648 649 again: /* jump here after setting a variable with ${var=text} */ 650 if (special) { 651 set = varisset(var, varflags & VSNUL); 652 val = NULL; 653 } else { 654 val = lookupvar(var); 655 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) { 656 val = NULL; 657 set = 0; 658 } else 659 set = 1; 660 } 661 662 varlen = 0; 663 startloc = expdest - stackblock(); 664 665 if (!set && uflag) { 666 switch (subtype) { 667 case VSNORMAL: 668 case VSTRIMLEFT: 669 case VSTRIMLEFTMAX: 670 case VSTRIMRIGHT: 671 case VSTRIMRIGHTMAX: 672 case VSLENGTH: 673 error("%.*s: parameter not set", 674 (int)(p - var - 1), var); 675 /* NOTREACHED */ 676 } 677 } 678 679 if (set && subtype != VSPLUS) { 680 /* insert the value of the variable */ 681 if (special) { 682 varvalue(var, varflags & VSQUOTE, subtype, flag); 683 if (subtype == VSLENGTH) { 684 varlen = expdest - stackblock() - startloc; 685 STADJUST(-varlen, expdest); 686 } 687 } else { 688 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX 689 : BASESYNTAX; 690 691 if (subtype == VSLENGTH) { 692 for (;*val; val++) 693 varlen++; 694 } else { 695 while (*val) { 696 if (quotes && syntax[(int)*val] == CCTL) 697 STPUTC(CTLESC, expdest); 698 STPUTC(*val++, expdest); 699 } 700 701 } 702 } 703 } 704 705 706 apply_ifs = ((varflags & VSQUOTE) == 0 || 707 (*var == '@' && shellparam.nparam != 1)); 708 709 switch (subtype) { 710 case VSLENGTH: 711 expdest = cvtnum(varlen, expdest); 712 break; 713 714 case VSNORMAL: 715 break; 716 717 case VSPLUS: 718 set = !set; 719 /* FALLTHROUGH */ 720 case VSMINUS: 721 if (!set) { 722 argstr(p, flag | (apply_ifs ? EXP_IFS_SPLIT : 0)); 723 /* 724 * ${x-a b c} doesn't get split, but removing the 725 * 'apply_ifs = 0' apparently breaks ${1+"$@"}.. 726 * ${x-'a b' c} should generate 2 args. 727 */ 728 /* We should have marked stuff already */ 729 apply_ifs = 0; 730 } 731 break; 732 733 case VSTRIMLEFT: 734 case VSTRIMLEFTMAX: 735 case VSTRIMRIGHT: 736 case VSTRIMRIGHTMAX: 737 if (!set) 738 break; 739 /* 740 * Terminate the string and start recording the pattern 741 * right after it 742 */ 743 STPUTC('\0', expdest); 744 patloc = expdest - stackblock(); 745 if (subevalvar(p, NULL, patloc, subtype, 746 startloc, varflags) == 0) { 747 int amount = (expdest - stackblock() - patloc) + 1; 748 STADJUST(-amount, expdest); 749 } 750 /* Remove any recorded regions beyond start of variable */ 751 removerecordregions(startloc); 752 apply_ifs = 1; 753 break; 754 755 case VSASSIGN: 756 case VSQUESTION: 757 if (set) 758 break; 759 if (subevalvar(p, var, 0, subtype, startloc, varflags)) { 760 varflags &= ~VSNUL; 761 /* 762 * Remove any recorded regions beyond 763 * start of variable 764 */ 765 removerecordregions(startloc); 766 goto again; 767 } 768 apply_ifs = 0; 769 break; 770 771 default: 772 abort(); 773 } 774 775 if (apply_ifs) 776 recordregion(startloc, expdest - stackblock(), 777 varflags & VSQUOTE); 778 779 if (subtype != VSNORMAL) { /* skip to end of alternative */ 780 int nesting = 1; 781 for (;;) { 782 if ((c = *p++) == CTLESC) 783 p++; 784 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) { 785 if (set) 786 argbackq = argbackq->next; 787 } else if (c == CTLVAR) { 788 if ((*p++ & VSTYPE) != VSNORMAL) 789 nesting++; 790 } else if (c == CTLENDVAR) { 791 if (--nesting == 0) 792 break; 793 } 794 } 795 } 796 return p; 797 } 798 799 800 801 /* 802 * Test whether a specialized variable is set. 803 */ 804 805 STATIC int 806 varisset(char *name, int nulok) 807 { 808 if (*name == '!') 809 return backgndpid != -1; 810 else if (*name == '@' || *name == '*') { 811 if (*shellparam.p == NULL) 812 return 0; 813 814 if (nulok) { 815 char **av; 816 817 for (av = shellparam.p; *av; av++) 818 if (**av != '\0') 819 return 1; 820 return 0; 821 } 822 } else if (is_digit(*name)) { 823 char *ap; 824 int num = atoi(name); 825 826 if (num > shellparam.nparam) 827 return 0; 828 829 if (num == 0) 830 ap = arg0; 831 else 832 ap = shellparam.p[num - 1]; 833 834 if (nulok && (ap == NULL || *ap == '\0')) 835 return 0; 836 } 837 return 1; 838 } 839 840 841 842 /* 843 * Add the value of a specialized variable to the stack string. 844 */ 845 846 STATIC void 847 varvalue(char *name, int quoted, int subtype, int flag) 848 { 849 int num; 850 char *p; 851 int i; 852 char sep; 853 char **ap; 854 char const *syntax; 855 856 #define STRTODEST(p) \ 857 do {\ 858 if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) { \ 859 syntax = quoted? DQSYNTAX : BASESYNTAX; \ 860 while (*p) { \ 861 if (syntax[(int)*p] == CCTL) \ 862 STPUTC(CTLESC, expdest); \ 863 STPUTC(*p++, expdest); \ 864 } \ 865 } else \ 866 while (*p) \ 867 STPUTC(*p++, expdest); \ 868 } while (0) 869 870 871 switch (*name) { 872 case '$': 873 num = rootpid; 874 goto numvar; 875 case '?': 876 num = exitstatus; 877 goto numvar; 878 case '#': 879 num = shellparam.nparam; 880 goto numvar; 881 case '!': 882 num = backgndpid; 883 numvar: 884 expdest = cvtnum(num, expdest); 885 break; 886 case '-': 887 for (i = 0; optlist[i].name; i++) { 888 if (optlist[i].val && optlist[i].letter) 889 STPUTC(optlist[i].letter, expdest); 890 } 891 break; 892 case '@': 893 if (flag & EXP_FULL && quoted) { 894 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 895 STRTODEST(p); 896 if (*ap) 897 /* A NUL separates args inside "" */ 898 STPUTC('\0', expdest); 899 } 900 break; 901 } 902 /* fall through */ 903 case '*': 904 if (ifsset() != 0) 905 sep = ifsval()[0]; 906 else 907 sep = ' '; 908 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 909 STRTODEST(p); 910 if (*ap && sep) 911 STPUTC(sep, expdest); 912 } 913 break; 914 case '0': 915 p = arg0; 916 STRTODEST(p); 917 break; 918 default: 919 if (is_digit(*name)) { 920 num = atoi(name); 921 if (num > 0 && num <= shellparam.nparam) { 922 p = shellparam.p[num - 1]; 923 STRTODEST(p); 924 } 925 } 926 break; 927 } 928 } 929 930 931 932 /* 933 * Record the fact that we have to scan this region of the 934 * string for IFS characters. 935 */ 936 937 STATIC void 938 recordregion(int start, int end, int inquotes) 939 { 940 struct ifsregion *ifsp; 941 942 if (ifslastp == NULL) { 943 ifsp = &ifsfirst; 944 } else { 945 if (ifslastp->endoff == start 946 && ifslastp->inquotes == inquotes) { 947 /* extend previous area */ 948 ifslastp->endoff = end; 949 return; 950 } 951 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion)); 952 ifslastp->next = ifsp; 953 } 954 ifslastp = ifsp; 955 ifslastp->next = NULL; 956 ifslastp->begoff = start; 957 ifslastp->endoff = end; 958 ifslastp->inquotes = inquotes; 959 } 960 961 962 963 /* 964 * Break the argument string into pieces based upon IFS and add the 965 * strings to the argument list. The regions of the string to be 966 * searched for IFS characters have been stored by recordregion. 967 */ 968 STATIC void 969 ifsbreakup(char *string, struct arglist *arglist) 970 { 971 struct ifsregion *ifsp; 972 struct strlist *sp; 973 char *start; 974 char *p; 975 char *q; 976 const char *ifs; 977 const char *ifsspc; 978 int had_param_ch = 0; 979 980 start = string; 981 982 if (ifslastp == NULL) { 983 /* Return entire argument, IFS doesn't apply to any of it */ 984 sp = (struct strlist *)stalloc(sizeof *sp); 985 sp->text = start; 986 *arglist->lastp = sp; 987 arglist->lastp = &sp->next; 988 return; 989 } 990 991 ifs = ifsset() ? ifsval() : " \t\n"; 992 993 for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) { 994 p = string + ifsp->begoff; 995 while (p < string + ifsp->endoff) { 996 had_param_ch = 1; 997 q = p; 998 if (*p == CTLESC) 999 p++; 1000 if (ifsp->inquotes) { 1001 /* Only NULs (should be from "$@") end args */ 1002 if (*p != 0) { 1003 p++; 1004 continue; 1005 } 1006 ifsspc = NULL; 1007 } else { 1008 if (!strchr(ifs, *p)) { 1009 p++; 1010 continue; 1011 } 1012 had_param_ch = 0; 1013 ifsspc = strchr(" \t\n", *p); 1014 1015 /* Ignore IFS whitespace at start */ 1016 if (q == start && ifsspc != NULL) { 1017 p++; 1018 start = p; 1019 continue; 1020 } 1021 } 1022 1023 /* Save this argument... */ 1024 *q = '\0'; 1025 sp = (struct strlist *)stalloc(sizeof *sp); 1026 sp->text = start; 1027 *arglist->lastp = sp; 1028 arglist->lastp = &sp->next; 1029 p++; 1030 1031 if (ifsspc != NULL) { 1032 /* Ignore further trailing IFS whitespace */ 1033 for (; p < string + ifsp->endoff; p++) { 1034 q = p; 1035 if (*p == CTLESC) 1036 p++; 1037 if (strchr(ifs, *p) == NULL) { 1038 p = q; 1039 break; 1040 } 1041 if (strchr(" \t\n", *p) == NULL) { 1042 p++; 1043 break; 1044 } 1045 } 1046 } 1047 start = p; 1048 } 1049 } 1050 1051 /* 1052 * Save anything left as an argument. 1053 * Traditionally we have treated 'IFS=':'; set -- x$IFS' as 1054 * generating 2 arguments, the second of which is empty. 1055 * Some recent clarification of the Posix spec say that it 1056 * should only generate one.... 1057 */ 1058 if (had_param_ch || *start != 0) { 1059 sp = (struct strlist *)stalloc(sizeof *sp); 1060 sp->text = start; 1061 *arglist->lastp = sp; 1062 arglist->lastp = &sp->next; 1063 } 1064 } 1065 1066 STATIC void 1067 ifsfree(void) 1068 { 1069 while (ifsfirst.next != NULL) { 1070 struct ifsregion *ifsp; 1071 INTOFF; 1072 ifsp = ifsfirst.next->next; 1073 ckfree(ifsfirst.next); 1074 ifsfirst.next = ifsp; 1075 INTON; 1076 } 1077 ifslastp = NULL; 1078 ifsfirst.next = NULL; 1079 } 1080 1081 1082 1083 /* 1084 * Expand shell metacharacters. At this point, the only control characters 1085 * should be escapes. The results are stored in the list exparg. 1086 */ 1087 1088 char *expdir; 1089 1090 1091 STATIC void 1092 expandmeta(struct strlist *str, int flag) 1093 { 1094 char *p; 1095 struct strlist **savelastp; 1096 struct strlist *sp; 1097 char c; 1098 /* TODO - EXP_REDIR */ 1099 1100 while (str) { 1101 if (fflag) 1102 goto nometa; 1103 p = str->text; 1104 for (;;) { /* fast check for meta chars */ 1105 if ((c = *p++) == '\0') 1106 goto nometa; 1107 if (c == '*' || c == '?' || c == '[' || c == '!') 1108 break; 1109 } 1110 savelastp = exparg.lastp; 1111 INTOFF; 1112 if (expdir == NULL) { 1113 int i = strlen(str->text); 1114 expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */ 1115 } 1116 1117 expmeta(expdir, str->text); 1118 ckfree(expdir); 1119 expdir = NULL; 1120 INTON; 1121 if (exparg.lastp == savelastp) { 1122 /* 1123 * no matches 1124 */ 1125 nometa: 1126 *exparg.lastp = str; 1127 rmescapes(str->text); 1128 exparg.lastp = &str->next; 1129 } else { 1130 *exparg.lastp = NULL; 1131 *savelastp = sp = expsort(*savelastp); 1132 while (sp->next != NULL) 1133 sp = sp->next; 1134 exparg.lastp = &sp->next; 1135 } 1136 str = str->next; 1137 } 1138 } 1139 1140 1141 /* 1142 * Do metacharacter (i.e. *, ?, [...]) expansion. 1143 */ 1144 1145 STATIC void 1146 expmeta(char *enddir, char *name) 1147 { 1148 char *p; 1149 const char *cp; 1150 char *q; 1151 char *start; 1152 char *endname; 1153 int metaflag; 1154 struct stat statb; 1155 DIR *dirp; 1156 struct dirent *dp; 1157 int atend; 1158 int matchdot; 1159 1160 metaflag = 0; 1161 start = name; 1162 for (p = name ; ; p++) { 1163 if (*p == '*' || *p == '?') 1164 metaflag = 1; 1165 else if (*p == '[') { 1166 q = p + 1; 1167 if (*q == '!') 1168 q++; 1169 for (;;) { 1170 while (*q == CTLQUOTEMARK) 1171 q++; 1172 if (*q == CTLESC) 1173 q++; 1174 if (*q == '/' || *q == '\0') 1175 break; 1176 if (*++q == ']') { 1177 metaflag = 1; 1178 break; 1179 } 1180 } 1181 } else if (*p == '!' && p[1] == '!' && (p == name || p[-1] == '/')) { 1182 metaflag = 1; 1183 } else if (*p == '\0') 1184 break; 1185 else if (*p == CTLQUOTEMARK) 1186 continue; 1187 else if (*p == CTLESC) 1188 p++; 1189 if (*p == '/') { 1190 if (metaflag) 1191 break; 1192 start = p + 1; 1193 } 1194 } 1195 if (metaflag == 0) { /* we've reached the end of the file name */ 1196 if (enddir != expdir) 1197 metaflag++; 1198 for (p = name ; ; p++) { 1199 if (*p == CTLQUOTEMARK) 1200 continue; 1201 if (*p == CTLESC) 1202 p++; 1203 *enddir++ = *p; 1204 if (*p == '\0') 1205 break; 1206 } 1207 if (metaflag == 0 || lstat(expdir, &statb) >= 0) 1208 addfname(expdir); 1209 return; 1210 } 1211 endname = p; 1212 if (start != name) { 1213 p = name; 1214 while (p < start) { 1215 while (*p == CTLQUOTEMARK) 1216 p++; 1217 if (*p == CTLESC) 1218 p++; 1219 *enddir++ = *p++; 1220 } 1221 } 1222 if (enddir == expdir) { 1223 cp = "."; 1224 } else if (enddir == expdir + 1 && *expdir == '/') { 1225 cp = "/"; 1226 } else { 1227 cp = expdir; 1228 enddir[-1] = '\0'; 1229 } 1230 if ((dirp = opendir(cp)) == NULL) 1231 return; 1232 if (enddir != expdir) 1233 enddir[-1] = '/'; 1234 if (*endname == 0) { 1235 atend = 1; 1236 } else { 1237 atend = 0; 1238 *endname++ = '\0'; 1239 } 1240 matchdot = 0; 1241 p = start; 1242 while (*p == CTLQUOTEMARK) 1243 p++; 1244 if (*p == CTLESC) 1245 p++; 1246 if (*p == '.') 1247 matchdot++; 1248 while (! int_pending() && (dp = readdir(dirp)) != NULL) { 1249 if (dp->d_name[0] == '.' && ! matchdot) 1250 continue; 1251 if (patmatch(start, dp->d_name, 0)) { 1252 if (atend) { 1253 scopy(dp->d_name, enddir); 1254 addfname(expdir); 1255 } else { 1256 for (p = enddir, cp = dp->d_name; 1257 (*p++ = *cp++) != '\0';) 1258 continue; 1259 p[-1] = '/'; 1260 expmeta(p, endname); 1261 } 1262 } 1263 } 1264 closedir(dirp); 1265 if (! atend) 1266 endname[-1] = '/'; 1267 } 1268 1269 1270 /* 1271 * Add a file name to the list. 1272 */ 1273 1274 STATIC void 1275 addfname(char *name) 1276 { 1277 char *p; 1278 struct strlist *sp; 1279 1280 p = stalloc(strlen(name) + 1); 1281 scopy(name, p); 1282 sp = (struct strlist *)stalloc(sizeof *sp); 1283 sp->text = p; 1284 *exparg.lastp = sp; 1285 exparg.lastp = &sp->next; 1286 } 1287 1288 1289 /* 1290 * Sort the results of file name expansion. It calculates the number of 1291 * strings to sort and then calls msort (short for merge sort) to do the 1292 * work. 1293 */ 1294 1295 STATIC struct strlist * 1296 expsort(struct strlist *str) 1297 { 1298 int len; 1299 struct strlist *sp; 1300 1301 len = 0; 1302 for (sp = str ; sp ; sp = sp->next) 1303 len++; 1304 return msort(str, len); 1305 } 1306 1307 1308 STATIC struct strlist * 1309 msort(struct strlist *list, int len) 1310 { 1311 struct strlist *p, *q = NULL; 1312 struct strlist **lpp; 1313 int half; 1314 int n; 1315 1316 if (len <= 1) 1317 return list; 1318 half = len >> 1; 1319 p = list; 1320 for (n = half ; --n >= 0 ; ) { 1321 q = p; 1322 p = p->next; 1323 } 1324 q->next = NULL; /* terminate first half of list */ 1325 q = msort(list, half); /* sort first half of list */ 1326 p = msort(p, len - half); /* sort second half */ 1327 lpp = &list; 1328 for (;;) { 1329 if (strcmp(p->text, q->text) < 0) { 1330 *lpp = p; 1331 lpp = &p->next; 1332 if ((p = *lpp) == NULL) { 1333 *lpp = q; 1334 break; 1335 } 1336 } else { 1337 *lpp = q; 1338 lpp = &q->next; 1339 if ((q = *lpp) == NULL) { 1340 *lpp = p; 1341 break; 1342 } 1343 } 1344 } 1345 return list; 1346 } 1347 1348 1349 1350 /* 1351 * Returns true if the pattern matches the string. 1352 */ 1353 1354 int 1355 patmatch(char *pattern, char *string, int squoted) 1356 { 1357 #ifdef notdef 1358 if (pattern[0] == '!' && pattern[1] == '!') 1359 return 1 - pmatch(pattern + 2, string); 1360 else 1361 #endif 1362 return pmatch(pattern, string, squoted); 1363 } 1364 1365 1366 STATIC int 1367 pmatch(char *pattern, char *string, int squoted) 1368 { 1369 char *p, *q; 1370 char c; 1371 1372 p = pattern; 1373 q = string; 1374 for (;;) { 1375 switch (c = *p++) { 1376 case '\0': 1377 goto breakloop; 1378 case CTLESC: 1379 if (squoted && *q == CTLESC) 1380 q++; 1381 if (*q++ != *p++) 1382 return 0; 1383 break; 1384 case CTLQUOTEMARK: 1385 continue; 1386 case '?': 1387 if (squoted && *q == CTLESC) 1388 q++; 1389 if (*q++ == '\0') 1390 return 0; 1391 break; 1392 case '*': 1393 c = *p; 1394 while (c == CTLQUOTEMARK || c == '*') 1395 c = *++p; 1396 if (c != CTLESC && c != CTLQUOTEMARK && 1397 c != '?' && c != '*' && c != '[') { 1398 while (*q != c) { 1399 if (squoted && *q == CTLESC && 1400 q[1] == c) 1401 break; 1402 if (*q == '\0') 1403 return 0; 1404 if (squoted && *q == CTLESC) 1405 q++; 1406 q++; 1407 } 1408 } 1409 do { 1410 if (pmatch(p, q, squoted)) 1411 return 1; 1412 if (squoted && *q == CTLESC) 1413 q++; 1414 } while (*q++ != '\0'); 1415 return 0; 1416 case '[': { 1417 char *endp; 1418 int invert, found; 1419 char chr; 1420 1421 endp = p; 1422 if (*endp == '!') 1423 endp++; 1424 for (;;) { 1425 while (*endp == CTLQUOTEMARK) 1426 endp++; 1427 if (*endp == '\0') 1428 goto dft; /* no matching ] */ 1429 if (*endp == CTLESC) 1430 endp++; 1431 if (*++endp == ']') 1432 break; 1433 } 1434 invert = 0; 1435 if (*p == '!') { 1436 invert++; 1437 p++; 1438 } 1439 found = 0; 1440 chr = *q++; 1441 if (squoted && chr == CTLESC) 1442 chr = *q++; 1443 if (chr == '\0') 1444 return 0; 1445 c = *p++; 1446 do { 1447 if (c == CTLQUOTEMARK) 1448 continue; 1449 if (c == CTLESC) 1450 c = *p++; 1451 if (*p == '-' && p[1] != ']') { 1452 p++; 1453 while (*p == CTLQUOTEMARK) 1454 p++; 1455 if (*p == CTLESC) 1456 p++; 1457 if (chr >= c && chr <= *p) 1458 found = 1; 1459 p++; 1460 } else { 1461 if (chr == c) 1462 found = 1; 1463 } 1464 } while ((c = *p++) != ']'); 1465 if (found == invert) 1466 return 0; 1467 break; 1468 } 1469 dft: default: 1470 if (squoted && *q == CTLESC) 1471 q++; 1472 if (*q++ != c) 1473 return 0; 1474 break; 1475 } 1476 } 1477 breakloop: 1478 if (*q != '\0') 1479 return 0; 1480 return 1; 1481 } 1482 1483 1484 1485 /* 1486 * Remove any CTLESC characters from a string. 1487 */ 1488 1489 void 1490 rmescapes(char *str) 1491 { 1492 char *p, *q; 1493 1494 p = str; 1495 while (*p != CTLESC && *p != CTLQUOTEMARK) { 1496 if (*p++ == '\0') 1497 return; 1498 } 1499 q = p; 1500 while (*p) { 1501 if (*p == CTLQUOTEMARK) { 1502 p++; 1503 continue; 1504 } 1505 if (*p == CTLESC) 1506 p++; 1507 *q++ = *p++; 1508 } 1509 *q = '\0'; 1510 } 1511 1512 1513 1514 /* 1515 * See if a pattern matches in a case statement. 1516 */ 1517 1518 int 1519 casematch(union node *pattern, char *val) 1520 { 1521 struct stackmark smark; 1522 int result; 1523 char *p; 1524 1525 setstackmark(&smark); 1526 argbackq = pattern->narg.backquote; 1527 STARTSTACKSTR(expdest); 1528 ifslastp = NULL; 1529 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE); 1530 STPUTC('\0', expdest); 1531 p = grabstackstr(expdest); 1532 result = patmatch(p, val, 0); 1533 popstackmark(&smark); 1534 return result; 1535 } 1536 1537 /* 1538 * Our own itoa(). 1539 */ 1540 1541 STATIC char * 1542 cvtnum(int num, char *buf) 1543 { 1544 char temp[32]; 1545 int neg = num < 0; 1546 char *p = temp + 31; 1547 1548 temp[31] = '\0'; 1549 1550 do { 1551 *--p = num % 10 + '0'; 1552 } while ((num /= 10) != 0); 1553 1554 if (neg) 1555 *--p = '-'; 1556 1557 while (*p) 1558 STPUTC(*p++, buf); 1559 return buf; 1560 } 1561 1562 /* 1563 * Do most of the work for wordexp(3). 1564 */ 1565 1566 int 1567 wordexpcmd(int argc, char **argv) 1568 { 1569 size_t len; 1570 int i; 1571 1572 out1fmt("%d", argc - 1); 1573 out1c('\0'); 1574 for (i = 1, len = 0; i < argc; i++) 1575 len += strlen(argv[i]); 1576 out1fmt("%zu", len); 1577 out1c('\0'); 1578 for (i = 1; i < argc; i++) { 1579 out1str(argv[i]); 1580 out1c('\0'); 1581 } 1582 return (0); 1583 } 1584