1 /*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * Copyright (c) 1997-2005 5 * Herbert Xu <herbert@gondor.apana.org.au>. 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 * 4. 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 #ifndef lint 36 #if 0 37 static char sccsid[] = "@(#)expand.c 8.5 (Berkeley) 5/15/95"; 38 #endif 39 #endif /* not lint */ 40 #include <sys/cdefs.h> 41 __FBSDID("$FreeBSD$"); 42 43 #include <sys/types.h> 44 #include <sys/time.h> 45 #include <sys/stat.h> 46 #include <errno.h> 47 #include <dirent.h> 48 #include <unistd.h> 49 #include <pwd.h> 50 #include <stdlib.h> 51 #include <limits.h> 52 #include <stdio.h> 53 #include <string.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 "var.h" 70 #include "input.h" 71 #include "output.h" 72 #include "memalloc.h" 73 #include "error.h" 74 #include "mystring.h" 75 #include "arith.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 STATIC char *expdest; /* output of current string */ 92 STATIC struct nodelist *argbackq; /* list of back quote expressions */ 93 STATIC struct ifsregion ifsfirst; /* first struct in list of ifs regions */ 94 STATIC struct ifsregion *ifslastp; /* last struct in list */ 95 STATIC 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 expandmeta(struct strlist *, int); 108 STATIC void expmeta(char *, char *); 109 STATIC void addfname(char *); 110 STATIC struct strlist *expsort(struct strlist *); 111 STATIC struct strlist *msort(struct strlist *, int); 112 STATIC char *cvtnum(int, char *); 113 STATIC int collate_range_cmp(int, int); 114 115 STATIC int 116 collate_range_cmp(int c1, int c2) 117 { 118 static char s1[2], s2[2]; 119 120 s1[0] = c1; 121 s2[0] = c2; 122 return (strcoll(s1, s2)); 123 } 124 125 /* 126 * Expand shell variables and backquotes inside a here document. 127 * union node *arg the document 128 * int fd; where to write the expanded version 129 */ 130 131 void 132 expandhere(union node *arg, int fd) 133 { 134 herefd = fd; 135 expandarg(arg, (struct arglist *)NULL, 0); 136 xwrite(fd, stackblock(), expdest - stackblock()); 137 } 138 139 140 /* 141 * Perform expansions on an argument, placing the resulting list of arguments 142 * in arglist. Parameter expansion, command substitution and arithmetic 143 * expansion are always performed; additional expansions can be requested 144 * via flag (EXP_*). 145 * The result is left in the stack string. 146 * When arglist is NULL, perform here document expansion. A partial result 147 * may be written to herefd, which is then not included in the stack string. 148 * 149 * Caution: this function uses global state and is not reentrant. 150 * However, a new invocation after an interrupted invocation is safe 151 * and will reset the global state for the new call. 152 */ 153 void 154 expandarg(union node *arg, struct arglist *arglist, int flag) 155 { 156 struct strlist *sp; 157 char *p; 158 159 argbackq = arg->narg.backquote; 160 STARTSTACKSTR(expdest); 161 ifsfirst.next = NULL; 162 ifslastp = NULL; 163 argstr(arg->narg.text, flag); 164 if (arglist == NULL) { 165 return; /* here document expanded */ 166 } 167 STPUTC('\0', expdest); 168 p = grabstackstr(expdest); 169 exparg.lastp = &exparg.list; 170 /* 171 * TODO - EXP_REDIR 172 */ 173 if (flag & EXP_FULL) { 174 ifsbreakup(p, &exparg); 175 *exparg.lastp = NULL; 176 exparg.lastp = &exparg.list; 177 expandmeta(exparg.list, flag); 178 } else { 179 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */ 180 rmescapes(p); 181 sp = (struct strlist *)stalloc(sizeof (struct strlist)); 182 sp->text = p; 183 *exparg.lastp = sp; 184 exparg.lastp = &sp->next; 185 } 186 while (ifsfirst.next != NULL) { 187 struct ifsregion *ifsp; 188 INTOFF; 189 ifsp = ifsfirst.next->next; 190 ckfree(ifsfirst.next); 191 ifsfirst.next = ifsp; 192 INTON; 193 } 194 *exparg.lastp = NULL; 195 if (exparg.list) { 196 *arglist->lastp = exparg.list; 197 arglist->lastp = exparg.lastp; 198 } 199 } 200 201 202 203 /* 204 * Perform parameter expansion, command substitution and arithmetic 205 * expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE. 206 * Processing ends at a CTLENDVAR character as well as '\0'. 207 * This is used to expand word in ${var+word} etc. 208 * If EXP_FULL, EXP_CASE or EXP_REDIR are set, keep and/or generate CTLESC 209 * characters to allow for further processing. 210 * If EXP_FULL is set, also preserve CTLQUOTEMARK characters. 211 */ 212 STATIC void 213 argstr(char *p, int flag) 214 { 215 char c; 216 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); /* do CTLESC */ 217 int firsteq = 1; 218 219 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE))) 220 p = exptilde(p, flag); 221 for (;;) { 222 switch (c = *p++) { 223 case '\0': 224 case CTLENDVAR: 225 goto breakloop; 226 case CTLQUOTEMARK: 227 /* "$@" syntax adherence hack */ 228 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=') 229 break; 230 if ((flag & EXP_FULL) != 0) 231 STPUTC(c, expdest); 232 break; 233 case CTLESC: 234 if (quotes) 235 STPUTC(c, expdest); 236 c = *p++; 237 STPUTC(c, expdest); 238 break; 239 case CTLVAR: 240 p = evalvar(p, flag); 241 break; 242 case CTLBACKQ: 243 case CTLBACKQ|CTLQUOTE: 244 expbackq(argbackq->n, c & CTLQUOTE, flag); 245 argbackq = argbackq->next; 246 break; 247 case CTLENDARI: 248 expari(flag); 249 break; 250 case ':': 251 case '=': 252 /* 253 * sort of a hack - expand tildes in variable 254 * assignments (after the first '=' and after ':'s). 255 */ 256 STPUTC(c, expdest); 257 if (flag & EXP_VARTILDE && *p == '~') { 258 if (c == '=') { 259 if (firsteq) 260 firsteq = 0; 261 else 262 break; 263 } 264 p = exptilde(p, flag); 265 } 266 break; 267 default: 268 STPUTC(c, expdest); 269 } 270 } 271 breakloop:; 272 } 273 274 /* 275 * Perform tilde expansion, placing the result in the stack string and 276 * returning the next position in the input string to process. 277 */ 278 STATIC char * 279 exptilde(char *p, int flag) 280 { 281 char c, *startp = p; 282 struct passwd *pw; 283 char *home; 284 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 285 286 while ((c = *p) != '\0') { 287 switch(c) { 288 case CTLESC: /* This means CTL* are always considered quoted. */ 289 case CTLVAR: 290 case CTLBACKQ: 291 case CTLBACKQ | CTLQUOTE: 292 case CTLARI: 293 case CTLENDARI: 294 case CTLQUOTEMARK: 295 return (startp); 296 case ':': 297 if (flag & EXP_VARTILDE) 298 goto done; 299 break; 300 case '/': 301 case CTLENDVAR: 302 goto done; 303 } 304 p++; 305 } 306 done: 307 *p = '\0'; 308 if (*(startp+1) == '\0') { 309 if ((home = lookupvar("HOME")) == NULL) 310 goto lose; 311 } else { 312 if ((pw = getpwnam(startp+1)) == NULL) 313 goto lose; 314 home = pw->pw_dir; 315 } 316 if (*home == '\0') 317 goto lose; 318 *p = c; 319 while ((c = *home++) != '\0') { 320 if (quotes && SQSYNTAX[(int)c] == CCTL) 321 STPUTC(CTLESC, expdest); 322 STPUTC(c, expdest); 323 } 324 return (p); 325 lose: 326 *p = c; 327 return (startp); 328 } 329 330 331 STATIC void 332 removerecordregions(int endoff) 333 { 334 if (ifslastp == NULL) 335 return; 336 337 if (ifsfirst.endoff > endoff) { 338 while (ifsfirst.next != NULL) { 339 struct ifsregion *ifsp; 340 INTOFF; 341 ifsp = ifsfirst.next->next; 342 ckfree(ifsfirst.next); 343 ifsfirst.next = ifsp; 344 INTON; 345 } 346 if (ifsfirst.begoff > endoff) 347 ifslastp = NULL; 348 else { 349 ifslastp = &ifsfirst; 350 ifsfirst.endoff = endoff; 351 } 352 return; 353 } 354 355 ifslastp = &ifsfirst; 356 while (ifslastp->next && ifslastp->next->begoff < endoff) 357 ifslastp=ifslastp->next; 358 while (ifslastp->next != NULL) { 359 struct ifsregion *ifsp; 360 INTOFF; 361 ifsp = ifslastp->next->next; 362 ckfree(ifslastp->next); 363 ifslastp->next = ifsp; 364 INTON; 365 } 366 if (ifslastp->endoff > endoff) 367 ifslastp->endoff = endoff; 368 } 369 370 /* 371 * Expand arithmetic expression. Backup to start of expression, 372 * evaluate, place result in (backed up) result, adjust string position. 373 */ 374 void 375 expari(int flag) 376 { 377 char *p, *q, *start; 378 arith_t result; 379 int begoff; 380 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 381 int quoted; 382 383 /* 384 * This routine is slightly over-complicated for 385 * efficiency. First we make sure there is 386 * enough space for the result, which may be bigger 387 * than the expression. Next we 388 * scan backwards looking for the start of arithmetic. If the 389 * next previous character is a CTLESC character, then we 390 * have to rescan starting from the beginning since CTLESC 391 * characters have to be processed left to right. 392 */ 393 CHECKSTRSPACE(DIGITS(result) - 2, expdest); 394 USTPUTC('\0', expdest); 395 start = stackblock(); 396 p = expdest - 2; 397 while (p >= start && *p != CTLARI) 398 --p; 399 if (p < start || *p != CTLARI) 400 error("missing CTLARI (shouldn't happen)"); 401 if (p > start && *(p - 1) == CTLESC) 402 for (p = start; *p != CTLARI; p++) 403 if (*p == CTLESC) 404 p++; 405 406 if (p[1] == '"') 407 quoted=1; 408 else 409 quoted=0; 410 begoff = p - start; 411 removerecordregions(begoff); 412 if (quotes) 413 rmescapes(p+2); 414 q = grabstackstr(expdest); 415 result = arith(p+2); 416 ungrabstackstr(q, expdest); 417 fmtstr(p, DIGITS(result), ARITH_FORMAT_STR, result); 418 while (*p++) 419 ; 420 if (quoted == 0) 421 recordregion(begoff, p - 1 - start, 0); 422 result = expdest - p + 1; 423 STADJUST(-result, expdest); 424 } 425 426 427 /* 428 * Perform command substitution. 429 */ 430 STATIC void 431 expbackq(union node *cmd, int quoted, int flag) 432 { 433 struct backcmd in; 434 int i; 435 char buf[128]; 436 char *p; 437 char *dest = expdest; 438 struct ifsregion saveifs, *savelastp; 439 struct nodelist *saveargbackq; 440 char lastc; 441 int startloc = dest - stackblock(); 442 char const *syntax = quoted? DQSYNTAX : BASESYNTAX; 443 int saveherefd; 444 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 445 int nnl; 446 447 INTOFF; 448 saveifs = ifsfirst; 449 savelastp = ifslastp; 450 saveargbackq = argbackq; 451 saveherefd = herefd; 452 herefd = -1; 453 p = grabstackstr(dest); 454 evalbackcmd(cmd, &in); 455 ungrabstackstr(p, dest); 456 ifsfirst = saveifs; 457 ifslastp = savelastp; 458 argbackq = saveargbackq; 459 herefd = saveherefd; 460 461 p = in.buf; 462 lastc = '\0'; 463 nnl = 0; 464 /* Don't copy trailing newlines */ 465 for (;;) { 466 if (--in.nleft < 0) { 467 if (in.fd < 0) 468 break; 469 while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR); 470 TRACE(("expbackq: read returns %d\n", i)); 471 if (i <= 0) 472 break; 473 p = buf; 474 in.nleft = i - 1; 475 } 476 lastc = *p++; 477 if (lastc != '\0') { 478 if (quotes && syntax[(int)lastc] == CCTL) 479 STPUTC(CTLESC, dest); 480 if (lastc == '\n') { 481 nnl++; 482 } else { 483 while (nnl > 0) { 484 nnl--; 485 STPUTC('\n', dest); 486 } 487 STPUTC(lastc, dest); 488 } 489 } 490 } 491 492 if (in.fd >= 0) 493 close(in.fd); 494 if (in.buf) 495 ckfree(in.buf); 496 if (in.jp) 497 exitstatus = waitforjob(in.jp, (int *)NULL); 498 if (quoted == 0) 499 recordregion(startloc, dest - stackblock(), 0); 500 TRACE(("evalbackq: size=%d: \"%.*s\"\n", 501 (dest - stackblock()) - startloc, 502 (dest - stackblock()) - startloc, 503 stackblock() + startloc)); 504 expdest = dest; 505 INTON; 506 } 507 508 509 510 STATIC int 511 subevalvar(char *p, char *str, int strloc, int subtype, int startloc, 512 int varflags) 513 { 514 char *startp; 515 char *loc = NULL; 516 char *q; 517 int c = 0; 518 int saveherefd = herefd; 519 struct nodelist *saveargbackq = argbackq; 520 int amount; 521 522 herefd = -1; 523 argstr(p, (subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX || 524 subtype == VSTRIMRIGHT || subtype == VSTRIMRIGHTMAX ? 525 EXP_CASE : 0) | EXP_TILDE); 526 STACKSTRNUL(expdest); 527 herefd = saveherefd; 528 argbackq = saveargbackq; 529 startp = stackblock() + startloc; 530 if (str == NULL) 531 str = stackblock() + strloc; 532 533 switch (subtype) { 534 case VSASSIGN: 535 setvar(str, startp, 0); 536 amount = startp - expdest; 537 STADJUST(amount, expdest); 538 varflags &= ~VSNUL; 539 if (c != 0) 540 *loc = c; 541 return 1; 542 543 case VSQUESTION: 544 if (*p != CTLENDVAR) { 545 outfmt(out2, "%s\n", startp); 546 error((char *)NULL); 547 } 548 error("%.*s: parameter %snot set", (int)(p - str - 1), 549 str, (varflags & VSNUL) ? "null or " 550 : nullstr); 551 return 0; 552 553 case VSTRIMLEFT: 554 for (loc = startp; loc < str; loc++) { 555 c = *loc; 556 *loc = '\0'; 557 if (patmatch(str, startp, varflags & VSQUOTE)) { 558 *loc = c; 559 goto recordleft; 560 } 561 *loc = c; 562 if ((varflags & VSQUOTE) && *loc == CTLESC) 563 loc++; 564 } 565 return 0; 566 567 case VSTRIMLEFTMAX: 568 for (loc = str - 1; loc >= startp;) { 569 c = *loc; 570 *loc = '\0'; 571 if (patmatch(str, startp, varflags & VSQUOTE)) { 572 *loc = c; 573 goto recordleft; 574 } 575 *loc = c; 576 loc--; 577 if ((varflags & VSQUOTE) && loc > startp && 578 *(loc - 1) == CTLESC) { 579 for (q = startp; q < loc; q++) 580 if (*q == CTLESC) 581 q++; 582 if (q > loc) 583 loc--; 584 } 585 } 586 return 0; 587 588 case VSTRIMRIGHT: 589 for (loc = str - 1; loc >= startp;) { 590 if (patmatch(str, loc, varflags & VSQUOTE)) { 591 amount = loc - expdest; 592 STADJUST(amount, expdest); 593 return 1; 594 } 595 loc--; 596 if ((varflags & VSQUOTE) && loc > startp && 597 *(loc - 1) == CTLESC) { 598 for (q = startp; q < loc; q++) 599 if (*q == CTLESC) 600 q++; 601 if (q > loc) 602 loc--; 603 } 604 } 605 return 0; 606 607 case VSTRIMRIGHTMAX: 608 for (loc = startp; loc < str - 1; loc++) { 609 if (patmatch(str, loc, varflags & VSQUOTE)) { 610 amount = loc - expdest; 611 STADJUST(amount, expdest); 612 return 1; 613 } 614 if ((varflags & VSQUOTE) && *loc == CTLESC) 615 loc++; 616 } 617 return 0; 618 619 620 default: 621 abort(); 622 } 623 624 recordleft: 625 amount = ((str - 1) - (loc - startp)) - expdest; 626 STADJUST(amount, expdest); 627 while (loc != str - 1) 628 *startp++ = *loc++; 629 return 1; 630 } 631 632 633 /* 634 * Expand a variable, and return a pointer to the next character in the 635 * input string. 636 */ 637 638 STATIC char * 639 evalvar(char *p, int flag) 640 { 641 int subtype; 642 int varflags; 643 char *var; 644 char *val; 645 int patloc; 646 int c; 647 int set; 648 int special; 649 int startloc; 650 int varlen; 651 int easy; 652 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 653 654 varflags = (unsigned char)*p++; 655 subtype = varflags & VSTYPE; 656 var = p; 657 special = 0; 658 if (! is_name(*p)) 659 special = 1; 660 p = strchr(p, '=') + 1; 661 again: /* jump here after setting a variable with ${var=text} */ 662 if (varflags & VSLINENO) { 663 set = 1; 664 special = 0; 665 val = var; 666 p[-1] = '\0'; /* temporarily overwrite '=' to have \0 667 terminated string */ 668 } else if (special) { 669 set = varisset(var, varflags & VSNUL); 670 val = NULL; 671 } else { 672 val = bltinlookup(var, 1); 673 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) { 674 val = NULL; 675 set = 0; 676 } else 677 set = 1; 678 } 679 varlen = 0; 680 startloc = expdest - stackblock(); 681 if (!set && uflag && *var != '@' && *var != '*') { 682 switch (subtype) { 683 case VSNORMAL: 684 case VSTRIMLEFT: 685 case VSTRIMLEFTMAX: 686 case VSTRIMRIGHT: 687 case VSTRIMRIGHTMAX: 688 case VSLENGTH: 689 error("%.*s: parameter not set", (int)(p - var - 1), 690 var); 691 } 692 } 693 if (set && subtype != VSPLUS) { 694 /* insert the value of the variable */ 695 if (special) { 696 varvalue(var, varflags & VSQUOTE, subtype, flag); 697 if (subtype == VSLENGTH) { 698 varlen = expdest - stackblock() - startloc; 699 STADJUST(-varlen, expdest); 700 } 701 } else { 702 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX 703 : BASESYNTAX; 704 705 if (subtype == VSLENGTH) { 706 for (;*val; val++) 707 varlen++; 708 } 709 else { 710 while (*val) { 711 if (quotes && 712 syntax[(int)*val] == CCTL) 713 STPUTC(CTLESC, expdest); 714 STPUTC(*val++, expdest); 715 } 716 717 } 718 } 719 } 720 721 if (subtype == VSPLUS) 722 set = ! set; 723 724 easy = ((varflags & VSQUOTE) == 0 || 725 (*var == '@' && shellparam.nparam != 1)); 726 727 728 switch (subtype) { 729 case VSLENGTH: 730 expdest = cvtnum(varlen, expdest); 731 goto record; 732 733 case VSNORMAL: 734 if (!easy) 735 break; 736 record: 737 recordregion(startloc, expdest - stackblock(), 738 varflags & VSQUOTE); 739 break; 740 741 case VSPLUS: 742 case VSMINUS: 743 if (!set) { 744 argstr(p, flag); 745 break; 746 } 747 if (easy) 748 goto record; 749 break; 750 751 case VSTRIMLEFT: 752 case VSTRIMLEFTMAX: 753 case VSTRIMRIGHT: 754 case VSTRIMRIGHTMAX: 755 if (!set) 756 break; 757 /* 758 * Terminate the string and start recording the pattern 759 * right after it 760 */ 761 STPUTC('\0', expdest); 762 patloc = expdest - stackblock(); 763 if (subevalvar(p, NULL, patloc, subtype, 764 startloc, varflags) == 0) { 765 int amount = (expdest - stackblock() - patloc) + 1; 766 STADJUST(-amount, expdest); 767 } 768 /* Remove any recorded regions beyond start of variable */ 769 removerecordregions(startloc); 770 goto record; 771 772 case VSASSIGN: 773 case VSQUESTION: 774 if (!set) { 775 if (subevalvar(p, var, 0, subtype, startloc, varflags)) { 776 varflags &= ~VSNUL; 777 /* 778 * Remove any recorded regions beyond 779 * start of variable 780 */ 781 removerecordregions(startloc); 782 goto again; 783 } 784 break; 785 } 786 if (easy) 787 goto record; 788 break; 789 790 case VSERROR: 791 c = p - var - 1; 792 error("${%.*s%s}: Bad substitution", c, var, 793 (c > 0 && *p != CTLENDVAR) ? "..." : ""); 794 795 default: 796 abort(); 797 } 798 p[-1] = '='; /* recover overwritten '=' */ 799 800 if (subtype != VSNORMAL) { /* skip to end of alternative */ 801 int nesting = 1; 802 for (;;) { 803 if ((c = *p++) == CTLESC) 804 p++; 805 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) { 806 if (set) 807 argbackq = argbackq->next; 808 } else if (c == CTLVAR) { 809 if ((*p++ & VSTYPE) != VSNORMAL) 810 nesting++; 811 } else if (c == CTLENDVAR) { 812 if (--nesting == 0) 813 break; 814 } 815 } 816 } 817 return p; 818 } 819 820 821 822 /* 823 * Test whether a specialized variable is set. 824 */ 825 826 STATIC int 827 varisset(char *name, int nulok) 828 { 829 830 if (*name == '!') 831 return backgndpidset(); 832 else if (*name == '@' || *name == '*') { 833 if (*shellparam.p == NULL) 834 return 0; 835 836 if (nulok) { 837 char **av; 838 839 for (av = shellparam.p; *av; av++) 840 if (**av != '\0') 841 return 1; 842 return 0; 843 } 844 } else if (is_digit(*name)) { 845 char *ap; 846 int num = atoi(name); 847 848 if (num > shellparam.nparam) 849 return 0; 850 851 if (num == 0) 852 ap = arg0; 853 else 854 ap = shellparam.p[num - 1]; 855 856 if (nulok && (ap == NULL || *ap == '\0')) 857 return 0; 858 } 859 return 1; 860 } 861 862 863 864 /* 865 * Add the value of a specialized variable to the stack string. 866 */ 867 868 STATIC void 869 varvalue(char *name, int quoted, int subtype, int flag) 870 { 871 int num; 872 char *p; 873 int i; 874 char sep; 875 char **ap; 876 char const *syntax; 877 878 #define STRTODEST(p) \ 879 do {\ 880 if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) { \ 881 syntax = quoted? DQSYNTAX : BASESYNTAX; \ 882 while (*p) { \ 883 if (syntax[(int)*p] == CCTL) \ 884 STPUTC(CTLESC, expdest); \ 885 STPUTC(*p++, expdest); \ 886 } \ 887 } else \ 888 while (*p) \ 889 STPUTC(*p++, expdest); \ 890 } while (0) 891 892 893 switch (*name) { 894 case '$': 895 num = rootpid; 896 goto numvar; 897 case '?': 898 num = oexitstatus; 899 goto numvar; 900 case '#': 901 num = shellparam.nparam; 902 goto numvar; 903 case '!': 904 num = backgndpidval(); 905 numvar: 906 expdest = cvtnum(num, expdest); 907 break; 908 case '-': 909 for (i = 0 ; i < NOPTS ; i++) { 910 if (optlist[i].val) 911 STPUTC(optlist[i].letter, expdest); 912 } 913 break; 914 case '@': 915 if (flag & EXP_FULL && quoted) { 916 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 917 STRTODEST(p); 918 if (*ap) 919 STPUTC('\0', expdest); 920 } 921 break; 922 } 923 /* FALLTHROUGH */ 924 case '*': 925 if (ifsset()) 926 sep = ifsval()[0]; 927 else 928 sep = ' '; 929 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 930 STRTODEST(p); 931 if (*ap && sep) 932 STPUTC(sep, expdest); 933 } 934 break; 935 case '0': 936 p = arg0; 937 STRTODEST(p); 938 break; 939 default: 940 if (is_digit(*name)) { 941 num = atoi(name); 942 if (num > 0 && num <= shellparam.nparam) { 943 p = shellparam.p[num - 1]; 944 STRTODEST(p); 945 } 946 } 947 break; 948 } 949 } 950 951 952 953 /* 954 * Record the the fact that we have to scan this region of the 955 * string for IFS characters. 956 */ 957 958 STATIC void 959 recordregion(int start, int end, int inquotes) 960 { 961 struct ifsregion *ifsp; 962 963 if (ifslastp == NULL) { 964 ifsp = &ifsfirst; 965 } else { 966 if (ifslastp->endoff == start 967 && ifslastp->inquotes == inquotes) { 968 /* extend previous area */ 969 ifslastp->endoff = end; 970 return; 971 } 972 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion)); 973 ifslastp->next = ifsp; 974 } 975 ifslastp = ifsp; 976 ifslastp->next = NULL; 977 ifslastp->begoff = start; 978 ifslastp->endoff = end; 979 ifslastp->inquotes = inquotes; 980 } 981 982 983 984 /* 985 * Break the argument string into pieces based upon IFS and add the 986 * strings to the argument list. The regions of the string to be 987 * searched for IFS characters have been stored by recordregion. 988 * CTLESC characters are preserved but have little effect in this pass 989 * other than escaping CTL* characters. In particular, they do not escape 990 * IFS characters: that should be done with the ifsregion mechanism. 991 * CTLQUOTEMARK characters are used to preserve empty quoted strings. 992 * This pass treats them as a regular character, making the string non-empty. 993 * Later, they are removed along with the other CTL* characters. 994 */ 995 STATIC void 996 ifsbreakup(char *string, struct arglist *arglist) 997 { 998 struct ifsregion *ifsp; 999 struct strlist *sp; 1000 char *start; 1001 char *p; 1002 char *q; 1003 const char *ifs; 1004 const char *ifsspc; 1005 int had_param_ch = 0; 1006 1007 start = string; 1008 1009 if (ifslastp == NULL) { 1010 /* Return entire argument, IFS doesn't apply to any of it */ 1011 sp = (struct strlist *)stalloc(sizeof *sp); 1012 sp->text = start; 1013 *arglist->lastp = sp; 1014 arglist->lastp = &sp->next; 1015 return; 1016 } 1017 1018 ifs = ifsset() ? ifsval() : " \t\n"; 1019 1020 for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) { 1021 p = string + ifsp->begoff; 1022 while (p < string + ifsp->endoff) { 1023 q = p; 1024 if (*p == CTLESC) 1025 p++; 1026 if (ifsp->inquotes) { 1027 /* Only NULs (should be from "$@") end args */ 1028 had_param_ch = 1; 1029 if (*p != 0) { 1030 p++; 1031 continue; 1032 } 1033 ifsspc = NULL; 1034 } else { 1035 if (!strchr(ifs, *p)) { 1036 had_param_ch = 1; 1037 p++; 1038 continue; 1039 } 1040 ifsspc = strchr(" \t\n", *p); 1041 1042 /* Ignore IFS whitespace at start */ 1043 if (q == start && ifsspc != NULL) { 1044 p++; 1045 start = p; 1046 continue; 1047 } 1048 had_param_ch = 0; 1049 } 1050 1051 /* Save this argument... */ 1052 *q = '\0'; 1053 sp = (struct strlist *)stalloc(sizeof *sp); 1054 sp->text = start; 1055 *arglist->lastp = sp; 1056 arglist->lastp = &sp->next; 1057 p++; 1058 1059 if (ifsspc != NULL) { 1060 /* Ignore further trailing IFS whitespace */ 1061 for (; p < string + ifsp->endoff; p++) { 1062 q = p; 1063 if (*p == CTLESC) 1064 p++; 1065 if (strchr(ifs, *p) == NULL) { 1066 p = q; 1067 break; 1068 } 1069 if (strchr(" \t\n", *p) == NULL) { 1070 p++; 1071 break; 1072 } 1073 } 1074 } 1075 start = p; 1076 } 1077 } 1078 1079 /* 1080 * Save anything left as an argument. 1081 * Traditionally we have treated 'IFS=':'; set -- x$IFS' as 1082 * generating 2 arguments, the second of which is empty. 1083 * Some recent clarification of the Posix spec say that it 1084 * should only generate one.... 1085 */ 1086 if (had_param_ch || *start != 0) { 1087 sp = (struct strlist *)stalloc(sizeof *sp); 1088 sp->text = start; 1089 *arglist->lastp = sp; 1090 arglist->lastp = &sp->next; 1091 } 1092 } 1093 1094 1095 STATIC char expdir[PATH_MAX]; 1096 #define expdir_end (expdir + sizeof(expdir)) 1097 1098 /* 1099 * Perform pathname generation and remove control characters. 1100 * At this point, the only control characters should be CTLESC and CTLQUOTEMARK. 1101 * The results are stored in the list exparg. 1102 */ 1103 STATIC void 1104 expandmeta(struct strlist *str, int flag __unused) 1105 { 1106 char *p; 1107 struct strlist **savelastp; 1108 struct strlist *sp; 1109 char c; 1110 /* TODO - EXP_REDIR */ 1111 1112 while (str) { 1113 if (fflag) 1114 goto nometa; 1115 p = str->text; 1116 for (;;) { /* fast check for meta chars */ 1117 if ((c = *p++) == '\0') 1118 goto nometa; 1119 if (c == '*' || c == '?' || c == '[') 1120 break; 1121 } 1122 savelastp = exparg.lastp; 1123 INTOFF; 1124 expmeta(expdir, str->text); 1125 INTON; 1126 if (exparg.lastp == savelastp) { 1127 /* 1128 * no matches 1129 */ 1130 nometa: 1131 *exparg.lastp = str; 1132 rmescapes(str->text); 1133 exparg.lastp = &str->next; 1134 } else { 1135 *exparg.lastp = NULL; 1136 *savelastp = sp = expsort(*savelastp); 1137 while (sp->next != NULL) 1138 sp = sp->next; 1139 exparg.lastp = &sp->next; 1140 } 1141 str = str->next; 1142 } 1143 } 1144 1145 1146 /* 1147 * Do metacharacter (i.e. *, ?, [...]) expansion. 1148 */ 1149 1150 STATIC void 1151 expmeta(char *enddir, char *name) 1152 { 1153 char *p; 1154 char *q; 1155 char *start; 1156 char *endname; 1157 int metaflag; 1158 struct stat statb; 1159 DIR *dirp; 1160 struct dirent *dp; 1161 int atend; 1162 int matchdot; 1163 int esc; 1164 1165 metaflag = 0; 1166 start = name; 1167 for (p = name; esc = 0, *p; p += esc + 1) { 1168 if (*p == '*' || *p == '?') 1169 metaflag = 1; 1170 else if (*p == '[') { 1171 q = p + 1; 1172 if (*q == '!' || *q == '^') 1173 q++; 1174 for (;;) { 1175 while (*q == CTLQUOTEMARK) 1176 q++; 1177 if (*q == CTLESC) 1178 q++; 1179 if (*q == '/' || *q == '\0') 1180 break; 1181 if (*++q == ']') { 1182 metaflag = 1; 1183 break; 1184 } 1185 } 1186 } else if (*p == '\0') 1187 break; 1188 else if (*p == CTLQUOTEMARK) 1189 continue; 1190 else { 1191 if (*p == CTLESC) 1192 esc++; 1193 if (p[esc] == '/') { 1194 if (metaflag) 1195 break; 1196 start = p + esc + 1; 1197 } 1198 } 1199 } 1200 if (metaflag == 0) { /* we've reached the end of the file name */ 1201 if (enddir != expdir) 1202 metaflag++; 1203 for (p = name ; ; p++) { 1204 if (*p == CTLQUOTEMARK) 1205 continue; 1206 if (*p == CTLESC) 1207 p++; 1208 *enddir++ = *p; 1209 if (*p == '\0') 1210 break; 1211 if (enddir == expdir_end) 1212 return; 1213 } 1214 if (metaflag == 0 || lstat(expdir, &statb) >= 0) 1215 addfname(expdir); 1216 return; 1217 } 1218 endname = p; 1219 if (start != name) { 1220 p = name; 1221 while (p < start) { 1222 while (*p == CTLQUOTEMARK) 1223 p++; 1224 if (*p == CTLESC) 1225 p++; 1226 *enddir++ = *p++; 1227 if (enddir == expdir_end) 1228 return; 1229 } 1230 } 1231 if (enddir == expdir) { 1232 p = "."; 1233 } else if (enddir == expdir + 1 && *expdir == '/') { 1234 p = "/"; 1235 } else { 1236 p = expdir; 1237 enddir[-1] = '\0'; 1238 } 1239 if ((dirp = opendir(p)) == NULL) 1240 return; 1241 if (enddir != expdir) 1242 enddir[-1] = '/'; 1243 if (*endname == 0) { 1244 atend = 1; 1245 } else { 1246 atend = 0; 1247 *endname = '\0'; 1248 endname += esc + 1; 1249 } 1250 matchdot = 0; 1251 p = start; 1252 while (*p == CTLQUOTEMARK) 1253 p++; 1254 if (*p == CTLESC) 1255 p++; 1256 if (*p == '.') 1257 matchdot++; 1258 while (! int_pending() && (dp = readdir(dirp)) != NULL) { 1259 if (dp->d_name[0] == '.' && ! matchdot) 1260 continue; 1261 if (patmatch(start, dp->d_name, 0)) { 1262 if (enddir + dp->d_namlen + 1 > expdir_end) 1263 continue; 1264 memcpy(enddir, dp->d_name, dp->d_namlen + 1); 1265 if (atend) 1266 addfname(expdir); 1267 else { 1268 if (enddir + dp->d_namlen + 2 > expdir_end) 1269 continue; 1270 enddir[dp->d_namlen] = '/'; 1271 enddir[dp->d_namlen + 1] = '\0'; 1272 expmeta(enddir + dp->d_namlen + 1, endname); 1273 } 1274 } 1275 } 1276 closedir(dirp); 1277 if (! atend) 1278 endname[-esc - 1] = esc ? CTLESC : '/'; 1279 } 1280 1281 1282 /* 1283 * Add a file name to the list. 1284 */ 1285 1286 STATIC void 1287 addfname(char *name) 1288 { 1289 char *p; 1290 struct strlist *sp; 1291 1292 p = stalloc(strlen(name) + 1); 1293 scopy(name, p); 1294 sp = (struct strlist *)stalloc(sizeof *sp); 1295 sp->text = p; 1296 *exparg.lastp = sp; 1297 exparg.lastp = &sp->next; 1298 } 1299 1300 1301 /* 1302 * Sort the results of file name expansion. It calculates the number of 1303 * strings to sort and then calls msort (short for merge sort) to do the 1304 * work. 1305 */ 1306 1307 STATIC struct strlist * 1308 expsort(struct strlist *str) 1309 { 1310 int len; 1311 struct strlist *sp; 1312 1313 len = 0; 1314 for (sp = str ; sp ; sp = sp->next) 1315 len++; 1316 return msort(str, len); 1317 } 1318 1319 1320 STATIC struct strlist * 1321 msort(struct strlist *list, int len) 1322 { 1323 struct strlist *p, *q = NULL; 1324 struct strlist **lpp; 1325 int half; 1326 int n; 1327 1328 if (len <= 1) 1329 return list; 1330 half = len >> 1; 1331 p = list; 1332 for (n = half ; --n >= 0 ; ) { 1333 q = p; 1334 p = p->next; 1335 } 1336 q->next = NULL; /* terminate first half of list */ 1337 q = msort(list, half); /* sort first half of list */ 1338 p = msort(p, len - half); /* sort second half */ 1339 lpp = &list; 1340 for (;;) { 1341 if (strcmp(p->text, q->text) < 0) { 1342 *lpp = p; 1343 lpp = &p->next; 1344 if ((p = *lpp) == NULL) { 1345 *lpp = q; 1346 break; 1347 } 1348 } else { 1349 *lpp = q; 1350 lpp = &q->next; 1351 if ((q = *lpp) == NULL) { 1352 *lpp = p; 1353 break; 1354 } 1355 } 1356 } 1357 return list; 1358 } 1359 1360 1361 1362 /* 1363 * Returns true if the pattern matches the string. 1364 */ 1365 1366 int 1367 patmatch(const char *pattern, const char *string, int squoted) 1368 { 1369 const 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 (patmatch(p, q, squoted)) 1411 return 1; 1412 if (squoted && *q == CTLESC) 1413 q++; 1414 } while (*q++ != '\0'); 1415 return 0; 1416 case '[': { 1417 const char *endp; 1418 int invert, found; 1419 char chr; 1420 1421 endp = p; 1422 if (*endp == '!' || *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 == '!' || *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 ( collate_range_cmp(chr, c) >= 0 1458 && collate_range_cmp(chr, *p) <= 0 1459 ) 1460 found = 1; 1461 p++; 1462 } else { 1463 if (chr == c) 1464 found = 1; 1465 } 1466 } while ((c = *p++) != ']'); 1467 if (found == invert) 1468 return 0; 1469 break; 1470 } 1471 dft: default: 1472 if (squoted && *q == CTLESC) 1473 q++; 1474 if (*q++ != c) 1475 return 0; 1476 break; 1477 } 1478 } 1479 breakloop: 1480 if (*q != '\0') 1481 return 0; 1482 return 1; 1483 } 1484 1485 1486 1487 /* 1488 * Remove any CTLESC and CTLQUOTEMARK characters from a string. 1489 */ 1490 1491 void 1492 rmescapes(char *str) 1493 { 1494 char *p, *q; 1495 1496 p = str; 1497 while (*p != CTLESC && *p != CTLQUOTEMARK) { 1498 if (*p++ == '\0') 1499 return; 1500 } 1501 q = p; 1502 while (*p) { 1503 if (*p == CTLQUOTEMARK) { 1504 p++; 1505 continue; 1506 } 1507 if (*p == CTLESC) 1508 p++; 1509 *q++ = *p++; 1510 } 1511 *q = '\0'; 1512 } 1513 1514 1515 1516 /* 1517 * See if a pattern matches in a case statement. 1518 */ 1519 1520 int 1521 casematch(union node *pattern, const char *val) 1522 { 1523 struct stackmark smark; 1524 int result; 1525 char *p; 1526 1527 setstackmark(&smark); 1528 argbackq = pattern->narg.backquote; 1529 STARTSTACKSTR(expdest); 1530 ifslastp = NULL; 1531 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE); 1532 STPUTC('\0', expdest); 1533 p = grabstackstr(expdest); 1534 result = patmatch(p, val, 0); 1535 popstackmark(&smark); 1536 return result; 1537 } 1538 1539 /* 1540 * Our own itoa(). 1541 */ 1542 1543 STATIC char * 1544 cvtnum(int num, char *buf) 1545 { 1546 char temp[32]; 1547 int neg = num < 0; 1548 char *p = temp + 31; 1549 1550 temp[31] = '\0'; 1551 1552 do { 1553 *--p = num % 10 + '0'; 1554 } while ((num /= 10) != 0); 1555 1556 if (neg) 1557 *--p = '-'; 1558 1559 while (*p) 1560 STPUTC(*p++, buf); 1561 return buf; 1562 } 1563 1564 /* 1565 * Do most of the work for wordexp(3). 1566 */ 1567 1568 int 1569 wordexpcmd(int argc, char **argv) 1570 { 1571 size_t len; 1572 int i; 1573 1574 out1fmt("%08x", argc - 1); 1575 for (i = 1, len = 0; i < argc; i++) 1576 len += strlen(argv[i]); 1577 out1fmt("%08x", (int)len); 1578 for (i = 1; i < argc; i++) { 1579 out1str(argv[i]); 1580 out1c('\0'); 1581 } 1582 return (0); 1583 } 1584