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 <dirent.h> 47 #include <errno.h> 48 #include <inttypes.h> 49 #include <limits.h> 50 #include <pwd.h> 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <unistd.h> 55 56 /* 57 * Routines to expand arguments to commands. We have to deal with 58 * backquotes, shell variables, and file metacharacters. 59 */ 60 61 #include "shell.h" 62 #include "main.h" 63 #include "nodes.h" 64 #include "eval.h" 65 #include "expand.h" 66 #include "syntax.h" 67 #include "parser.h" 68 #include "jobs.h" 69 #include "options.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 "arith.h" 77 #include "show.h" 78 79 /* 80 * Structure specifying which parts of the string should be searched 81 * for IFS characters. 82 */ 83 84 struct ifsregion { 85 struct ifsregion *next; /* next region in list */ 86 int begoff; /* offset of start of region */ 87 int endoff; /* offset of end of region */ 88 int inquotes; /* search for nul bytes only */ 89 }; 90 91 92 static char *expdest; /* output of current string */ 93 static struct nodelist *argbackq; /* list of back quote expressions */ 94 static struct ifsregion ifsfirst; /* first struct in list of ifs regions */ 95 static struct ifsregion *ifslastp; /* last struct in list */ 96 static struct arglist exparg; /* holds expanded arg list */ 97 98 static void argstr(char *, int); 99 static char *exptilde(char *, int); 100 static void expbackq(union node *, int, int); 101 static int subevalvar(char *, char *, int, int, int, int, int); 102 static char *evalvar(char *, int); 103 static int varisset(char *, int); 104 static void varvalue(char *, int, int, int); 105 static void recordregion(int, int, int); 106 static void removerecordregions(int); 107 static void ifsbreakup(char *, struct arglist *); 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 char *cvtnum(int, char *); 114 static int collate_range_cmp(int, int); 115 116 static int 117 collate_range_cmp(int c1, int c2) 118 { 119 static char s1[2], s2[2]; 120 121 s1[0] = c1; 122 s2[0] = c2; 123 return (strcoll(s1, s2)); 124 } 125 126 /* 127 * Expand shell variables and backquotes inside a here document. 128 * union node *arg the document 129 * int fd; where to write the expanded version 130 */ 131 132 void 133 expandhere(union node *arg, int fd) 134 { 135 expandarg(arg, (struct arglist *)NULL, 0); 136 xwrite(fd, stackblock(), expdest - stackblock()); 137 } 138 139 static char * 140 stputs_quotes(const char *data, const char *syntax, char *p) 141 { 142 while (*data) { 143 CHECKSTRSPACE(2, p); 144 if (syntax[(int)*data] == CCTL) 145 USTPUTC(CTLESC, p); 146 USTPUTC(*data++, p); 147 } 148 return (p); 149 } 150 #define STPUTS_QUOTES(data, syntax, p) p = stputs_quotes((data), syntax, p) 151 152 /* 153 * Perform expansions on an argument, placing the resulting list of arguments 154 * in arglist. Parameter expansion, command substitution and arithmetic 155 * expansion are always performed; additional expansions can be requested 156 * via flag (EXP_*). 157 * The result is left in the stack string. 158 * When arglist is NULL, perform here document expansion. 159 * 160 * Caution: this function uses global state and is not reentrant. 161 * However, a new invocation after an interrupted invocation is safe 162 * and will reset the global state for the new call. 163 */ 164 void 165 expandarg(union node *arg, struct arglist *arglist, int flag) 166 { 167 struct strlist *sp; 168 char *p; 169 170 argbackq = arg->narg.backquote; 171 STARTSTACKSTR(expdest); 172 ifsfirst.next = NULL; 173 ifslastp = NULL; 174 argstr(arg->narg.text, flag); 175 if (arglist == NULL) { 176 return; /* here document expanded */ 177 } 178 STPUTC('\0', expdest); 179 p = grabstackstr(expdest); 180 exparg.lastp = &exparg.list; 181 /* 182 * TODO - EXP_REDIR 183 */ 184 if (flag & EXP_FULL) { 185 ifsbreakup(p, &exparg); 186 *exparg.lastp = NULL; 187 exparg.lastp = &exparg.list; 188 expandmeta(exparg.list, flag); 189 } else { 190 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */ 191 rmescapes(p); 192 sp = (struct strlist *)stalloc(sizeof (struct strlist)); 193 sp->text = p; 194 *exparg.lastp = sp; 195 exparg.lastp = &sp->next; 196 } 197 while (ifsfirst.next != NULL) { 198 struct ifsregion *ifsp; 199 INTOFF; 200 ifsp = ifsfirst.next->next; 201 ckfree(ifsfirst.next); 202 ifsfirst.next = ifsp; 203 INTON; 204 } 205 *exparg.lastp = NULL; 206 if (exparg.list) { 207 *arglist->lastp = exparg.list; 208 arglist->lastp = exparg.lastp; 209 } 210 } 211 212 213 214 /* 215 * Perform parameter expansion, command substitution and arithmetic 216 * expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE. 217 * Processing ends at a CTLENDVAR character as well as '\0'. 218 * This is used to expand word in ${var+word} etc. 219 * If EXP_FULL, EXP_CASE or EXP_REDIR are set, keep and/or generate CTLESC 220 * characters to allow for further processing. 221 * If EXP_FULL is set, also preserve CTLQUOTEMARK characters. 222 */ 223 static void 224 argstr(char *p, int flag) 225 { 226 char c; 227 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); /* do CTLESC */ 228 int firsteq = 1; 229 int split_lit; 230 int lit_quoted; 231 232 split_lit = flag & EXP_SPLIT_LIT; 233 lit_quoted = flag & EXP_LIT_QUOTED; 234 flag &= ~(EXP_SPLIT_LIT | EXP_LIT_QUOTED); 235 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE))) 236 p = exptilde(p, flag); 237 for (;;) { 238 CHECKSTRSPACE(2, expdest); 239 switch (c = *p++) { 240 case '\0': 241 case CTLENDVAR: 242 goto breakloop; 243 case CTLQUOTEMARK: 244 lit_quoted = 1; 245 /* "$@" syntax adherence hack */ 246 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=') 247 break; 248 if ((flag & EXP_FULL) != 0) 249 USTPUTC(c, expdest); 250 break; 251 case CTLQUOTEEND: 252 lit_quoted = 0; 253 break; 254 case CTLESC: 255 if (quotes) 256 USTPUTC(c, expdest); 257 c = *p++; 258 USTPUTC(c, expdest); 259 if (split_lit && !lit_quoted) 260 recordregion(expdest - stackblock() - 261 (quotes ? 2 : 1), 262 expdest - stackblock(), 0); 263 break; 264 case CTLVAR: 265 p = evalvar(p, flag); 266 break; 267 case CTLBACKQ: 268 case CTLBACKQ|CTLQUOTE: 269 expbackq(argbackq->n, c & CTLQUOTE, flag); 270 argbackq = argbackq->next; 271 break; 272 case CTLENDARI: 273 expari(flag); 274 break; 275 case ':': 276 case '=': 277 /* 278 * sort of a hack - expand tildes in variable 279 * assignments (after the first '=' and after ':'s). 280 */ 281 USTPUTC(c, expdest); 282 if (split_lit && !lit_quoted) 283 recordregion(expdest - stackblock() - 1, 284 expdest - stackblock(), 0); 285 if (flag & EXP_VARTILDE && *p == '~' && 286 (c != '=' || firsteq)) { 287 if (c == '=') 288 firsteq = 0; 289 p = exptilde(p, flag); 290 } 291 break; 292 default: 293 USTPUTC(c, expdest); 294 if (split_lit && !lit_quoted) 295 recordregion(expdest - stackblock() - 1, 296 expdest - stackblock(), 0); 297 } 298 } 299 breakloop:; 300 } 301 302 /* 303 * Perform tilde expansion, placing the result in the stack string and 304 * returning the next position in the input string to process. 305 */ 306 static char * 307 exptilde(char *p, int flag) 308 { 309 char c, *startp = p; 310 struct passwd *pw; 311 char *home; 312 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 313 314 while ((c = *p) != '\0') { 315 switch(c) { 316 case CTLESC: /* This means CTL* are always considered quoted. */ 317 case CTLVAR: 318 case CTLBACKQ: 319 case CTLBACKQ | CTLQUOTE: 320 case CTLARI: 321 case CTLENDARI: 322 case CTLQUOTEMARK: 323 return (startp); 324 case ':': 325 if (flag & EXP_VARTILDE) 326 goto done; 327 break; 328 case '/': 329 case CTLENDVAR: 330 goto done; 331 } 332 p++; 333 } 334 done: 335 *p = '\0'; 336 if (*(startp+1) == '\0') { 337 if ((home = lookupvar("HOME")) == NULL) 338 goto lose; 339 } else { 340 if ((pw = getpwnam(startp+1)) == NULL) 341 goto lose; 342 home = pw->pw_dir; 343 } 344 if (*home == '\0') 345 goto lose; 346 *p = c; 347 if (quotes) 348 STPUTS_QUOTES(home, SQSYNTAX, expdest); 349 else 350 STPUTS(home, expdest); 351 return (p); 352 lose: 353 *p = c; 354 return (startp); 355 } 356 357 358 static void 359 removerecordregions(int endoff) 360 { 361 if (ifslastp == NULL) 362 return; 363 364 if (ifsfirst.endoff > endoff) { 365 while (ifsfirst.next != NULL) { 366 struct ifsregion *ifsp; 367 INTOFF; 368 ifsp = ifsfirst.next->next; 369 ckfree(ifsfirst.next); 370 ifsfirst.next = ifsp; 371 INTON; 372 } 373 if (ifsfirst.begoff > endoff) 374 ifslastp = NULL; 375 else { 376 ifslastp = &ifsfirst; 377 ifsfirst.endoff = endoff; 378 } 379 return; 380 } 381 382 ifslastp = &ifsfirst; 383 while (ifslastp->next && ifslastp->next->begoff < endoff) 384 ifslastp=ifslastp->next; 385 while (ifslastp->next != NULL) { 386 struct ifsregion *ifsp; 387 INTOFF; 388 ifsp = ifslastp->next->next; 389 ckfree(ifslastp->next); 390 ifslastp->next = ifsp; 391 INTON; 392 } 393 if (ifslastp->endoff > endoff) 394 ifslastp->endoff = endoff; 395 } 396 397 /* 398 * Expand arithmetic expression. Backup to start of expression, 399 * evaluate, place result in (backed up) result, adjust string position. 400 */ 401 void 402 expari(int flag) 403 { 404 char *p, *q, *start; 405 arith_t result; 406 int begoff; 407 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 408 int quoted; 409 410 /* 411 * This routine is slightly over-complicated for 412 * efficiency. First we make sure there is 413 * enough space for the result, which may be bigger 414 * than the expression. Next we 415 * scan backwards looking for the start of arithmetic. If the 416 * next previous character is a CTLESC character, then we 417 * have to rescan starting from the beginning since CTLESC 418 * characters have to be processed left to right. 419 */ 420 CHECKSTRSPACE(DIGITS(result) - 2, expdest); 421 USTPUTC('\0', expdest); 422 start = stackblock(); 423 p = expdest - 2; 424 while (p >= start && *p != CTLARI) 425 --p; 426 if (p < start || *p != CTLARI) 427 error("missing CTLARI (shouldn't happen)"); 428 if (p > start && *(p - 1) == CTLESC) 429 for (p = start; *p != CTLARI; p++) 430 if (*p == CTLESC) 431 p++; 432 433 if (p[1] == '"') 434 quoted=1; 435 else 436 quoted=0; 437 begoff = p - start; 438 removerecordregions(begoff); 439 if (quotes) 440 rmescapes(p+2); 441 q = grabstackstr(expdest); 442 result = arith(p+2); 443 ungrabstackstr(q, expdest); 444 fmtstr(p, DIGITS(result), ARITH_FORMAT_STR, result); 445 while (*p++) 446 ; 447 if (quoted == 0) 448 recordregion(begoff, p - 1 - start, 0); 449 result = expdest - p + 1; 450 STADJUST(-result, expdest); 451 } 452 453 454 /* 455 * Perform command substitution. 456 */ 457 static void 458 expbackq(union node *cmd, int quoted, int flag) 459 { 460 struct backcmd in; 461 int i; 462 char buf[128]; 463 char *p; 464 char *dest = expdest; 465 struct ifsregion saveifs, *savelastp; 466 struct nodelist *saveargbackq; 467 char lastc; 468 int startloc = dest - stackblock(); 469 char const *syntax = quoted? DQSYNTAX : BASESYNTAX; 470 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 471 int nnl; 472 473 INTOFF; 474 saveifs = ifsfirst; 475 savelastp = ifslastp; 476 saveargbackq = argbackq; 477 p = grabstackstr(dest); 478 evalbackcmd(cmd, &in); 479 ungrabstackstr(p, dest); 480 ifsfirst = saveifs; 481 ifslastp = savelastp; 482 argbackq = saveargbackq; 483 484 p = in.buf; 485 lastc = '\0'; 486 nnl = 0; 487 /* Don't copy trailing newlines */ 488 for (;;) { 489 if (--in.nleft < 0) { 490 if (in.fd < 0) 491 break; 492 while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR); 493 TRACE(("expbackq: read returns %d\n", i)); 494 if (i <= 0) 495 break; 496 p = buf; 497 in.nleft = i - 1; 498 } 499 lastc = *p++; 500 if (lastc != '\0') { 501 if (lastc == '\n') { 502 nnl++; 503 } else { 504 CHECKSTRSPACE(nnl + 2, dest); 505 while (nnl > 0) { 506 nnl--; 507 USTPUTC('\n', dest); 508 } 509 if (quotes && syntax[(int)lastc] == CCTL) 510 USTPUTC(CTLESC, dest); 511 USTPUTC(lastc, dest); 512 } 513 } 514 } 515 516 if (in.fd >= 0) 517 close(in.fd); 518 if (in.buf) 519 ckfree(in.buf); 520 if (in.jp) 521 exitstatus = waitforjob(in.jp, (int *)NULL); 522 if (quoted == 0) 523 recordregion(startloc, dest - stackblock(), 0); 524 TRACE(("expbackq: size=%td: \"%.*s\"\n", 525 ((dest - stackblock()) - startloc), 526 (int)((dest - stackblock()) - startloc), 527 stackblock() + startloc)); 528 expdest = dest; 529 INTON; 530 } 531 532 533 534 static int 535 subevalvar(char *p, char *str, int strloc, int subtype, int startloc, 536 int varflags, int quotes) 537 { 538 char *startp; 539 char *loc = NULL; 540 char *q; 541 int c = 0; 542 struct nodelist *saveargbackq = argbackq; 543 int amount; 544 545 argstr(p, (subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX || 546 subtype == VSTRIMRIGHT || subtype == VSTRIMRIGHTMAX ? 547 EXP_CASE : 0) | EXP_TILDE); 548 STACKSTRNUL(expdest); 549 argbackq = saveargbackq; 550 startp = stackblock() + startloc; 551 if (str == NULL) 552 str = stackblock() + strloc; 553 554 switch (subtype) { 555 case VSASSIGN: 556 setvar(str, startp, 0); 557 amount = startp - expdest; 558 STADJUST(amount, expdest); 559 varflags &= ~VSNUL; 560 return 1; 561 562 case VSQUESTION: 563 if (*p != CTLENDVAR) { 564 outfmt(out2, "%s\n", startp); 565 error((char *)NULL); 566 } 567 error("%.*s: parameter %snot set", (int)(p - str - 1), 568 str, (varflags & VSNUL) ? "null or " 569 : nullstr); 570 return 0; 571 572 case VSTRIMLEFT: 573 for (loc = startp; loc < str; loc++) { 574 c = *loc; 575 *loc = '\0'; 576 if (patmatch(str, startp, quotes)) { 577 *loc = c; 578 goto recordleft; 579 } 580 *loc = c; 581 if (quotes && *loc == CTLESC) 582 loc++; 583 } 584 return 0; 585 586 case VSTRIMLEFTMAX: 587 for (loc = str - 1; loc >= startp;) { 588 c = *loc; 589 *loc = '\0'; 590 if (patmatch(str, startp, quotes)) { 591 *loc = c; 592 goto recordleft; 593 } 594 *loc = c; 595 loc--; 596 if (quotes && loc > startp && *(loc - 1) == CTLESC) { 597 for (q = startp; q < loc; q++) 598 if (*q == CTLESC) 599 q++; 600 if (q > loc) 601 loc--; 602 } 603 } 604 return 0; 605 606 case VSTRIMRIGHT: 607 for (loc = str - 1; loc >= startp;) { 608 if (patmatch(str, loc, quotes)) { 609 amount = loc - expdest; 610 STADJUST(amount, expdest); 611 return 1; 612 } 613 loc--; 614 if (quotes && loc > startp && *(loc - 1) == CTLESC) { 615 for (q = startp; q < loc; q++) 616 if (*q == CTLESC) 617 q++; 618 if (q > loc) 619 loc--; 620 } 621 } 622 return 0; 623 624 case VSTRIMRIGHTMAX: 625 for (loc = startp; loc < str - 1; loc++) { 626 if (patmatch(str, loc, quotes)) { 627 amount = loc - expdest; 628 STADJUST(amount, expdest); 629 return 1; 630 } 631 if (quotes && *loc == CTLESC) 632 loc++; 633 } 634 return 0; 635 636 637 default: 638 abort(); 639 } 640 641 recordleft: 642 amount = ((str - 1) - (loc - startp)) - expdest; 643 STADJUST(amount, expdest); 644 while (loc != str - 1) 645 *startp++ = *loc++; 646 return 1; 647 } 648 649 650 /* 651 * Expand a variable, and return a pointer to the next character in the 652 * input string. 653 */ 654 655 static char * 656 evalvar(char *p, int flag) 657 { 658 int subtype; 659 int varflags; 660 char *var; 661 char *val; 662 int patloc; 663 int c; 664 int set; 665 int special; 666 int startloc; 667 int varlen; 668 int easy; 669 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 670 671 varflags = (unsigned char)*p++; 672 subtype = varflags & VSTYPE; 673 var = p; 674 special = 0; 675 if (! is_name(*p)) 676 special = 1; 677 p = strchr(p, '=') + 1; 678 again: /* jump here after setting a variable with ${var=text} */ 679 if (varflags & VSLINENO) { 680 set = 1; 681 special = 0; 682 val = var; 683 p[-1] = '\0'; /* temporarily overwrite '=' to have \0 684 terminated string */ 685 } else if (special) { 686 set = varisset(var, varflags & VSNUL); 687 val = NULL; 688 } else { 689 val = bltinlookup(var, 1); 690 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) { 691 val = NULL; 692 set = 0; 693 } else 694 set = 1; 695 } 696 varlen = 0; 697 startloc = expdest - stackblock(); 698 if (!set && uflag && *var != '@' && *var != '*') { 699 switch (subtype) { 700 case VSNORMAL: 701 case VSTRIMLEFT: 702 case VSTRIMLEFTMAX: 703 case VSTRIMRIGHT: 704 case VSTRIMRIGHTMAX: 705 case VSLENGTH: 706 error("%.*s: parameter not set", (int)(p - var - 1), 707 var); 708 } 709 } 710 if (set && subtype != VSPLUS) { 711 /* insert the value of the variable */ 712 if (special) { 713 varvalue(var, varflags & VSQUOTE, subtype, flag); 714 if (subtype == VSLENGTH) { 715 varlen = expdest - stackblock() - startloc; 716 STADJUST(-varlen, expdest); 717 } 718 } else { 719 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX 720 : BASESYNTAX; 721 722 if (subtype == VSLENGTH) { 723 for (;*val; val++) 724 varlen++; 725 } 726 else { 727 if (quotes) 728 STPUTS_QUOTES(val, syntax, expdest); 729 else 730 STPUTS(val, expdest); 731 732 } 733 } 734 } 735 736 if (subtype == VSPLUS) 737 set = ! set; 738 739 easy = ((varflags & VSQUOTE) == 0 || 740 (*var == '@' && shellparam.nparam != 1)); 741 742 743 switch (subtype) { 744 case VSLENGTH: 745 expdest = cvtnum(varlen, expdest); 746 goto record; 747 748 case VSNORMAL: 749 if (!easy) 750 break; 751 record: 752 recordregion(startloc, expdest - stackblock(), 753 varflags & VSQUOTE); 754 break; 755 756 case VSPLUS: 757 case VSMINUS: 758 if (!set) { 759 argstr(p, flag | (flag & EXP_FULL ? EXP_SPLIT_LIT : 0) | 760 (varflags & VSQUOTE ? EXP_LIT_QUOTED : 0)); 761 break; 762 } 763 if (easy) 764 goto record; 765 break; 766 767 case VSTRIMLEFT: 768 case VSTRIMLEFTMAX: 769 case VSTRIMRIGHT: 770 case VSTRIMRIGHTMAX: 771 if (!set) 772 break; 773 /* 774 * Terminate the string and start recording the pattern 775 * right after it 776 */ 777 STPUTC('\0', expdest); 778 patloc = expdest - stackblock(); 779 if (subevalvar(p, NULL, patloc, subtype, 780 startloc, varflags, quotes) == 0) { 781 int amount = (expdest - stackblock() - patloc) + 1; 782 STADJUST(-amount, expdest); 783 } 784 /* Remove any recorded regions beyond start of variable */ 785 removerecordregions(startloc); 786 goto record; 787 788 case VSASSIGN: 789 case VSQUESTION: 790 if (!set) { 791 if (subevalvar(p, var, 0, subtype, startloc, varflags, 792 quotes)) { 793 varflags &= ~VSNUL; 794 /* 795 * Remove any recorded regions beyond 796 * start of variable 797 */ 798 removerecordregions(startloc); 799 goto again; 800 } 801 break; 802 } 803 if (easy) 804 goto record; 805 break; 806 807 case VSERROR: 808 c = p - var - 1; 809 error("${%.*s%s}: Bad substitution", c, var, 810 (c > 0 && *p != CTLENDVAR) ? "..." : ""); 811 812 default: 813 abort(); 814 } 815 p[-1] = '='; /* recover overwritten '=' */ 816 817 if (subtype != VSNORMAL) { /* skip to end of alternative */ 818 int nesting = 1; 819 for (;;) { 820 if ((c = *p++) == CTLESC) 821 p++; 822 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) { 823 if (set) 824 argbackq = argbackq->next; 825 } else if (c == CTLVAR) { 826 if ((*p++ & VSTYPE) != VSNORMAL) 827 nesting++; 828 } else if (c == CTLENDVAR) { 829 if (--nesting == 0) 830 break; 831 } 832 } 833 } 834 return p; 835 } 836 837 838 839 /* 840 * Test whether a specialized variable is set. 841 */ 842 843 static int 844 varisset(char *name, int nulok) 845 { 846 847 if (*name == '!') 848 return backgndpidset(); 849 else if (*name == '@' || *name == '*') { 850 if (*shellparam.p == NULL) 851 return 0; 852 853 if (nulok) { 854 char **av; 855 856 for (av = shellparam.p; *av; av++) 857 if (**av != '\0') 858 return 1; 859 return 0; 860 } 861 } else if (is_digit(*name)) { 862 char *ap; 863 int num = atoi(name); 864 865 if (num > shellparam.nparam) 866 return 0; 867 868 if (num == 0) 869 ap = arg0; 870 else 871 ap = shellparam.p[num - 1]; 872 873 if (nulok && (ap == NULL || *ap == '\0')) 874 return 0; 875 } 876 return 1; 877 } 878 879 static void 880 strtodest(const char *p, int flag, int subtype, int quoted) 881 { 882 if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) 883 STPUTS_QUOTES(p, quoted ? DQSYNTAX : BASESYNTAX, expdest); 884 else 885 STPUTS(p, expdest); 886 } 887 888 /* 889 * Add the value of a specialized variable to the stack string. 890 */ 891 892 static void 893 varvalue(char *name, int quoted, int subtype, int flag) 894 { 895 int num; 896 char *p; 897 int i; 898 char sep; 899 char **ap; 900 901 switch (*name) { 902 case '$': 903 num = rootpid; 904 goto numvar; 905 case '?': 906 num = oexitstatus; 907 goto numvar; 908 case '#': 909 num = shellparam.nparam; 910 goto numvar; 911 case '!': 912 num = backgndpidval(); 913 numvar: 914 expdest = cvtnum(num, expdest); 915 break; 916 case '-': 917 for (i = 0 ; i < NOPTS ; i++) { 918 if (optlist[i].val) 919 STPUTC(optlist[i].letter, expdest); 920 } 921 break; 922 case '@': 923 if (flag & EXP_FULL && quoted) { 924 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 925 strtodest(p, flag, subtype, quoted); 926 if (*ap) 927 STPUTC('\0', expdest); 928 } 929 break; 930 } 931 /* FALLTHROUGH */ 932 case '*': 933 if (ifsset()) 934 sep = ifsval()[0]; 935 else 936 sep = ' '; 937 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 938 strtodest(p, flag, subtype, quoted); 939 if (*ap && sep) 940 STPUTC(sep, expdest); 941 } 942 break; 943 case '0': 944 p = arg0; 945 strtodest(p, flag, subtype, quoted); 946 break; 947 default: 948 if (is_digit(*name)) { 949 num = atoi(name); 950 if (num > 0 && num <= shellparam.nparam) { 951 p = shellparam.p[num - 1]; 952 strtodest(p, flag, subtype, quoted); 953 } 954 } 955 break; 956 } 957 } 958 959 960 961 /* 962 * Record the fact that we have to scan this region of the 963 * string for IFS characters. 964 */ 965 966 static void 967 recordregion(int start, int end, int inquotes) 968 { 969 struct ifsregion *ifsp; 970 971 if (ifslastp == NULL) { 972 ifsp = &ifsfirst; 973 } else { 974 if (ifslastp->endoff == start 975 && ifslastp->inquotes == inquotes) { 976 /* extend previous area */ 977 ifslastp->endoff = end; 978 return; 979 } 980 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion)); 981 ifslastp->next = ifsp; 982 } 983 ifslastp = ifsp; 984 ifslastp->next = NULL; 985 ifslastp->begoff = start; 986 ifslastp->endoff = end; 987 ifslastp->inquotes = inquotes; 988 } 989 990 991 992 /* 993 * Break the argument string into pieces based upon IFS and add the 994 * strings to the argument list. The regions of the string to be 995 * searched for IFS characters have been stored by recordregion. 996 * CTLESC characters are preserved but have little effect in this pass 997 * other than escaping CTL* characters. In particular, they do not escape 998 * IFS characters: that should be done with the ifsregion mechanism. 999 * CTLQUOTEMARK characters are used to preserve empty quoted strings. 1000 * This pass treats them as a regular character, making the string non-empty. 1001 * Later, they are removed along with the other CTL* characters. 1002 */ 1003 static void 1004 ifsbreakup(char *string, struct arglist *arglist) 1005 { 1006 struct ifsregion *ifsp; 1007 struct strlist *sp; 1008 char *start; 1009 char *p; 1010 char *q; 1011 const char *ifs; 1012 const char *ifsspc; 1013 int had_param_ch = 0; 1014 1015 start = string; 1016 1017 if (ifslastp == NULL) { 1018 /* Return entire argument, IFS doesn't apply to any of it */ 1019 sp = (struct strlist *)stalloc(sizeof *sp); 1020 sp->text = start; 1021 *arglist->lastp = sp; 1022 arglist->lastp = &sp->next; 1023 return; 1024 } 1025 1026 ifs = ifsset() ? ifsval() : " \t\n"; 1027 1028 for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) { 1029 p = string + ifsp->begoff; 1030 while (p < string + ifsp->endoff) { 1031 q = p; 1032 if (*p == CTLESC) 1033 p++; 1034 if (ifsp->inquotes) { 1035 /* Only NULs (should be from "$@") end args */ 1036 had_param_ch = 1; 1037 if (*p != 0) { 1038 p++; 1039 continue; 1040 } 1041 ifsspc = NULL; 1042 } else { 1043 if (!strchr(ifs, *p)) { 1044 had_param_ch = 1; 1045 p++; 1046 continue; 1047 } 1048 ifsspc = strchr(" \t\n", *p); 1049 1050 /* Ignore IFS whitespace at start */ 1051 if (q == start && ifsspc != NULL) { 1052 p++; 1053 start = p; 1054 continue; 1055 } 1056 had_param_ch = 0; 1057 } 1058 1059 /* Save this argument... */ 1060 *q = '\0'; 1061 sp = (struct strlist *)stalloc(sizeof *sp); 1062 sp->text = start; 1063 *arglist->lastp = sp; 1064 arglist->lastp = &sp->next; 1065 p++; 1066 1067 if (ifsspc != NULL) { 1068 /* Ignore further trailing IFS whitespace */ 1069 for (; p < string + ifsp->endoff; p++) { 1070 q = p; 1071 if (*p == CTLESC) 1072 p++; 1073 if (strchr(ifs, *p) == NULL) { 1074 p = q; 1075 break; 1076 } 1077 if (strchr(" \t\n", *p) == NULL) { 1078 p++; 1079 break; 1080 } 1081 } 1082 } 1083 start = p; 1084 } 1085 } 1086 1087 /* 1088 * Save anything left as an argument. 1089 * Traditionally we have treated 'IFS=':'; set -- x$IFS' as 1090 * generating 2 arguments, the second of which is empty. 1091 * Some recent clarification of the Posix spec say that it 1092 * should only generate one.... 1093 */ 1094 if (had_param_ch || *start != 0) { 1095 sp = (struct strlist *)stalloc(sizeof *sp); 1096 sp->text = start; 1097 *arglist->lastp = sp; 1098 arglist->lastp = &sp->next; 1099 } 1100 } 1101 1102 1103 static char expdir[PATH_MAX]; 1104 #define expdir_end (expdir + sizeof(expdir)) 1105 1106 /* 1107 * Perform pathname generation and remove control characters. 1108 * At this point, the only control characters should be CTLESC and CTLQUOTEMARK. 1109 * The results are stored in the list exparg. 1110 */ 1111 static void 1112 expandmeta(struct strlist *str, int flag __unused) 1113 { 1114 char *p; 1115 struct strlist **savelastp; 1116 struct strlist *sp; 1117 char c; 1118 /* TODO - EXP_REDIR */ 1119 1120 while (str) { 1121 if (fflag) 1122 goto nometa; 1123 p = str->text; 1124 for (;;) { /* fast check for meta chars */ 1125 if ((c = *p++) == '\0') 1126 goto nometa; 1127 if (c == '*' || c == '?' || c == '[') 1128 break; 1129 } 1130 savelastp = exparg.lastp; 1131 INTOFF; 1132 expmeta(expdir, str->text); 1133 INTON; 1134 if (exparg.lastp == savelastp) { 1135 /* 1136 * no matches 1137 */ 1138 nometa: 1139 *exparg.lastp = str; 1140 rmescapes(str->text); 1141 exparg.lastp = &str->next; 1142 } else { 1143 *exparg.lastp = NULL; 1144 *savelastp = sp = expsort(*savelastp); 1145 while (sp->next != NULL) 1146 sp = sp->next; 1147 exparg.lastp = &sp->next; 1148 } 1149 str = str->next; 1150 } 1151 } 1152 1153 1154 /* 1155 * Do metacharacter (i.e. *, ?, [...]) expansion. 1156 */ 1157 1158 static void 1159 expmeta(char *enddir, char *name) 1160 { 1161 char *p; 1162 char *q; 1163 char *start; 1164 char *endname; 1165 int metaflag; 1166 struct stat statb; 1167 DIR *dirp; 1168 struct dirent *dp; 1169 int atend; 1170 int matchdot; 1171 int esc; 1172 1173 metaflag = 0; 1174 start = name; 1175 for (p = name; esc = 0, *p; p += esc + 1) { 1176 if (*p == '*' || *p == '?') 1177 metaflag = 1; 1178 else if (*p == '[') { 1179 q = p + 1; 1180 if (*q == '!' || *q == '^') 1181 q++; 1182 for (;;) { 1183 while (*q == CTLQUOTEMARK) 1184 q++; 1185 if (*q == CTLESC) 1186 q++; 1187 if (*q == '/' || *q == '\0') 1188 break; 1189 if (*++q == ']') { 1190 metaflag = 1; 1191 break; 1192 } 1193 } 1194 } else if (*p == '\0') 1195 break; 1196 else if (*p == CTLQUOTEMARK) 1197 continue; 1198 else { 1199 if (*p == CTLESC) 1200 esc++; 1201 if (p[esc] == '/') { 1202 if (metaflag) 1203 break; 1204 start = p + esc + 1; 1205 } 1206 } 1207 } 1208 if (metaflag == 0) { /* we've reached the end of the file name */ 1209 if (enddir != expdir) 1210 metaflag++; 1211 for (p = name ; ; p++) { 1212 if (*p == CTLQUOTEMARK) 1213 continue; 1214 if (*p == CTLESC) 1215 p++; 1216 *enddir++ = *p; 1217 if (*p == '\0') 1218 break; 1219 if (enddir == expdir_end) 1220 return; 1221 } 1222 if (metaflag == 0 || lstat(expdir, &statb) >= 0) 1223 addfname(expdir); 1224 return; 1225 } 1226 endname = p; 1227 if (start != name) { 1228 p = name; 1229 while (p < start) { 1230 while (*p == CTLQUOTEMARK) 1231 p++; 1232 if (*p == CTLESC) 1233 p++; 1234 *enddir++ = *p++; 1235 if (enddir == expdir_end) 1236 return; 1237 } 1238 } 1239 if (enddir == expdir) { 1240 p = "."; 1241 } else if (enddir == expdir + 1 && *expdir == '/') { 1242 p = "/"; 1243 } else { 1244 p = expdir; 1245 enddir[-1] = '\0'; 1246 } 1247 if ((dirp = opendir(p)) == NULL) 1248 return; 1249 if (enddir != expdir) 1250 enddir[-1] = '/'; 1251 if (*endname == 0) { 1252 atend = 1; 1253 } else { 1254 atend = 0; 1255 *endname = '\0'; 1256 endname += esc + 1; 1257 } 1258 matchdot = 0; 1259 p = start; 1260 while (*p == CTLQUOTEMARK) 1261 p++; 1262 if (*p == CTLESC) 1263 p++; 1264 if (*p == '.') 1265 matchdot++; 1266 while (! int_pending() && (dp = readdir(dirp)) != NULL) { 1267 if (dp->d_name[0] == '.' && ! matchdot) 1268 continue; 1269 if (patmatch(start, dp->d_name, 0)) { 1270 if (enddir + dp->d_namlen + 1 > expdir_end) 1271 continue; 1272 memcpy(enddir, dp->d_name, dp->d_namlen + 1); 1273 if (atend) 1274 addfname(expdir); 1275 else { 1276 if (enddir + dp->d_namlen + 2 > expdir_end) 1277 continue; 1278 enddir[dp->d_namlen] = '/'; 1279 enddir[dp->d_namlen + 1] = '\0'; 1280 expmeta(enddir + dp->d_namlen + 1, endname); 1281 } 1282 } 1283 } 1284 closedir(dirp); 1285 if (! atend) 1286 endname[-esc - 1] = esc ? CTLESC : '/'; 1287 } 1288 1289 1290 /* 1291 * Add a file name to the list. 1292 */ 1293 1294 static void 1295 addfname(char *name) 1296 { 1297 char *p; 1298 struct strlist *sp; 1299 1300 p = stalloc(strlen(name) + 1); 1301 scopy(name, p); 1302 sp = (struct strlist *)stalloc(sizeof *sp); 1303 sp->text = p; 1304 *exparg.lastp = sp; 1305 exparg.lastp = &sp->next; 1306 } 1307 1308 1309 /* 1310 * Sort the results of file name expansion. It calculates the number of 1311 * strings to sort and then calls msort (short for merge sort) to do the 1312 * work. 1313 */ 1314 1315 static struct strlist * 1316 expsort(struct strlist *str) 1317 { 1318 int len; 1319 struct strlist *sp; 1320 1321 len = 0; 1322 for (sp = str ; sp ; sp = sp->next) 1323 len++; 1324 return msort(str, len); 1325 } 1326 1327 1328 static struct strlist * 1329 msort(struct strlist *list, int len) 1330 { 1331 struct strlist *p, *q = NULL; 1332 struct strlist **lpp; 1333 int half; 1334 int n; 1335 1336 if (len <= 1) 1337 return list; 1338 half = len >> 1; 1339 p = list; 1340 for (n = half ; --n >= 0 ; ) { 1341 q = p; 1342 p = p->next; 1343 } 1344 q->next = NULL; /* terminate first half of list */ 1345 q = msort(list, half); /* sort first half of list */ 1346 p = msort(p, len - half); /* sort second half */ 1347 lpp = &list; 1348 for (;;) { 1349 if (strcmp(p->text, q->text) < 0) { 1350 *lpp = p; 1351 lpp = &p->next; 1352 if ((p = *lpp) == NULL) { 1353 *lpp = q; 1354 break; 1355 } 1356 } else { 1357 *lpp = q; 1358 lpp = &q->next; 1359 if ((q = *lpp) == NULL) { 1360 *lpp = p; 1361 break; 1362 } 1363 } 1364 } 1365 return list; 1366 } 1367 1368 1369 1370 /* 1371 * Returns true if the pattern matches the string. 1372 */ 1373 1374 int 1375 patmatch(const char *pattern, const char *string, int squoted) 1376 { 1377 const char *p, *q; 1378 char c; 1379 1380 p = pattern; 1381 q = string; 1382 for (;;) { 1383 switch (c = *p++) { 1384 case '\0': 1385 goto breakloop; 1386 case CTLESC: 1387 if (squoted && *q == CTLESC) 1388 q++; 1389 if (*q++ != *p++) 1390 return 0; 1391 break; 1392 case CTLQUOTEMARK: 1393 continue; 1394 case '?': 1395 if (squoted && *q == CTLESC) 1396 q++; 1397 if (*q++ == '\0') 1398 return 0; 1399 break; 1400 case '*': 1401 c = *p; 1402 while (c == CTLQUOTEMARK || c == '*') 1403 c = *++p; 1404 if (c != CTLESC && c != CTLQUOTEMARK && 1405 c != '?' && c != '*' && c != '[') { 1406 while (*q != c) { 1407 if (squoted && *q == CTLESC && 1408 q[1] == c) 1409 break; 1410 if (*q == '\0') 1411 return 0; 1412 if (squoted && *q == CTLESC) 1413 q++; 1414 q++; 1415 } 1416 } 1417 do { 1418 if (patmatch(p, q, squoted)) 1419 return 1; 1420 if (squoted && *q == CTLESC) 1421 q++; 1422 } while (*q++ != '\0'); 1423 return 0; 1424 case '[': { 1425 const char *endp; 1426 int invert, found; 1427 char chr; 1428 1429 endp = p; 1430 if (*endp == '!' || *endp == '^') 1431 endp++; 1432 for (;;) { 1433 while (*endp == CTLQUOTEMARK) 1434 endp++; 1435 if (*endp == '\0') 1436 goto dft; /* no matching ] */ 1437 if (*endp == CTLESC) 1438 endp++; 1439 if (*++endp == ']') 1440 break; 1441 } 1442 invert = 0; 1443 if (*p == '!' || *p == '^') { 1444 invert++; 1445 p++; 1446 } 1447 found = 0; 1448 chr = *q++; 1449 if (squoted && chr == CTLESC) 1450 chr = *q++; 1451 if (chr == '\0') 1452 return 0; 1453 c = *p++; 1454 do { 1455 if (c == CTLQUOTEMARK) 1456 continue; 1457 if (c == CTLESC) 1458 c = *p++; 1459 if (*p == '-' && p[1] != ']') { 1460 p++; 1461 while (*p == CTLQUOTEMARK) 1462 p++; 1463 if (*p == CTLESC) 1464 p++; 1465 if ( collate_range_cmp(chr, c) >= 0 1466 && collate_range_cmp(chr, *p) <= 0 1467 ) 1468 found = 1; 1469 p++; 1470 } else { 1471 if (chr == c) 1472 found = 1; 1473 } 1474 } while ((c = *p++) != ']'); 1475 if (found == invert) 1476 return 0; 1477 break; 1478 } 1479 dft: default: 1480 if (squoted && *q == CTLESC) 1481 q++; 1482 if (*q++ != c) 1483 return 0; 1484 break; 1485 } 1486 } 1487 breakloop: 1488 if (*q != '\0') 1489 return 0; 1490 return 1; 1491 } 1492 1493 1494 1495 /* 1496 * Remove any CTLESC and CTLQUOTEMARK characters from a string. 1497 */ 1498 1499 void 1500 rmescapes(char *str) 1501 { 1502 char *p, *q; 1503 1504 p = str; 1505 while (*p != CTLESC && *p != CTLQUOTEMARK && *p != CTLQUOTEEND) { 1506 if (*p++ == '\0') 1507 return; 1508 } 1509 q = p; 1510 while (*p) { 1511 if (*p == CTLQUOTEMARK || *p == CTLQUOTEEND) { 1512 p++; 1513 continue; 1514 } 1515 if (*p == CTLESC) 1516 p++; 1517 *q++ = *p++; 1518 } 1519 *q = '\0'; 1520 } 1521 1522 1523 1524 /* 1525 * See if a pattern matches in a case statement. 1526 */ 1527 1528 int 1529 casematch(union node *pattern, const char *val) 1530 { 1531 struct stackmark smark; 1532 int result; 1533 char *p; 1534 1535 setstackmark(&smark); 1536 argbackq = pattern->narg.backquote; 1537 STARTSTACKSTR(expdest); 1538 ifslastp = NULL; 1539 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE); 1540 STPUTC('\0', expdest); 1541 p = grabstackstr(expdest); 1542 result = patmatch(p, val, 0); 1543 popstackmark(&smark); 1544 return result; 1545 } 1546 1547 /* 1548 * Our own itoa(). 1549 */ 1550 1551 static char * 1552 cvtnum(int num, char *buf) 1553 { 1554 char temp[32]; 1555 int neg = num < 0; 1556 char *p = temp + 31; 1557 1558 temp[31] = '\0'; 1559 1560 do { 1561 *--p = num % 10 + '0'; 1562 } while ((num /= 10) != 0); 1563 1564 if (neg) 1565 *--p = '-'; 1566 1567 STPUTS(p, buf); 1568 return buf; 1569 } 1570 1571 /* 1572 * Check statically if expanding a string may have side effects. 1573 */ 1574 int 1575 expandhassideeffects(const char *p) 1576 { 1577 int c; 1578 int arinest; 1579 1580 arinest = 0; 1581 while ((c = *p++) != '\0') { 1582 switch (c) { 1583 case CTLESC: 1584 p++; 1585 break; 1586 case CTLVAR: 1587 c = *p++; 1588 /* Expanding $! sets the job to remembered. */ 1589 if (*p == '!') 1590 return 1; 1591 if ((c & VSTYPE) == VSASSIGN) 1592 return 1; 1593 /* 1594 * If we are in arithmetic, the parameter may contain 1595 * '=' which may cause side effects. Exceptions are 1596 * the length of a parameter and $$, $# and $? which 1597 * are always numeric. 1598 */ 1599 if ((c & VSTYPE) == VSLENGTH) { 1600 while (*p != '=') 1601 p++; 1602 p++; 1603 break; 1604 } 1605 if ((*p == '$' || *p == '#' || *p == '?') && 1606 p[1] == '=') { 1607 p += 2; 1608 break; 1609 } 1610 if (arinest > 0) 1611 return 1; 1612 break; 1613 case CTLBACKQ: 1614 case CTLBACKQ | CTLQUOTE: 1615 if (arinest > 0) 1616 return 1; 1617 break; 1618 case CTLARI: 1619 arinest++; 1620 break; 1621 case CTLENDARI: 1622 arinest--; 1623 break; 1624 case '=': 1625 if (*p == '=') { 1626 /* Allow '==' operator. */ 1627 p++; 1628 continue; 1629 } 1630 if (arinest > 0) 1631 return 1; 1632 break; 1633 case '!': case '<': case '>': 1634 /* Allow '!=', '<=', '>=' operators. */ 1635 if (*p == '=') 1636 p++; 1637 break; 1638 } 1639 } 1640 return 0; 1641 } 1642 1643 /* 1644 * Do most of the work for wordexp(3). 1645 */ 1646 1647 int 1648 wordexpcmd(int argc, char **argv) 1649 { 1650 size_t len; 1651 int i; 1652 1653 out1fmt("%08x", argc - 1); 1654 for (i = 1, len = 0; i < argc; i++) 1655 len += strlen(argv[i]); 1656 out1fmt("%08x", (int)len); 1657 for (i = 1; i < argc; i++) 1658 outbin(argv[i], strlen(argv[i]) + 1, out1); 1659 return (0); 1660 } 1661