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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)expand.c 8.5 (Berkeley) 5/15/95 39 * $FreeBSD: src/bin/sh/expand.c,v 1.83 2011/02/21 09:01:34 brucec Exp $ 40 */ 41 42 #include <sys/types.h> 43 #include <sys/time.h> 44 #include <sys/stat.h> 45 #include <dirent.h> 46 #include <errno.h> 47 #include <inttypes.h> 48 #include <limits.h> 49 #include <pwd.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <unistd.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, 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 expandarg(arg, NULL, 0); 135 xwrite(fd, stackblock(), expdest - stackblock()); 136 } 137 138 static char * 139 stputs_quotes(const char *data, const char *syntax, char *p) 140 { 141 while (*data) { 142 CHECKSTRSPACE(2, p); 143 if (syntax[(int)*data] == CCTL) 144 USTPUTC(CTLESC, p); 145 USTPUTC(*data++, p); 146 } 147 return (p); 148 } 149 #define STPUTS_QUOTES(data, syntax, p) p = stputs_quotes((data), syntax, p) 150 151 /* 152 * Perform expansions on an argument, placing the resulting list of arguments 153 * in arglist. Parameter expansion, command substitution and arithmetic 154 * expansion are always performed; additional expansions can be requested 155 * via flag (EXP_*). 156 * The result is left in the stack string. 157 * When arglist is NULL, perform here document expansion. 158 * 159 * Caution: this function uses global state and is not reentrant. 160 * However, a new invocation after an interrupted invocation is safe 161 * and will reset the global state for the new call. 162 */ 163 void 164 expandarg(union node *arg, struct arglist *arglist, int flag) 165 { 166 struct strlist *sp; 167 char *p; 168 169 argbackq = arg->narg.backquote; 170 STARTSTACKSTR(expdest); 171 ifsfirst.next = NULL; 172 ifslastp = NULL; 173 argstr(arg->narg.text, flag); 174 if (arglist == NULL) { 175 return; /* here document expanded */ 176 } 177 STPUTC('\0', expdest); 178 p = grabstackstr(expdest); 179 exparg.lastp = &exparg.list; 180 /* 181 * TODO - EXP_REDIR 182 */ 183 if (flag & EXP_FULL) { 184 ifsbreakup(p, &exparg); 185 *exparg.lastp = NULL; 186 exparg.lastp = &exparg.list; 187 expandmeta(exparg.list, flag); 188 } else { 189 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */ 190 rmescapes(p); 191 sp = (struct strlist *)stalloc(sizeof (struct strlist)); 192 sp->text = p; 193 *exparg.lastp = sp; 194 exparg.lastp = &sp->next; 195 } 196 while (ifsfirst.next != NULL) { 197 struct ifsregion *ifsp; 198 INTOFF; 199 ifsp = ifsfirst.next->next; 200 ckfree(ifsfirst.next); 201 ifsfirst.next = ifsp; 202 INTON; 203 } 204 *exparg.lastp = NULL; 205 if (exparg.list) { 206 *arglist->lastp = exparg.list; 207 arglist->lastp = exparg.lastp; 208 } 209 } 210 211 212 213 /* 214 * Perform parameter expansion, command substitution and arithmetic 215 * expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE. 216 * Processing ends at a CTLENDVAR character as well as '\0'. 217 * This is used to expand word in ${var+word} etc. 218 * If EXP_FULL, EXP_CASE or EXP_REDIR are set, keep and/or generate CTLESC 219 * characters to allow for further processing. 220 * If EXP_FULL is set, also preserve CTLQUOTEMARK characters. 221 */ 222 static void 223 argstr(char *p, int flag) 224 { 225 char c; 226 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); /* do CTLESC */ 227 int firsteq = 1; 228 int split_lit; 229 int lit_quoted; 230 231 split_lit = flag & EXP_SPLIT_LIT; 232 lit_quoted = flag & EXP_LIT_QUOTED; 233 flag &= ~(EXP_SPLIT_LIT | EXP_LIT_QUOTED); 234 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE))) 235 p = exptilde(p, flag); 236 for (;;) { 237 CHECKSTRSPACE(2, expdest); 238 switch (c = *p++) { 239 case '\0': 240 case CTLENDVAR: 241 goto breakloop; 242 case CTLQUOTEMARK: 243 lit_quoted = 1; 244 /* "$@" syntax adherence hack */ 245 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=') 246 break; 247 if ((flag & EXP_FULL) != 0) 248 USTPUTC(c, expdest); 249 break; 250 case CTLQUOTEEND: 251 lit_quoted = 0; 252 break; 253 case CTLESC: 254 if (quotes) 255 USTPUTC(c, expdest); 256 c = *p++; 257 USTPUTC(c, expdest); 258 if (split_lit && !lit_quoted) 259 recordregion(expdest - stackblock() - 260 (quotes ? 2 : 1), 261 expdest - stackblock(), 0); 262 break; 263 case CTLVAR: 264 p = evalvar(p, flag); 265 break; 266 case CTLBACKQ: 267 case CTLBACKQ|CTLQUOTE: 268 expbackq(argbackq->n, c & CTLQUOTE, flag); 269 argbackq = argbackq->next; 270 break; 271 case CTLENDARI: 272 expari(flag); 273 break; 274 case ':': 275 case '=': 276 /* 277 * sort of a hack - expand tildes in variable 278 * assignments (after the first '=' and after ':'s). 279 */ 280 USTPUTC(c, expdest); 281 if (split_lit && !lit_quoted) 282 recordregion(expdest - stackblock() - 1, 283 expdest - stackblock(), 0); 284 if (flag & EXP_VARTILDE && *p == '~' && 285 (c != '=' || firsteq)) { 286 if (c == '=') 287 firsteq = 0; 288 p = exptilde(p, flag); 289 } 290 break; 291 default: 292 USTPUTC(c, expdest); 293 if (split_lit && !lit_quoted) 294 recordregion(expdest - stackblock() - 1, 295 expdest - stackblock(), 0); 296 } 297 } 298 breakloop:; 299 } 300 301 /* 302 * Perform tilde expansion, placing the result in the stack string and 303 * returning the next position in the input string to process. 304 */ 305 static char * 306 exptilde(char *p, int flag) 307 { 308 char c, *startp = p; 309 struct passwd *pw; 310 char *home; 311 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 312 313 while ((c = *p) != '\0') { 314 switch(c) { 315 case CTLESC: /* This means CTL* are always considered quoted. */ 316 case CTLVAR: 317 case CTLBACKQ: 318 case CTLBACKQ | CTLQUOTE: 319 case CTLARI: 320 case CTLENDARI: 321 case CTLQUOTEMARK: 322 return (startp); 323 case ':': 324 if (flag & EXP_VARTILDE) 325 goto done; 326 break; 327 case '/': 328 case CTLENDVAR: 329 goto done; 330 } 331 p++; 332 } 333 done: 334 *p = '\0'; 335 if (*(startp+1) == '\0') { 336 if ((home = lookupvar("HOME")) == NULL) 337 goto lose; 338 } else { 339 if ((pw = getpwnam(startp+1)) == NULL) 340 goto lose; 341 home = pw->pw_dir; 342 } 343 if (*home == '\0') 344 goto lose; 345 *p = c; 346 if (quotes) 347 STPUTS_QUOTES(home, SQSYNTAX, expdest); 348 else 349 STPUTS(home, expdest); 350 return (p); 351 lose: 352 *p = c; 353 return (startp); 354 } 355 356 357 static void 358 removerecordregions(int endoff) 359 { 360 if (ifslastp == NULL) 361 return; 362 363 if (ifsfirst.endoff > endoff) { 364 while (ifsfirst.next != NULL) { 365 struct ifsregion *ifsp; 366 INTOFF; 367 ifsp = ifsfirst.next->next; 368 ckfree(ifsfirst.next); 369 ifsfirst.next = ifsp; 370 INTON; 371 } 372 if (ifsfirst.begoff > endoff) 373 ifslastp = NULL; 374 else { 375 ifslastp = &ifsfirst; 376 ifsfirst.endoff = endoff; 377 } 378 return; 379 } 380 381 ifslastp = &ifsfirst; 382 while (ifslastp->next && ifslastp->next->begoff < endoff) 383 ifslastp=ifslastp->next; 384 while (ifslastp->next != NULL) { 385 struct ifsregion *ifsp; 386 INTOFF; 387 ifsp = ifslastp->next->next; 388 ckfree(ifslastp->next); 389 ifslastp->next = ifsp; 390 INTON; 391 } 392 if (ifslastp->endoff > endoff) 393 ifslastp->endoff = endoff; 394 } 395 396 /* 397 * Expand arithmetic expression. Backup to start of expression, 398 * evaluate, place result in (backed up) result, adjust string position. 399 */ 400 void 401 expari(int flag) 402 { 403 char *p, *q, *start; 404 arith_t result; 405 int begoff; 406 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 407 int quoted; 408 409 /* 410 * This routine is slightly over-complicated for 411 * efficiency. First we make sure there is 412 * enough space for the result, which may be bigger 413 * than the expression. Next we 414 * scan backwards looking for the start of arithmetic. If the 415 * next previous character is a CTLESC character, then we 416 * have to rescan starting from the beginning since CTLESC 417 * characters have to be processed left to right. 418 */ 419 CHECKSTRSPACE(DIGITS(result) - 2, expdest); 420 USTPUTC('\0', expdest); 421 start = stackblock(); 422 p = expdest - 2; 423 while (p >= start && *p != CTLARI) 424 --p; 425 if (p < start || *p != CTLARI) 426 error("missing CTLARI (shouldn't happen)"); 427 if (p > start && *(p - 1) == CTLESC) 428 for (p = start; *p != CTLARI; p++) 429 if (*p == CTLESC) 430 p++; 431 432 if (p[1] == '"') 433 quoted=1; 434 else 435 quoted=0; 436 begoff = p - start; 437 removerecordregions(begoff); 438 if (quotes) 439 rmescapes(p+2); 440 q = grabstackstr(expdest); 441 result = arith(p+2); 442 ungrabstackstr(q, expdest); 443 fmtstr(p, DIGITS(result), ARITH_FORMAT_STR, result); 444 while (*p++) 445 ; 446 if (quoted == 0) 447 recordregion(begoff, p - 1 - start, 0); 448 result = expdest - p + 1; 449 STADJUST(-result, expdest); 450 } 451 452 453 /* 454 * Perform command substitution. 455 */ 456 static void 457 expbackq(union node *cmd, int quoted, int flag) 458 { 459 struct backcmd in; 460 int i; 461 char buf[128]; 462 char *p; 463 char *dest = expdest; 464 struct ifsregion saveifs, *savelastp; 465 struct nodelist *saveargbackq; 466 char lastc; 467 int startloc = dest - stackblock(); 468 char const *syntax = quoted? DQSYNTAX : BASESYNTAX; 469 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 470 int nnl; 471 472 INTOFF; 473 saveifs = ifsfirst; 474 savelastp = ifslastp; 475 saveargbackq = argbackq; 476 p = grabstackstr(dest); 477 evalbackcmd(cmd, &in); 478 ungrabstackstr(p, dest); 479 ifsfirst = saveifs; 480 ifslastp = savelastp; 481 argbackq = saveargbackq; 482 483 p = in.buf; 484 lastc = '\0'; 485 nnl = 0; 486 /* Don't copy trailing newlines */ 487 for (;;) { 488 if (--in.nleft < 0) { 489 if (in.fd < 0) 490 break; 491 while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR); 492 TRACE(("expbackq: read returns %d\n", i)); 493 if (i <= 0) 494 break; 495 p = buf; 496 in.nleft = i - 1; 497 } 498 lastc = *p++; 499 if (lastc != '\0') { 500 if (lastc == '\n') { 501 nnl++; 502 } else { 503 CHECKSTRSPACE(nnl + 2, dest); 504 while (nnl > 0) { 505 nnl--; 506 USTPUTC('\n', dest); 507 } 508 if (quotes && syntax[(int)lastc] == CCTL) 509 USTPUTC(CTLESC, dest); 510 USTPUTC(lastc, dest); 511 } 512 } 513 } 514 515 if (in.fd >= 0) 516 close(in.fd); 517 if (in.buf) 518 ckfree(in.buf); 519 if (in.jp) 520 exitstatus = waitforjob(in.jp, NULL); 521 if (quoted == 0) 522 recordregion(startloc, dest - stackblock(), 0); 523 TRACE(("expbackq: size=%td: \"%.*s\"\n", 524 ((dest - stackblock()) - startloc), 525 (int)((dest - stackblock()) - startloc), 526 stackblock() + startloc)); 527 expdest = dest; 528 INTON; 529 } 530 531 532 533 static int 534 subevalvar(char *p, char *str, int strloc, int subtype, int startloc, 535 int varflags, int quotes) 536 { 537 char *startp; 538 char *loc = NULL; 539 char *q; 540 int c = 0; 541 struct nodelist *saveargbackq = argbackq; 542 int amount; 543 544 argstr(p, (subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX || 545 subtype == VSTRIMRIGHT || subtype == VSTRIMRIGHTMAX ? 546 EXP_CASE : 0) | EXP_TILDE); 547 STACKSTRNUL(expdest); 548 argbackq = saveargbackq; 549 startp = stackblock() + startloc; 550 if (str == NULL) 551 str = stackblock() + strloc; 552 553 switch (subtype) { 554 case VSASSIGN: 555 setvar(str, startp, 0); 556 amount = startp - expdest; 557 STADJUST(amount, expdest); 558 varflags &= ~VSNUL; 559 return 1; 560 561 case VSQUESTION: 562 if (*p != CTLENDVAR) { 563 outfmt(out2, "%s\n", startp); 564 error(NULL); 565 } 566 error("%.*s: parameter %snot set", (int)(p - str - 1), 567 str, (varflags & VSNUL) ? "null or " 568 : nullstr); 569 return 0; 570 571 case VSTRIMLEFT: 572 for (loc = startp; loc < str; loc++) { 573 c = *loc; 574 *loc = '\0'; 575 if (patmatch(str, startp, quotes)) { 576 *loc = c; 577 goto recordleft; 578 } 579 *loc = c; 580 if (quotes && *loc == CTLESC) 581 loc++; 582 } 583 return 0; 584 585 case VSTRIMLEFTMAX: 586 for (loc = str - 1; loc >= startp;) { 587 c = *loc; 588 *loc = '\0'; 589 if (patmatch(str, startp, quotes)) { 590 *loc = c; 591 goto recordleft; 592 } 593 *loc = c; 594 loc--; 595 if (quotes && loc > startp && *(loc - 1) == CTLESC) { 596 for (q = startp; q < loc; q++) 597 if (*q == CTLESC) 598 q++; 599 if (q > loc) 600 loc--; 601 } 602 } 603 return 0; 604 605 case VSTRIMRIGHT: 606 for (loc = str - 1; loc >= startp;) { 607 if (patmatch(str, loc, quotes)) { 608 amount = loc - expdest; 609 STADJUST(amount, expdest); 610 return 1; 611 } 612 loc--; 613 if (quotes && loc > startp && *(loc - 1) == CTLESC) { 614 for (q = startp; q < loc; q++) 615 if (*q == CTLESC) 616 q++; 617 if (q > loc) 618 loc--; 619 } 620 } 621 return 0; 622 623 case VSTRIMRIGHTMAX: 624 for (loc = startp; loc < str - 1; loc++) { 625 if (patmatch(str, loc, quotes)) { 626 amount = loc - expdest; 627 STADJUST(amount, expdest); 628 return 1; 629 } 630 if (quotes && *loc == CTLESC) 631 loc++; 632 } 633 return 0; 634 635 636 default: 637 abort(); 638 } 639 640 recordleft: 641 amount = ((str - 1) - (loc - startp)) - expdest; 642 STADJUST(amount, expdest); 643 while (loc != str - 1) 644 *startp++ = *loc++; 645 return 1; 646 } 647 648 649 /* 650 * Expand a variable, and return a pointer to the next character in the 651 * input string. 652 */ 653 654 static char * 655 evalvar(char *p, int flag) 656 { 657 int subtype; 658 int varflags; 659 char *var; 660 char *val; 661 int patloc; 662 int c; 663 int set; 664 int special; 665 int startloc; 666 int varlen; 667 int easy; 668 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 669 670 varflags = (unsigned char)*p++; 671 subtype = varflags & VSTYPE; 672 var = p; 673 special = 0; 674 if (! is_name(*p)) 675 special = 1; 676 p = strchr(p, '=') + 1; 677 again: /* jump here after setting a variable with ${var=text} */ 678 if (varflags & VSLINENO) { 679 set = 1; 680 special = 0; 681 val = var; 682 p[-1] = '\0'; /* temporarily overwrite '=' to have \0 683 terminated string */ 684 } else if (special) { 685 set = varisset(var, varflags & VSNUL); 686 val = NULL; 687 } else { 688 val = bltinlookup(var, 1); 689 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) { 690 val = NULL; 691 set = 0; 692 } else 693 set = 1; 694 } 695 varlen = 0; 696 startloc = expdest - stackblock(); 697 if (!set && uflag && *var != '@' && *var != '*') { 698 switch (subtype) { 699 case VSNORMAL: 700 case VSTRIMLEFT: 701 case VSTRIMLEFTMAX: 702 case VSTRIMRIGHT: 703 case VSTRIMRIGHTMAX: 704 case VSLENGTH: 705 error("%.*s: parameter not set", (int)(p - var - 1), 706 var); 707 } 708 } 709 if (set && subtype != VSPLUS) { 710 /* insert the value of the variable */ 711 if (special) { 712 varvalue(var, varflags & VSQUOTE, subtype, flag); 713 if (subtype == VSLENGTH) { 714 varlen = expdest - stackblock() - startloc; 715 STADJUST(-varlen, expdest); 716 } 717 } else { 718 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX 719 : BASESYNTAX; 720 721 if (subtype == VSLENGTH) { 722 for (;*val; val++) 723 varlen++; 724 } 725 else { 726 if (quotes) 727 STPUTS_QUOTES(val, syntax, expdest); 728 else 729 STPUTS(val, expdest); 730 731 } 732 } 733 } 734 735 if (subtype == VSPLUS) 736 set = ! set; 737 738 easy = ((varflags & VSQUOTE) == 0 || 739 (*var == '@' && shellparam.nparam != 1)); 740 741 742 switch (subtype) { 743 case VSLENGTH: 744 expdest = cvtnum(varlen, expdest); 745 goto record; 746 747 case VSNORMAL: 748 if (!easy) 749 break; 750 record: 751 recordregion(startloc, expdest - stackblock(), 752 varflags & VSQUOTE); 753 break; 754 755 case VSPLUS: 756 case VSMINUS: 757 if (!set) { 758 argstr(p, flag | (flag & EXP_FULL ? EXP_SPLIT_LIT : 0) | 759 (varflags & VSQUOTE ? EXP_LIT_QUOTED : 0)); 760 break; 761 } 762 if (easy) 763 goto record; 764 break; 765 766 case VSTRIMLEFT: 767 case VSTRIMLEFTMAX: 768 case VSTRIMRIGHT: 769 case VSTRIMRIGHTMAX: 770 if (!set) 771 break; 772 /* 773 * Terminate the string and start recording the pattern 774 * right after it 775 */ 776 STPUTC('\0', expdest); 777 patloc = expdest - stackblock(); 778 if (subevalvar(p, NULL, patloc, subtype, 779 startloc, varflags, quotes) == 0) { 780 int amount = (expdest - stackblock() - patloc) + 1; 781 STADJUST(-amount, expdest); 782 } 783 /* Remove any recorded regions beyond start of variable */ 784 removerecordregions(startloc); 785 goto record; 786 787 case VSASSIGN: 788 case VSQUESTION: 789 if (!set) { 790 if (subevalvar(p, var, 0, subtype, startloc, varflags, 791 quotes)) { 792 varflags &= ~VSNUL; 793 /* 794 * Remove any recorded regions beyond 795 * start of variable 796 */ 797 removerecordregions(startloc); 798 goto again; 799 } 800 break; 801 } 802 if (easy) 803 goto record; 804 break; 805 806 case VSERROR: 807 c = p - var - 1; 808 error("${%.*s%s}: Bad substitution", c, var, 809 (c > 0 && *p != CTLENDVAR) ? "..." : ""); 810 811 default: 812 abort(); 813 } 814 p[-1] = '='; /* recover overwritten '=' */ 815 816 if (subtype != VSNORMAL) { /* skip to end of alternative */ 817 int nesting = 1; 818 for (;;) { 819 if ((c = *p++) == CTLESC) 820 p++; 821 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) { 822 if (set) 823 argbackq = argbackq->next; 824 } else if (c == CTLVAR) { 825 if ((*p++ & VSTYPE) != VSNORMAL) 826 nesting++; 827 } else if (c == CTLENDVAR) { 828 if (--nesting == 0) 829 break; 830 } 831 } 832 } 833 return p; 834 } 835 836 837 838 /* 839 * Test whether a specialized variable is set. 840 */ 841 842 static int 843 varisset(char *name, int nulok) 844 { 845 846 if (*name == '!') 847 return backgndpidset(); 848 else if (*name == '@' || *name == '*') { 849 if (*shellparam.p == NULL) 850 return 0; 851 852 if (nulok) { 853 char **av; 854 855 for (av = shellparam.p; *av; av++) 856 if (**av != '\0') 857 return 1; 858 return 0; 859 } 860 } else if (is_digit(*name)) { 861 char *ap; 862 int num = atoi(name); 863 864 if (num > shellparam.nparam) 865 return 0; 866 867 if (num == 0) 868 ap = arg0; 869 else 870 ap = shellparam.p[num - 1]; 871 872 if (nulok && (ap == NULL || *ap == '\0')) 873 return 0; 874 } 875 return 1; 876 } 877 878 static void 879 strtodest(const char *p, int flag, int subtype, int quoted) 880 { 881 if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) 882 STPUTS_QUOTES(p, quoted ? DQSYNTAX : BASESYNTAX, expdest); 883 else 884 STPUTS(p, expdest); 885 } 886 887 /* 888 * Add the value of a specialized variable to the stack string. 889 */ 890 891 static void 892 varvalue(char *name, int quoted, int subtype, int flag) 893 { 894 int num; 895 char *p; 896 int i; 897 char sep; 898 char **ap; 899 900 switch (*name) { 901 case '$': 902 num = rootpid; 903 goto numvar; 904 case '?': 905 num = oexitstatus; 906 goto numvar; 907 case '#': 908 num = shellparam.nparam; 909 goto numvar; 910 case '!': 911 num = backgndpidval(); 912 numvar: 913 expdest = cvtnum(num, expdest); 914 break; 915 case '-': 916 for (i = 0 ; i < NOPTS ; i++) { 917 if (optlist[i].val) 918 STPUTC(optlist[i].letter, expdest); 919 } 920 break; 921 case '@': 922 if (flag & EXP_FULL && quoted) { 923 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 924 strtodest(p, flag, subtype, quoted); 925 if (*ap) 926 STPUTC('\0', expdest); 927 } 928 break; 929 } 930 /* FALLTHROUGH */ 931 case '*': 932 if (ifsset()) 933 sep = ifsval()[0]; 934 else 935 sep = ' '; 936 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 937 strtodest(p, flag, subtype, quoted); 938 if (*ap && sep) 939 STPUTC(sep, expdest); 940 } 941 break; 942 case '0': 943 p = arg0; 944 strtodest(p, flag, subtype, quoted); 945 break; 946 default: 947 if (is_digit(*name)) { 948 num = atoi(name); 949 if (num > 0 && num <= shellparam.nparam) { 950 p = shellparam.p[num - 1]; 951 strtodest(p, flag, subtype, quoted); 952 } 953 } 954 break; 955 } 956 } 957 958 959 960 /* 961 * Record the fact that we have to scan this region of the 962 * string for IFS characters. 963 */ 964 965 static void 966 recordregion(int start, int end, int inquotes) 967 { 968 struct ifsregion *ifsp; 969 970 if (ifslastp == NULL) { 971 ifsp = &ifsfirst; 972 } else { 973 if (ifslastp->endoff == start 974 && ifslastp->inquotes == inquotes) { 975 /* extend previous area */ 976 ifslastp->endoff = end; 977 return; 978 } 979 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion)); 980 ifslastp->next = ifsp; 981 } 982 ifslastp = ifsp; 983 ifslastp->next = NULL; 984 ifslastp->begoff = start; 985 ifslastp->endoff = end; 986 ifslastp->inquotes = inquotes; 987 } 988 989 990 991 /* 992 * Break the argument string into pieces based upon IFS and add the 993 * strings to the argument list. The regions of the string to be 994 * searched for IFS characters have been stored by recordregion. 995 * CTLESC characters are preserved but have little effect in this pass 996 * other than escaping CTL* characters. In particular, they do not escape 997 * IFS characters: that should be done with the ifsregion mechanism. 998 * CTLQUOTEMARK characters are used to preserve empty quoted strings. 999 * This pass treats them as a regular character, making the string non-empty. 1000 * Later, they are removed along with the other CTL* characters. 1001 */ 1002 static void 1003 ifsbreakup(char *string, struct arglist *arglist) 1004 { 1005 struct ifsregion *ifsp; 1006 struct strlist *sp; 1007 char *start; 1008 char *p; 1009 char *q; 1010 const char *ifs; 1011 const char *ifsspc; 1012 int had_param_ch = 0; 1013 1014 start = string; 1015 1016 if (ifslastp == NULL) { 1017 /* Return entire argument, IFS doesn't apply to any of it */ 1018 sp = (struct strlist *)stalloc(sizeof *sp); 1019 sp->text = start; 1020 *arglist->lastp = sp; 1021 arglist->lastp = &sp->next; 1022 return; 1023 } 1024 1025 ifs = ifsset() ? ifsval() : " \t\n"; 1026 1027 for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) { 1028 p = string + ifsp->begoff; 1029 while (p < string + ifsp->endoff) { 1030 q = p; 1031 if (*p == CTLESC) 1032 p++; 1033 if (ifsp->inquotes) { 1034 /* Only NULs (should be from "$@") end args */ 1035 had_param_ch = 1; 1036 if (*p != 0) { 1037 p++; 1038 continue; 1039 } 1040 ifsspc = NULL; 1041 } else { 1042 if (!strchr(ifs, *p)) { 1043 had_param_ch = 1; 1044 p++; 1045 continue; 1046 } 1047 ifsspc = strchr(" \t\n", *p); 1048 1049 /* Ignore IFS whitespace at start */ 1050 if (q == start && ifsspc != NULL) { 1051 p++; 1052 start = p; 1053 continue; 1054 } 1055 had_param_ch = 0; 1056 } 1057 1058 /* Save this argument... */ 1059 *q = '\0'; 1060 sp = (struct strlist *)stalloc(sizeof *sp); 1061 sp->text = start; 1062 *arglist->lastp = sp; 1063 arglist->lastp = &sp->next; 1064 p++; 1065 1066 if (ifsspc != NULL) { 1067 /* Ignore further trailing IFS whitespace */ 1068 for (; p < string + ifsp->endoff; p++) { 1069 q = p; 1070 if (*p == CTLESC) 1071 p++; 1072 if (strchr(ifs, *p) == NULL) { 1073 p = q; 1074 break; 1075 } 1076 if (strchr(" \t\n", *p) == NULL) { 1077 p++; 1078 break; 1079 } 1080 } 1081 } 1082 start = p; 1083 } 1084 } 1085 1086 /* 1087 * Save anything left as an argument. 1088 * Traditionally we have treated 'IFS=':'; set -- x$IFS' as 1089 * generating 2 arguments, the second of which is empty. 1090 * Some recent clarification of the Posix spec say that it 1091 * should only generate one.... 1092 */ 1093 if (had_param_ch || *start != 0) { 1094 sp = (struct strlist *)stalloc(sizeof *sp); 1095 sp->text = start; 1096 *arglist->lastp = sp; 1097 arglist->lastp = &sp->next; 1098 } 1099 } 1100 1101 1102 static char expdir[PATH_MAX]; 1103 #define expdir_end (expdir + sizeof(expdir)) 1104 1105 /* 1106 * Perform pathname generation and remove control characters. 1107 * At this point, the only control characters should be CTLESC and CTLQUOTEMARK. 1108 * The results are stored in the list exparg. 1109 */ 1110 static void 1111 expandmeta(struct strlist *str, int flag __unused) 1112 { 1113 char *p; 1114 struct strlist **savelastp; 1115 struct strlist *sp; 1116 char c; 1117 /* TODO - EXP_REDIR */ 1118 1119 while (str) { 1120 if (fflag) 1121 goto nometa; 1122 p = str->text; 1123 for (;;) { /* fast check for meta chars */ 1124 if ((c = *p++) == '\0') 1125 goto nometa; 1126 if (c == '*' || c == '?' || c == '[') 1127 break; 1128 } 1129 savelastp = exparg.lastp; 1130 INTOFF; 1131 expmeta(expdir, str->text); 1132 INTON; 1133 if (exparg.lastp == savelastp) { 1134 /* 1135 * no matches 1136 */ 1137 nometa: 1138 *exparg.lastp = str; 1139 rmescapes(str->text); 1140 exparg.lastp = &str->next; 1141 } else { 1142 *exparg.lastp = NULL; 1143 *savelastp = sp = expsort(*savelastp); 1144 while (sp->next != NULL) 1145 sp = sp->next; 1146 exparg.lastp = &sp->next; 1147 } 1148 str = str->next; 1149 } 1150 } 1151 1152 1153 /* 1154 * Do metacharacter (i.e. *, ?, [...]) expansion. 1155 */ 1156 1157 static void 1158 expmeta(char *enddir, char *name) 1159 { 1160 char *p; 1161 char *q; 1162 char *start; 1163 char *endname; 1164 int metaflag; 1165 struct stat statb; 1166 DIR *dirp; 1167 struct dirent *dp; 1168 int atend; 1169 int matchdot; 1170 int esc; 1171 1172 metaflag = 0; 1173 start = name; 1174 for (p = name; esc = 0, *p; p += esc + 1) { 1175 if (*p == '*' || *p == '?') 1176 metaflag = 1; 1177 else if (*p == '[') { 1178 q = p + 1; 1179 if (*q == '!' || *q == '^') 1180 q++; 1181 for (;;) { 1182 while (*q == CTLQUOTEMARK) 1183 q++; 1184 if (*q == CTLESC) 1185 q++; 1186 if (*q == '/' || *q == '\0') 1187 break; 1188 if (*++q == ']') { 1189 metaflag = 1; 1190 break; 1191 } 1192 } 1193 } else if (*p == '\0') 1194 break; 1195 else if (*p == CTLQUOTEMARK) 1196 continue; 1197 else { 1198 if (*p == CTLESC) 1199 esc++; 1200 if (p[esc] == '/') { 1201 if (metaflag) 1202 break; 1203 start = p + esc + 1; 1204 } 1205 } 1206 } 1207 if (metaflag == 0) { /* we've reached the end of the file name */ 1208 if (enddir != expdir) 1209 metaflag++; 1210 for (p = name ; ; p++) { 1211 if (*p == CTLQUOTEMARK) 1212 continue; 1213 if (*p == CTLESC) 1214 p++; 1215 *enddir++ = *p; 1216 if (*p == '\0') 1217 break; 1218 if (enddir == expdir_end) 1219 return; 1220 } 1221 if (metaflag == 0 || lstat(expdir, &statb) >= 0) 1222 addfname(expdir); 1223 return; 1224 } 1225 endname = p; 1226 if (start != name) { 1227 p = name; 1228 while (p < start) { 1229 while (*p == CTLQUOTEMARK) 1230 p++; 1231 if (*p == CTLESC) 1232 p++; 1233 *enddir++ = *p++; 1234 if (enddir == expdir_end) 1235 return; 1236 } 1237 } 1238 if (enddir == expdir) { 1239 p = __DECONST(char *, "."); 1240 } else if (enddir == expdir + 1 && *expdir == '/') { 1241 p = __DECONST(char *, "/"); 1242 } else { 1243 p = expdir; 1244 enddir[-1] = '\0'; 1245 } 1246 if ((dirp = opendir(p)) == NULL) 1247 return; 1248 if (enddir != expdir) 1249 enddir[-1] = '/'; 1250 if (*endname == 0) { 1251 atend = 1; 1252 } else { 1253 atend = 0; 1254 *endname = '\0'; 1255 endname += esc + 1; 1256 } 1257 matchdot = 0; 1258 p = start; 1259 while (*p == CTLQUOTEMARK) 1260 p++; 1261 if (*p == CTLESC) 1262 p++; 1263 if (*p == '.') 1264 matchdot++; 1265 while (! int_pending() && (dp = readdir(dirp)) != NULL) { 1266 if (dp->d_name[0] == '.' && ! matchdot) 1267 continue; 1268 if (patmatch(start, dp->d_name, 0)) { 1269 if (enddir + dp->d_namlen + 1 > expdir_end) 1270 continue; 1271 memcpy(enddir, dp->d_name, dp->d_namlen + 1); 1272 if (atend) 1273 addfname(expdir); 1274 else { 1275 if (enddir + dp->d_namlen + 2 > expdir_end) 1276 continue; 1277 enddir[dp->d_namlen] = '/'; 1278 enddir[dp->d_namlen + 1] = '\0'; 1279 expmeta(enddir + dp->d_namlen + 1, endname); 1280 } 1281 } 1282 } 1283 closedir(dirp); 1284 if (! atend) 1285 endname[-esc - 1] = esc ? CTLESC : '/'; 1286 } 1287 1288 1289 /* 1290 * Add a file name to the list. 1291 */ 1292 1293 static void 1294 addfname(char *name) 1295 { 1296 char *p; 1297 struct strlist *sp; 1298 1299 p = stalloc(strlen(name) + 1); 1300 scopy(name, p); 1301 sp = (struct strlist *)stalloc(sizeof *sp); 1302 sp->text = p; 1303 *exparg.lastp = sp; 1304 exparg.lastp = &sp->next; 1305 } 1306 1307 1308 /* 1309 * Sort the results of file name expansion. It calculates the number of 1310 * strings to sort and then calls msort (short for merge sort) to do the 1311 * work. 1312 */ 1313 1314 static struct strlist * 1315 expsort(struct strlist *str) 1316 { 1317 int len; 1318 struct strlist *sp; 1319 1320 len = 0; 1321 for (sp = str ; sp ; sp = sp->next) 1322 len++; 1323 return msort(str, len); 1324 } 1325 1326 1327 static struct strlist * 1328 msort(struct strlist *list, int len) 1329 { 1330 struct strlist *p, *q = NULL; 1331 struct strlist **lpp; 1332 int half; 1333 int n; 1334 1335 if (len <= 1) 1336 return list; 1337 half = len >> 1; 1338 p = list; 1339 for (n = half ; --n >= 0 ; ) { 1340 q = p; 1341 p = p->next; 1342 } 1343 q->next = NULL; /* terminate first half of list */ 1344 q = msort(list, half); /* sort first half of list */ 1345 p = msort(p, len - half); /* sort second half */ 1346 lpp = &list; 1347 for (;;) { 1348 if (strcmp(p->text, q->text) < 0) { 1349 *lpp = p; 1350 lpp = &p->next; 1351 if ((p = *lpp) == NULL) { 1352 *lpp = q; 1353 break; 1354 } 1355 } else { 1356 *lpp = q; 1357 lpp = &q->next; 1358 if ((q = *lpp) == NULL) { 1359 *lpp = p; 1360 break; 1361 } 1362 } 1363 } 1364 return list; 1365 } 1366 1367 1368 1369 /* 1370 * Returns true if the pattern matches the string. 1371 */ 1372 1373 int 1374 patmatch(const char *pattern, const char *string, int squoted) 1375 { 1376 const char *p, *q; 1377 char c; 1378 1379 p = pattern; 1380 q = string; 1381 for (;;) { 1382 switch (c = *p++) { 1383 case '\0': 1384 goto breakloop; 1385 case CTLESC: 1386 if (squoted && *q == CTLESC) 1387 q++; 1388 if (*q++ != *p++) 1389 return 0; 1390 break; 1391 case CTLQUOTEMARK: 1392 continue; 1393 case '?': 1394 if (squoted && *q == CTLESC) 1395 q++; 1396 if (*q++ == '\0') 1397 return 0; 1398 break; 1399 case '*': 1400 c = *p; 1401 while (c == CTLQUOTEMARK || c == '*') 1402 c = *++p; 1403 if (c != CTLESC && c != CTLQUOTEMARK && 1404 c != '?' && c != '*' && c != '[') { 1405 while (*q != c) { 1406 if (squoted && *q == CTLESC && 1407 q[1] == c) 1408 break; 1409 if (*q == '\0') 1410 return 0; 1411 if (squoted && *q == CTLESC) 1412 q++; 1413 q++; 1414 } 1415 } 1416 do { 1417 if (patmatch(p, q, squoted)) 1418 return 1; 1419 if (squoted && *q == CTLESC) 1420 q++; 1421 } while (*q++ != '\0'); 1422 return 0; 1423 case '[': { 1424 const char *endp; 1425 int invert, found; 1426 char chr; 1427 1428 endp = p; 1429 if (*endp == '!' || *endp == '^') 1430 endp++; 1431 for (;;) { 1432 while (*endp == CTLQUOTEMARK) 1433 endp++; 1434 if (*endp == '\0') 1435 goto dft; /* no matching ] */ 1436 if (*endp == CTLESC) 1437 endp++; 1438 if (*++endp == ']') 1439 break; 1440 } 1441 invert = 0; 1442 if (*p == '!' || *p == '^') { 1443 invert++; 1444 p++; 1445 } 1446 found = 0; 1447 chr = *q++; 1448 if (squoted && chr == CTLESC) 1449 chr = *q++; 1450 if (chr == '\0') 1451 return 0; 1452 c = *p++; 1453 do { 1454 if (c == CTLQUOTEMARK) 1455 continue; 1456 if (c == CTLESC) 1457 c = *p++; 1458 if (*p == '-' && p[1] != ']') { 1459 p++; 1460 while (*p == CTLQUOTEMARK) 1461 p++; 1462 if (*p == CTLESC) 1463 p++; 1464 if ( collate_range_cmp(chr, c) >= 0 1465 && collate_range_cmp(chr, *p) <= 0 1466 ) 1467 found = 1; 1468 p++; 1469 } else { 1470 if (chr == c) 1471 found = 1; 1472 } 1473 } while ((c = *p++) != ']'); 1474 if (found == invert) 1475 return 0; 1476 break; 1477 } 1478 dft: default: 1479 if (squoted && *q == CTLESC) 1480 q++; 1481 if (*q++ != c) 1482 return 0; 1483 break; 1484 } 1485 } 1486 breakloop: 1487 if (*q != '\0') 1488 return 0; 1489 return 1; 1490 } 1491 1492 1493 1494 /* 1495 * Remove any CTLESC and CTLQUOTEMARK characters from a string. 1496 */ 1497 1498 void 1499 rmescapes(char *str) 1500 { 1501 char *p, *q; 1502 1503 p = str; 1504 while (*p != CTLESC && *p != CTLQUOTEMARK && *p != CTLQUOTEEND) { 1505 if (*p++ == '\0') 1506 return; 1507 } 1508 q = p; 1509 while (*p) { 1510 if (*p == CTLQUOTEMARK || *p == CTLQUOTEEND) { 1511 p++; 1512 continue; 1513 } 1514 if (*p == CTLESC) 1515 p++; 1516 *q++ = *p++; 1517 } 1518 *q = '\0'; 1519 } 1520 1521 1522 1523 /* 1524 * See if a pattern matches in a case statement. 1525 */ 1526 1527 int 1528 casematch(union node *pattern, const char *val) 1529 { 1530 struct stackmark smark; 1531 int result; 1532 char *p; 1533 1534 setstackmark(&smark); 1535 argbackq = pattern->narg.backquote; 1536 STARTSTACKSTR(expdest); 1537 ifslastp = NULL; 1538 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE); 1539 STPUTC('\0', expdest); 1540 p = grabstackstr(expdest); 1541 result = patmatch(p, val, 0); 1542 popstackmark(&smark); 1543 return result; 1544 } 1545 1546 /* 1547 * Our own itoa(). 1548 */ 1549 1550 static char * 1551 cvtnum(int num, char *buf) 1552 { 1553 char temp[32]; 1554 int neg = num < 0; 1555 char *p = temp + 31; 1556 1557 temp[31] = '\0'; 1558 1559 do { 1560 *--p = num % 10 + '0'; 1561 } while ((num /= 10) != 0); 1562 1563 if (neg) 1564 *--p = '-'; 1565 1566 STPUTS(p, buf); 1567 return buf; 1568 } 1569 1570 /* 1571 * Check statically if expanding a string may have side effects. 1572 */ 1573 int 1574 expandhassideeffects(const char *p) 1575 { 1576 int c; 1577 int arinest; 1578 1579 arinest = 0; 1580 while ((c = *p++) != '\0') { 1581 switch (c) { 1582 case CTLESC: 1583 p++; 1584 break; 1585 case CTLVAR: 1586 c = *p++; 1587 /* Expanding $! sets the job to remembered. */ 1588 if (*p == '!') 1589 return 1; 1590 if ((c & VSTYPE) == VSASSIGN) 1591 return 1; 1592 /* 1593 * If we are in arithmetic, the parameter may contain 1594 * '=' which may cause side effects. Exceptions are 1595 * the length of a parameter and $$, $# and $? which 1596 * are always numeric. 1597 */ 1598 if ((c & VSTYPE) == VSLENGTH) { 1599 while (*p != '=') 1600 p++; 1601 p++; 1602 break; 1603 } 1604 if ((*p == '$' || *p == '#' || *p == '?') && 1605 p[1] == '=') { 1606 p += 2; 1607 break; 1608 } 1609 if (arinest > 0) 1610 return 1; 1611 break; 1612 case CTLBACKQ: 1613 case CTLBACKQ | CTLQUOTE: 1614 if (arinest > 0) 1615 return 1; 1616 break; 1617 case CTLARI: 1618 arinest++; 1619 break; 1620 case CTLENDARI: 1621 arinest--; 1622 break; 1623 case '=': 1624 if (*p == '=') { 1625 /* Allow '==' operator. */ 1626 p++; 1627 continue; 1628 } 1629 if (arinest > 0) 1630 return 1; 1631 break; 1632 case '!': case '<': case '>': 1633 /* Allow '!=', '<=', '>=' operators. */ 1634 if (*p == '=') 1635 p++; 1636 break; 1637 } 1638 } 1639 return 0; 1640 } 1641 1642 /* 1643 * Do most of the work for wordexp(3). 1644 */ 1645 1646 int 1647 wordexpcmd(int argc, char **argv) 1648 { 1649 size_t len; 1650 int i; 1651 1652 out1fmt("%08x", argc - 1); 1653 for (i = 1, len = 0; i < argc; i++) 1654 len += strlen(argv[i]); 1655 out1fmt("%08x", (int)len); 1656 for (i = 1; i < argc; i++) 1657 outbin(argv[i], strlen(argv[i]) + 1, out1); 1658 return (0); 1659 } 1660