bin/sh/expand.c

   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  * @(#)expand.c 8.5 (Berkeley) 5/15/95
  35  * $FreeBSD: head/bin/sh/expand.c 246288 2013-02-03 15:54:57Z jilles $
  36  */
  37
  38 #include <sys/types.h>
  39 #include <sys/time.h>
  40 #include <sys/stat.h>
  41 #include <dirent.h>
  42 #include <errno.h>
  43 #include <inttypes.h>
  44 #include <limits.h>
  45 #include <pwd.h>
  46 #include <stdio.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <unistd.h>
  50 #include <wchar.h>
  51 #include <wctype.h>
  52
  53 /*
  54  * Routines to expand arguments to commands.  We have to deal with
  55  * backquotes, shell variables, and file metacharacters.
  56  */
  57
  58 #include "shell.h"
  59 #include "main.h"
  60 #include "nodes.h"
  61 #include "eval.h"
  62 #include "expand.h"
  63 #include "syntax.h"
  64 #include "parser.h"
  65 #include "jobs.h"
  66 #include "options.h"
  67 #include "var.h"
  68 #include "input.h"
  69 #include "output.h"
  70 #include "memalloc.h"
  71 #include "error.h"
  72 #include "mystring.h"
  73 #include "arith.h"
  74 #include "show.h"
  75 #include "builtins.h"
  76
  77 /*
  78  * Structure specifying which parts of the string should be searched
  79  * for IFS characters.
  80  */
  81
  82 struct ifsregion {
  83         struct ifsregion *next; /* next region in list */
  84         int begoff;             /* offset of start of region */
  85         int endoff;             /* offset of end of region */
  86         int inquotes;           /* search for nul bytes only */
  87 };
  88
  89
  90 static char *expdest;                   /* output of current string */
  91 static struct nodelist *argbackq;       /* list of back quote expressions */
  92 static struct ifsregion ifsfirst;       /* first struct in list of ifs regions */
  93 static struct ifsregion *ifslastp;      /* last struct in list */
  94 static struct arglist exparg;           /* holds expanded arg list */
  95
  96 static void argstr(char *, int);
  97 static char *exptilde(char *, int);
  98 static void expbackq(union node *, int, int);
  99 static int subevalvar(char *, char *, int, int, int, int, int);
 100 static char *evalvar(char *, int);
 101 static int varisset(char *, int);
 102 static void varvalue(char *, int, int, int);
 103 static void recordregion(int, int, int);
 104 static void removerecordregions(int);
 105 static void ifsbreakup(char *, struct arglist *);
 106 static void expandmeta(struct strlist *, int);
 107 static void expmeta(char *, char *);
 108 static void addfname(char *);
 109 static struct strlist *expsort(struct strlist *);
 110 static struct strlist *msort(struct strlist *, int);
 111 static int patmatch(const char *, const char *, int);
 112 static char *cvtnum(int, char *);
 113 static int collate_range_cmp(wchar_t, wchar_t);
 114
 115 static int
 116 collate_range_cmp(wchar_t c1, wchar_t c2)
 117 {
 118         static wchar_t s1[2], s2[2];
 119
 120         s1[0] = c1;
 121         s2[0] = c2;
 122         return (wcscoll(s1, s2));
 123 }
 124
 125 static char *
 126 stputs_quotes(const char *data, const char *syntax, char *p)
 127 {
 128         while (*data) {
 129                 CHECKSTRSPACE(2, p);
 130                 if (syntax[(int)*data] == CCTL)
 131                         USTPUTC(CTLESC, p);
 132                 USTPUTC(*data++, p);
 133         }
 134         return (p);
 135 }
 136 #define STPUTS_QUOTES(data, syntax, p) p = stputs_quotes((data), syntax, p)
 137
 138 /*
 139  * Perform expansions on an argument, placing the resulting list of arguments
 140  * in arglist.  Parameter expansion, command substitution and arithmetic
 141  * expansion are always performed; additional expansions can be requested
 142  * via flag (EXP_*).
 143  * The result is left in the stack string.
 144  * When arglist is NULL, perform here document expansion.
 145  *
 146  * Caution: this function uses global state and is not reentrant.
 147  * However, a new invocation after an interrupted invocation is safe
 148  * and will reset the global state for the new call.
 149  */
 150 void
 151 expandarg(union node *arg, struct arglist *arglist, int flag)
 152 {
 153         struct strlist *sp;
 154         char *p;
 155
 156         argbackq = arg->narg.backquote;
 157         STARTSTACKSTR(expdest);
 158         ifsfirst.next = NULL;
 159         ifslastp = NULL;
 160         argstr(arg->narg.text, flag);
 161         if (arglist == NULL) {
 162                 STACKSTRNUL(expdest);
 163                 return;                 /* here document expanded */
 164         }
 165         STPUTC('\0', expdest);
 166         p = grabstackstr(expdest);
 167         exparg.lastp = &exparg.list;
 168         /*
 169          * TODO - EXP_REDIR
 170          */
 171         if (flag & EXP_FULL) {
 172                 ifsbreakup(p, &exparg);
 173                 *exparg.lastp = NULL;
 174                 exparg.lastp = &exparg.list;
 175                 expandmeta(exparg.list, flag);
 176         } else {
 177                 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
 178                         rmescapes(p);
 179                 sp = (struct strlist *)stalloc(sizeof (struct strlist));
 180                 sp->text = p;
 181                 *exparg.lastp = sp;
 182                 exparg.lastp = &sp->next;
 183         }
 184         while (ifsfirst.next != NULL) {
 185                 struct ifsregion *ifsp;
 186                 INTOFF;
 187                 ifsp = ifsfirst.next->next;
 188                 ckfree(ifsfirst.next);
 189                 ifsfirst.next = ifsp;
 190                 INTON;
 191         }
 192         *exparg.lastp = NULL;
 193         if (exparg.list) {
 194                 *arglist->lastp = exparg.list;
 195                 arglist->lastp = exparg.lastp;
 196         }
 197 }
 198
 199
 200
 201 /*
 202  * Perform parameter expansion, command substitution and arithmetic
 203  * expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE.
 204  * Processing ends at a CTLENDVAR character as well as '\0'.
 205  * This is used to expand word in ${var+word} etc.
 206  * If EXP_FULL, EXP_CASE or EXP_REDIR are set, keep and/or generate CTLESC
 207  * characters to allow for further processing.
 208  * If EXP_FULL is set, also preserve CTLQUOTEMARK characters.
 209  */
 210 static void
 211 argstr(char *p, int flag)
 212 {
 213         char c;
 214         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);  /* do CTLESC */
 215         int firsteq = 1;
 216         int split_lit;
 217         int lit_quoted;
 218
 219         split_lit = flag & EXP_SPLIT_LIT;
 220         lit_quoted = flag & EXP_LIT_QUOTED;
 221         flag &= ~(EXP_SPLIT_LIT | EXP_LIT_QUOTED);
 222         if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
 223                 p = exptilde(p, flag);
 224         for (;;) {
 225                 CHECKSTRSPACE(2, expdest);
 226                 switch (c = *p++) {
 227                 case '\0':
 228                 case CTLENDVAR:
 229                         goto breakloop;
 230                 case CTLQUOTEMARK:
 231                         lit_quoted = 1;
 232                         /* "$@" syntax adherence hack */
 233                         if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
 234                                 break;
 235                         if ((flag & EXP_FULL) != 0)
 236                                 USTPUTC(c, expdest);
 237                         break;
 238                 case CTLQUOTEEND:
 239                         lit_quoted = 0;
 240                         break;
 241                 case CTLESC:
 242                         if (quotes)
 243                                 USTPUTC(c, expdest);
 244                         c = *p++;
 245                         USTPUTC(c, expdest);
 246                         if (split_lit && !lit_quoted)
 247                                 recordregion(expdest - stackblock() -
 248                                     (quotes ? 2 : 1),
 249                                     expdest - stackblock(), 0);
 250                         break;
 251                 case CTLVAR:
 252                         p = evalvar(p, flag);
 253                         break;
 254                 case CTLBACKQ:
 255                 case CTLBACKQ|CTLQUOTE:
 256                         expbackq(argbackq->n, c & CTLQUOTE, flag);
 257                         argbackq = argbackq->next;
 258                         break;
 259                 case CTLENDARI:
 260                         expari(flag);
 261                         break;
 262                 case ':':
 263                 case '=':
 264                         /*
 265                          * sort of a hack - expand tildes in variable
 266                          * assignments (after the first '=' and after ':'s).
 267                          */
 268                         USTPUTC(c, expdest);
 269                         if (split_lit && !lit_quoted)
 270                                 recordregion(expdest - stackblock() - 1,
 271                                     expdest - stackblock(), 0);
 272                         if (flag & EXP_VARTILDE && *p == '~' &&
 273                             (c != '=' || firsteq)) {
 274                                 if (c == '=')
 275                                         firsteq = 0;
 276                                 p = exptilde(p, flag);
 277                         }
 278                         break;
 279                 default:
 280                         USTPUTC(c, expdest);
 281                         if (split_lit && !lit_quoted)
 282                                 recordregion(expdest - stackblock() - 1,
 283                                     expdest - stackblock(), 0);
 284                 }
 285         }
 286 breakloop:;
 287 }
 288
 289 /*
 290  * Perform tilde expansion, placing the result in the stack string and
 291  * returning the next position in the input string to process.
 292  */
 293 static char *
 294 exptilde(char *p, int flag)
 295 {
 296         char c, *startp = p;
 297         struct passwd *pw;
 298         char *home;
 299         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 300
 301         while ((c = *p) != '\0') {
 302                 switch(c) {
 303                 case CTLESC: /* This means CTL* are always considered quoted. */
 304                 case CTLVAR:
 305                 case CTLBACKQ:
 306                 case CTLBACKQ | CTLQUOTE:
 307                 case CTLARI:
 308                 case CTLENDARI:
 309                 case CTLQUOTEMARK:
 310                         return (startp);
 311                 case ':':
 312                         if (flag & EXP_VARTILDE)
 313                                 goto done;
 314                         break;
 315                 case '/':
 316                 case CTLENDVAR:
 317                         goto done;
 318                 }
 319                 p++;
 320         }
 321 done:
 322         *p = '\0';
 323         if (*(startp+1) == '\0') {
 324                 if ((home = lookupvar("HOME")) == NULL)
 325                         goto lose;
 326         } else {
 327                 if ((pw = getpwnam(startp+1)) == NULL)
 328                         goto lose;
 329                 home = pw->pw_dir;
 330         }
 331         if (*home == '\0')
 332                 goto lose;
 333         *p = c;
 334         if (quotes)
 335                 STPUTS_QUOTES(home, SQSYNTAX, expdest);
 336         else
 337                 STPUTS(home, expdest);
 338         return (p);
 339 lose:
 340         *p = c;
 341         return (startp);
 342 }
 343
 344
 345 static void
 346 removerecordregions(int endoff)
 347 {
 348         if (ifslastp == NULL)
 349                 return;
 350
 351         if (ifsfirst.endoff > endoff) {
 352                 while (ifsfirst.next != NULL) {
 353                         struct ifsregion *ifsp;
 354                         INTOFF;
 355                         ifsp = ifsfirst.next->next;
 356                         ckfree(ifsfirst.next);
 357                         ifsfirst.next = ifsp;
 358                         INTON;
 359                 }
 360                 if (ifsfirst.begoff > endoff)
 361                         ifslastp = NULL;
 362                 else {
 363                         ifslastp = &ifsfirst;
 364                         ifsfirst.endoff = endoff;
 365                 }
 366                 return;
 367         }
 368
 369         ifslastp = &ifsfirst;
 370         while (ifslastp->next && ifslastp->next->begoff < endoff)
 371                 ifslastp=ifslastp->next;
 372         while (ifslastp->next != NULL) {
 373                 struct ifsregion *ifsp;
 374                 INTOFF;
 375                 ifsp = ifslastp->next->next;
 376                 ckfree(ifslastp->next);
 377                 ifslastp->next = ifsp;
 378                 INTON;
 379         }
 380         if (ifslastp->endoff > endoff)
 381                 ifslastp->endoff = endoff;
 382 }
 383
 384 /*
 385  * Expand arithmetic expression.  Backup to start of expression,
 386  * evaluate, place result in (backed up) result, adjust string position.
 387  */
 388 void
 389 expari(int flag)
 390 {
 391         char *p, *q, *start;
 392         arith_t result;
 393         int begoff;
 394         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 395         int quoted;
 396
 397         /*
 398          * This routine is slightly over-complicated for
 399          * efficiency.  First we make sure there is
 400          * enough space for the result, which may be bigger
 401          * than the expression.  Next we
 402          * scan backwards looking for the start of arithmetic.  If the
 403          * next previous character is a CTLESC character, then we
 404          * have to rescan starting from the beginning since CTLESC
 405          * characters have to be processed left to right.
 406          */
 407         CHECKSTRSPACE(DIGITS(result) - 2, expdest);
 408         USTPUTC('\0', expdest);
 409         start = stackblock();
 410         p = expdest - 2;
 411         while (p >= start && *p != CTLARI)
 412                 --p;
 413         if (p < start || *p != CTLARI)
 414                 error("missing CTLARI (shouldn't happen)");
 415         if (p > start && *(p - 1) == CTLESC)
 416                 for (p = start; *p != CTLARI; p++)
 417                         if (*p == CTLESC)
 418                                 p++;
 419
 420         if (p[1] == '"')
 421                 quoted=1;
 422         else
 423                 quoted=0;
 424         begoff = p - start;
 425         removerecordregions(begoff);
 426         if (quotes)
 427                 rmescapes(p+2);
 428         q = grabstackstr(expdest);
 429         result = arith(p+2);
 430         ungrabstackstr(q, expdest);
 431         fmtstr(p, DIGITS(result), ARITH_FORMAT_STR, result);
 432         while (*p++)
 433                 ;
 434         if (quoted == 0)
 435                 recordregion(begoff, p - 1 - start, 0);
 436         result = expdest - p + 1;
 437         STADJUST(-result, expdest);
 438 }
 439
 440
 441 /*
 442  * Perform command substitution.
 443  */
 444 static void
 445 expbackq(union node *cmd, int quoted, int flag)
 446 {
 447         struct backcmd in;
 448         int i;
 449         char buf[128];
 450         char *p;
 451         char *dest = expdest;
 452         struct ifsregion saveifs, *savelastp;
 453         struct nodelist *saveargbackq;
 454         char lastc;
 455         int startloc = dest - stackblock();
 456         char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
 457         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 458         int nnl;
 459
 460         INTOFF;
 461         saveifs = ifsfirst;
 462         savelastp = ifslastp;
 463         saveargbackq = argbackq;
 464         p = grabstackstr(dest);
 465         evalbackcmd(cmd, &in);
 466         ungrabstackstr(p, dest);
 467         ifsfirst = saveifs;
 468         ifslastp = savelastp;
 469         argbackq = saveargbackq;
 470
 471         p = in.buf;
 472         lastc = '\0';
 473         nnl = 0;
 474         /* Don't copy trailing newlines */
 475         for (;;) {
 476                 if (--in.nleft < 0) {
 477                         if (in.fd < 0)
 478                                 break;
 479                         while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR);
 480                         TRACE(("expbackq: read returns %d\n", i));
 481                         if (i <= 0)
 482                                 break;
 483                         p = buf;
 484                         in.nleft = i - 1;
 485                 }
 486                 lastc = *p++;
 487                 if (lastc != '\0') {
 488                         if (lastc == '\n') {
 489                                 nnl++;
 490                         } else {
 491                                 CHECKSTRSPACE(nnl + 2, dest);
 492                                 while (nnl > 0) {
 493                                         nnl--;
 494                                         USTPUTC('\n', dest);
 495                                 }
 496                                 if (quotes && syntax[(int)lastc] == CCTL)
 497                                         USTPUTC(CTLESC, dest);
 498                                 USTPUTC(lastc, dest);
 499                         }
 500                 }
 501         }
 502
 503         if (in.fd >= 0)
 504                 close(in.fd);
 505         if (in.buf)
 506                 ckfree(in.buf);
 507         if (in.jp)
 508                 exitstatus = waitforjob(in.jp, NULL);
 509         if (quoted == 0)
 510                 recordregion(startloc, dest - stackblock(), 0);
 511         TRACE(("expbackq: size=%td: \"%.*s\"\n",
 512                 ((dest - stackblock()) - startloc),
 513                 (int)((dest - stackblock()) - startloc),
 514                 stackblock() + startloc));
 515         expdest = dest;
 516         INTON;
 517 }
 518
 519
 520
 521 static int
 522 subevalvar(char *p, char *str, int strloc, int subtype, int startloc,
 523   int varflags, int quotes)
 524 {
 525         char *startp;
 526         char *loc = NULL;
 527         char *q;
 528         int c = 0;
 529         struct nodelist *saveargbackq = argbackq;
 530         int amount;
 531
 532         argstr(p, (subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX ||
 533             subtype == VSTRIMRIGHT || subtype == VSTRIMRIGHTMAX ?
 534             EXP_CASE : 0) | EXP_TILDE);
 535         STACKSTRNUL(expdest);
 536         argbackq = saveargbackq;
 537         startp = stackblock() + startloc;
 538         if (str == NULL)
 539             str = stackblock() + strloc;
 540
 541         switch (subtype) {
 542         case VSASSIGN:
 543                 setvar(str, startp, 0);
 544                 amount = startp - expdest;
 545                 STADJUST(amount, expdest);
 546                 varflags &= ~VSNUL;
 547                 return 1;
 548
 549         case VSQUESTION:
 550                 if (*p != CTLENDVAR) {
 551                         outfmt(out2, "%s\n", startp);
 552                         error(NULL);
 553                 }
 554                 error("%.*s: parameter %snot set", (int)(p - str - 1),
 555                       str, (varflags & VSNUL) ? "null or "
 556                                               : nullstr);
 557                 return 0;
 558
 559         case VSTRIMLEFT:
 560                 for (loc = startp; loc < str; loc++) {
 561                         c = *loc;
 562                         *loc = '\0';
 563                         if (patmatch(str, startp, quotes)) {
 564                                 *loc = c;
 565                                 goto recordleft;
 566                         }
 567                         *loc = c;
 568                         if (quotes && *loc == CTLESC)
 569                                 loc++;
 570                 }
 571                 return 0;
 572
 573         case VSTRIMLEFTMAX:
 574                 for (loc = str - 1; loc >= startp;) {
 575                         c = *loc;
 576                         *loc = '\0';
 577                         if (patmatch(str, startp, quotes)) {
 578                                 *loc = c;
 579                                 goto recordleft;
 580                         }
 581                         *loc = c;
 582                         loc--;
 583                         if (quotes && loc > startp && *(loc - 1) == CTLESC) {
 584                                 for (q = startp; q < loc; q++)
 585                                         if (*q == CTLESC)
 586                                                 q++;
 587                                 if (q > loc)
 588                                         loc--;
 589                         }
 590                 }
 591                 return 0;
 592
 593         case VSTRIMRIGHT:
 594                 for (loc = str - 1; loc >= startp;) {
 595                         if (patmatch(str, loc, quotes)) {
 596                                 amount = loc - expdest;
 597                                 STADJUST(amount, expdest);
 598                                 return 1;
 599                         }
 600                         loc--;
 601                         if (quotes && loc > startp && *(loc - 1) == CTLESC) {
 602                                 for (q = startp; q < loc; q++)
 603                                         if (*q == CTLESC)
 604                                                 q++;
 605                                 if (q > loc)
 606                                         loc--;
 607                         }
 608                 }
 609                 return 0;
 610
 611         case VSTRIMRIGHTMAX:
 612                 for (loc = startp; loc < str - 1; loc++) {
 613                         if (patmatch(str, loc, quotes)) {
 614                                 amount = loc - expdest;
 615                                 STADJUST(amount, expdest);
 616                                 return 1;
 617                         }
 618                         if (quotes && *loc == CTLESC)
 619                                 loc++;
 620                 }
 621                 return 0;
 622
 623
 624         default:
 625                 abort();
 626         }
 627
 628 recordleft:
 629         amount = ((str - 1) - (loc - startp)) - expdest;
 630         STADJUST(amount, expdest);
 631         while (loc != str - 1)
 632                 *startp++ = *loc++;
 633         return 1;
 634 }
 635
 636
 637 /*
 638  * Expand a variable, and return a pointer to the next character in the
 639  * input string.
 640  */
 641
 642 static char *
 643 evalvar(char *p, int flag)
 644 {
 645         int subtype;
 646         int varflags;
 647         char *var;
 648         char *val;
 649         int patloc;
 650         int c;
 651         int set;
 652         int special;
 653         int startloc;
 654         int varlen;
 655         int varlenb;
 656         int easy;
 657         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 658
 659         varflags = (unsigned char)*p++;
 660         subtype = varflags & VSTYPE;
 661         var = p;
 662         special = 0;
 663         if (! is_name(*p))
 664                 special = 1;
 665         p = strchr(p, '=') + 1;
 666 again: /* jump here after setting a variable with ${var=text} */
 667         if (varflags & VSLINENO) {
 668                 set = 1;
 669                 special = 0;
 670                 val = var;
 671                 p[-1] = '\0';   /* temporarily overwrite '=' to have \0
 672                                    terminated string */
 673         } else if (special) {
 674                 set = varisset(var, varflags & VSNUL);
 675                 val = NULL;
 676         } else {
 677                 val = bltinlookup(var, 1);
 678                 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
 679                         val = NULL;
 680                         set = 0;
 681                 } else
 682                         set = 1;
 683         }
 684         varlen = 0;
 685         startloc = expdest - stackblock();
 686         if (!set && uflag && *var != '@' && *var != '*') {
 687                 switch (subtype) {
 688                 case VSNORMAL:
 689                 case VSTRIMLEFT:
 690                 case VSTRIMLEFTMAX:
 691                 case VSTRIMRIGHT:
 692                 case VSTRIMRIGHTMAX:
 693                 case VSLENGTH:
 694                         error("%.*s: parameter not set", (int)(p - var - 1),
 695                             var);
 696                 }
 697         }
 698         if (set && subtype != VSPLUS) {
 699                 /* insert the value of the variable */
 700                 if (special) {
 701                         varvalue(var, varflags & VSQUOTE, subtype, flag);
 702                         if (subtype == VSLENGTH) {
 703                                 varlenb = expdest - stackblock() - startloc;
 704                                 varlen = varlenb;
 705                                 if (localeisutf8) {
 706                                         val = stackblock() + startloc;
 707                                         for (;val != expdest; val++)
 708                                                 if ((*val & 0xC0) == 0x80)
 709                                                         varlen--;
 710                                 }
 711                                 STADJUST(-varlenb, expdest);
 712                         }
 713                 } else {
 714                         char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX
 715                                                                   : BASESYNTAX;
 716
 717                         if (subtype == VSLENGTH) {
 718                                 for (;*val; val++)
 719                                         if (!localeisutf8 ||
 720                                             (*val & 0xC0) != 0x80)
 721                                                 varlen++;
 722                         }
 723                         else {
 724                                 if (quotes)
 725                                         STPUTS_QUOTES(val, syntax, expdest);
 726                                 else
 727                                         STPUTS(val, expdest);
 728
 729                         }
 730                 }
 731         }
 732
 733         if (subtype == VSPLUS)
 734                 set = ! set;
 735
 736         easy = ((varflags & VSQUOTE) == 0 ||
 737                 (*var == '@' && shellparam.nparam != 1));
 738
 739
 740         switch (subtype) {
 741         case VSLENGTH:
 742                 expdest = cvtnum(varlen, expdest);
 743                 goto record;
 744
 745         case VSNORMAL:
 746                 if (!easy)
 747                         break;
 748 record:
 749                 recordregion(startloc, expdest - stackblock(),
 750                     varflags & VSQUOTE || (ifsset() && ifsval()[0] == '\0' &&
 751                     (*var == '@' || *var == '*')));
 752                 break;
 753
 754         case VSPLUS:
 755         case VSMINUS:
 756                 if (!set) {
 757                         argstr(p, flag | (flag & EXP_FULL ? EXP_SPLIT_LIT : 0) |
 758                             (varflags & VSQUOTE ? EXP_LIT_QUOTED : 0));
 759                         break;
 760                 }
 761                 if (easy)
 762                         goto record;
 763                 break;
 764
 765         case VSTRIMLEFT:
 766         case VSTRIMLEFTMAX:
 767         case VSTRIMRIGHT:
 768         case VSTRIMRIGHTMAX:
 769                 if (!set)
 770                         break;
 771                 /*
 772                  * Terminate the string and start recording the pattern
 773                  * right after it
 774                  */
 775                 STPUTC('\0', expdest);
 776                 patloc = expdest - stackblock();
 777                 if (subevalvar(p, NULL, patloc, subtype,
 778                     startloc, varflags, quotes) == 0) {
 779                         int amount = (expdest - stackblock() - patloc) + 1;
 780                         STADJUST(-amount, expdest);
 781                 }
 782                 /* Remove any recorded regions beyond start of variable */
 783                 removerecordregions(startloc);
 784                 goto record;
 785
 786         case VSASSIGN:
 787         case VSQUESTION:
 788                 if (!set) {
 789                         if (subevalvar(p, var, 0, subtype, startloc, varflags,
 790                             quotes)) {
 791                                 varflags &= ~VSNUL;
 792                                 /*
 793                                  * Remove any recorded regions beyond
 794                                  * start of variable
 795                                  */
 796                                 removerecordregions(startloc);
 797                                 goto again;
 798                         }
 799                         break;
 800                 }
 801                 if (easy)
 802                         goto record;
 803                 break;
 804
 805         case VSERROR:
 806                 c = p - var - 1;
 807                 error("${%.*s%s}: Bad substitution", c, var,
 808                     (c > 0 && *p != CTLENDVAR) ? "..." : "");
 809
 810         default:
 811                 abort();
 812         }
 813         p[-1] = '=';    /* recover overwritten '=' */
 814
 815         if (subtype != VSNORMAL) {      /* skip to end of alternative */
 816                 int nesting = 1;
 817                 for (;;) {
 818                         if ((c = *p++) == CTLESC)
 819                                 p++;
 820                         else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
 821                                 if (set)
 822                                         argbackq = argbackq->next;
 823                         } else if (c == CTLVAR) {
 824                                 if ((*p++ & VSTYPE) != VSNORMAL)
 825                                         nesting++;
 826                         } else if (c == CTLENDVAR) {
 827                                 if (--nesting == 0)
 828                                         break;
 829                         }
 830                 }
 831         }
 832         return p;
 833 }
 834
 835
 836
 837 /*
 838  * Test whether a specialized variable is set.
 839  */
 840
 841 static int
 842 varisset(char *name, int nulok)
 843 {
 844
 845         if (*name == '!')
 846                 return backgndpidset();
 847         else if (*name == '@' || *name == '*') {
 848                 if (*shellparam.p == NULL)
 849                         return 0;
 850
 851                 if (nulok) {
 852                         char **av;
 853
 854                         for (av = shellparam.p; *av; av++)
 855                                 if (**av != '\0')
 856                                         return 1;
 857                         return 0;
 858                 }
 859         } else if (is_digit(*name)) {
 860                 char *ap;
 861                 int num = atoi(name);
 862
 863                 if (num > shellparam.nparam)
 864                         return 0;
 865
 866                 if (num == 0)
 867                         ap = arg0;
 868                 else
 869                         ap = shellparam.p[num - 1];
 870
 871                 if (nulok && (ap == NULL || *ap == '\0'))
 872                         return 0;
 873         }
 874         return 1;
 875 }
 876
 877 static void
 878 strtodest(const char *p, int flag, int subtype, int quoted)
 879 {
 880         if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH)
 881                 STPUTS_QUOTES(p, quoted ? DQSYNTAX : BASESYNTAX, expdest);
 882         else
 883                 STPUTS(p, expdest);
 884 }
 885
 886 /*
 887  * Add the value of a specialized variable to the stack string.
 888  */
 889
 890 static void
 891 varvalue(char *name, int quoted, int subtype, int flag)
 892 {
 893         int num;
 894         char *p;
 895         int i;
 896         char sep;
 897         char **ap;
 898
 899         switch (*name) {
 900         case '$':
 901                 num = rootpid;
 902                 goto numvar;
 903         case '?':
 904                 num = oexitstatus;
 905                 goto numvar;
 906         case '#':
 907                 num = shellparam.nparam;
 908                 goto numvar;
 909         case '!':
 910                 num = backgndpidval();
 911 numvar:
 912                 expdest = cvtnum(num, expdest);
 913                 break;
 914         case '-':
 915                 for (i = 0 ; i < NOPTS ; i++) {
 916                         if (optlist[i].val)
 917                                 STPUTC(optlist[i].letter, expdest);
 918                 }
 919                 break;
 920         case '@':
 921                 if (flag & EXP_FULL && quoted) {
 922                         for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 923                                 strtodest(p, flag, subtype, quoted);
 924                                 if (*ap)
 925                                         STPUTC('\0', expdest);
 926                         }
 927                         break;
 928                 }
 929                 /* FALLTHROUGH */
 930         case '*':
 931                 if (ifsset())
 932                         sep = ifsval()[0];
 933                 else
 934                         sep = ' ';
 935                 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 936                         strtodest(p, flag, subtype, quoted);
 937                         if (!*ap)
 938                                 break;
 939                         if (sep || (flag & EXP_FULL && !quoted && **ap != '\0'))
 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         int namlen;
1173
1174         metaflag = 0;
1175         start = name;
1176         for (p = name; esc = 0, *p; p += esc + 1) {
1177                 if (*p == '*' || *p == '?')
1178                         metaflag = 1;
1179                 else if (*p == '[') {
1180                         q = p + 1;
1181                         if (*q == '!' || *q == '^')
1182                                 q++;
1183                         for (;;) {
1184                                 while (*q == CTLQUOTEMARK)
1185                                         q++;
1186                                 if (*q == CTLESC)
1187                                         q++;
1188                                 if (*q == '/' || *q == '\0')
1189                                         break;
1190                                 if (*++q == ']') {
1191                                         metaflag = 1;
1192                                         break;
1193                                 }
1194                         }
1195                 } else if (*p == '\0')
1196                         break;
1197                 else if (*p == CTLQUOTEMARK)
1198                         continue;
1199                 else {
1200                         if (*p == CTLESC)
1201                                 esc++;
1202                         if (p[esc] == '/') {
1203                                 if (metaflag)
1204                                         break;
1205                                 start = p + esc + 1;
1206                         }
1207                 }
1208         }
1209         if (metaflag == 0) {    /* we've reached the end of the file name */
1210                 if (enddir != expdir)
1211                         metaflag++;
1212                 for (p = name ; ; p++) {
1213                         if (*p == CTLQUOTEMARK)
1214                                 continue;
1215                         if (*p == CTLESC)
1216                                 p++;
1217                         *enddir++ = *p;
1218                         if (*p == '\0')
1219                                 break;
1220                         if (enddir == expdir_end)
1221                                 return;
1222                 }
1223                 if (metaflag == 0 || lstat(expdir, &statb) >= 0)
1224                         addfname(expdir);
1225                 return;
1226         }
1227         endname = p;
1228         if (start != name) {
1229                 p = name;
1230                 while (p < start) {
1231                         while (*p == CTLQUOTEMARK)
1232                                 p++;
1233                         if (*p == CTLESC)
1234                                 p++;
1235                         *enddir++ = *p++;
1236                         if (enddir == expdir_end)
1237                                 return;
1238                 }
1239         }
1240         if (enddir == expdir) {
1241                 p = __DECONST(char *, ".");
1242         } else if (enddir == expdir + 1 && *expdir == '/') {
1243                 p = __DECONST(char *, "/");
1244         } else {
1245                 p = expdir;
1246                 enddir[-1] = '\0';
1247         }
1248         if ((dirp = opendir(p)) == NULL)
1249                 return;
1250         if (enddir != expdir)
1251                 enddir[-1] = '/';
1252         if (*endname == 0) {
1253                 atend = 1;
1254         } else {
1255                 atend = 0;
1256                 *endname = '\0';
1257                 endname += esc + 1;
1258         }
1259         matchdot = 0;
1260         p = start;
1261         while (*p == CTLQUOTEMARK)
1262                 p++;
1263         if (*p == CTLESC)
1264                 p++;
1265         if (*p == '.')
1266                 matchdot++;
1267         while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1268                 if (dp->d_name[0] == '.' && ! matchdot)
1269                         continue;
1270                 if (patmatch(start, dp->d_name, 0)) {
1271                         namlen = dp->d_namlen;
1272                         if (enddir + namlen + 1 > expdir_end)
1273                                 continue;
1274                         memcpy(enddir, dp->d_name, namlen + 1);
1275                         if (atend)
1276                                 addfname(expdir);
1277                         else {
1278                                 if (dp->d_type != DT_UNKNOWN &&
1279                                     dp->d_type != DT_DIR &&
1280                                     dp->d_type != DT_LNK)
1281                                         continue;
1282                                 if (enddir + namlen + 2 > expdir_end)
1283                                         continue;
1284                                 enddir[namlen] = '/';
1285                                 enddir[namlen + 1] = '\0';
1286                                 expmeta(enddir + namlen + 1, endname);
1287                         }
1288                 }
1289         }
1290         closedir(dirp);
1291         if (! atend)
1292                 endname[-esc - 1] = esc ? CTLESC : '/';
1293 }
1294
1295
1296 /*
1297  * Add a file name to the list.
1298  */
1299
1300 static void
1301 addfname(char *name)
1302 {
1303         char *p;
1304         struct strlist *sp;
1305
1306         p = stalloc(strlen(name) + 1);
1307         scopy(name, p);
1308         sp = (struct strlist *)stalloc(sizeof *sp);
1309         sp->text = p;
1310         *exparg.lastp = sp;
1311         exparg.lastp = &sp->next;
1312 }
1313
1314
1315 /*
1316  * Sort the results of file name expansion.  It calculates the number of
1317  * strings to sort and then calls msort (short for merge sort) to do the
1318  * work.
1319  */
1320
1321 static struct strlist *
1322 expsort(struct strlist *str)
1323 {
1324         int len;
1325         struct strlist *sp;
1326
1327         len = 0;
1328         for (sp = str ; sp ; sp = sp->next)
1329                 len++;
1330         return msort(str, len);
1331 }
1332
1333
1334 static struct strlist *
1335 msort(struct strlist *list, int len)
1336 {
1337         struct strlist *p, *q = NULL;
1338         struct strlist **lpp;
1339         int half;
1340         int n;
1341
1342         if (len <= 1)
1343                 return list;
1344         half = len >> 1;
1345         p = list;
1346         for (n = half ; --n >= 0 ; ) {
1347                 q = p;
1348                 p = p->next;
1349         }
1350         q->next = NULL;                 /* terminate first half of list */
1351         q = msort(list, half);          /* sort first half of list */
1352         p = msort(p, len - half);               /* sort second half */
1353         lpp = &list;
1354         for (;;) {
1355                 if (strcmp(p->text, q->text) < 0) {
1356                         *lpp = p;
1357                         lpp = &p->next;
1358                         if ((p = *lpp) == NULL) {
1359                                 *lpp = q;
1360                                 break;
1361                         }
1362                 } else {
1363                         *lpp = q;
1364                         lpp = &q->next;
1365                         if ((q = *lpp) == NULL) {
1366                                 *lpp = p;
1367                                 break;
1368                         }
1369                 }
1370         }
1371         return list;
1372 }
1373
1374
1375
1376 static wchar_t
1377 get_wc(const char **p)
1378 {
1379         wchar_t c;
1380         int chrlen;
1381
1382         chrlen = mbtowc(&c, *p, 4);
1383         if (chrlen == 0)
1384                 return 0;
1385         else if (chrlen == -1)
1386                 c = 0;
1387         else
1388                 *p += chrlen;
1389         return c;
1390 }
1391
1392
1393 /*
1394  * See if a character matches a character class, starting at the first colon
1395  * of "[:class:]".
1396  * If a valid character class is recognized, a pointer to the next character
1397  * after the final closing bracket is stored into *end, otherwise a null
1398  * pointer is stored into *end.
1399  */
1400 static int
1401 match_charclass(const char *p, wchar_t chr, const char **end)
1402 {
1403         char name[20];
1404         const char *nameend;
1405         wctype_t cclass;
1406
1407         *end = NULL;
1408         p++;
1409         nameend = strstr(p, ":]");
1410         if (nameend == NULL || nameend - p >= (int)sizeof(name) || nameend == p)
1411                 return 0;
1412         memcpy(name, p, nameend - p);
1413         name[nameend - p] = '\0';
1414         *end = nameend + 2;
1415         cclass = wctype(name);
1416         /* An unknown class matches nothing but is valid nevertheless. */
1417         if (cclass == 0)
1418                 return 0;
1419         return iswctype(chr, cclass);
1420 }
1421
1422
1423 /*
1424  * Returns true if the pattern matches the string.
1425  */
1426
1427 static int
1428 patmatch(const char *pattern, const char *string, int squoted)
1429 {
1430         const char *p, *q, *end;
1431         const char *bt_p, *bt_q;
1432         char c;
1433         wchar_t wc, wc2;
1434
1435         p = pattern;
1436         q = string;
1437         bt_p = NULL;
1438         bt_q = NULL;
1439         for (;;) {
1440                 switch (c = *p++) {
1441                 case '\0':
1442                         if (*q != '\0')
1443                                 goto backtrack;
1444                         return 1;
1445                 case CTLESC:
1446                         if (squoted && *q == CTLESC)
1447                                 q++;
1448                         if (*q++ != *p++)
1449                                 goto backtrack;
1450                         break;
1451                 case CTLQUOTEMARK:
1452                         continue;
1453                 case '?':
1454                         if (squoted && *q == CTLESC)
1455                                 q++;
1456                         if (*q == '\0')
1457                                 return 0;
1458                         if (localeisutf8) {
1459                                 wc = get_wc(&q);
1460                                 /*
1461                                  * A '?' does not match invalid UTF-8 but a
1462                                  * '*' does, so backtrack.
1463                                  */
1464                                 if (wc == 0)
1465                                         goto backtrack;
1466                         } else
1467                                 wc = (unsigned char)*q++;
1468                         break;
1469                 case '*':
1470                         c = *p;
1471                         while (c == CTLQUOTEMARK || c == '*')
1472                                 c = *++p;
1473                         /*
1474                          * If the pattern ends here, we know the string
1475                          * matches without needing to look at the rest of it.
1476                          */
1477                         if (c == '\0')
1478                                 return 1;
1479                         /*
1480                          * First try the shortest match for the '*' that
1481                          * could work. We can forget any earlier '*' since
1482                          * there is no way having it match more characters
1483                          * can help us, given that we are already here.
1484                          */
1485                         bt_p = p;
1486                         bt_q = q;
1487                         break;
1488                 case '[': {
1489                         const char *endp;
1490                         int invert, found;
1491                         wchar_t chr;
1492
1493                         endp = p;
1494                         if (*endp == '!' || *endp == '^')
1495                                 endp++;
1496                         for (;;) {
1497                                 while (*endp == CTLQUOTEMARK)
1498                                         endp++;
1499                                 if (*endp == 0)
1500                                         goto dft;               /* no matching ] */
1501                                 if (*endp == CTLESC)
1502                                         endp++;
1503                                 if (*++endp == ']')
1504                                         break;
1505                         }
1506                         invert = 0;
1507                         if (*p == '!' || *p == '^') {
1508                                 invert++;
1509                                 p++;
1510                         }
1511                         found = 0;
1512                         if (squoted && *q == CTLESC)
1513                                 q++;
1514                         if (*q == '\0')
1515                                 return 0;
1516                         if (localeisutf8) {
1517                                 chr = get_wc(&q);
1518                                 if (chr == 0)
1519                                         goto backtrack;
1520                         } else
1521                                 chr = (unsigned char)*q++;
1522                         c = *p++;
1523                         do {
1524                                 if (c == CTLQUOTEMARK)
1525                                         continue;
1526                                 if (c == '[' && *p == ':') {
1527                                         found |= match_charclass(p, chr, &end);
1528                                         if (end != NULL)
1529                                                 p = end;
1530                                 }
1531                                 if (c == CTLESC)
1532                                         c = *p++;
1533                                 if (localeisutf8 && c & 0x80) {
1534                                         p--;
1535                                         wc = get_wc(&p);
1536                                         if (wc == 0) /* bad utf-8 */
1537                                                 return 0;
1538                                 } else
1539                                         wc = (unsigned char)c;
1540                                 if (*p == '-' && p[1] != ']') {
1541                                         p++;
1542                                         while (*p == CTLQUOTEMARK)
1543                                                 p++;
1544                                         if (*p == CTLESC)
1545                                                 p++;
1546                                         if (localeisutf8) {
1547                                                 wc2 = get_wc(&p);
1548                                                 if (wc2 == 0) /* bad utf-8 */
1549                                                         return 0;
1550                                         } else
1551                                                 wc2 = (unsigned char)*p++;
1552                                         if (   collate_range_cmp(chr, wc) >= 0
1553                                             && collate_range_cmp(chr, wc2) <= 0
1554                                            )
1555                                                 found = 1;
1556                                 } else {
1557                                         if (chr == wc)
1558                                                 found = 1;
1559                                 }
1560                         } while ((c = *p++) != ']');
1561                         if (found == invert)
1562                                 goto backtrack;
1563                         break;
1564                 }
1565 dft:            default:
1566                         if (squoted && *q == CTLESC)
1567                                 q++;
1568                         if (*q == '\0')
1569                                 return 0;
1570                         if (*q++ == c)
1571                                 break;
1572 backtrack:
1573                         /*
1574                          * If we have a mismatch (other than hitting the end
1575                          * of the string), go back to the last '*' seen and
1576                          * have it match one additional character.
1577                          */
1578                         if (bt_p == NULL)
1579                                 return 0;
1580                         if (squoted && *bt_q == CTLESC)
1581                                 bt_q++;
1582                         if (*bt_q == '\0')
1583                                 return 0;
1584                         bt_q++;
1585                         p = bt_p;
1586                         q = bt_q;
1587                         break;
1588                 }
1589         }
1590 }
1591
1592
1593
1594 /*
1595  * Remove any CTLESC and CTLQUOTEMARK characters from a string.
1596  */
1597
1598 void
1599 rmescapes(char *str)
1600 {
1601         char *p, *q;
1602
1603         p = str;
1604         while (*p != CTLESC && *p != CTLQUOTEMARK && *p != CTLQUOTEEND) {
1605                 if (*p++ == '\0')
1606                         return;
1607         }
1608         q = p;
1609         while (*p) {
1610                 if (*p == CTLQUOTEMARK || *p == CTLQUOTEEND) {
1611                         p++;
1612                         continue;
1613                 }
1614                 if (*p == CTLESC)
1615                         p++;
1616                 *q++ = *p++;
1617         }
1618         *q = '\0';
1619 }
1620
1621
1622
1623 /*
1624  * See if a pattern matches in a case statement.
1625  */
1626
1627 int
1628 casematch(union node *pattern, const char *val)
1629 {
1630         struct stackmark smark;
1631         int result;
1632         char *p;
1633
1634         setstackmark(&smark);
1635         argbackq = pattern->narg.backquote;
1636         STARTSTACKSTR(expdest);
1637         ifslastp = NULL;
1638         argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
1639         STPUTC('\0', expdest);
1640         p = grabstackstr(expdest);
1641         result = patmatch(p, val, 0);
1642         popstackmark(&smark);
1643         return result;
1644 }
1645
1646 /*
1647  * Our own itoa().
1648  */
1649
1650 static char *
1651 cvtnum(int num, char *buf)
1652 {
1653         char temp[32];
1654         int neg = num < 0;
1655         char *p = temp + 31;
1656
1657         temp[31] = '\0';
1658
1659         do {
1660                 *--p = num % 10 + '0';
1661         } while ((num /= 10) != 0);
1662
1663         if (neg)
1664                 *--p = '-';
1665
1666         STPUTS(p, buf);
1667         return buf;
1668 }
1669
1670 /*
1671  * Do most of the work for wordexp(3).
1672  */
1673
1674 int
1675 wordexpcmd(int argc, char **argv)
1676 {
1677         size_t len;
1678         int i;
1679
1680         out1fmt("%08x", argc - 1);
1681         for (i = 1, len = 0; i < argc; i++)
1682                 len += strlen(argv[i]);
1683         out1fmt("%08x", (int)len);
1684         for (i = 1; i < argc; i++)
1685                 outbin(argv[i], strlen(argv[i]) + 1, out1);
1686         return (0);
1687 }