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
  35 #ifndef lint
  36 #if 0
  37 static char sccsid[] = "@(#)expand.c    8.5 (Berkeley) 5/15/95";
  38 #endif
  39 #endif /* not lint */
  40 #include <sys/cdefs.h>
  41 __FBSDID("$FreeBSD$");
  42
  43 #include <sys/types.h>
  44 #include <sys/time.h>
  45 #include <sys/stat.h>
  46 #include <dirent.h>
  47 #include <errno.h>
  48 #include <inttypes.h>
  49 #include <limits.h>
  50 #include <pwd.h>
  51 #include <stdio.h>
  52 #include <stdlib.h>
  53 #include <string.h>
  54 #include <unistd.h>
  55 #include <wchar.h>
  56 #include <wctype.h>
  57
  58 /*
  59  * Routines to expand arguments to commands.  We have to deal with
  60  * backquotes, shell variables, and file metacharacters.
  61  */
  62
  63 #include "shell.h"
  64 #include "main.h"
  65 #include "nodes.h"
  66 #include "eval.h"
  67 #include "expand.h"
  68 #include "syntax.h"
  69 #include "parser.h"
  70 #include "jobs.h"
  71 #include "options.h"
  72 #include "var.h"
  73 #include "input.h"
  74 #include "output.h"
  75 #include "memalloc.h"
  76 #include "error.h"
  77 #include "mystring.h"
  78 #include "arith.h"
  79 #include "show.h"
  80 #include "builtins.h"
  81
  82 /*
  83  * Structure specifying which parts of the string should be searched
  84  * for IFS characters.
  85  */
  86
  87 struct ifsregion {
  88         struct ifsregion *next; /* next region in list */
  89         int begoff;             /* offset of start of region */
  90         int endoff;             /* offset of end of region */
  91         int inquotes;           /* search for nul bytes only */
  92 };
  93
  94
  95 static char *expdest;                   /* output of current string */
  96 static struct nodelist *argbackq;       /* list of back quote expressions */
  97 static struct ifsregion ifsfirst;       /* first struct in list of ifs regions */
  98 static struct ifsregion *ifslastp;      /* last struct in list */
  99 static struct arglist exparg;           /* holds expanded arg list */
 100
 101 static char *argstr(char *, int);
 102 static char *exptilde(char *, int);
 103 static char *expari(char *);
 104 static void expbackq(union node *, int, int);
 105 static int subevalvar(char *, char *, int, int, int, int, int);
 106 static char *evalvar(char *, int);
 107 static int varisset(const char *, int);
 108 static void varvalue(const char *, int, int, int);
 109 static void recordregion(int, int, int);
 110 static void removerecordregions(int);
 111 static void ifsbreakup(char *, struct arglist *);
 112 static void expandmeta(struct strlist *, int);
 113 static void expmeta(char *, char *);
 114 static void addfname(char *);
 115 static struct strlist *expsort(struct strlist *);
 116 static struct strlist *msort(struct strlist *, int);
 117 static int patmatch(const char *, const char *, int);
 118 static char *cvtnum(int, char *);
 119 static int collate_range_cmp(wchar_t, wchar_t);
 120
 121 static int
 122 collate_range_cmp(wchar_t c1, wchar_t c2)
 123 {
 124         static wchar_t s1[2], s2[2];
 125
 126         s1[0] = c1;
 127         s2[0] = c2;
 128         return (wcscoll(s1, s2));
 129 }
 130
 131 static char *
 132 stputs_quotes(const char *data, const char *syntax, char *p)
 133 {
 134         while (*data) {
 135                 CHECKSTRSPACE(2, p);
 136                 if (syntax[(int)*data] == CCTL)
 137                         USTPUTC(CTLESC, p);
 138                 USTPUTC(*data++, p);
 139         }
 140         return (p);
 141 }
 142 #define STPUTS_QUOTES(data, syntax, p) p = stputs_quotes((data), syntax, p)
 143
 144 /*
 145  * Perform expansions on an argument, placing the resulting list of arguments
 146  * in arglist.  Parameter expansion, command substitution and arithmetic
 147  * expansion are always performed; additional expansions can be requested
 148  * via flag (EXP_*).
 149  * The result is left in the stack string.
 150  * When arglist is NULL, perform here document expansion.
 151  *
 152  * Caution: this function uses global state and is not reentrant.
 153  * However, a new invocation after an interrupted invocation is safe
 154  * and will reset the global state for the new call.
 155  */
 156 void
 157 expandarg(union node *arg, struct arglist *arglist, int flag)
 158 {
 159         struct strlist *sp;
 160         char *p;
 161
 162         argbackq = arg->narg.backquote;
 163         STARTSTACKSTR(expdest);
 164         ifsfirst.next = NULL;
 165         ifslastp = NULL;
 166         argstr(arg->narg.text, flag);
 167         if (arglist == NULL) {
 168                 STACKSTRNUL(expdest);
 169                 return;                 /* here document expanded */
 170         }
 171         STPUTC('\0', expdest);
 172         p = grabstackstr(expdest);
 173         exparg.lastp = &exparg.list;
 174         /*
 175          * TODO - EXP_REDIR
 176          */
 177         if (flag & EXP_FULL) {
 178                 ifsbreakup(p, &exparg);
 179                 *exparg.lastp = NULL;
 180                 exparg.lastp = &exparg.list;
 181                 expandmeta(exparg.list, flag);
 182         } else {
 183                 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
 184                         rmescapes(p);
 185                 sp = (struct strlist *)stalloc(sizeof (struct strlist));
 186                 sp->text = p;
 187                 *exparg.lastp = sp;
 188                 exparg.lastp = &sp->next;
 189         }
 190         while (ifsfirst.next != NULL) {
 191                 struct ifsregion *ifsp;
 192                 INTOFF;
 193                 ifsp = ifsfirst.next->next;
 194                 ckfree(ifsfirst.next);
 195                 ifsfirst.next = ifsp;
 196                 INTON;
 197         }
 198         *exparg.lastp = NULL;
 199         if (exparg.list) {
 200                 *arglist->lastp = exparg.list;
 201                 arglist->lastp = exparg.lastp;
 202         }
 203 }
 204
 205
 206
 207 /*
 208  * Perform parameter expansion, command substitution and arithmetic
 209  * expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE.
 210  * Processing ends at a CTLENDVAR or CTLENDARI character as well as '\0'.
 211  * This is used to expand word in ${var+word} etc.
 212  * If EXP_FULL, EXP_CASE or EXP_REDIR are set, keep and/or generate CTLESC
 213  * characters to allow for further processing.
 214  * If EXP_FULL is set, also preserve CTLQUOTEMARK characters.
 215  */
 216 static char *
 217 argstr(char *p, int flag)
 218 {
 219         char c;
 220         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);  /* do CTLESC */
 221         int firsteq = 1;
 222         int split_lit;
 223         int lit_quoted;
 224
 225         split_lit = flag & EXP_SPLIT_LIT;
 226         lit_quoted = flag & EXP_LIT_QUOTED;
 227         flag &= ~(EXP_SPLIT_LIT | EXP_LIT_QUOTED);
 228         if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
 229                 p = exptilde(p, flag);
 230         for (;;) {
 231                 CHECKSTRSPACE(2, expdest);
 232                 switch (c = *p++) {
 233                 case '\0':
 234                         return (p - 1);
 235                 case CTLENDVAR:
 236                 case CTLENDARI:
 237                         return (p);
 238                 case CTLQUOTEMARK:
 239                         lit_quoted = 1;
 240                         /* "$@" syntax adherence hack */
 241                         if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
 242                                 break;
 243                         if ((flag & EXP_FULL) != 0)
 244                                 USTPUTC(c, expdest);
 245                         break;
 246                 case CTLQUOTEEND:
 247                         lit_quoted = 0;
 248                         break;
 249                 case CTLESC:
 250                         if (quotes)
 251                                 USTPUTC(c, expdest);
 252                         c = *p++;
 253                         USTPUTC(c, expdest);
 254                         if (split_lit && !lit_quoted)
 255                                 recordregion(expdest - stackblock() -
 256                                     (quotes ? 2 : 1),
 257                                     expdest - stackblock(), 0);
 258                         break;
 259                 case CTLVAR:
 260                         p = evalvar(p, flag);
 261                         break;
 262                 case CTLBACKQ:
 263                 case CTLBACKQ|CTLQUOTE:
 264                         expbackq(argbackq->n, c & CTLQUOTE, flag);
 265                         argbackq = argbackq->next;
 266                         break;
 267                 case CTLARI:
 268                         p = expari(p);
 269                         break;
 270                 case ':':
 271                 case '=':
 272                         /*
 273                          * sort of a hack - expand tildes in variable
 274                          * assignments (after the first '=' and after ':'s).
 275                          */
 276                         USTPUTC(c, expdest);
 277                         if (split_lit && !lit_quoted)
 278                                 recordregion(expdest - stackblock() - 1,
 279                                     expdest - stackblock(), 0);
 280                         if (flag & EXP_VARTILDE && *p == '~' &&
 281                             (c != '=' || firsteq)) {
 282                                 if (c == '=')
 283                                         firsteq = 0;
 284                                 p = exptilde(p, flag);
 285                         }
 286                         break;
 287                 default:
 288                         USTPUTC(c, expdest);
 289                         if (split_lit && !lit_quoted)
 290                                 recordregion(expdest - stackblock() - 1,
 291                                     expdest - stackblock(), 0);
 292                 }
 293         }
 294 }
 295
 296 /*
 297  * Perform tilde expansion, placing the result in the stack string and
 298  * returning the next position in the input string to process.
 299  */
 300 static char *
 301 exptilde(char *p, int flag)
 302 {
 303         char c, *startp = p;
 304         struct passwd *pw;
 305         char *home;
 306         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 307
 308         while ((c = *p) != '\0') {
 309                 switch(c) {
 310                 case CTLESC: /* This means CTL* are always considered quoted. */
 311                 case CTLVAR:
 312                 case CTLBACKQ:
 313                 case CTLBACKQ | CTLQUOTE:
 314                 case CTLARI:
 315                 case CTLENDARI:
 316                 case CTLQUOTEMARK:
 317                         return (startp);
 318                 case ':':
 319                         if (flag & EXP_VARTILDE)
 320                                 goto done;
 321                         break;
 322                 case '/':
 323                 case CTLENDVAR:
 324                         goto done;
 325                 }
 326                 p++;
 327         }
 328 done:
 329         *p = '\0';
 330         if (*(startp+1) == '\0') {
 331                 home = lookupvar("HOME");
 332         } else {
 333                 pw = getpwnam(startp+1);
 334                 home = pw != NULL ? pw->pw_dir : NULL;
 335         }
 336         *p = c;
 337         if (home == NULL || *home == '\0')
 338                 return (startp);
 339         if (quotes)
 340                 STPUTS_QUOTES(home, DQSYNTAX, expdest);
 341         else
 342                 STPUTS(home, expdest);
 343         return (p);
 344 }
 345
 346
 347 static void
 348 removerecordregions(int endoff)
 349 {
 350         if (ifslastp == NULL)
 351                 return;
 352
 353         if (ifsfirst.endoff > endoff) {
 354                 while (ifsfirst.next != NULL) {
 355                         struct ifsregion *ifsp;
 356                         INTOFF;
 357                         ifsp = ifsfirst.next->next;
 358                         ckfree(ifsfirst.next);
 359                         ifsfirst.next = ifsp;
 360                         INTON;
 361                 }
 362                 if (ifsfirst.begoff > endoff)
 363                         ifslastp = NULL;
 364                 else {
 365                         ifslastp = &ifsfirst;
 366                         ifsfirst.endoff = endoff;
 367                 }
 368                 return;
 369         }
 370
 371         ifslastp = &ifsfirst;
 372         while (ifslastp->next && ifslastp->next->begoff < endoff)
 373                 ifslastp=ifslastp->next;
 374         while (ifslastp->next != NULL) {
 375                 struct ifsregion *ifsp;
 376                 INTOFF;
 377                 ifsp = ifslastp->next->next;
 378                 ckfree(ifslastp->next);
 379                 ifslastp->next = ifsp;
 380                 INTON;
 381         }
 382         if (ifslastp->endoff > endoff)
 383                 ifslastp->endoff = endoff;
 384 }
 385
 386 /*
 387  * Expand arithmetic expression.
 388  * Note that flag is not required as digits never require CTLESC characters.
 389  */
 390 static char *
 391 expari(char *p)
 392 {
 393         char *q, *start;
 394         arith_t result;
 395         int begoff;
 396         int quoted;
 397         int adj;
 398
 399         quoted = *p++ == '"';
 400         begoff = expdest - stackblock();
 401         p = argstr(p, 0);
 402         removerecordregions(begoff);
 403         STPUTC('\0', expdest);
 404         start = stackblock() + begoff;
 405
 406         q = grabstackstr(expdest);
 407         result = arith(start);
 408         ungrabstackstr(q, expdest);
 409
 410         start = stackblock() + begoff;
 411         adj = start - expdest;
 412         STADJUST(adj, expdest);
 413
 414         CHECKSTRSPACE((int)(DIGITS(result) + 1), expdest);
 415         fmtstr(expdest, DIGITS(result), ARITH_FORMAT_STR, result);
 416         adj = strlen(expdest);
 417         STADJUST(adj, expdest);
 418         if (!quoted)
 419                 recordregion(begoff, expdest - stackblock(), 0);
 420         return p;
 421 }
 422
 423
 424 /*
 425  * Perform command substitution.
 426  */
 427 static void
 428 expbackq(union node *cmd, int quoted, int flag)
 429 {
 430         struct backcmd in;
 431         int i;
 432         char buf[128];
 433         char *p;
 434         char *dest = expdest;
 435         struct ifsregion saveifs, *savelastp;
 436         struct nodelist *saveargbackq;
 437         char lastc;
 438         int startloc = dest - stackblock();
 439         char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
 440         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 441         size_t nnl;
 442
 443         INTOFF;
 444         saveifs = ifsfirst;
 445         savelastp = ifslastp;
 446         saveargbackq = argbackq;
 447         p = grabstackstr(dest);
 448         evalbackcmd(cmd, &in);
 449         ungrabstackstr(p, dest);
 450         ifsfirst = saveifs;
 451         ifslastp = savelastp;
 452         argbackq = saveargbackq;
 453
 454         p = in.buf;
 455         lastc = '\0';
 456         nnl = 0;
 457         /* Don't copy trailing newlines */
 458         for (;;) {
 459                 if (--in.nleft < 0) {
 460                         if (in.fd < 0)
 461                                 break;
 462                         while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR);
 463                         TRACE(("expbackq: read returns %d\n", i));
 464                         if (i <= 0)
 465                                 break;
 466                         p = buf;
 467                         in.nleft = i - 1;
 468                 }
 469                 lastc = *p++;
 470                 if (lastc != '\0') {
 471                         if (lastc == '\n') {
 472                                 nnl++;
 473                         } else {
 474                                 CHECKSTRSPACE(nnl + 2, dest);
 475                                 while (nnl > 0) {
 476                                         nnl--;
 477                                         USTPUTC('\n', dest);
 478                                 }
 479                                 if (quotes && syntax[(int)lastc] == CCTL)
 480                                         USTPUTC(CTLESC, dest);
 481                                 USTPUTC(lastc, dest);
 482                         }
 483                 }
 484         }
 485
 486         if (in.fd >= 0)
 487                 close(in.fd);
 488         if (in.buf)
 489                 ckfree(in.buf);
 490         if (in.jp)
 491                 exitstatus = waitforjob(in.jp, (int *)NULL);
 492         if (quoted == 0)
 493                 recordregion(startloc, dest - stackblock(), 0);
 494         TRACE(("expbackq: size=%td: \"%.*s\"\n",
 495                 ((dest - stackblock()) - startloc),
 496                 (int)((dest - stackblock()) - startloc),
 497                 stackblock() + startloc));
 498         expdest = dest;
 499         INTON;
 500 }
 501
 502
 503
 504 static int
 505 subevalvar(char *p, char *str, int strloc, int subtype, int startloc,
 506   int varflags, int quotes)
 507 {
 508         char *startp;
 509         char *loc = NULL;
 510         char *q;
 511         int c = 0;
 512         struct nodelist *saveargbackq = argbackq;
 513         int amount;
 514
 515         argstr(p, (subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX ||
 516             subtype == VSTRIMRIGHT || subtype == VSTRIMRIGHTMAX ?
 517             EXP_CASE : 0) | EXP_TILDE);
 518         STACKSTRNUL(expdest);
 519         argbackq = saveargbackq;
 520         startp = stackblock() + startloc;
 521         if (str == NULL)
 522             str = stackblock() + strloc;
 523
 524         switch (subtype) {
 525         case VSASSIGN:
 526                 setvar(str, startp, 0);
 527                 amount = startp - expdest;
 528                 STADJUST(amount, expdest);
 529                 varflags &= ~VSNUL;
 530                 return 1;
 531
 532         case VSQUESTION:
 533                 if (*p != CTLENDVAR) {
 534                         outfmt(out2, "%s\n", startp);
 535                         error((char *)NULL);
 536                 }
 537                 error("%.*s: parameter %snot set", (int)(p - str - 1),
 538                       str, (varflags & VSNUL) ? "null or "
 539                                               : nullstr);
 540                 return 0;
 541
 542         case VSTRIMLEFT:
 543                 for (loc = startp; loc < str; loc++) {
 544                         c = *loc;
 545                         *loc = '\0';
 546                         if (patmatch(str, startp, quotes)) {
 547                                 *loc = c;
 548                                 goto recordleft;
 549                         }
 550                         *loc = c;
 551                         if (quotes && *loc == CTLESC)
 552                                 loc++;
 553                 }
 554                 return 0;
 555
 556         case VSTRIMLEFTMAX:
 557                 for (loc = str - 1; loc >= startp;) {
 558                         c = *loc;
 559                         *loc = '\0';
 560                         if (patmatch(str, startp, quotes)) {
 561                                 *loc = c;
 562                                 goto recordleft;
 563                         }
 564                         *loc = c;
 565                         loc--;
 566                         if (quotes && loc > startp && *(loc - 1) == CTLESC) {
 567                                 for (q = startp; q < loc; q++)
 568                                         if (*q == CTLESC)
 569                                                 q++;
 570                                 if (q > loc)
 571                                         loc--;
 572                         }
 573                 }
 574                 return 0;
 575
 576         case VSTRIMRIGHT:
 577                 for (loc = str - 1; loc >= startp;) {
 578                         if (patmatch(str, loc, quotes)) {
 579                                 amount = loc - expdest;
 580                                 STADJUST(amount, expdest);
 581                                 return 1;
 582                         }
 583                         loc--;
 584                         if (quotes && loc > startp && *(loc - 1) == CTLESC) {
 585                                 for (q = startp; q < loc; q++)
 586                                         if (*q == CTLESC)
 587                                                 q++;
 588                                 if (q > loc)
 589                                         loc--;
 590                         }
 591                 }
 592                 return 0;
 593
 594         case VSTRIMRIGHTMAX:
 595                 for (loc = startp; loc < str - 1; loc++) {
 596                         if (patmatch(str, loc, quotes)) {
 597                                 amount = loc - expdest;
 598                                 STADJUST(amount, expdest);
 599                                 return 1;
 600                         }
 601                         if (quotes && *loc == CTLESC)
 602                                 loc++;
 603                 }
 604                 return 0;
 605
 606
 607         default:
 608                 abort();
 609         }
 610
 611 recordleft:
 612         amount = ((str - 1) - (loc - startp)) - expdest;
 613         STADJUST(amount, expdest);
 614         while (loc != str - 1)
 615                 *startp++ = *loc++;
 616         return 1;
 617 }
 618
 619
 620 /*
 621  * Expand a variable, and return a pointer to the next character in the
 622  * input string.
 623  */
 624
 625 static char *
 626 evalvar(char *p, int flag)
 627 {
 628         int subtype;
 629         int varflags;
 630         char *var;
 631         const char *val;
 632         int patloc;
 633         int c;
 634         int set;
 635         int special;
 636         int startloc;
 637         int varlen;
 638         int varlenb;
 639         int easy;
 640         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 641
 642         varflags = (unsigned char)*p++;
 643         subtype = varflags & VSTYPE;
 644         var = p;
 645         special = 0;
 646         if (! is_name(*p))
 647                 special = 1;
 648         p = strchr(p, '=') + 1;
 649 again: /* jump here after setting a variable with ${var=text} */
 650         if (varflags & VSLINENO) {
 651                 set = 1;
 652                 special = 1;
 653                 val = NULL;
 654         } else if (special) {
 655                 set = varisset(var, varflags & VSNUL);
 656                 val = NULL;
 657         } else {
 658                 val = bltinlookup(var, 1);
 659                 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
 660                         val = NULL;
 661                         set = 0;
 662                 } else
 663                         set = 1;
 664         }
 665         varlen = 0;
 666         startloc = expdest - stackblock();
 667         if (!set && uflag && *var != '@' && *var != '*') {
 668                 switch (subtype) {
 669                 case VSNORMAL:
 670                 case VSTRIMLEFT:
 671                 case VSTRIMLEFTMAX:
 672                 case VSTRIMRIGHT:
 673                 case VSTRIMRIGHTMAX:
 674                 case VSLENGTH:
 675                         error("%.*s: parameter not set", (int)(p - var - 1),
 676                             var);
 677                 }
 678         }
 679         if (set && subtype != VSPLUS) {
 680                 /* insert the value of the variable */
 681                 if (special) {
 682                         if (varflags & VSLINENO)
 683                                 STPUTBIN(var, p - var - 1, expdest);
 684                         else
 685                                 varvalue(var, varflags & VSQUOTE, subtype, flag);
 686                         if (subtype == VSLENGTH) {
 687                                 varlenb = expdest - stackblock() - startloc;
 688                                 varlen = varlenb;
 689                                 if (localeisutf8) {
 690                                         val = stackblock() + startloc;
 691                                         for (;val != expdest; val++)
 692                                                 if ((*val & 0xC0) == 0x80)
 693                                                         varlen--;
 694                                 }
 695                                 STADJUST(-varlenb, expdest);
 696                         }
 697                 } else {
 698                         char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX
 699                                                                   : BASESYNTAX;
 700
 701                         if (subtype == VSLENGTH) {
 702                                 for (;*val; val++)
 703                                         if (!localeisutf8 ||
 704                                             (*val & 0xC0) != 0x80)
 705                                                 varlen++;
 706                         }
 707                         else {
 708                                 if (quotes)
 709                                         STPUTS_QUOTES(val, syntax, expdest);
 710                                 else
 711                                         STPUTS(val, expdest);
 712
 713                         }
 714                 }
 715         }
 716
 717         if (subtype == VSPLUS)
 718                 set = ! set;
 719
 720         easy = ((varflags & VSQUOTE) == 0 ||
 721                 (*var == '@' && shellparam.nparam != 1));
 722
 723
 724         switch (subtype) {
 725         case VSLENGTH:
 726                 expdest = cvtnum(varlen, expdest);
 727                 goto record;
 728
 729         case VSNORMAL:
 730                 if (!easy)
 731                         break;
 732 record:
 733                 recordregion(startloc, expdest - stackblock(),
 734                     varflags & VSQUOTE || (ifsset() && ifsval()[0] == '\0' &&
 735                     (*var == '@' || *var == '*')));
 736                 break;
 737
 738         case VSPLUS:
 739         case VSMINUS:
 740                 if (!set) {
 741                         argstr(p, flag | (flag & EXP_FULL ? EXP_SPLIT_LIT : 0) |
 742                             (varflags & VSQUOTE ? EXP_LIT_QUOTED : 0));
 743                         break;
 744                 }
 745                 if (easy)
 746                         goto record;
 747                 break;
 748
 749         case VSTRIMLEFT:
 750         case VSTRIMLEFTMAX:
 751         case VSTRIMRIGHT:
 752         case VSTRIMRIGHTMAX:
 753                 if (!set)
 754                         break;
 755                 /*
 756                  * Terminate the string and start recording the pattern
 757                  * right after it
 758                  */
 759                 STPUTC('\0', expdest);
 760                 patloc = expdest - stackblock();
 761                 if (subevalvar(p, NULL, patloc, subtype,
 762                     startloc, varflags, quotes) == 0) {
 763                         int amount = (expdest - stackblock() - patloc) + 1;
 764                         STADJUST(-amount, expdest);
 765                 }
 766                 /* Remove any recorded regions beyond start of variable */
 767                 removerecordregions(startloc);
 768                 goto record;
 769
 770         case VSASSIGN:
 771         case VSQUESTION:
 772                 if (!set) {
 773                         if (subevalvar(p, var, 0, subtype, startloc, varflags,
 774                             quotes)) {
 775                                 varflags &= ~VSNUL;
 776                                 /*
 777                                  * Remove any recorded regions beyond
 778                                  * start of variable
 779                                  */
 780                                 removerecordregions(startloc);
 781                                 goto again;
 782                         }
 783                         break;
 784                 }
 785                 if (easy)
 786                         goto record;
 787                 break;
 788
 789         case VSERROR:
 790                 c = p - var - 1;
 791                 error("${%.*s%s}: Bad substitution", c, var,
 792                     (c > 0 && *p != CTLENDVAR) ? "..." : "");
 793
 794         default:
 795                 abort();
 796         }
 797
 798         if (subtype != VSNORMAL) {      /* skip to end of alternative */
 799                 int nesting = 1;
 800                 for (;;) {
 801                         if ((c = *p++) == CTLESC)
 802                                 p++;
 803                         else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
 804                                 if (set)
 805                                         argbackq = argbackq->next;
 806                         } else if (c == CTLVAR) {
 807                                 if ((*p++ & VSTYPE) != VSNORMAL)
 808                                         nesting++;
 809                         } else if (c == CTLENDVAR) {
 810                                 if (--nesting == 0)
 811                                         break;
 812                         }
 813                 }
 814         }
 815         return p;
 816 }
 817
 818
 819
 820 /*
 821  * Test whether a specialized variable is set.
 822  */
 823
 824 static int
 825 varisset(const char *name, int nulok)
 826 {
 827
 828         if (*name == '!')
 829                 return backgndpidset();
 830         else if (*name == '@' || *name == '*') {
 831                 if (*shellparam.p == NULL)
 832                         return 0;
 833
 834                 if (nulok) {
 835                         char **av;
 836
 837                         for (av = shellparam.p; *av; av++)
 838                                 if (**av != '\0')
 839                                         return 1;
 840                         return 0;
 841                 }
 842         } else if (is_digit(*name)) {
 843                 char *ap;
 844                 long num;
 845
 846                 errno = 0;
 847                 num = strtol(name, NULL, 10);
 848                 if (errno != 0 || num > shellparam.nparam)
 849                         return 0;
 850
 851                 if (num == 0)
 852                         ap = arg0;
 853                 else
 854                         ap = shellparam.p[num - 1];
 855
 856                 if (nulok && (ap == NULL || *ap == '\0'))
 857                         return 0;
 858         }
 859         return 1;
 860 }
 861
 862 static void
 863 strtodest(const char *p, int flag, int subtype, int quoted)
 864 {
 865         if (flag & (EXP_FULL | EXP_CASE | EXP_REDIR) && subtype != VSLENGTH)
 866                 STPUTS_QUOTES(p, quoted ? DQSYNTAX : BASESYNTAX, expdest);
 867         else
 868                 STPUTS(p, expdest);
 869 }
 870
 871 /*
 872  * Add the value of a specialized variable to the stack string.
 873  */
 874
 875 static void
 876 varvalue(const char *name, int quoted, int subtype, int flag)
 877 {
 878         int num;
 879         char *p;
 880         int i;
 881         char sep[2];
 882         char **ap;
 883
 884         switch (*name) {
 885         case '$':
 886                 num = rootpid;
 887                 break;
 888         case '?':
 889                 num = oexitstatus;
 890                 break;
 891         case '#':
 892                 num = shellparam.nparam;
 893                 break;
 894         case '!':
 895                 num = backgndpidval();
 896                 break;
 897         case '-':
 898                 for (i = 0 ; i < NOPTS ; i++) {
 899                         if (optlist[i].val)
 900                                 STPUTC(optlist[i].letter, expdest);
 901                 }
 902                 return;
 903         case '@':
 904                 if (flag & EXP_FULL && quoted) {
 905                         for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 906                                 strtodest(p, flag, subtype, quoted);
 907                                 if (*ap)
 908                                         STPUTC('\0', expdest);
 909                         }
 910                         return;
 911                 }
 912                 /* FALLTHROUGH */
 913         case '*':
 914                 if (ifsset())
 915                         sep[0] = ifsval()[0];
 916                 else
 917                         sep[0] = ' ';
 918                 sep[1] = '\0';
 919                 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 920                         strtodest(p, flag, subtype, quoted);
 921                         if (!*ap)
 922                                 break;
 923                         if (sep[0])
 924                                 strtodest(sep, flag, subtype, quoted);
 925                         else if (flag & EXP_FULL && !quoted && **ap != '\0')
 926                                 STPUTC('\0', expdest);
 927                 }
 928                 return;
 929         default:
 930                 if (is_digit(*name)) {
 931                         num = atoi(name);
 932                         if (num == 0)
 933                                 p = arg0;
 934                         else if (num > 0 && num <= shellparam.nparam)
 935                                 p = shellparam.p[num - 1];
 936                         else
 937                                 return;
 938                         strtodest(p, flag, subtype, quoted);
 939                 }
 940                 return;
 941         }
 942         expdest = cvtnum(num, expdest);
 943 }
 944
 945
 946
 947 /*
 948  * Record the fact that we have to scan this region of the
 949  * string for IFS characters.
 950  */
 951
 952 static void
 953 recordregion(int start, int end, int inquotes)
 954 {
 955         struct ifsregion *ifsp;
 956
 957         INTOFF;
 958         if (ifslastp == NULL) {
 959                 ifsp = &ifsfirst;
 960         } else {
 961                 if (ifslastp->endoff == start
 962                     && ifslastp->inquotes == inquotes) {
 963                         /* extend previous area */
 964                         ifslastp->endoff = end;
 965                         INTON;
 966                         return;
 967                 }
 968                 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
 969                 ifslastp->next = ifsp;
 970         }
 971         ifslastp = ifsp;
 972         ifslastp->next = NULL;
 973         ifslastp->begoff = start;
 974         ifslastp->endoff = end;
 975         ifslastp->inquotes = inquotes;
 976         INTON;
 977 }
 978
 979
 980
 981 /*
 982  * Break the argument string into pieces based upon IFS and add the
 983  * strings to the argument list.  The regions of the string to be
 984  * searched for IFS characters have been stored by recordregion.
 985  * CTLESC characters are preserved but have little effect in this pass
 986  * other than escaping CTL* characters.  In particular, they do not escape
 987  * IFS characters: that should be done with the ifsregion mechanism.
 988  * CTLQUOTEMARK characters are used to preserve empty quoted strings.
 989  * This pass treats them as a regular character, making the string non-empty.
 990  * Later, they are removed along with the other CTL* characters.
 991  */
 992 static void
 993 ifsbreakup(char *string, struct arglist *arglist)
 994 {
 995         struct ifsregion *ifsp;
 996         struct strlist *sp;
 997         char *start;
 998         char *p;
 999         char *q;
1000         const char *ifs;
1001         const char *ifsspc;
1002         int had_param_ch = 0;
1003
1004         start = string;
1005
1006         if (ifslastp == NULL) {
1007                 /* Return entire argument, IFS doesn't apply to any of it */
1008                 sp = (struct strlist *)stalloc(sizeof *sp);
1009                 sp->text = start;
1010                 *arglist->lastp = sp;
1011                 arglist->lastp = &sp->next;
1012                 return;
1013         }
1014
1015         ifs = ifsset() ? ifsval() : " \t\n";
1016
1017         for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) {
1018                 p = string + ifsp->begoff;
1019                 while (p < string + ifsp->endoff) {
1020                         q = p;
1021                         if (*p == CTLESC)
1022                                 p++;
1023                         if (ifsp->inquotes) {
1024                                 /* Only NULs (should be from "$@") end args */
1025                                 had_param_ch = 1;
1026                                 if (*p != 0) {
1027                                         p++;
1028                                         continue;
1029                                 }
1030                                 ifsspc = NULL;
1031                         } else {
1032                                 if (!strchr(ifs, *p)) {
1033                                         had_param_ch = 1;
1034                                         p++;
1035                                         continue;
1036                                 }
1037                                 ifsspc = strchr(" \t\n", *p);
1038
1039                                 /* Ignore IFS whitespace at start */
1040                                 if (q == start && ifsspc != NULL) {
1041                                         p++;
1042                                         start = p;
1043                                         continue;
1044                                 }
1045                                 had_param_ch = 0;
1046                         }
1047
1048                         /* Save this argument... */
1049                         *q = '\0';
1050                         sp = (struct strlist *)stalloc(sizeof *sp);
1051                         sp->text = start;
1052                         *arglist->lastp = sp;
1053                         arglist->lastp = &sp->next;
1054                         p++;
1055
1056                         if (ifsspc != NULL) {
1057                                 /* Ignore further trailing IFS whitespace */
1058                                 for (; p < string + ifsp->endoff; p++) {
1059                                         q = p;
1060                                         if (*p == CTLESC)
1061                                                 p++;
1062                                         if (strchr(ifs, *p) == NULL) {
1063                                                 p = q;
1064                                                 break;
1065                                         }
1066                                         if (strchr(" \t\n", *p) == NULL) {
1067                                                 p++;
1068                                                 break;
1069                                         }
1070                                 }
1071                         }
1072                         start = p;
1073                 }
1074         }
1075
1076         /*
1077          * Save anything left as an argument.
1078          * Traditionally we have treated 'IFS=':'; set -- x$IFS' as
1079          * generating 2 arguments, the second of which is empty.
1080          * Some recent clarification of the Posix spec say that it
1081          * should only generate one....
1082          */
1083         if (had_param_ch || *start != 0) {
1084                 sp = (struct strlist *)stalloc(sizeof *sp);
1085                 sp->text = start;
1086                 *arglist->lastp = sp;
1087                 arglist->lastp = &sp->next;
1088         }
1089 }
1090
1091
1092 static char expdir[PATH_MAX];
1093 #define expdir_end (expdir + sizeof(expdir))
1094
1095 /*
1096  * Perform pathname generation and remove control characters.
1097  * At this point, the only control characters should be CTLESC and CTLQUOTEMARK.
1098  * The results are stored in the list exparg.
1099  */
1100 static void
1101 expandmeta(struct strlist *str, int flag __unused)
1102 {
1103         char *p;
1104         struct strlist **savelastp;
1105         struct strlist *sp;
1106         char c;
1107         /* TODO - EXP_REDIR */
1108
1109         while (str) {
1110                 savelastp = exparg.lastp;
1111                 if (!fflag) {
1112                         p = str->text;
1113                         for (; (c = *p) != '\0'; p++) {
1114                                 /* fast check for meta chars */
1115                                 if (c == '*' || c == '?' || c == '[') {
1116                                         INTOFF;
1117                                         expmeta(expdir, str->text);
1118                                         INTON;
1119                                         break;
1120                                 }
1121                         }
1122                 }
1123                 if (exparg.lastp == savelastp) {
1124                         /*
1125                          * no matches
1126                          */
1127                         *exparg.lastp = str;
1128                         rmescapes(str->text);
1129                         exparg.lastp = &str->next;
1130                 } else {
1131                         *exparg.lastp = NULL;
1132                         *savelastp = sp = expsort(*savelastp);
1133                         while (sp->next != NULL)
1134                                 sp = sp->next;
1135                         exparg.lastp = &sp->next;
1136                 }
1137                 str = str->next;
1138         }
1139 }
1140
1141
1142 /*
1143  * Do metacharacter (i.e. *, ?, [...]) expansion.
1144  */
1145
1146 static void
1147 expmeta(char *enddir, char *name)
1148 {
1149         const char *p;
1150         const char *q;
1151         const char *start;
1152         char *endname;
1153         int metaflag;
1154         struct stat statb;
1155         DIR *dirp;
1156         struct dirent *dp;
1157         int atend;
1158         int matchdot;
1159         int esc;
1160         int namlen;
1161
1162         metaflag = 0;
1163         start = name;
1164         for (p = name; esc = 0, *p; p += esc + 1) {
1165                 if (*p == '*' || *p == '?')
1166                         metaflag = 1;
1167                 else if (*p == '[') {
1168                         q = p + 1;
1169                         if (*q == '!' || *q == '^')
1170                                 q++;
1171                         for (;;) {
1172                                 while (*q == CTLQUOTEMARK)
1173                                         q++;
1174                                 if (*q == CTLESC)
1175                                         q++;
1176                                 if (*q == '/' || *q == '\0')
1177                                         break;
1178                                 if (*++q == ']') {
1179                                         metaflag = 1;
1180                                         break;
1181                                 }
1182                         }
1183                 } else if (*p == '\0')
1184                         break;
1185                 else if (*p == CTLQUOTEMARK)
1186                         continue;
1187                 else {
1188                         if (*p == CTLESC)
1189                                 esc++;
1190                         if (p[esc] == '/') {
1191                                 if (metaflag)
1192                                         break;
1193                                 start = p + esc + 1;
1194                         }
1195                 }
1196         }
1197         if (metaflag == 0) {    /* we've reached the end of the file name */
1198                 if (enddir != expdir)
1199                         metaflag++;
1200                 for (p = name ; ; p++) {
1201                         if (*p == CTLQUOTEMARK)
1202                                 continue;
1203                         if (*p == CTLESC)
1204                                 p++;
1205                         *enddir++ = *p;
1206                         if (*p == '\0')
1207                                 break;
1208                         if (enddir == expdir_end)
1209                                 return;
1210                 }
1211                 if (metaflag == 0 || lstat(expdir, &statb) >= 0)
1212                         addfname(expdir);
1213                 return;
1214         }
1215         endname = name + (p - name);
1216         if (start != name) {
1217                 p = name;
1218                 while (p < start) {
1219                         while (*p == CTLQUOTEMARK)
1220                                 p++;
1221                         if (*p == CTLESC)
1222                                 p++;
1223                         *enddir++ = *p++;
1224                         if (enddir == expdir_end)
1225                                 return;
1226                 }
1227         }
1228         if (enddir == expdir) {
1229                 p = ".";
1230         } else if (enddir == expdir + 1 && *expdir == '/') {
1231                 p = "/";
1232         } else {
1233                 p = expdir;
1234                 enddir[-1] = '\0';
1235         }
1236         if ((dirp = opendir(p)) == NULL)
1237                 return;
1238         if (enddir != expdir)
1239                 enddir[-1] = '/';
1240         if (*endname == 0) {
1241                 atend = 1;
1242         } else {
1243                 atend = 0;
1244                 *endname = '\0';
1245                 endname += esc + 1;
1246         }
1247         matchdot = 0;
1248         p = start;
1249         while (*p == CTLQUOTEMARK)
1250                 p++;
1251         if (*p == CTLESC)
1252                 p++;
1253         if (*p == '.')
1254                 matchdot++;
1255         while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1256                 if (dp->d_name[0] == '.' && ! matchdot)
1257                         continue;
1258                 if (patmatch(start, dp->d_name, 0)) {
1259                         namlen = dp->d_namlen;
1260                         if (enddir + namlen + 1 > expdir_end)
1261                                 continue;
1262                         memcpy(enddir, dp->d_name, namlen + 1);
1263                         if (atend)
1264                                 addfname(expdir);
1265                         else {
1266                                 if (dp->d_type != DT_UNKNOWN &&
1267                                     dp->d_type != DT_DIR &&
1268                                     dp->d_type != DT_LNK)
1269                                         continue;
1270                                 if (enddir + namlen + 2 > expdir_end)
1271                                         continue;
1272                                 enddir[namlen] = '/';
1273                                 enddir[namlen + 1] = '\0';
1274                                 expmeta(enddir + namlen + 1, endname);
1275                         }
1276                 }
1277         }
1278         closedir(dirp);
1279         if (! atend)
1280                 endname[-esc - 1] = esc ? CTLESC : '/';
1281 }
1282
1283
1284 /*
1285  * Add a file name to the list.
1286  */
1287
1288 static void
1289 addfname(char *name)
1290 {
1291         char *p;
1292         struct strlist *sp;
1293         size_t len;
1294
1295         len = strlen(name);
1296         p = stalloc(len + 1);
1297         memcpy(p, name, len + 1);
1298         sp = (struct strlist *)stalloc(sizeof *sp);
1299         sp->text = p;
1300         *exparg.lastp = sp;
1301         exparg.lastp = &sp->next;
1302 }
1303
1304
1305 /*
1306  * Sort the results of file name expansion.  It calculates the number of
1307  * strings to sort and then calls msort (short for merge sort) to do the
1308  * work.
1309  */
1310
1311 static struct strlist *
1312 expsort(struct strlist *str)
1313 {
1314         int len;
1315         struct strlist *sp;
1316
1317         len = 0;
1318         for (sp = str ; sp ; sp = sp->next)
1319                 len++;
1320         return msort(str, len);
1321 }
1322
1323
1324 static struct strlist *
1325 msort(struct strlist *list, int len)
1326 {
1327         struct strlist *p, *q = NULL;
1328         struct strlist **lpp;
1329         int half;
1330         int n;
1331
1332         if (len <= 1)
1333                 return list;
1334         half = len >> 1;
1335         p = list;
1336         for (n = half ; --n >= 0 ; ) {
1337                 q = p;
1338                 p = p->next;
1339         }
1340         q->next = NULL;                 /* terminate first half of list */
1341         q = msort(list, half);          /* sort first half of list */
1342         p = msort(p, len - half);               /* sort second half */
1343         lpp = &list;
1344         for (;;) {
1345                 if (strcmp(p->text, q->text) < 0) {
1346                         *lpp = p;
1347                         lpp = &p->next;
1348                         if ((p = *lpp) == NULL) {
1349                                 *lpp = q;
1350                                 break;
1351                         }
1352                 } else {
1353                         *lpp = q;
1354                         lpp = &q->next;
1355                         if ((q = *lpp) == NULL) {
1356                                 *lpp = p;
1357                                 break;
1358                         }
1359                 }
1360         }
1361         return list;
1362 }
1363
1364
1365
1366 static wchar_t
1367 get_wc(const char **p)
1368 {
1369         wchar_t c;
1370         int chrlen;
1371
1372         chrlen = mbtowc(&c, *p, 4);
1373         if (chrlen == 0)
1374                 return 0;
1375         else if (chrlen == -1)
1376                 c = 0;
1377         else
1378                 *p += chrlen;
1379         return c;
1380 }
1381
1382
1383 /*
1384  * See if a character matches a character class, starting at the first colon
1385  * of "[:class:]".
1386  * If a valid character class is recognized, a pointer to the next character
1387  * after the final closing bracket is stored into *end, otherwise a null
1388  * pointer is stored into *end.
1389  */
1390 static int
1391 match_charclass(const char *p, wchar_t chr, const char **end)
1392 {
1393         char name[20];
1394         const char *nameend;
1395         wctype_t cclass;
1396
1397         *end = NULL;
1398         p++;
1399         nameend = strstr(p, ":]");
1400         if (nameend == NULL || (size_t)(nameend - p) >= sizeof(name) ||
1401             nameend == p)
1402                 return 0;
1403         memcpy(name, p, nameend - p);
1404         name[nameend - p] = '\0';
1405         *end = nameend + 2;
1406         cclass = wctype(name);
1407         /* An unknown class matches nothing but is valid nevertheless. */
1408         if (cclass == 0)
1409                 return 0;
1410         return iswctype(chr, cclass);
1411 }
1412
1413
1414 /*
1415  * Returns true if the pattern matches the string.
1416  */
1417
1418 static int
1419 patmatch(const char *pattern, const char *string, int squoted)
1420 {
1421         const char *p, *q, *end;
1422         const char *bt_p, *bt_q;
1423         char c;
1424         wchar_t wc, wc2;
1425
1426         p = pattern;
1427         q = string;
1428         bt_p = NULL;
1429         bt_q = NULL;
1430         for (;;) {
1431                 switch (c = *p++) {
1432                 case '\0':
1433                         if (*q != '\0')
1434                                 goto backtrack;
1435                         return 1;
1436                 case CTLESC:
1437                         if (squoted && *q == CTLESC)
1438                                 q++;
1439                         if (*q++ != *p++)
1440                                 goto backtrack;
1441                         break;
1442                 case CTLQUOTEMARK:
1443                         continue;
1444                 case '?':
1445                         if (squoted && *q == CTLESC)
1446                                 q++;
1447                         if (*q == '\0')
1448                                 return 0;
1449                         if (localeisutf8) {
1450                                 wc = get_wc(&q);
1451                                 /*
1452                                  * A '?' does not match invalid UTF-8 but a
1453                                  * '*' does, so backtrack.
1454                                  */
1455                                 if (wc == 0)
1456                                         goto backtrack;
1457                         } else
1458                                 wc = (unsigned char)*q++;
1459                         break;
1460                 case '*':
1461                         c = *p;
1462                         while (c == CTLQUOTEMARK || c == '*')
1463                                 c = *++p;
1464                         /*
1465                          * If the pattern ends here, we know the string
1466                          * matches without needing to look at the rest of it.
1467                          */
1468                         if (c == '\0')
1469                                 return 1;
1470                         /*
1471                          * First try the shortest match for the '*' that
1472                          * could work. We can forget any earlier '*' since
1473                          * there is no way having it match more characters
1474                          * can help us, given that we are already here.
1475                          */
1476                         bt_p = p;
1477                         bt_q = q;
1478                         break;
1479                 case '[': {
1480                         const char *endp;
1481                         int invert, found;
1482                         wchar_t chr;
1483
1484                         endp = p;
1485                         if (*endp == '!' || *endp == '^')
1486                                 endp++;
1487                         for (;;) {
1488                                 while (*endp == CTLQUOTEMARK)
1489                                         endp++;
1490                                 if (*endp == 0)
1491                                         goto dft;               /* no matching ] */
1492                                 if (*endp == CTLESC)
1493                                         endp++;
1494                                 if (*++endp == ']')
1495                                         break;
1496                         }
1497                         invert = 0;
1498                         if (*p == '!' || *p == '^') {
1499                                 invert++;
1500                                 p++;
1501                         }
1502                         found = 0;
1503                         if (squoted && *q == CTLESC)
1504                                 q++;
1505                         if (*q == '\0')
1506                                 return 0;
1507                         if (localeisutf8) {
1508                                 chr = get_wc(&q);
1509                                 if (chr == 0)
1510                                         goto backtrack;
1511                         } else
1512                                 chr = (unsigned char)*q++;
1513                         c = *p++;
1514                         do {
1515                                 if (c == CTLQUOTEMARK)
1516                                         continue;
1517                                 if (c == '[' && *p == ':') {
1518                                         found |= match_charclass(p, chr, &end);
1519                                         if (end != NULL)
1520                                                 p = end;
1521                                 }
1522                                 if (c == CTLESC)
1523                                         c = *p++;
1524                                 if (localeisutf8 && c & 0x80) {
1525                                         p--;
1526                                         wc = get_wc(&p);
1527                                         if (wc == 0) /* bad utf-8 */
1528                                                 return 0;
1529                                 } else
1530                                         wc = (unsigned char)c;
1531                                 if (*p == '-' && p[1] != ']') {
1532                                         p++;
1533                                         while (*p == CTLQUOTEMARK)
1534                                                 p++;
1535                                         if (*p == CTLESC)
1536                                                 p++;
1537                                         if (localeisutf8) {
1538                                                 wc2 = get_wc(&p);
1539                                                 if (wc2 == 0) /* bad utf-8 */
1540                                                         return 0;
1541                                         } else
1542                                                 wc2 = (unsigned char)*p++;
1543                                         if (   collate_range_cmp(chr, wc) >= 0
1544                                             && collate_range_cmp(chr, wc2) <= 0
1545                                            )
1546                                                 found = 1;
1547                                 } else {
1548                                         if (chr == wc)
1549                                                 found = 1;
1550                                 }
1551                         } while ((c = *p++) != ']');
1552                         if (found == invert)
1553                                 goto backtrack;
1554                         break;
1555                 }
1556 dft:            default:
1557                         if (squoted && *q == CTLESC)
1558                                 q++;
1559                         if (*q == '\0')
1560                                 return 0;
1561                         if (*q++ == c)
1562                                 break;
1563 backtrack:
1564                         /*
1565                          * If we have a mismatch (other than hitting the end
1566                          * of the string), go back to the last '*' seen and
1567                          * have it match one additional character.
1568                          */
1569                         if (bt_p == NULL)
1570                                 return 0;
1571                         if (squoted && *bt_q == CTLESC)
1572                                 bt_q++;
1573                         if (*bt_q == '\0')
1574                                 return 0;
1575                         bt_q++;
1576                         p = bt_p;
1577                         q = bt_q;
1578                         break;
1579                 }
1580         }
1581 }
1582
1583
1584
1585 /*
1586  * Remove any CTLESC and CTLQUOTEMARK characters from a string.
1587  */
1588
1589 void
1590 rmescapes(char *str)
1591 {
1592         char *p, *q;
1593
1594         p = str;
1595         while (*p != CTLESC && *p != CTLQUOTEMARK && *p != CTLQUOTEEND) {
1596                 if (*p++ == '\0')
1597                         return;
1598         }
1599         q = p;
1600         while (*p) {
1601                 if (*p == CTLQUOTEMARK || *p == CTLQUOTEEND) {
1602                         p++;
1603                         continue;
1604                 }
1605                 if (*p == CTLESC)
1606                         p++;
1607                 *q++ = *p++;
1608         }
1609         *q = '\0';
1610 }
1611
1612
1613
1614 /*
1615  * See if a pattern matches in a case statement.
1616  */
1617
1618 int
1619 casematch(union node *pattern, const char *val)
1620 {
1621         struct stackmark smark;
1622         int result;
1623         char *p;
1624
1625         setstackmark(&smark);
1626         argbackq = pattern->narg.backquote;
1627         STARTSTACKSTR(expdest);
1628         ifslastp = NULL;
1629         argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
1630         STPUTC('\0', expdest);
1631         p = grabstackstr(expdest);
1632         result = patmatch(p, val, 0);
1633         popstackmark(&smark);
1634         return result;
1635 }
1636
1637 /*
1638  * Our own itoa().
1639  */
1640
1641 static char *
1642 cvtnum(int num, char *buf)
1643 {
1644         char temp[32];
1645         int neg = num < 0;
1646         char *p = temp + 31;
1647
1648         temp[31] = '\0';
1649
1650         do {
1651                 *--p = num % 10 + '0';
1652         } while ((num /= 10) != 0);
1653
1654         if (neg)
1655                 *--p = '-';
1656
1657         STPUTS(p, buf);
1658         return buf;
1659 }
1660
1661 /*
1662  * Do most of the work for wordexp(3).
1663  */
1664
1665 int
1666 wordexpcmd(int argc, char **argv)
1667 {
1668         size_t len;
1669         int i;
1670
1671         out1fmt("%08x", argc - 1);
1672         for (i = 1, len = 0; i < argc; i++)
1673                 len += strlen(argv[i]);
1674         out1fmt("%08x", (int)len);
1675         for (i = 1; i < argc; i++)
1676                 outbin(argv[i], strlen(argv[i]) + 1, out1);
1677         return (0);
1678 }