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         if (flag & EXP_FULL) {
 175                 ifsbreakup(p, &exparg);
 176                 *exparg.lastp = NULL;
 177                 exparg.lastp = &exparg.list;
 178                 expandmeta(exparg.list, flag);
 179         } else {
 180                 sp = (struct strlist *)stalloc(sizeof (struct strlist));
 181                 sp->text = p;
 182                 *exparg.lastp = sp;
 183                 exparg.lastp = &sp->next;
 184         }
 185         while (ifsfirst.next != NULL) {
 186                 struct ifsregion *ifsp;
 187                 INTOFF;
 188                 ifsp = ifsfirst.next->next;
 189                 ckfree(ifsfirst.next);
 190                 ifsfirst.next = ifsp;
 191                 INTON;
 192         }
 193         *exparg.lastp = NULL;
 194         if (exparg.list) {
 195                 *arglist->lastp = exparg.list;
 196                 arglist->lastp = exparg.lastp;
 197         }
 198 }
 199
 200
 201
 202 /*
 203  * Perform parameter expansion, command substitution and arithmetic
 204  * expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE.
 205  * Processing ends at a CTLENDVAR or CTLENDARI character as well as '\0'.
 206  * This is used to expand word in ${var+word} etc.
 207  * If EXP_FULL or EXP_CASE are set, keep and/or generate CTLESC
 208  * characters to allow for further processing.
 209  * If EXP_FULL is set, also preserve CTLQUOTEMARK characters.
 210  */
 211 static char *
 212 argstr(char *p, int flag)
 213 {
 214         char c;
 215         int quotes = flag & (EXP_FULL | EXP_CASE);      /* do CTLESC */
 216         int firsteq = 1;
 217         int split_lit;
 218         int lit_quoted;
 219
 220         split_lit = flag & EXP_SPLIT_LIT;
 221         lit_quoted = flag & EXP_LIT_QUOTED;
 222         flag &= ~(EXP_SPLIT_LIT | EXP_LIT_QUOTED);
 223         if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
 224                 p = exptilde(p, flag);
 225         for (;;) {
 226                 CHECKSTRSPACE(2, expdest);
 227                 switch (c = *p++) {
 228                 case '\0':
 229                         return (p - 1);
 230                 case CTLENDVAR:
 231                 case CTLENDARI:
 232                         return (p);
 233                 case CTLQUOTEMARK:
 234                         lit_quoted = 1;
 235                         /* "$@" syntax adherence hack */
 236                         if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
 237                                 break;
 238                         if ((flag & EXP_FULL) != 0)
 239                                 USTPUTC(c, expdest);
 240                         break;
 241                 case CTLQUOTEEND:
 242                         lit_quoted = 0;
 243                         break;
 244                 case CTLESC:
 245                         if (quotes)
 246                                 USTPUTC(c, expdest);
 247                         c = *p++;
 248                         USTPUTC(c, expdest);
 249                         if (split_lit && !lit_quoted)
 250                                 recordregion(expdest - stackblock() -
 251                                     (quotes ? 2 : 1),
 252                                     expdest - stackblock(), 0);
 253                         break;
 254                 case CTLVAR:
 255                         p = evalvar(p, flag);
 256                         break;
 257                 case CTLBACKQ:
 258                 case CTLBACKQ|CTLQUOTE:
 259                         expbackq(argbackq->n, c & CTLQUOTE, flag);
 260                         argbackq = argbackq->next;
 261                         break;
 262                 case CTLARI:
 263                         p = expari(p);
 264                         break;
 265                 case ':':
 266                 case '=':
 267                         /*
 268                          * sort of a hack - expand tildes in variable
 269                          * assignments (after the first '=' and after ':'s).
 270                          */
 271                         USTPUTC(c, expdest);
 272                         if (split_lit && !lit_quoted)
 273                                 recordregion(expdest - stackblock() - 1,
 274                                     expdest - stackblock(), 0);
 275                         if (flag & EXP_VARTILDE && *p == '~' &&
 276                             (c != '=' || firsteq)) {
 277                                 if (c == '=')
 278                                         firsteq = 0;
 279                                 p = exptilde(p, flag);
 280                         }
 281                         break;
 282                 default:
 283                         USTPUTC(c, expdest);
 284                         if (split_lit && !lit_quoted)
 285                                 recordregion(expdest - stackblock() - 1,
 286                                     expdest - stackblock(), 0);
 287                 }
 288         }
 289 }
 290
 291 /*
 292  * Perform tilde expansion, placing the result in the stack string and
 293  * returning the next position in the input string to process.
 294  */
 295 static char *
 296 exptilde(char *p, int flag)
 297 {
 298         char c, *startp = p;
 299         struct passwd *pw;
 300         char *home;
 301         int quotes = flag & (EXP_FULL | EXP_CASE);
 302
 303         while ((c = *p) != '\0') {
 304                 switch(c) {
 305                 case CTLESC: /* This means CTL* are always considered quoted. */
 306                 case CTLVAR:
 307                 case CTLBACKQ:
 308                 case CTLBACKQ | CTLQUOTE:
 309                 case CTLARI:
 310                 case CTLENDARI:
 311                 case CTLQUOTEMARK:
 312                         return (startp);
 313                 case ':':
 314                         if (flag & EXP_VARTILDE)
 315                                 goto done;
 316                         break;
 317                 case '/':
 318                 case CTLENDVAR:
 319                         goto done;
 320                 }
 321                 p++;
 322         }
 323 done:
 324         *p = '\0';
 325         if (*(startp+1) == '\0') {
 326                 if ((home = lookupvar("HOME")) == NULL)
 327                         goto lose;
 328         } else {
 329                 if ((pw = getpwnam(startp+1)) == NULL)
 330                         goto lose;
 331                 home = pw->pw_dir;
 332         }
 333         if (*home == '\0')
 334                 goto lose;
 335         *p = c;
 336         if (quotes)
 337                 STPUTS_QUOTES(home, DQSYNTAX, expdest);
 338         else
 339                 STPUTS(home, expdest);
 340         return (p);
 341 lose:
 342         *p = c;
 343         return (startp);
 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);
 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);
 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) && 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;
 882         char **ap;
 883
 884         switch (*name) {
 885         case '$':
 886                 num = rootpid;
 887                 goto numvar;
 888         case '?':
 889                 num = oexitstatus;
 890                 goto numvar;
 891         case '#':
 892                 num = shellparam.nparam;
 893                 goto numvar;
 894         case '!':
 895                 num = backgndpidval();
 896 numvar:
 897                 expdest = cvtnum(num, expdest);
 898                 break;
 899         case '-':
 900                 for (i = 0 ; i < NOPTS ; i++) {
 901                         if (optlist[i].val)
 902                                 STPUTC(optlist[i].letter, expdest);
 903                 }
 904                 break;
 905         case '@':
 906                 if (flag & EXP_FULL && quoted) {
 907                         for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 908                                 strtodest(p, flag, subtype, quoted);
 909                                 if (*ap)
 910                                         STPUTC('\0', expdest);
 911                         }
 912                         break;
 913                 }
 914                 /* FALLTHROUGH */
 915         case '*':
 916                 if (ifsset())
 917                         sep = ifsval()[0];
 918                 else
 919                         sep = ' ';
 920                 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 921                         strtodest(p, flag, subtype, quoted);
 922                         if (!*ap)
 923                                 break;
 924                         if (sep || (flag & EXP_FULL && !quoted && **ap != '\0'))
 925                                 STPUTC(sep, expdest);
 926                 }
 927                 break;
 928         case '0':
 929                 p = arg0;
 930                 strtodest(p, flag, subtype, quoted);
 931                 break;
 932         default:
 933                 if (is_digit(*name)) {
 934                         num = atoi(name);
 935                         if (num > 0 && num <= shellparam.nparam) {
 936                                 p = shellparam.p[num - 1];
 937                                 strtodest(p, flag, subtype, quoted);
 938                         }
 939                 }
 940                 break;
 941         }
 942 }
 943
 944
 945
 946 /*
 947  * Record the fact that we have to scan this region of the
 948  * string for IFS characters.
 949  */
 950
 951 static void
 952 recordregion(int start, int end, int inquotes)
 953 {
 954         struct ifsregion *ifsp;
 955
 956         INTOFF;
 957         if (ifslastp == NULL) {
 958                 ifsp = &ifsfirst;
 959         } else {
 960                 if (ifslastp->endoff == start
 961                     && ifslastp->inquotes == inquotes) {
 962                         /* extend previous area */
 963                         ifslastp->endoff = end;
 964                         INTON;
 965                         return;
 966                 }
 967                 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
 968                 ifslastp->next = ifsp;
 969         }
 970         ifslastp = ifsp;
 971         ifslastp->next = NULL;
 972         ifslastp->begoff = start;
 973         ifslastp->endoff = end;
 974         ifslastp->inquotes = inquotes;
 975         INTON;
 976 }
 977
 978
 979
 980 /*
 981  * Break the argument string into pieces based upon IFS and add the
 982  * strings to the argument list.  The regions of the string to be
 983  * searched for IFS characters have been stored by recordregion.
 984  * CTLESC characters are preserved but have little effect in this pass
 985  * other than escaping CTL* characters.  In particular, they do not escape
 986  * IFS characters: that should be done with the ifsregion mechanism.
 987  * CTLQUOTEMARK characters are used to preserve empty quoted strings.
 988  * This pass treats them as a regular character, making the string non-empty.
 989  * Later, they are removed along with the other CTL* characters.
 990  */
 991 static void
 992 ifsbreakup(char *string, struct arglist *arglist)
 993 {
 994         struct ifsregion *ifsp;
 995         struct strlist *sp;
 996         char *start;
 997         char *p;
 998         char *q;
 999         const char *ifs;
1000         const char *ifsspc;
1001         int had_param_ch = 0;
1002
1003         start = string;
1004
1005         if (ifslastp == NULL) {
1006                 /* Return entire argument, IFS doesn't apply to any of it */
1007                 sp = (struct strlist *)stalloc(sizeof *sp);
1008                 sp->text = start;
1009                 *arglist->lastp = sp;
1010                 arglist->lastp = &sp->next;
1011                 return;
1012         }
1013
1014         ifs = ifsset() ? ifsval() : " \t\n";
1015
1016         for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) {
1017                 p = string + ifsp->begoff;
1018                 while (p < string + ifsp->endoff) {
1019                         q = p;
1020                         if (*p == CTLESC)
1021                                 p++;
1022                         if (ifsp->inquotes) {
1023                                 /* Only NULs (should be from "$@") end args */
1024                                 had_param_ch = 1;
1025                                 if (*p != 0) {
1026                                         p++;
1027                                         continue;
1028                                 }
1029                                 ifsspc = NULL;
1030                         } else {
1031                                 if (!strchr(ifs, *p)) {
1032                                         had_param_ch = 1;
1033                                         p++;
1034                                         continue;
1035                                 }
1036                                 ifsspc = strchr(" \t\n", *p);
1037
1038                                 /* Ignore IFS whitespace at start */
1039                                 if (q == start && ifsspc != NULL) {
1040                                         p++;
1041                                         start = p;
1042                                         continue;
1043                                 }
1044                                 had_param_ch = 0;
1045                         }
1046
1047                         /* Save this argument... */
1048                         *q = '\0';
1049                         sp = (struct strlist *)stalloc(sizeof *sp);
1050                         sp->text = start;
1051                         *arglist->lastp = sp;
1052                         arglist->lastp = &sp->next;
1053                         p++;
1054
1055                         if (ifsspc != NULL) {
1056                                 /* Ignore further trailing IFS whitespace */
1057                                 for (; p < string + ifsp->endoff; p++) {
1058                                         q = p;
1059                                         if (*p == CTLESC)
1060                                                 p++;
1061                                         if (strchr(ifs, *p) == NULL) {
1062                                                 p = q;
1063                                                 break;
1064                                         }
1065                                         if (strchr(" \t\n", *p) == NULL) {
1066                                                 p++;
1067                                                 break;
1068                                         }
1069                                 }
1070                         }
1071                         start = p;
1072                 }
1073         }
1074
1075         /*
1076          * Save anything left as an argument.
1077          * Traditionally we have treated 'IFS=':'; set -- x$IFS' as
1078          * generating 2 arguments, the second of which is empty.
1079          * Some recent clarification of the Posix spec say that it
1080          * should only generate one....
1081          */
1082         if (had_param_ch || *start != 0) {
1083                 sp = (struct strlist *)stalloc(sizeof *sp);
1084                 sp->text = start;
1085                 *arglist->lastp = sp;
1086                 arglist->lastp = &sp->next;
1087         }
1088 }
1089
1090
1091 static char expdir[PATH_MAX];
1092 #define expdir_end (expdir + sizeof(expdir))
1093
1094 /*
1095  * Perform pathname generation and remove control characters.
1096  * At this point, the only control characters should be CTLESC and CTLQUOTEMARK.
1097  * The results are stored in the list exparg.
1098  */
1099 static void
1100 expandmeta(struct strlist *str, int flag __unused)
1101 {
1102         char *p;
1103         struct strlist **savelastp;
1104         struct strlist *sp;
1105         char c;
1106
1107         while (str) {
1108                 if (fflag)
1109                         goto nometa;
1110                 p = str->text;
1111                 for (;;) {                      /* fast check for meta chars */
1112                         if ((c = *p++) == '\0')
1113                                 goto nometa;
1114                         if (c == '*' || c == '?' || c == '[')
1115                                 break;
1116                 }
1117                 savelastp = exparg.lastp;
1118                 INTOFF;
1119                 expmeta(expdir, str->text);
1120                 INTON;
1121                 if (exparg.lastp == savelastp) {
1122                         /*
1123                          * no matches
1124                          */
1125 nometa:
1126                         *exparg.lastp = str;
1127                         rmescapes(str->text);
1128                         exparg.lastp = &str->next;
1129                 } else {
1130                         *exparg.lastp = NULL;
1131                         *savelastp = sp = expsort(*savelastp);
1132                         while (sp->next != NULL)
1133                                 sp = sp->next;
1134                         exparg.lastp = &sp->next;
1135                 }
1136                 str = str->next;
1137         }
1138 }
1139
1140
1141 /*
1142  * Do metacharacter (i.e. *, ?, [...]) expansion.
1143  */
1144
1145 static void
1146 expmeta(char *enddir, char *name)
1147 {
1148         const char *p;
1149         const char *q;
1150         const char *start;
1151         char *endname;
1152         int metaflag;
1153         struct stat statb;
1154         DIR *dirp;
1155         struct dirent *dp;
1156         int atend;
1157         int matchdot;
1158         int esc;
1159         int namlen;
1160
1161         metaflag = 0;
1162         start = name;
1163         for (p = name; esc = 0, *p; p += esc + 1) {
1164                 if (*p == '*' || *p == '?')
1165                         metaflag = 1;
1166                 else if (*p == '[') {
1167                         q = p + 1;
1168                         if (*q == '!' || *q == '^')
1169                                 q++;
1170                         for (;;) {
1171                                 while (*q == CTLQUOTEMARK)
1172                                         q++;
1173                                 if (*q == CTLESC)
1174                                         q++;
1175                                 if (*q == '/' || *q == '\0')
1176                                         break;
1177                                 if (*++q == ']') {
1178                                         metaflag = 1;
1179                                         break;
1180                                 }
1181                         }
1182                 } else if (*p == '\0')
1183                         break;
1184                 else if (*p == CTLQUOTEMARK)
1185                         continue;
1186                 else {
1187                         if (*p == CTLESC)
1188                                 esc++;
1189                         if (p[esc] == '/') {
1190                                 if (metaflag)
1191                                         break;
1192                                 start = p + esc + 1;
1193                         }
1194                 }
1195         }
1196         if (metaflag == 0) {    /* we've reached the end of the file name */
1197                 if (enddir != expdir)
1198                         metaflag++;
1199                 for (p = name ; ; p++) {
1200                         if (*p == CTLQUOTEMARK)
1201                                 continue;
1202                         if (*p == CTLESC)
1203                                 p++;
1204                         *enddir++ = *p;
1205                         if (*p == '\0')
1206                                 break;
1207                         if (enddir == expdir_end)
1208                                 return;
1209                 }
1210                 if (metaflag == 0 || lstat(expdir, &statb) >= 0)
1211                         addfname(expdir);
1212                 return;
1213         }
1214         endname = name + (p - name);
1215         if (start != name) {
1216                 p = name;
1217                 while (p < start) {
1218                         while (*p == CTLQUOTEMARK)
1219                                 p++;
1220                         if (*p == CTLESC)
1221                                 p++;
1222                         *enddir++ = *p++;
1223                         if (enddir == expdir_end)
1224                                 return;
1225                 }
1226         }
1227         if (enddir == expdir) {
1228                 p = ".";
1229         } else if (enddir == expdir + 1 && *expdir == '/') {
1230                 p = "/";
1231         } else {
1232                 p = expdir;
1233                 enddir[-1] = '\0';
1234         }
1235         if ((dirp = opendir(p)) == NULL)
1236                 return;
1237         if (enddir != expdir)
1238                 enddir[-1] = '/';
1239         if (*endname == 0) {
1240                 atend = 1;
1241         } else {
1242                 atend = 0;
1243                 *endname = '\0';
1244                 endname += esc + 1;
1245         }
1246         matchdot = 0;
1247         p = start;
1248         while (*p == CTLQUOTEMARK)
1249                 p++;
1250         if (*p == CTLESC)
1251                 p++;
1252         if (*p == '.')
1253                 matchdot++;
1254         while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1255                 if (dp->d_name[0] == '.' && ! matchdot)
1256                         continue;
1257                 if (patmatch(start, dp->d_name, 0)) {
1258                         namlen = dp->d_namlen;
1259                         if (enddir + namlen + 1 > expdir_end)
1260                                 continue;
1261                         memcpy(enddir, dp->d_name, namlen + 1);
1262                         if (atend)
1263                                 addfname(expdir);
1264                         else {
1265                                 if (dp->d_type != DT_UNKNOWN &&
1266                                     dp->d_type != DT_DIR &&
1267                                     dp->d_type != DT_LNK)
1268                                         continue;
1269                                 if (enddir + namlen + 2 > expdir_end)
1270                                         continue;
1271                                 enddir[namlen] = '/';
1272                                 enddir[namlen + 1] = '\0';
1273                                 expmeta(enddir + namlen + 1, endname);
1274                         }
1275                 }
1276         }
1277         closedir(dirp);
1278         if (! atend)
1279                 endname[-esc - 1] = esc ? CTLESC : '/';
1280 }
1281
1282
1283 /*
1284  * Add a file name to the list.
1285  */
1286
1287 static void
1288 addfname(char *name)
1289 {
1290         char *p;
1291         struct strlist *sp;
1292         size_t len;
1293
1294         len = strlen(name);
1295         p = stalloc(len + 1);
1296         memcpy(p, name, len + 1);
1297         sp = (struct strlist *)stalloc(sizeof *sp);
1298         sp->text = p;
1299         *exparg.lastp = sp;
1300         exparg.lastp = &sp->next;
1301 }
1302
1303
1304 /*
1305  * Sort the results of file name expansion.  It calculates the number of
1306  * strings to sort and then calls msort (short for merge sort) to do the
1307  * work.
1308  */
1309
1310 static struct strlist *
1311 expsort(struct strlist *str)
1312 {
1313         int len;
1314         struct strlist *sp;
1315
1316         len = 0;
1317         for (sp = str ; sp ; sp = sp->next)
1318                 len++;
1319         return msort(str, len);
1320 }
1321
1322
1323 static struct strlist *
1324 msort(struct strlist *list, int len)
1325 {
1326         struct strlist *p, *q = NULL;
1327         struct strlist **lpp;
1328         int half;
1329         int n;
1330
1331         if (len <= 1)
1332                 return list;
1333         half = len >> 1;
1334         p = list;
1335         for (n = half ; --n >= 0 ; ) {
1336                 q = p;
1337                 p = p->next;
1338         }
1339         q->next = NULL;                 /* terminate first half of list */
1340         q = msort(list, half);          /* sort first half of list */
1341         p = msort(p, len - half);               /* sort second half */
1342         lpp = &list;
1343         for (;;) {
1344                 if (strcmp(p->text, q->text) < 0) {
1345                         *lpp = p;
1346                         lpp = &p->next;
1347                         if ((p = *lpp) == NULL) {
1348                                 *lpp = q;
1349                                 break;
1350                         }
1351                 } else {
1352                         *lpp = q;
1353                         lpp = &q->next;
1354                         if ((q = *lpp) == NULL) {
1355                                 *lpp = p;
1356                                 break;
1357                         }
1358                 }
1359         }
1360         return list;
1361 }
1362
1363
1364
1365 static wchar_t
1366 get_wc(const char **p)
1367 {
1368         wchar_t c;
1369         int chrlen;
1370
1371         chrlen = mbtowc(&c, *p, 4);
1372         if (chrlen == 0)
1373                 return 0;
1374         else if (chrlen == -1)
1375                 c = 0;
1376         else
1377                 *p += chrlen;
1378         return c;
1379 }
1380
1381
1382 /*
1383  * See if a character matches a character class, starting at the first colon
1384  * of "[:class:]".
1385  * If a valid character class is recognized, a pointer to the next character
1386  * after the final closing bracket is stored into *end, otherwise a null
1387  * pointer is stored into *end.
1388  */
1389 static int
1390 match_charclass(const char *p, wchar_t chr, const char **end)
1391 {
1392         char name[20];
1393         const char *nameend;
1394         wctype_t cclass;
1395
1396         *end = NULL;
1397         p++;
1398         nameend = strstr(p, ":]");
1399         if (nameend == NULL || (size_t)(nameend - p) >= sizeof(name) ||
1400             nameend == p)
1401                 return 0;
1402         memcpy(name, p, nameend - p);
1403         name[nameend - p] = '\0';
1404         *end = nameend + 2;
1405         cclass = wctype(name);
1406         /* An unknown class matches nothing but is valid nevertheless. */
1407         if (cclass == 0)
1408                 return 0;
1409         return iswctype(chr, cclass);
1410 }
1411
1412
1413 /*
1414  * Returns true if the pattern matches the string.
1415  */
1416
1417 static int
1418 patmatch(const char *pattern, const char *string, int squoted)
1419 {
1420         const char *p, *q, *end;
1421         const char *bt_p, *bt_q;
1422         char c;
1423         wchar_t wc, wc2;
1424
1425         p = pattern;
1426         q = string;
1427         bt_p = NULL;
1428         bt_q = NULL;
1429         for (;;) {
1430                 switch (c = *p++) {
1431                 case '\0':
1432                         if (*q != '\0')
1433                                 goto backtrack;
1434                         return 1;
1435                 case CTLESC:
1436                         if (squoted && *q == CTLESC)
1437                                 q++;
1438                         if (*q++ != *p++)
1439                                 goto backtrack;
1440                         break;
1441                 case CTLQUOTEMARK:
1442                         continue;
1443                 case '?':
1444                         if (squoted && *q == CTLESC)
1445                                 q++;
1446                         if (*q == '\0')
1447                                 return 0;
1448                         if (localeisutf8) {
1449                                 wc = get_wc(&q);
1450                                 /*
1451                                  * A '?' does not match invalid UTF-8 but a
1452                                  * '*' does, so backtrack.
1453                                  */
1454                                 if (wc == 0)
1455                                         goto backtrack;
1456                         } else
1457                                 wc = (unsigned char)*q++;
1458                         break;
1459                 case '*':
1460                         c = *p;
1461                         while (c == CTLQUOTEMARK || c == '*')
1462                                 c = *++p;
1463                         /*
1464                          * If the pattern ends here, we know the string
1465                          * matches without needing to look at the rest of it.
1466                          */
1467                         if (c == '\0')
1468                                 return 1;
1469                         /*
1470                          * First try the shortest match for the '*' that
1471                          * could work. We can forget any earlier '*' since
1472                          * there is no way having it match more characters
1473                          * can help us, given that we are already here.
1474                          */
1475                         bt_p = p;
1476                         bt_q = q;
1477                         break;
1478                 case '[': {
1479                         const char *endp;
1480                         int invert, found;
1481                         wchar_t chr;
1482
1483                         endp = p;
1484                         if (*endp == '!' || *endp == '^')
1485                                 endp++;
1486                         for (;;) {
1487                                 while (*endp == CTLQUOTEMARK)
1488                                         endp++;
1489                                 if (*endp == 0)
1490                                         goto dft;               /* no matching ] */
1491                                 if (*endp == CTLESC)
1492                                         endp++;
1493                                 if (*++endp == ']')
1494                                         break;
1495                         }
1496                         invert = 0;
1497                         if (*p == '!' || *p == '^') {
1498                                 invert++;
1499                                 p++;
1500                         }
1501                         found = 0;
1502                         if (squoted && *q == CTLESC)
1503                                 q++;
1504                         if (*q == '\0')
1505                                 return 0;
1506                         if (localeisutf8) {
1507                                 chr = get_wc(&q);
1508                                 if (chr == 0)
1509                                         goto backtrack;
1510                         } else
1511                                 chr = (unsigned char)*q++;
1512                         c = *p++;
1513                         do {
1514                                 if (c == CTLQUOTEMARK)
1515                                         continue;
1516                                 if (c == '[' && *p == ':') {
1517                                         found |= match_charclass(p, chr, &end);
1518                                         if (end != NULL)
1519                                                 p = end;
1520                                 }
1521                                 if (c == CTLESC)
1522                                         c = *p++;
1523                                 if (localeisutf8 && c & 0x80) {
1524                                         p--;
1525                                         wc = get_wc(&p);
1526                                         if (wc == 0) /* bad utf-8 */
1527                                                 return 0;
1528                                 } else
1529                                         wc = (unsigned char)c;
1530                                 if (*p == '-' && p[1] != ']') {
1531                                         p++;
1532                                         while (*p == CTLQUOTEMARK)
1533                                                 p++;
1534                                         if (*p == CTLESC)
1535                                                 p++;
1536                                         if (localeisutf8) {
1537                                                 wc2 = get_wc(&p);
1538                                                 if (wc2 == 0) /* bad utf-8 */
1539                                                         return 0;
1540                                         } else
1541                                                 wc2 = (unsigned char)*p++;
1542                                         if (   collate_range_cmp(chr, wc) >= 0
1543                                             && collate_range_cmp(chr, wc2) <= 0
1544                                            )
1545                                                 found = 1;
1546                                 } else {
1547                                         if (chr == wc)
1548                                                 found = 1;
1549                                 }
1550                         } while ((c = *p++) != ']');
1551                         if (found == invert)
1552                                 goto backtrack;
1553                         break;
1554                 }
1555 dft:            default:
1556                         if (squoted && *q == CTLESC)
1557                                 q++;
1558                         if (*q == '\0')
1559                                 return 0;
1560                         if (*q++ == c)
1561                                 break;
1562 backtrack:
1563                         /*
1564                          * If we have a mismatch (other than hitting the end
1565                          * of the string), go back to the last '*' seen and
1566                          * have it match one additional character.
1567                          */
1568                         if (bt_p == NULL)
1569                                 return 0;
1570                         if (squoted && *bt_q == CTLESC)
1571                                 bt_q++;
1572                         if (*bt_q == '\0')
1573                                 return 0;
1574                         bt_q++;
1575                         p = bt_p;
1576                         q = bt_q;
1577                         break;
1578                 }
1579         }
1580 }
1581
1582
1583
1584 /*
1585  * Remove any CTLESC and CTLQUOTEMARK characters from a string.
1586  */
1587
1588 void
1589 rmescapes(char *str)
1590 {
1591         char *p, *q;
1592
1593         p = str;
1594         while (*p != CTLESC && *p != CTLQUOTEMARK && *p != CTLQUOTEEND) {
1595                 if (*p++ == '\0')
1596                         return;
1597         }
1598         q = p;
1599         while (*p) {
1600                 if (*p == CTLQUOTEMARK || *p == CTLQUOTEEND) {
1601                         p++;
1602                         continue;
1603                 }
1604                 if (*p == CTLESC)
1605                         p++;
1606                 *q++ = *p++;
1607         }
1608         *q = '\0';
1609 }
1610
1611
1612
1613 /*
1614  * See if a pattern matches in a case statement.
1615  */
1616
1617 int
1618 casematch(union node *pattern, const char *val)
1619 {
1620         struct stackmark smark;
1621         int result;
1622         char *p;
1623
1624         setstackmark(&smark);
1625         argbackq = pattern->narg.backquote;
1626         STARTSTACKSTR(expdest);
1627         ifslastp = NULL;
1628         argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
1629         STPUTC('\0', expdest);
1630         p = grabstackstr(expdest);
1631         result = patmatch(p, val, 0);
1632         popstackmark(&smark);
1633         return result;
1634 }
1635
1636 /*
1637  * Our own itoa().
1638  */
1639
1640 static char *
1641 cvtnum(int num, char *buf)
1642 {
1643         char temp[32];
1644         int neg = num < 0;
1645         char *p = temp + 31;
1646
1647         temp[31] = '\0';
1648
1649         do {
1650                 *--p = num % 10 + '0';
1651         } while ((num /= 10) != 0);
1652
1653         if (neg)
1654                 *--p = '-';
1655
1656         STPUTS(p, buf);
1657         return buf;
1658 }
1659
1660 /*
1661  * Do most of the work for wordexp(3).
1662  */
1663
1664 int
1665 wordexpcmd(int argc, char **argv)
1666 {
1667         size_t len;
1668         int i;
1669
1670         out1fmt("%08x", argc - 1);
1671         for (i = 1, len = 0; i < argc; i++)
1672                 len += strlen(argv[i]);
1673         out1fmt("%08x", (int)len);
1674         for (i = 1; i < argc; i++)
1675                 outbin(argv[i], strlen(argv[i]) + 1, out1);
1676         return (0);
1677 }