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