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