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  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *      This product includes software developed by the University of
  21  *      California, Berkeley and its contributors.
  22  * 4. Neither the name of the University nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  *
  38  * @(#)expand.c 8.5 (Berkeley) 5/15/95
  39  * $FreeBSD: src/bin/sh/expand.c,v 1.86 2011/05/27 15:56:13 jilles Exp $
  40  */
  41
  42 #include <sys/types.h>
  43 #include <sys/time.h>
  44 #include <sys/stat.h>
  45 #include <dirent.h>
  46 #include <errno.h>
  47 #include <inttypes.h>
  48 #include <limits.h>
  49 #include <pwd.h>
  50 #include <stdio.h>
  51 #include <stdlib.h>
  52 #include <string.h>
  53 #include <unistd.h>
  54 #include <wchar.h>
  55
  56 /*
  57  * Routines to expand arguments to commands.  We have to deal with
  58  * backquotes, shell variables, and file metacharacters.
  59  */
  60
  61 #include "shell.h"
  62 #include "main.h"
  63 #include "nodes.h"
  64 #include "eval.h"
  65 #include "expand.h"
  66 #include "syntax.h"
  67 #include "parser.h"
  68 #include "jobs.h"
  69 #include "options.h"
  70 #include "var.h"
  71 #include "input.h"
  72 #include "output.h"
  73 #include "memalloc.h"
  74 #include "error.h"
  75 #include "mystring.h"
  76 #include "arith.h"
  77 #include "show.h"
  78
  79 /*
  80  * Structure specifying which parts of the string should be searched
  81  * for IFS characters.
  82  */
  83
  84 struct ifsregion {
  85         struct ifsregion *next; /* next region in list */
  86         int begoff;             /* offset of start of region */
  87         int endoff;             /* offset of end of region */
  88         int inquotes;           /* search for nul bytes only */
  89 };
  90
  91
  92 static char *expdest;                   /* output of current string */
  93 static struct nodelist *argbackq;       /* list of back quote expressions */
  94 static struct ifsregion ifsfirst;       /* first struct in list of ifs regions */
  95 static struct ifsregion *ifslastp;      /* last struct in list */
  96 static struct arglist exparg;           /* holds expanded arg list */
  97
  98 static void argstr(char *, int);
  99 static char *exptilde(char *, int);
 100 static void expbackq(union node *, int, int);
 101 static int subevalvar(char *, char *, int, int, int, int, int);
 102 static char *evalvar(char *, int);
 103 static int varisset(char *, int);
 104 static void varvalue(char *, int, int, int);
 105 static void recordregion(int, int, int);
 106 static void removerecordregions(int);
 107 static void ifsbreakup(char *, struct arglist *);
 108 static void expandmeta(struct strlist *, int);
 109 static void expmeta(char *, char *);
 110 static void addfname(char *);
 111 static struct strlist *expsort(struct strlist *);
 112 static struct strlist *msort(struct strlist *, int);
 113 static char *cvtnum(int, char *);
 114 static int collate_range_cmp(wchar_t, wchar_t);
 115
 116 static int
 117 collate_range_cmp(wchar_t c1, wchar_t c2)
 118 {
 119         static wchar_t s1[2], s2[2];
 120
 121         s1[0] = c1;
 122         s2[0] = c2;
 123         return (wcscoll(s1, s2));
 124 }
 125
 126 /*
 127  * Expand shell variables and backquotes inside a here document.
 128  *      union node *arg         the document
 129  *      int fd;                 where to write the expanded version
 130  */
 131
 132 void
 133 expandhere(union node *arg, int fd)
 134 {
 135         expandarg(arg, NULL, 0);
 136         xwrite(fd, stackblock(), expdest - stackblock());
 137 }
 138
 139 static char *
 140 stputs_quotes(const char *data, const char *syntax, char *p)
 141 {
 142         while (*data) {
 143                 CHECKSTRSPACE(2, p);
 144                 if (syntax[(int)*data] == CCTL)
 145                         USTPUTC(CTLESC, p);
 146                 USTPUTC(*data++, p);
 147         }
 148         return (p);
 149 }
 150 #define STPUTS_QUOTES(data, syntax, p) p = stputs_quotes((data), syntax, p)
 151
 152 /*
 153  * Perform expansions on an argument, placing the resulting list of arguments
 154  * in arglist.  Parameter expansion, command substitution and arithmetic
 155  * expansion are always performed; additional expansions can be requested
 156  * via flag (EXP_*).
 157  * The result is left in the stack string.
 158  * When arglist is NULL, perform here document expansion.
 159  *
 160  * Caution: this function uses global state and is not reentrant.
 161  * However, a new invocation after an interrupted invocation is safe
 162  * and will reset the global state for the new call.
 163  */
 164 void
 165 expandarg(union node *arg, struct arglist *arglist, int flag)
 166 {
 167         struct strlist *sp;
 168         char *p;
 169
 170         argbackq = arg->narg.backquote;
 171         STARTSTACKSTR(expdest);
 172         ifsfirst.next = NULL;
 173         ifslastp = NULL;
 174         argstr(arg->narg.text, flag);
 175         if (arglist == NULL) {
 176                 return;                 /* here document expanded */
 177         }
 178         STPUTC('\0', expdest);
 179         p = grabstackstr(expdest);
 180         exparg.lastp = &exparg.list;
 181         /*
 182          * TODO - EXP_REDIR
 183          */
 184         if (flag & EXP_FULL) {
 185                 ifsbreakup(p, &exparg);
 186                 *exparg.lastp = NULL;
 187                 exparg.lastp = &exparg.list;
 188                 expandmeta(exparg.list, flag);
 189         } else {
 190                 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
 191                         rmescapes(p);
 192                 sp = (struct strlist *)stalloc(sizeof (struct strlist));
 193                 sp->text = p;
 194                 *exparg.lastp = sp;
 195                 exparg.lastp = &sp->next;
 196         }
 197         while (ifsfirst.next != NULL) {
 198                 struct ifsregion *ifsp;
 199                 INTOFF;
 200                 ifsp = ifsfirst.next->next;
 201                 ckfree(ifsfirst.next);
 202                 ifsfirst.next = ifsp;
 203                 INTON;
 204         }
 205         *exparg.lastp = NULL;
 206         if (exparg.list) {
 207                 *arglist->lastp = exparg.list;
 208                 arglist->lastp = exparg.lastp;
 209         }
 210 }
 211
 212
 213
 214 /*
 215  * Perform parameter expansion, command substitution and arithmetic
 216  * expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE.
 217  * Processing ends at a CTLENDVAR character as well as '\0'.
 218  * This is used to expand word in ${var+word} etc.
 219  * If EXP_FULL, EXP_CASE or EXP_REDIR are set, keep and/or generate CTLESC
 220  * characters to allow for further processing.
 221  * If EXP_FULL is set, also preserve CTLQUOTEMARK characters.
 222  */
 223 static void
 224 argstr(char *p, int flag)
 225 {
 226         char c;
 227         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);  /* do CTLESC */
 228         int firsteq = 1;
 229         int split_lit;
 230         int lit_quoted;
 231
 232         split_lit = flag & EXP_SPLIT_LIT;
 233         lit_quoted = flag & EXP_LIT_QUOTED;
 234         flag &= ~(EXP_SPLIT_LIT | EXP_LIT_QUOTED);
 235         if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
 236                 p = exptilde(p, flag);
 237         for (;;) {
 238                 CHECKSTRSPACE(2, expdest);
 239                 switch (c = *p++) {
 240                 case '\0':
 241                 case CTLENDVAR:
 242                         goto breakloop;
 243                 case CTLQUOTEMARK:
 244                         lit_quoted = 1;
 245                         /* "$@" syntax adherence hack */
 246                         if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
 247                                 break;
 248                         if ((flag & EXP_FULL) != 0)
 249                                 USTPUTC(c, expdest);
 250                         break;
 251                 case CTLQUOTEEND:
 252                         lit_quoted = 0;
 253                         break;
 254                 case CTLESC:
 255                         if (quotes)
 256                                 USTPUTC(c, expdest);
 257                         c = *p++;
 258                         USTPUTC(c, expdest);
 259                         if (split_lit && !lit_quoted)
 260                                 recordregion(expdest - stackblock() -
 261                                     (quotes ? 2 : 1),
 262                                     expdest - stackblock(), 0);
 263                         break;
 264                 case CTLVAR:
 265                         p = evalvar(p, flag);
 266                         break;
 267                 case CTLBACKQ:
 268                 case CTLBACKQ|CTLQUOTE:
 269                         expbackq(argbackq->n, c & CTLQUOTE, flag);
 270                         argbackq = argbackq->next;
 271                         break;
 272                 case CTLENDARI:
 273                         expari(flag);
 274                         break;
 275                 case ':':
 276                 case '=':
 277                         /*
 278                          * sort of a hack - expand tildes in variable
 279                          * assignments (after the first '=' and after ':'s).
 280                          */
 281                         USTPUTC(c, expdest);
 282                         if (split_lit && !lit_quoted)
 283                                 recordregion(expdest - stackblock() - 1,
 284                                     expdest - stackblock(), 0);
 285                         if (flag & EXP_VARTILDE && *p == '~' &&
 286                             (c != '=' || firsteq)) {
 287                                 if (c == '=')
 288                                         firsteq = 0;
 289                                 p = exptilde(p, flag);
 290                         }
 291                         break;
 292                 default:
 293                         USTPUTC(c, expdest);
 294                         if (split_lit && !lit_quoted)
 295                                 recordregion(expdest - stackblock() - 1,
 296                                     expdest - stackblock(), 0);
 297                 }
 298         }
 299 breakloop:;
 300 }
 301
 302 /*
 303  * Perform tilde expansion, placing the result in the stack string and
 304  * returning the next position in the input string to process.
 305  */
 306 static char *
 307 exptilde(char *p, int flag)
 308 {
 309         char c, *startp = p;
 310         struct passwd *pw;
 311         char *home;
 312         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 313
 314         while ((c = *p) != '\0') {
 315                 switch(c) {
 316                 case CTLESC: /* This means CTL* are always considered quoted. */
 317                 case CTLVAR:
 318                 case CTLBACKQ:
 319                 case CTLBACKQ | CTLQUOTE:
 320                 case CTLARI:
 321                 case CTLENDARI:
 322                 case CTLQUOTEMARK:
 323                         return (startp);
 324                 case ':':
 325                         if (flag & EXP_VARTILDE)
 326                                 goto done;
 327                         break;
 328                 case '/':
 329                 case CTLENDVAR:
 330                         goto done;
 331                 }
 332                 p++;
 333         }
 334 done:
 335         *p = '\0';
 336         if (*(startp+1) == '\0') {
 337                 if ((home = lookupvar("HOME")) == NULL)
 338                         goto lose;
 339         } else {
 340                 if ((pw = getpwnam(startp+1)) == NULL)
 341                         goto lose;
 342                 home = pw->pw_dir;
 343         }
 344         if (*home == '\0')
 345                 goto lose;
 346         *p = c;
 347         if (quotes)
 348                 STPUTS_QUOTES(home, SQSYNTAX, expdest);
 349         else
 350                 STPUTS(home, expdest);
 351         return (p);
 352 lose:
 353         *p = c;
 354         return (startp);
 355 }
 356
 357
 358 static void
 359 removerecordregions(int endoff)
 360 {
 361         if (ifslastp == NULL)
 362                 return;
 363
 364         if (ifsfirst.endoff > endoff) {
 365                 while (ifsfirst.next != NULL) {
 366                         struct ifsregion *ifsp;
 367                         INTOFF;
 368                         ifsp = ifsfirst.next->next;
 369                         ckfree(ifsfirst.next);
 370                         ifsfirst.next = ifsp;
 371                         INTON;
 372                 }
 373                 if (ifsfirst.begoff > endoff)
 374                         ifslastp = NULL;
 375                 else {
 376                         ifslastp = &ifsfirst;
 377                         ifsfirst.endoff = endoff;
 378                 }
 379                 return;
 380         }
 381
 382         ifslastp = &ifsfirst;
 383         while (ifslastp->next && ifslastp->next->begoff < endoff)
 384                 ifslastp=ifslastp->next;
 385         while (ifslastp->next != NULL) {
 386                 struct ifsregion *ifsp;
 387                 INTOFF;
 388                 ifsp = ifslastp->next->next;
 389                 ckfree(ifslastp->next);
 390                 ifslastp->next = ifsp;
 391                 INTON;
 392         }
 393         if (ifslastp->endoff > endoff)
 394                 ifslastp->endoff = endoff;
 395 }
 396
 397 /*
 398  * Expand arithmetic expression.  Backup to start of expression,
 399  * evaluate, place result in (backed up) result, adjust string position.
 400  */
 401 void
 402 expari(int flag)
 403 {
 404         char *p, *q, *start;
 405         arith_t result;
 406         int begoff;
 407         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 408         int quoted;
 409
 410         /*
 411          * This routine is slightly over-complicated for
 412          * efficiency.  First we make sure there is
 413          * enough space for the result, which may be bigger
 414          * than the expression.  Next we
 415          * scan backwards looking for the start of arithmetic.  If the
 416          * next previous character is a CTLESC character, then we
 417          * have to rescan starting from the beginning since CTLESC
 418          * characters have to be processed left to right.
 419          */
 420         CHECKSTRSPACE(DIGITS(result) - 2, expdest);
 421         USTPUTC('\0', expdest);
 422         start = stackblock();
 423         p = expdest - 2;
 424         while (p >= start && *p != CTLARI)
 425                 --p;
 426         if (p < start || *p != CTLARI)
 427                 error("missing CTLARI (shouldn't happen)");
 428         if (p > start && *(p - 1) == CTLESC)
 429                 for (p = start; *p != CTLARI; p++)
 430                         if (*p == CTLESC)
 431                                 p++;
 432
 433         if (p[1] == '"')
 434                 quoted=1;
 435         else
 436                 quoted=0;
 437         begoff = p - start;
 438         removerecordregions(begoff);
 439         if (quotes)
 440                 rmescapes(p+2);
 441         q = grabstackstr(expdest);
 442         result = arith(p+2);
 443         ungrabstackstr(q, expdest);
 444         fmtstr(p, DIGITS(result), ARITH_FORMAT_STR, result);
 445         while (*p++)
 446                 ;
 447         if (quoted == 0)
 448                 recordregion(begoff, p - 1 - start, 0);
 449         result = expdest - p + 1;
 450         STADJUST(-result, expdest);
 451 }
 452
 453
 454 /*
 455  * Perform command substitution.
 456  */
 457 static void
 458 expbackq(union node *cmd, int quoted, int flag)
 459 {
 460         struct backcmd in;
 461         int i;
 462         char buf[128];
 463         char *p;
 464         char *dest = expdest;
 465         struct ifsregion saveifs, *savelastp;
 466         struct nodelist *saveargbackq;
 467         char lastc;
 468         int startloc = dest - stackblock();
 469         char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
 470         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 471         int nnl;
 472
 473         INTOFF;
 474         saveifs = ifsfirst;
 475         savelastp = ifslastp;
 476         saveargbackq = argbackq;
 477         p = grabstackstr(dest);
 478         evalbackcmd(cmd, &in);
 479         ungrabstackstr(p, dest);
 480         ifsfirst = saveifs;
 481         ifslastp = savelastp;
 482         argbackq = saveargbackq;
 483
 484         p = in.buf;
 485         lastc = '\0';
 486         nnl = 0;
 487         /* Don't copy trailing newlines */
 488         for (;;) {
 489                 if (--in.nleft < 0) {
 490                         if (in.fd < 0)
 491                                 break;
 492                         while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR);
 493                         TRACE(("expbackq: read returns %d\n", i));
 494                         if (i <= 0)
 495                                 break;
 496                         p = buf;
 497                         in.nleft = i - 1;
 498                 }
 499                 lastc = *p++;
 500                 if (lastc != '\0') {
 501                         if (lastc == '\n') {
 502                                 nnl++;
 503                         } else {
 504                                 CHECKSTRSPACE(nnl + 2, dest);
 505                                 while (nnl > 0) {
 506                                         nnl--;
 507                                         USTPUTC('\n', dest);
 508                                 }
 509                                 if (quotes && syntax[(int)lastc] == CCTL)
 510                                         USTPUTC(CTLESC, dest);
 511                                 USTPUTC(lastc, dest);
 512                         }
 513                 }
 514         }
 515
 516         if (in.fd >= 0)
 517                 close(in.fd);
 518         if (in.buf)
 519                 ckfree(in.buf);
 520         if (in.jp)
 521                 exitstatus = waitforjob(in.jp, NULL);
 522         if (quoted == 0)
 523                 recordregion(startloc, dest - stackblock(), 0);
 524         TRACE(("expbackq: size=%td: \"%.*s\"\n",
 525                 ((dest - stackblock()) - startloc),
 526                 (int)((dest - stackblock()) - startloc),
 527                 stackblock() + startloc));
 528         expdest = dest;
 529         INTON;
 530 }
 531
 532
 533
 534 static int
 535 subevalvar(char *p, char *str, int strloc, int subtype, int startloc,
 536   int varflags, int quotes)
 537 {
 538         char *startp;
 539         char *loc = NULL;
 540         char *q;
 541         int c = 0;
 542         struct nodelist *saveargbackq = argbackq;
 543         int amount;
 544
 545         argstr(p, (subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX ||
 546             subtype == VSTRIMRIGHT || subtype == VSTRIMRIGHTMAX ?
 547             EXP_CASE : 0) | EXP_TILDE);
 548         STACKSTRNUL(expdest);
 549         argbackq = saveargbackq;
 550         startp = stackblock() + startloc;
 551         if (str == NULL)
 552             str = stackblock() + strloc;
 553
 554         switch (subtype) {
 555         case VSASSIGN:
 556                 setvar(str, startp, 0);
 557                 amount = startp - expdest;
 558                 STADJUST(amount, expdest);
 559                 varflags &= ~VSNUL;
 560                 return 1;
 561
 562         case VSQUESTION:
 563                 if (*p != CTLENDVAR) {
 564                         outfmt(out2, "%s\n", startp);
 565                         error(NULL);
 566                 }
 567                 error("%.*s: parameter %snot set", (int)(p - str - 1),
 568                       str, (varflags & VSNUL) ? "null or "
 569                                               : nullstr);
 570                 return 0;
 571
 572         case VSTRIMLEFT:
 573                 for (loc = startp; loc < str; loc++) {
 574                         c = *loc;
 575                         *loc = '\0';
 576                         if (patmatch(str, startp, quotes)) {
 577                                 *loc = c;
 578                                 goto recordleft;
 579                         }
 580                         *loc = c;
 581                         if (quotes && *loc == CTLESC)
 582                                 loc++;
 583                 }
 584                 return 0;
 585
 586         case VSTRIMLEFTMAX:
 587                 for (loc = str - 1; loc >= startp;) {
 588                         c = *loc;
 589                         *loc = '\0';
 590                         if (patmatch(str, startp, quotes)) {
 591                                 *loc = c;
 592                                 goto recordleft;
 593                         }
 594                         *loc = c;
 595                         loc--;
 596                         if (quotes && loc > startp && *(loc - 1) == CTLESC) {
 597                                 for (q = startp; q < loc; q++)
 598                                         if (*q == CTLESC)
 599                                                 q++;
 600                                 if (q > loc)
 601                                         loc--;
 602                         }
 603                 }
 604                 return 0;
 605
 606         case VSTRIMRIGHT:
 607                 for (loc = str - 1; loc >= startp;) {
 608                         if (patmatch(str, loc, quotes)) {
 609                                 amount = loc - expdest;
 610                                 STADJUST(amount, expdest);
 611                                 return 1;
 612                         }
 613                         loc--;
 614                         if (quotes && loc > startp && *(loc - 1) == CTLESC) {
 615                                 for (q = startp; q < loc; q++)
 616                                         if (*q == CTLESC)
 617                                                 q++;
 618                                 if (q > loc)
 619                                         loc--;
 620                         }
 621                 }
 622                 return 0;
 623
 624         case VSTRIMRIGHTMAX:
 625                 for (loc = startp; loc < str - 1; loc++) {
 626                         if (patmatch(str, loc, quotes)) {
 627                                 amount = loc - expdest;
 628                                 STADJUST(amount, expdest);
 629                                 return 1;
 630                         }
 631                         if (quotes && *loc == CTLESC)
 632                                 loc++;
 633                 }
 634                 return 0;
 635
 636
 637         default:
 638                 abort();
 639         }
 640
 641 recordleft:
 642         amount = ((str - 1) - (loc - startp)) - expdest;
 643         STADJUST(amount, expdest);
 644         while (loc != str - 1)
 645                 *startp++ = *loc++;
 646         return 1;
 647 }
 648
 649
 650 /*
 651  * Expand a variable, and return a pointer to the next character in the
 652  * input string.
 653  */
 654
 655 static char *
 656 evalvar(char *p, int flag)
 657 {
 658         int subtype;
 659         int varflags;
 660         char *var;
 661         char *val;
 662         int patloc;
 663         int c;
 664         int set;
 665         int special;
 666         int startloc;
 667         int varlen;
 668         int varlenb;
 669         int easy;
 670         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 671
 672         varflags = (unsigned char)*p++;
 673         subtype = varflags & VSTYPE;
 674         var = p;
 675         special = 0;
 676         if (! is_name(*p))
 677                 special = 1;
 678         p = strchr(p, '=') + 1;
 679 again: /* jump here after setting a variable with ${var=text} */
 680         if (varflags & VSLINENO) {
 681                 set = 1;
 682                 special = 0;
 683                 val = var;
 684                 p[-1] = '\0';   /* temporarily overwrite '=' to have \0
 685                                    terminated string */
 686         } else if (special) {
 687                 set = varisset(var, varflags & VSNUL);
 688                 val = NULL;
 689         } else {
 690                 val = bltinlookup(var, 1);
 691                 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
 692                         val = NULL;
 693                         set = 0;
 694                 } else
 695                         set = 1;
 696         }
 697         varlen = 0;
 698         startloc = expdest - stackblock();
 699         if (!set && uflag && *var != '@' && *var != '*') {
 700                 switch (subtype) {
 701                 case VSNORMAL:
 702                 case VSTRIMLEFT:
 703                 case VSTRIMLEFTMAX:
 704                 case VSTRIMRIGHT:
 705                 case VSTRIMRIGHTMAX:
 706                 case VSLENGTH:
 707                         error("%.*s: parameter not set", (int)(p - var - 1),
 708                             var);
 709                 }
 710         }
 711         if (set && subtype != VSPLUS) {
 712                 /* insert the value of the variable */
 713                 if (special) {
 714                         varvalue(var, varflags & VSQUOTE, subtype, flag);
 715                         if (subtype == VSLENGTH) {
 716                                 varlenb = expdest - stackblock() - startloc;
 717                                 varlen = varlenb;
 718                                 if (localeisutf8) {
 719                                         val = stackblock() + startloc;
 720                                         for (;val != expdest; val++)
 721                                                 if ((*val & 0xC0) == 0x80)
 722                                                         varlen--;
 723                                 }
 724                                 STADJUST(-varlenb, expdest);
 725                         }
 726                 } else {
 727                         char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX
 728                                                                   : BASESYNTAX;
 729
 730                         if (subtype == VSLENGTH) {
 731                                 for (;*val; val++)
 732                                         if (!localeisutf8 ||
 733                                             (*val & 0xC0) != 0x80)
 734                                                 varlen++;
 735                         }
 736                         else {
 737                                 if (quotes)
 738                                         STPUTS_QUOTES(val, syntax, expdest);
 739                                 else
 740                                         STPUTS(val, expdest);
 741
 742                         }
 743                 }
 744         }
 745
 746         if (subtype == VSPLUS)
 747                 set = ! set;
 748
 749         easy = ((varflags & VSQUOTE) == 0 ||
 750                 (*var == '@' && shellparam.nparam != 1));
 751
 752
 753         switch (subtype) {
 754         case VSLENGTH:
 755                 expdest = cvtnum(varlen, expdest);
 756                 goto record;
 757
 758         case VSNORMAL:
 759                 if (!easy)
 760                         break;
 761 record:
 762                 recordregion(startloc, expdest - stackblock(),
 763                     varflags & VSQUOTE || (ifsset() && ifsval()[0] == '\0' &&
 764                     (*var == '@' || *var == '*')));
 765                 break;
 766
 767         case VSPLUS:
 768         case VSMINUS:
 769                 if (!set) {
 770                         argstr(p, flag | (flag & EXP_FULL ? EXP_SPLIT_LIT : 0) |
 771                             (varflags & VSQUOTE ? EXP_LIT_QUOTED : 0));
 772                         break;
 773                 }
 774                 if (easy)
 775                         goto record;
 776                 break;
 777
 778         case VSTRIMLEFT:
 779         case VSTRIMLEFTMAX:
 780         case VSTRIMRIGHT:
 781         case VSTRIMRIGHTMAX:
 782                 if (!set)
 783                         break;
 784                 /*
 785                  * Terminate the string and start recording the pattern
 786                  * right after it
 787                  */
 788                 STPUTC('\0', expdest);
 789                 patloc = expdest - stackblock();
 790                 if (subevalvar(p, NULL, patloc, subtype,
 791                     startloc, varflags, quotes) == 0) {
 792                         int amount = (expdest - stackblock() - patloc) + 1;
 793                         STADJUST(-amount, expdest);
 794                 }
 795                 /* Remove any recorded regions beyond start of variable */
 796                 removerecordregions(startloc);
 797                 goto record;
 798
 799         case VSASSIGN:
 800         case VSQUESTION:
 801                 if (!set) {
 802                         if (subevalvar(p, var, 0, subtype, startloc, varflags,
 803                             quotes)) {
 804                                 varflags &= ~VSNUL;
 805                                 /*
 806                                  * Remove any recorded regions beyond
 807                                  * start of variable
 808                                  */
 809                                 removerecordregions(startloc);
 810                                 goto again;
 811                         }
 812                         break;
 813                 }
 814                 if (easy)
 815                         goto record;
 816                 break;
 817
 818         case VSERROR:
 819                 c = p - var - 1;
 820                 error("${%.*s%s}: Bad substitution", c, var,
 821                     (c > 0 && *p != CTLENDVAR) ? "..." : "");
 822
 823         default:
 824                 abort();
 825         }
 826         p[-1] = '=';    /* recover overwritten '=' */
 827
 828         if (subtype != VSNORMAL) {      /* skip to end of alternative */
 829                 int nesting = 1;
 830                 for (;;) {
 831                         if ((c = *p++) == CTLESC)
 832                                 p++;
 833                         else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
 834                                 if (set)
 835                                         argbackq = argbackq->next;
 836                         } else if (c == CTLVAR) {
 837                                 if ((*p++ & VSTYPE) != VSNORMAL)
 838                                         nesting++;
 839                         } else if (c == CTLENDVAR) {
 840                                 if (--nesting == 0)
 841                                         break;
 842                         }
 843                 }
 844         }
 845         return p;
 846 }
 847
 848
 849
 850 /*
 851  * Test whether a specialized variable is set.
 852  */
 853
 854 static int
 855 varisset(char *name, int nulok)
 856 {
 857
 858         if (*name == '!')
 859                 return backgndpidset();
 860         else if (*name == '@' || *name == '*') {
 861                 if (*shellparam.p == NULL)
 862                         return 0;
 863
 864                 if (nulok) {
 865                         char **av;
 866
 867                         for (av = shellparam.p; *av; av++)
 868                                 if (**av != '\0')
 869                                         return 1;
 870                         return 0;
 871                 }
 872         } else if (is_digit(*name)) {
 873                 char *ap;
 874                 int num = atoi(name);
 875
 876                 if (num > shellparam.nparam)
 877                         return 0;
 878
 879                 if (num == 0)
 880                         ap = arg0;
 881                 else
 882                         ap = shellparam.p[num - 1];
 883
 884                 if (nulok && (ap == NULL || *ap == '\0'))
 885                         return 0;
 886         }
 887         return 1;
 888 }
 889
 890 static void
 891 strtodest(const char *p, int flag, int subtype, int quoted)
 892 {
 893         if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH)
 894                 STPUTS_QUOTES(p, quoted ? DQSYNTAX : BASESYNTAX, expdest);
 895         else
 896                 STPUTS(p, expdest);
 897 }
 898
 899 /*
 900  * Add the value of a specialized variable to the stack string.
 901  */
 902
 903 static void
 904 varvalue(char *name, int quoted, int subtype, int flag)
 905 {
 906         int num;
 907         char *p;
 908         int i;
 909         char sep;
 910         char **ap;
 911
 912         switch (*name) {
 913         case '$':
 914                 num = rootpid;
 915                 goto numvar;
 916         case '?':
 917                 num = oexitstatus;
 918                 goto numvar;
 919         case '#':
 920                 num = shellparam.nparam;
 921                 goto numvar;
 922         case '!':
 923                 num = backgndpidval();
 924 numvar:
 925                 expdest = cvtnum(num, expdest);
 926                 break;
 927         case '-':
 928                 for (i = 0 ; i < NOPTS ; i++) {
 929                         if (optlist[i].val)
 930                                 STPUTC(optlist[i].letter, expdest);
 931                 }
 932                 break;
 933         case '@':
 934                 if (flag & EXP_FULL && quoted) {
 935                         for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 936                                 strtodest(p, flag, subtype, quoted);
 937                                 if (*ap)
 938                                         STPUTC('\0', expdest);
 939                         }
 940                         break;
 941                 }
 942                 /* FALLTHROUGH */
 943         case '*':
 944                 if (ifsset())
 945                         sep = ifsval()[0];
 946                 else
 947                         sep = ' ';
 948                 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 949                         strtodest(p, flag, subtype, quoted);
 950                         if (!*ap)
 951                                 break;
 952                         if (sep || (flag & EXP_FULL && !quoted && **ap != '\0'))
 953                                 STPUTC(sep, expdest);
 954                 }
 955                 break;
 956         case '0':
 957                 p = arg0;
 958                 strtodest(p, flag, subtype, quoted);
 959                 break;
 960         default:
 961                 if (is_digit(*name)) {
 962                         num = atoi(name);
 963                         if (num > 0 && num <= shellparam.nparam) {
 964                                 p = shellparam.p[num - 1];
 965                                 strtodest(p, flag, subtype, quoted);
 966                         }
 967                 }
 968                 break;
 969         }
 970 }
 971
 972
 973
 974 /*
 975  * Record the fact that we have to scan this region of the
 976  * string for IFS characters.
 977  */
 978
 979 static void
 980 recordregion(int start, int end, int inquotes)
 981 {
 982         struct ifsregion *ifsp;
 983
 984         if (ifslastp == NULL) {
 985                 ifsp = &ifsfirst;
 986         } else {
 987                 if (ifslastp->endoff == start
 988                     && ifslastp->inquotes == inquotes) {
 989                         /* extend previous area */
 990                         ifslastp->endoff = end;
 991                         return;
 992                 }
 993                 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
 994                 ifslastp->next = ifsp;
 995         }
 996         ifslastp = ifsp;
 997         ifslastp->next = NULL;
 998         ifslastp->begoff = start;
 999         ifslastp->endoff = end;
1000         ifslastp->inquotes = inquotes;
1001 }
1002
1003
1004
1005 /*
1006  * Break the argument string into pieces based upon IFS and add the
1007  * strings to the argument list.  The regions of the string to be
1008  * searched for IFS characters have been stored by recordregion.
1009  * CTLESC characters are preserved but have little effect in this pass
1010  * other than escaping CTL* characters.  In particular, they do not escape
1011  * IFS characters: that should be done with the ifsregion mechanism.
1012  * CTLQUOTEMARK characters are used to preserve empty quoted strings.
1013  * This pass treats them as a regular character, making the string non-empty.
1014  * Later, they are removed along with the other CTL* characters.
1015  */
1016 static void
1017 ifsbreakup(char *string, struct arglist *arglist)
1018 {
1019         struct ifsregion *ifsp;
1020         struct strlist *sp;
1021         char *start;
1022         char *p;
1023         char *q;
1024         const char *ifs;
1025         const char *ifsspc;
1026         int had_param_ch = 0;
1027
1028         start = string;
1029
1030         if (ifslastp == NULL) {
1031                 /* Return entire argument, IFS doesn't apply to any of it */
1032                 sp = (struct strlist *)stalloc(sizeof *sp);
1033                 sp->text = start;
1034                 *arglist->lastp = sp;
1035                 arglist->lastp = &sp->next;
1036                 return;
1037         }
1038
1039         ifs = ifsset() ? ifsval() : " \t\n";
1040
1041         for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) {
1042                 p = string + ifsp->begoff;
1043                 while (p < string + ifsp->endoff) {
1044                         q = p;
1045                         if (*p == CTLESC)
1046                                 p++;
1047                         if (ifsp->inquotes) {
1048                                 /* Only NULs (should be from "$@") end args */
1049                                 had_param_ch = 1;
1050                                 if (*p != 0) {
1051                                         p++;
1052                                         continue;
1053                                 }
1054                                 ifsspc = NULL;
1055                         } else {
1056                                 if (!strchr(ifs, *p)) {
1057                                         had_param_ch = 1;
1058                                         p++;
1059                                         continue;
1060                                 }
1061                                 ifsspc = strchr(" \t\n", *p);
1062
1063                                 /* Ignore IFS whitespace at start */
1064                                 if (q == start && ifsspc != NULL) {
1065                                         p++;
1066                                         start = p;
1067                                         continue;
1068                                 }
1069                                 had_param_ch = 0;
1070                         }
1071
1072                         /* Save this argument... */
1073                         *q = '\0';
1074                         sp = (struct strlist *)stalloc(sizeof *sp);
1075                         sp->text = start;
1076                         *arglist->lastp = sp;
1077                         arglist->lastp = &sp->next;
1078                         p++;
1079
1080                         if (ifsspc != NULL) {
1081                                 /* Ignore further trailing IFS whitespace */
1082                                 for (; p < string + ifsp->endoff; p++) {
1083                                         q = p;
1084                                         if (*p == CTLESC)
1085                                                 p++;
1086                                         if (strchr(ifs, *p) == NULL) {
1087                                                 p = q;
1088                                                 break;
1089                                         }
1090                                         if (strchr(" \t\n", *p) == NULL) {
1091                                                 p++;
1092                                                 break;
1093                                         }
1094                                 }
1095                         }
1096                         start = p;
1097                 }
1098         }
1099
1100         /*
1101          * Save anything left as an argument.
1102          * Traditionally we have treated 'IFS=':'; set -- x$IFS' as
1103          * generating 2 arguments, the second of which is empty.
1104          * Some recent clarification of the Posix spec say that it
1105          * should only generate one....
1106          */
1107         if (had_param_ch || *start != 0) {
1108                 sp = (struct strlist *)stalloc(sizeof *sp);
1109                 sp->text = start;
1110                 *arglist->lastp = sp;
1111                 arglist->lastp = &sp->next;
1112         }
1113 }
1114
1115
1116 static char expdir[PATH_MAX];
1117 #define expdir_end (expdir + sizeof(expdir))
1118
1119 /*
1120  * Perform pathname generation and remove control characters.
1121  * At this point, the only control characters should be CTLESC and CTLQUOTEMARK.
1122  * The results are stored in the list exparg.
1123  */
1124 static void
1125 expandmeta(struct strlist *str, int flag __unused)
1126 {
1127         char *p;
1128         struct strlist **savelastp;
1129         struct strlist *sp;
1130         char c;
1131         /* TODO - EXP_REDIR */
1132
1133         while (str) {
1134                 if (fflag)
1135                         goto nometa;
1136                 p = str->text;
1137                 for (;;) {                      /* fast check for meta chars */
1138                         if ((c = *p++) == '\0')
1139                                 goto nometa;
1140                         if (c == '*' || c == '?' || c == '[')
1141                                 break;
1142                 }
1143                 savelastp = exparg.lastp;
1144                 INTOFF;
1145                 expmeta(expdir, str->text);
1146                 INTON;
1147                 if (exparg.lastp == savelastp) {
1148                         /*
1149                          * no matches
1150                          */
1151 nometa:
1152                         *exparg.lastp = str;
1153                         rmescapes(str->text);
1154                         exparg.lastp = &str->next;
1155                 } else {
1156                         *exparg.lastp = NULL;
1157                         *savelastp = sp = expsort(*savelastp);
1158                         while (sp->next != NULL)
1159                                 sp = sp->next;
1160                         exparg.lastp = &sp->next;
1161                 }
1162                 str = str->next;
1163         }
1164 }
1165
1166
1167 /*
1168  * Do metacharacter (i.e. *, ?, [...]) expansion.
1169  */
1170
1171 static void
1172 expmeta(char *enddir, char *name)
1173 {
1174         char *p;
1175         char *q;
1176         char *start;
1177         char *endname;
1178         int metaflag;
1179         struct stat statb;
1180         DIR *dirp;
1181         struct dirent *dp;
1182         int atend;
1183         int matchdot;
1184         int esc;
1185
1186         metaflag = 0;
1187         start = name;
1188         for (p = name; esc = 0, *p; p += esc + 1) {
1189                 if (*p == '*' || *p == '?')
1190                         metaflag = 1;
1191                 else if (*p == '[') {
1192                         q = p + 1;
1193                         if (*q == '!' || *q == '^')
1194                                 q++;
1195                         for (;;) {
1196                                 while (*q == CTLQUOTEMARK)
1197                                         q++;
1198                                 if (*q == CTLESC)
1199                                         q++;
1200                                 if (*q == '/' || *q == '\0')
1201                                         break;
1202                                 if (*++q == ']') {
1203                                         metaflag = 1;
1204                                         break;
1205                                 }
1206                         }
1207                 } else if (*p == '\0')
1208                         break;
1209                 else if (*p == CTLQUOTEMARK)
1210                         continue;
1211                 else {
1212                         if (*p == CTLESC)
1213                                 esc++;
1214                         if (p[esc] == '/') {
1215                                 if (metaflag)
1216                                         break;
1217                                 start = p + esc + 1;
1218                         }
1219                 }
1220         }
1221         if (metaflag == 0) {    /* we've reached the end of the file name */
1222                 if (enddir != expdir)
1223                         metaflag++;
1224                 for (p = name ; ; p++) {
1225                         if (*p == CTLQUOTEMARK)
1226                                 continue;
1227                         if (*p == CTLESC)
1228                                 p++;
1229                         *enddir++ = *p;
1230                         if (*p == '\0')
1231                                 break;
1232                         if (enddir == expdir_end)
1233                                 return;
1234                 }
1235                 if (metaflag == 0 || lstat(expdir, &statb) >= 0)
1236                         addfname(expdir);
1237                 return;
1238         }
1239         endname = p;
1240         if (start != name) {
1241                 p = name;
1242                 while (p < start) {
1243                         while (*p == CTLQUOTEMARK)
1244                                 p++;
1245                         if (*p == CTLESC)
1246                                 p++;
1247                         *enddir++ = *p++;
1248                         if (enddir == expdir_end)
1249                                 return;
1250                 }
1251         }
1252         if (enddir == expdir) {
1253                 p = __DECONST(char *, ".");
1254         } else if (enddir == expdir + 1 && *expdir == '/') {
1255                 p = __DECONST(char *, "/");
1256         } else {
1257                 p = expdir;
1258                 enddir[-1] = '\0';
1259         }
1260         if ((dirp = opendir(p)) == NULL)
1261                 return;
1262         if (enddir != expdir)
1263                 enddir[-1] = '/';
1264         if (*endname == 0) {
1265                 atend = 1;
1266         } else {
1267                 atend = 0;
1268                 *endname = '\0';
1269                 endname += esc + 1;
1270         }
1271         matchdot = 0;
1272         p = start;
1273         while (*p == CTLQUOTEMARK)
1274                 p++;
1275         if (*p == CTLESC)
1276                 p++;
1277         if (*p == '.')
1278                 matchdot++;
1279         while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1280                 if (dp->d_name[0] == '.' && ! matchdot)
1281                         continue;
1282                 if (patmatch(start, dp->d_name, 0)) {
1283                         if (enddir + dp->d_namlen + 1 > expdir_end)
1284                                 continue;
1285                         memcpy(enddir, dp->d_name, dp->d_namlen + 1);
1286                         if (atend)
1287                                 addfname(expdir);
1288                         else {
1289                                 if (enddir + dp->d_namlen + 2 > expdir_end)
1290                                         continue;
1291                                 enddir[dp->d_namlen] = '/';
1292                                 enddir[dp->d_namlen + 1] = '\0';
1293                                 expmeta(enddir + dp->d_namlen + 1, endname);
1294                         }
1295                 }
1296         }
1297         closedir(dirp);
1298         if (! atend)
1299                 endname[-esc - 1] = esc ? CTLESC : '/';
1300 }
1301
1302
1303 /*
1304  * Add a file name to the list.
1305  */
1306
1307 static void
1308 addfname(char *name)
1309 {
1310         char *p;
1311         struct strlist *sp;
1312
1313         p = stalloc(strlen(name) + 1);
1314         scopy(name, p);
1315         sp = (struct strlist *)stalloc(sizeof *sp);
1316         sp->text = p;
1317         *exparg.lastp = sp;
1318         exparg.lastp = &sp->next;
1319 }
1320
1321
1322 /*
1323  * Sort the results of file name expansion.  It calculates the number of
1324  * strings to sort and then calls msort (short for merge sort) to do the
1325  * work.
1326  */
1327
1328 static struct strlist *
1329 expsort(struct strlist *str)
1330 {
1331         int len;
1332         struct strlist *sp;
1333
1334         len = 0;
1335         for (sp = str ; sp ; sp = sp->next)
1336                 len++;
1337         return msort(str, len);
1338 }
1339
1340
1341 static struct strlist *
1342 msort(struct strlist *list, int len)
1343 {
1344         struct strlist *p, *q = NULL;
1345         struct strlist **lpp;
1346         int half;
1347         int n;
1348
1349         if (len <= 1)
1350                 return list;
1351         half = len >> 1;
1352         p = list;
1353         for (n = half ; --n >= 0 ; ) {
1354                 q = p;
1355                 p = p->next;
1356         }
1357         q->next = NULL;                 /* terminate first half of list */
1358         q = msort(list, half);          /* sort first half of list */
1359         p = msort(p, len - half);               /* sort second half */
1360         lpp = &list;
1361         for (;;) {
1362                 if (strcmp(p->text, q->text) < 0) {
1363                         *lpp = p;
1364                         lpp = &p->next;
1365                         if ((p = *lpp) == NULL) {
1366                                 *lpp = q;
1367                                 break;
1368                         }
1369                 } else {
1370                         *lpp = q;
1371                         lpp = &q->next;
1372                         if ((q = *lpp) == NULL) {
1373                                 *lpp = p;
1374                                 break;
1375                         }
1376                 }
1377         }
1378         return list;
1379 }
1380
1381
1382
1383 static wchar_t
1384 get_wc(const char **p)
1385 {
1386         wchar_t c;
1387         int chrlen;
1388
1389         chrlen = mbtowc(&c, *p, 4);
1390         if (chrlen == 0)
1391                 return 0;
1392         else if (chrlen == -1)
1393                 c = 0;
1394         else
1395                 *p += chrlen;
1396         return c;
1397 }
1398
1399
1400 /*
1401  * Returns true if the pattern matches the string.
1402  */
1403
1404 int
1405 patmatch(const char *pattern, const char *string, int squoted)
1406 {
1407         const char *p, *q;
1408         char c;
1409         wchar_t wc, wc2;
1410
1411         p = pattern;
1412         q = string;
1413         for (;;) {
1414                 switch (c = *p++) {
1415                 case '\0':
1416                         goto breakloop;
1417                 case CTLESC:
1418                         if (squoted && *q == CTLESC)
1419                                 q++;
1420                         if (*q++ != *p++)
1421                                 return 0;
1422                         break;
1423                 case CTLQUOTEMARK:
1424                         continue;
1425                 case '?':
1426                         if (squoted && *q == CTLESC)
1427                                 q++;
1428                         if (localeisutf8)
1429                                 wc = get_wc(&q);
1430                         else
1431                                 wc = (unsigned char)*q++;
1432                         if (wc == '\0')
1433                                 return 0;
1434                         break;
1435                 case '*':
1436                         c = *p;
1437                         while (c == CTLQUOTEMARK || c == '*')
1438                                 c = *++p;
1439                         if (c != CTLESC &&  c != CTLQUOTEMARK &&
1440                             c != '?' && c != '*' && c != '[') {
1441                                 while (*q != c) {
1442                                         if (squoted && *q == CTLESC &&
1443                                             q[1] == c)
1444                                                 break;
1445                                         if (*q == '\0')
1446                                                 return 0;
1447                                         if (squoted && *q == CTLESC)
1448                                                 q++;
1449                                         q++;
1450                                 }
1451                         }
1452                         do {
1453                                 if (patmatch(p, q, squoted))
1454                                         return 1;
1455                                 if (squoted && *q == CTLESC)
1456                                         q++;
1457                         } while (*q++ != '\0');
1458                         return 0;
1459                 case '[': {
1460                         const char *endp;
1461                         int invert, found;
1462                         wchar_t chr;
1463
1464                         endp = p;
1465                         if (*endp == '!' || *endp == '^')
1466                                 endp++;
1467                         for (;;) {
1468                                 while (*endp == CTLQUOTEMARK)
1469                                         endp++;
1470                                 if (*endp == '\0')
1471                                         goto dft;               /* no matching ] */
1472                                 if (*endp == CTLESC)
1473                                         endp++;
1474                                 if (*++endp == ']')
1475                                         break;
1476                         }
1477                         invert = 0;
1478                         if (*p == '!' || *p == '^') {
1479                                 invert++;
1480                                 p++;
1481                         }
1482                         found = 0;
1483                         if (squoted && *q == CTLESC)
1484                                 q++;
1485                         if (localeisutf8)
1486                                 chr = get_wc(&q);
1487                         else
1488                                 chr = (unsigned char)*q++;
1489                         if (chr == '\0')
1490                                 return 0;
1491                         c = *p++;
1492                         do {
1493                                 if (c == CTLQUOTEMARK)
1494                                         continue;
1495                                 if (c == CTLESC)
1496                                         c = *p++;
1497                                 if (localeisutf8 && c & 0x80) {
1498                                         p--;
1499                                         wc = get_wc(&p);
1500                                         if (wc == 0) /* bad utf-8 */
1501                                                 return 0;
1502                                 } else
1503                                         wc = (unsigned char)c;
1504                                 if (*p == '-' && p[1] != ']') {
1505                                         p++;
1506                                         while (*p == CTLQUOTEMARK)
1507                                                 p++;
1508                                         if (*p == CTLESC)
1509                                                 p++;
1510                                         if (localeisutf8) {
1511                                                 wc2 = get_wc(&p);
1512                                                 if (wc2 == 0) /* bad utf-8 */
1513                                                         return 0;
1514                                         } else
1515                                                 wc2 = (unsigned char)*p++;
1516                                         if (   collate_range_cmp(chr, wc) >= 0
1517                                             && collate_range_cmp(chr, wc2) <= 0
1518                                            )
1519                                                 found = 1;
1520                                 } else {
1521                                         if (chr == wc)
1522                                                 found = 1;
1523                                 }
1524                         } while ((c = *p++) != ']');
1525                         if (found == invert)
1526                                 return 0;
1527                         break;
1528                 }
1529 dft:            default:
1530                         if (squoted && *q == CTLESC)
1531                                 q++;
1532                         if (*q++ != c)
1533                                 return 0;
1534                         break;
1535                 }
1536         }
1537 breakloop:
1538         if (*q != '\0')
1539                 return 0;
1540         return 1;
1541 }
1542
1543
1544
1545 /*
1546  * Remove any CTLESC and CTLQUOTEMARK characters from a string.
1547  */
1548
1549 void
1550 rmescapes(char *str)
1551 {
1552         char *p, *q;
1553
1554         p = str;
1555         while (*p != CTLESC && *p != CTLQUOTEMARK && *p != CTLQUOTEEND) {
1556                 if (*p++ == '\0')
1557                         return;
1558         }
1559         q = p;
1560         while (*p) {
1561                 if (*p == CTLQUOTEMARK || *p == CTLQUOTEEND) {
1562                         p++;
1563                         continue;
1564                 }
1565                 if (*p == CTLESC)
1566                         p++;
1567                 *q++ = *p++;
1568         }
1569         *q = '\0';
1570 }
1571
1572
1573
1574 /*
1575  * See if a pattern matches in a case statement.
1576  */
1577
1578 int
1579 casematch(union node *pattern, const char *val)
1580 {
1581         struct stackmark smark;
1582         int result;
1583         char *p;
1584
1585         setstackmark(&smark);
1586         argbackq = pattern->narg.backquote;
1587         STARTSTACKSTR(expdest);
1588         ifslastp = NULL;
1589         argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
1590         STPUTC('\0', expdest);
1591         p = grabstackstr(expdest);
1592         result = patmatch(p, val, 0);
1593         popstackmark(&smark);
1594         return result;
1595 }
1596
1597 /*
1598  * Our own itoa().
1599  */
1600
1601 static char *
1602 cvtnum(int num, char *buf)
1603 {
1604         char temp[32];
1605         int neg = num < 0;
1606         char *p = temp + 31;
1607
1608         temp[31] = '\0';
1609
1610         do {
1611                 *--p = num % 10 + '0';
1612         } while ((num /= 10) != 0);
1613
1614         if (neg)
1615                 *--p = '-';
1616
1617         STPUTS(p, buf);
1618         return buf;
1619 }
1620
1621 /*
1622  * Check statically if expanding a string may have side effects.
1623  */
1624 int
1625 expandhassideeffects(const char *p)
1626 {
1627         int c;
1628         int arinest;
1629
1630         arinest = 0;
1631         while ((c = *p++) != '\0') {
1632                 switch (c) {
1633                 case CTLESC:
1634                         p++;
1635                         break;
1636                 case CTLVAR:
1637                         c = *p++;
1638                         /* Expanding $! sets the job to remembered. */
1639                         if (*p == '!')
1640                                 return 1;
1641                         if ((c & VSTYPE) == VSASSIGN)
1642                                 return 1;
1643                         /*
1644                          * If we are in arithmetic, the parameter may contain
1645                          * '=' which may cause side effects. Exceptions are
1646                          * the length of a parameter and $$, $# and $? which
1647                          * are always numeric.
1648                          */
1649                         if ((c & VSTYPE) == VSLENGTH) {
1650                                 while (*p != '=')
1651                                         p++;
1652                                 p++;
1653                                 break;
1654                         }
1655                         if ((*p == '$' || *p == '#' || *p == '?') &&
1656                             p[1] == '=') {
1657                                 p += 2;
1658                                 break;
1659                         }
1660                         if (arinest > 0)
1661                                 return 1;
1662                         break;
1663                 case CTLBACKQ:
1664                 case CTLBACKQ | CTLQUOTE:
1665                         if (arinest > 0)
1666                                 return 1;
1667                         break;
1668                 case CTLARI:
1669                         arinest++;
1670                         break;
1671                 case CTLENDARI:
1672                         arinest--;
1673                         break;
1674                 case '=':
1675                         if (*p == '=') {
1676                                 /* Allow '==' operator. */
1677                                 p++;
1678                                 continue;
1679                         }
1680                         if (arinest > 0)
1681                                 return 1;
1682                         break;
1683                 case '!': case '<': case '>':
1684                         /* Allow '!=', '<=', '>=' operators. */
1685                         if (*p == '=')
1686                                 p++;
1687                         break;
1688                 }
1689         }
1690         return 0;
1691 }
1692
1693 /*
1694  * Do most of the work for wordexp(3).
1695  */
1696
1697 int
1698 wordexpcmd(int argc, char **argv)
1699 {
1700         size_t len;
1701         int i;
1702
1703         out1fmt("%08x", argc - 1);
1704         for (i = 1, len = 0; i < argc; i++)
1705                 len += strlen(argv[i]);
1706         out1fmt("%08x", (int)len);
1707         for (i = 1; i < argc; i++)
1708                 outbin(argv[i], strlen(argv[i]) + 1, out1);
1709         return (0);
1710 }