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
  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);
 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 int pmatch(const char *, const char *, int);
 114 static char *cvtnum(int, char *);
 115 static int collate_range_cmp(int, int);
 116
 117 static int
 118 collate_range_cmp(int c1, int c2)
 119 {
 120         static char s1[2], s2[2];
 121
 122         s1[0] = c1;
 123         s2[0] = c2;
 124         return (strcoll(s1, s2));
 125 }
 126
 127 /*
 128  * Expand shell variables and backquotes inside a here document.
 129  *      union node *arg         the document
 130  *      int fd;                 where to write the expanded version
 131  */
 132
 133 void
 134 expandhere(union node *arg, int fd)
 135 {
 136         herefd = fd;
 137         expandarg(arg, (struct arglist *)NULL, 0);
 138         xwrite(fd, stackblock(), expdest - stackblock());
 139 }
 140
 141
 142 /*
 143  * Perform expansions on an argument, placing the resulting list of arguments
 144  * in arglist.  Parameter expansion, command substitution and arithmetic
 145  * expansion are always performed; additional expansions can be requested
 146  * via flag (EXP_*).
 147  * The result is left in the stack string.
 148  * When arglist is NULL, perform here document expansion.  A partial result
 149  * may be written to herefd, which is then not included in the stack string.
 150  *
 151  * Caution: this function uses global state and is not reentrant.
 152  * However, a new invocation after an interrupted invocation is safe
 153  * and will reset the global state for the new call.
 154  */
 155 void
 156 expandarg(union node *arg, struct arglist *arglist, int flag)
 157 {
 158         struct strlist *sp;
 159         char *p;
 160
 161         argbackq = arg->narg.backquote;
 162         STARTSTACKSTR(expdest);
 163         ifsfirst.next = NULL;
 164         ifslastp = NULL;
 165         argstr(arg->narg.text, flag);
 166         if (arglist == NULL) {
 167                 return;                 /* here document expanded */
 168         }
 169         STPUTC('\0', expdest);
 170         p = grabstackstr(expdest);
 171         exparg.lastp = &exparg.list;
 172         /*
 173          * TODO - EXP_REDIR
 174          */
 175         if (flag & EXP_FULL) {
 176                 ifsbreakup(p, &exparg);
 177                 *exparg.lastp = NULL;
 178                 exparg.lastp = &exparg.list;
 179                 expandmeta(exparg.list, flag);
 180         } else {
 181                 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
 182                         rmescapes(p);
 183                 sp = (struct strlist *)stalloc(sizeof (struct strlist));
 184                 sp->text = p;
 185                 *exparg.lastp = sp;
 186                 exparg.lastp = &sp->next;
 187         }
 188         while (ifsfirst.next != NULL) {
 189                 struct ifsregion *ifsp;
 190                 INTOFF;
 191                 ifsp = ifsfirst.next->next;
 192                 ckfree(ifsfirst.next);
 193                 ifsfirst.next = ifsp;
 194                 INTON;
 195         }
 196         *exparg.lastp = NULL;
 197         if (exparg.list) {
 198                 *arglist->lastp = exparg.list;
 199                 arglist->lastp = exparg.lastp;
 200         }
 201 }
 202
 203
 204
 205 /*
 206  * Perform parameter expansion, command substitution and arithmetic
 207  * expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE.
 208  * Processing ends at a CTLENDVAR character as well as '\0'.
 209  * This is used to expand word in ${var+word} etc.
 210  * If EXP_FULL, EXP_CASE or EXP_REDIR are set, keep and/or generate CTLESC
 211  * characters to allow for further processing.
 212  * If EXP_FULL is set, also preserve CTLQUOTEMARK characters.
 213  */
 214 static void
 215 argstr(char *p, int flag)
 216 {
 217         char c;
 218         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);  /* do CTLESC */
 219         int firsteq = 1;
 220
 221         if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
 222                 p = exptilde(p, flag);
 223         for (;;) {
 224                 switch (c = *p++) {
 225                 case '\0':
 226                 case CTLENDVAR:
 227                         goto breakloop;
 228                 case CTLQUOTEMARK:
 229                         /* "$@" syntax adherence hack */
 230                         if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
 231                                 break;
 232                         if ((flag & EXP_FULL) != 0)
 233                                 STPUTC(c, expdest);
 234                         break;
 235                 case CTLESC:
 236                         if (quotes)
 237                                 STPUTC(c, expdest);
 238                         c = *p++;
 239                         STPUTC(c, expdest);
 240                         break;
 241                 case CTLVAR:
 242                         p = evalvar(p, flag);
 243                         break;
 244                 case CTLBACKQ:
 245                 case CTLBACKQ|CTLQUOTE:
 246                         expbackq(argbackq->n, c & CTLQUOTE, flag);
 247                         argbackq = argbackq->next;
 248                         break;
 249                 case CTLENDARI:
 250                         expari(flag);
 251                         break;
 252                 case ':':
 253                 case '=':
 254                         /*
 255                          * sort of a hack - expand tildes in variable
 256                          * assignments (after the first '=' and after ':'s).
 257                          */
 258                         STPUTC(c, expdest);
 259                         if (flag & EXP_VARTILDE && *p == '~') {
 260                                 if (c == '=') {
 261                                         if (firsteq)
 262                                                 firsteq = 0;
 263                                         else
 264                                                 break;
 265                                 }
 266                                 p = exptilde(p, flag);
 267                         }
 268                         break;
 269                 default:
 270                         STPUTC(c, expdest);
 271                 }
 272         }
 273 breakloop:;
 274 }
 275
 276 /*
 277  * Perform tilde expansion, placing the result in the stack string and
 278  * returning the next position in the input string to process.
 279  */
 280 static char *
 281 exptilde(char *p, int flag)
 282 {
 283         char c, *startp = p;
 284         struct passwd *pw;
 285         char *home;
 286         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 287
 288         while ((c = *p) != '\0') {
 289                 switch(c) {
 290                 case CTLESC:
 291                         return (startp);
 292                 case CTLQUOTEMARK:
 293                         return (startp);
 294                 case ':':
 295                         if (flag & EXP_VARTILDE)
 296                                 goto done;
 297                         break;
 298                 case '/':
 299                         goto done;
 300                 }
 301                 p++;
 302         }
 303 done:
 304         *p = '\0';
 305         if (*(startp+1) == '\0') {
 306                 if ((home = lookupvar("HOME")) == NULL)
 307                         goto lose;
 308         } else {
 309                 if ((pw = getpwnam(startp+1)) == NULL)
 310                         goto lose;
 311                 home = pw->pw_dir;
 312         }
 313         if (*home == '\0')
 314                 goto lose;
 315         *p = c;
 316         while ((c = *home++) != '\0') {
 317                 if (quotes && SQSYNTAX[(int)c] == CCTL)
 318                         STPUTC(CTLESC, expdest);
 319                 STPUTC(c, expdest);
 320         }
 321         return (p);
 322 lose:
 323         *p = c;
 324         return (startp);
 325 }
 326
 327
 328 static void
 329 removerecordregions(int endoff)
 330 {
 331         if (ifslastp == NULL)
 332                 return;
 333
 334         if (ifsfirst.endoff > endoff) {
 335                 while (ifsfirst.next != NULL) {
 336                         struct ifsregion *ifsp;
 337                         INTOFF;
 338                         ifsp = ifsfirst.next->next;
 339                         ckfree(ifsfirst.next);
 340                         ifsfirst.next = ifsp;
 341                         INTON;
 342                 }
 343                 if (ifsfirst.begoff > endoff)
 344                         ifslastp = NULL;
 345                 else {
 346                         ifslastp = &ifsfirst;
 347                         ifsfirst.endoff = endoff;
 348                 }
 349                 return;
 350         }
 351
 352         ifslastp = &ifsfirst;
 353         while (ifslastp->next && ifslastp->next->begoff < endoff)
 354                 ifslastp=ifslastp->next;
 355         while (ifslastp->next != NULL) {
 356                 struct ifsregion *ifsp;
 357                 INTOFF;
 358                 ifsp = ifslastp->next->next;
 359                 ckfree(ifslastp->next);
 360                 ifslastp->next = ifsp;
 361                 INTON;
 362         }
 363         if (ifslastp->endoff > endoff)
 364                 ifslastp->endoff = endoff;
 365 }
 366
 367 /*
 368  * Expand arithmetic expression.  Backup to start of expression,
 369  * evaluate, place result in (backed up) result, adjust string position.
 370  */
 371 void
 372 expari(int flag)
 373 {
 374         char *p, *start;
 375         arith_t result;
 376         int begoff;
 377         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 378         int quoted;
 379
 380         /*
 381          * This routine is slightly over-complicated for
 382          * efficiency.  First we make sure there is
 383          * enough space for the result, which may be bigger
 384          * than the expression.  Next we
 385          * scan backwards looking for the start of arithmetic.  If the
 386          * next previous character is a CTLESC character, then we
 387          * have to rescan starting from the beginning since CTLESC
 388          * characters have to be processed left to right.
 389          */
 390         CHECKSTRSPACE(DIGITS(result) - 2, expdest);
 391         USTPUTC('\0', expdest);
 392         start = stackblock();
 393         p = expdest - 2;
 394         while (p >= start && *p != CTLARI)
 395                 --p;
 396         if (p < start || *p != CTLARI)
 397                 error("missing CTLARI (shouldn't happen)");
 398         if (p > start && *(p - 1) == CTLESC)
 399                 for (p = start; *p != CTLARI; p++)
 400                         if (*p == CTLESC)
 401                                 p++;
 402
 403         if (p[1] == '"')
 404                 quoted=1;
 405         else
 406                 quoted=0;
 407         begoff = p - start;
 408         removerecordregions(begoff);
 409         if (quotes)
 410                 rmescapes(p+2);
 411         result = arith(p+2);
 412         fmtstr(p, DIGITS(result), ARITH_FORMAT_STR, result);
 413         while (*p++)
 414                 ;
 415         if (quoted == 0)
 416                 recordregion(begoff, p - 1 - start, 0);
 417         result = expdest - p + 1;
 418         STADJUST(-result, expdest);
 419 }
 420
 421
 422 /*
 423  * Perform command substitution.
 424  */
 425 static void
 426 expbackq(union node *cmd, int quoted, int flag)
 427 {
 428         struct backcmd in;
 429         int i;
 430         char buf[128];
 431         char *p;
 432         char *dest = expdest;
 433         struct ifsregion saveifs, *savelastp;
 434         struct nodelist *saveargbackq;
 435         char lastc;
 436         int startloc = dest - stackblock();
 437         char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
 438         int saveherefd;
 439         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 440         int nnl;
 441
 442         INTOFF;
 443         saveifs = ifsfirst;
 444         savelastp = ifslastp;
 445         saveargbackq = argbackq;
 446         saveherefd = herefd;
 447         herefd = -1;
 448         p = grabstackstr(dest);
 449         evalbackcmd(cmd, &in);
 450         ungrabstackstr(p, dest);
 451         ifsfirst = saveifs;
 452         ifslastp = savelastp;
 453         argbackq = saveargbackq;
 454         herefd = saveherefd;
 455
 456         p = in.buf;
 457         lastc = '\0';
 458         nnl = 0;
 459         /* Don't copy trailing newlines */
 460         for (;;) {
 461                 if (--in.nleft < 0) {
 462                         if (in.fd < 0)
 463                                 break;
 464                         while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR);
 465                         TRACE(("expbackq: read returns %d\n", i));
 466                         if (i <= 0)
 467                                 break;
 468                         p = buf;
 469                         in.nleft = i - 1;
 470                 }
 471                 lastc = *p++;
 472                 if (lastc != '\0') {
 473                         if (quotes && syntax[(int)lastc] == CCTL)
 474                                 STPUTC(CTLESC, dest);
 475                         if (lastc == '\n') {
 476                                 nnl++;
 477                         } else {
 478                                 while (nnl > 0) {
 479                                         nnl--;
 480                                         STPUTC('\n', dest);
 481                                 }
 482                                 STPUTC(lastc, dest);
 483                         }
 484                 }
 485         }
 486
 487         if (in.fd >= 0)
 488                 close(in.fd);
 489         if (in.buf)
 490                 ckfree(in.buf);
 491         if (in.jp)
 492                 exitstatus = waitforjob(in.jp, (int *)NULL);
 493         if (quoted == 0)
 494                 recordregion(startloc, dest - stackblock(), 0);
 495         TRACE(("expbackq: size=%td: \"%.*s\"\n",
 496                 ((dest - stackblock()) - startloc),
 497                 (int)((dest - stackblock()) - startloc),
 498                 stackblock() + startloc));
 499         expdest = dest;
 500         INTON;
 501 }
 502
 503
 504
 505 static int
 506 subevalvar(char *p, char *str, int strloc, int subtype, int startloc,
 507   int varflags)
 508 {
 509         char *startp;
 510         char *loc = NULL;
 511         char *q;
 512         int c = 0;
 513         int saveherefd = herefd;
 514         struct nodelist *saveargbackq = argbackq;
 515         int amount;
 516
 517         herefd = -1;
 518         argstr(p, 0);
 519         STACKSTRNUL(expdest);
 520         herefd = saveherefd;
 521         argbackq = saveargbackq;
 522         startp = stackblock() + startloc;
 523         if (str == NULL)
 524             str = stackblock() + strloc;
 525
 526         switch (subtype) {
 527         case VSASSIGN:
 528                 setvar(str, startp, 0);
 529                 amount = startp - expdest;
 530                 STADJUST(amount, expdest);
 531                 varflags &= ~VSNUL;
 532                 if (c != 0)
 533                         *loc = c;
 534                 return 1;
 535
 536         case VSQUESTION:
 537                 if (*p != CTLENDVAR) {
 538                         outfmt(&errout, "%s\n", startp);
 539                         error((char *)NULL);
 540                 }
 541                 error("%.*s: parameter %snot set", (int)(p - str - 1),
 542                       str, (varflags & VSNUL) ? "null or "
 543                                               : nullstr);
 544                 return 0;
 545
 546         case VSTRIMLEFT:
 547                 for (loc = startp; loc < str; loc++) {
 548                         c = *loc;
 549                         *loc = '\0';
 550                         if (patmatch(str, startp, varflags & VSQUOTE)) {
 551                                 *loc = c;
 552                                 goto recordleft;
 553                         }
 554                         *loc = c;
 555                         if ((varflags & VSQUOTE) && *loc == CTLESC)
 556                                 loc++;
 557                 }
 558                 return 0;
 559
 560         case VSTRIMLEFTMAX:
 561                 for (loc = str - 1; loc >= startp;) {
 562                         c = *loc;
 563                         *loc = '\0';
 564                         if (patmatch(str, startp, varflags & VSQUOTE)) {
 565                                 *loc = c;
 566                                 goto recordleft;
 567                         }
 568                         *loc = c;
 569                         loc--;
 570                         if ((varflags & VSQUOTE) && loc > startp &&
 571                             *(loc - 1) == CTLESC) {
 572                                 for (q = startp; q < loc; q++)
 573                                         if (*q == CTLESC)
 574                                                 q++;
 575                                 if (q > loc)
 576                                         loc--;
 577                         }
 578                 }
 579                 return 0;
 580
 581         case VSTRIMRIGHT:
 582                 for (loc = str - 1; loc >= startp;) {
 583                         if (patmatch(str, loc, varflags & VSQUOTE)) {
 584                                 amount = loc - expdest;
 585                                 STADJUST(amount, expdest);
 586                                 return 1;
 587                         }
 588                         loc--;
 589                         if ((varflags & VSQUOTE) && loc > startp &&
 590                             *(loc - 1) == CTLESC) {
 591                                 for (q = startp; q < loc; q++)
 592                                         if (*q == CTLESC)
 593                                                 q++;
 594                                 if (q > loc)
 595                                         loc--;
 596                         }
 597                 }
 598                 return 0;
 599
 600         case VSTRIMRIGHTMAX:
 601                 for (loc = startp; loc < str - 1; loc++) {
 602                         if (patmatch(str, loc, varflags & VSQUOTE)) {
 603                                 amount = loc - expdest;
 604                                 STADJUST(amount, expdest);
 605                                 return 1;
 606                         }
 607                         if ((varflags & VSQUOTE) && *loc == CTLESC)
 608                                 loc++;
 609                 }
 610                 return 0;
 611
 612
 613         default:
 614                 abort();
 615         }
 616
 617 recordleft:
 618         amount = ((str - 1) - (loc - startp)) - expdest;
 619         STADJUST(amount, expdest);
 620         while (loc != str - 1)
 621                 *startp++ = *loc++;
 622         return 1;
 623 }
 624
 625
 626 /*
 627  * Expand a variable, and return a pointer to the next character in the
 628  * input string.
 629  */
 630
 631 static char *
 632 evalvar(char *p, int flag)
 633 {
 634         int subtype;
 635         int varflags;
 636         char *var;
 637         char *val;
 638         int patloc;
 639         int c;
 640         int set;
 641         int special;
 642         int startloc;
 643         int varlen;
 644         int easy;
 645         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 646
 647         varflags = (unsigned char)*p++;
 648         subtype = varflags & VSTYPE;
 649         var = p;
 650         special = 0;
 651         if (! is_name(*p))
 652                 special = 1;
 653         p = strchr(p, '=') + 1;
 654 again: /* jump here after setting a variable with ${var=text} */
 655         if (varflags & VSLINENO) {
 656                 set = 1;
 657                 special = 0;
 658                 val = var;
 659                 p[-1] = '\0';   /* temporarily overwrite '=' to have \0
 660                                    terminated string */
 661         } else if (special) {
 662                 set = varisset(var, varflags & VSNUL);
 663                 val = NULL;
 664         } else {
 665                 val = bltinlookup(var, 1);
 666                 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
 667                         val = NULL;
 668                         set = 0;
 669                 } else
 670                         set = 1;
 671         }
 672         varlen = 0;
 673         startloc = expdest - stackblock();
 674         if (!set && uflag && *var != '@' && *var != '*') {
 675                 switch (subtype) {
 676                 case VSNORMAL:
 677                 case VSTRIMLEFT:
 678                 case VSTRIMLEFTMAX:
 679                 case VSTRIMRIGHT:
 680                 case VSTRIMRIGHTMAX:
 681                 case VSLENGTH:
 682                         error("%.*s: parameter not set", (int)(p - var - 1),
 683                             var);
 684                 }
 685         }
 686         if (set && subtype != VSPLUS) {
 687                 /* insert the value of the variable */
 688                 if (special) {
 689                         varvalue(var, varflags & VSQUOTE, subtype, flag);
 690                         if (subtype == VSLENGTH) {
 691                                 varlen = expdest - stackblock() - startloc;
 692                                 STADJUST(-varlen, expdest);
 693                         }
 694                 } else {
 695                         char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX
 696                                                                   : BASESYNTAX;
 697
 698                         if (subtype == VSLENGTH) {
 699                                 for (;*val; val++)
 700                                         varlen++;
 701                         }
 702                         else {
 703                                 while (*val) {
 704                                         if (quotes &&
 705                                             syntax[(int)*val] == CCTL)
 706                                                 STPUTC(CTLESC, expdest);
 707                                         STPUTC(*val++, expdest);
 708                                 }
 709
 710                         }
 711                 }
 712         }
 713
 714         if (subtype == VSPLUS)
 715                 set = ! set;
 716
 717         easy = ((varflags & VSQUOTE) == 0 ||
 718                 (*var == '@' && shellparam.nparam != 1));
 719
 720
 721         switch (subtype) {
 722         case VSLENGTH:
 723                 expdest = cvtnum(varlen, expdest);
 724                 goto record;
 725
 726         case VSNORMAL:
 727                 if (!easy)
 728                         break;
 729 record:
 730                 recordregion(startloc, expdest - stackblock(),
 731                              varflags & VSQUOTE);
 732                 break;
 733
 734         case VSPLUS:
 735         case VSMINUS:
 736                 if (!set) {
 737                         argstr(p, flag);
 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) == 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                                 varflags &= ~VSNUL;
 770                                 /*
 771                                  * Remove any recorded regions beyond
 772                                  * start of variable
 773                                  */
 774                                 removerecordregions(startloc);
 775                                 goto again;
 776                         }
 777                         break;
 778                 }
 779                 if (easy)
 780                         goto record;
 781                 break;
 782
 783         case VSERROR:
 784                 c = p - var - 1;
 785                 error("${%.*s%s}: Bad substitution", c, var,
 786                     (c > 0 && *p != CTLENDVAR) ? "..." : "");
 787
 788         default:
 789                 abort();
 790         }
 791         p[-1] = '=';    /* recover overwritten '=' */
 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(char *name, int nulok)
 821 {
 822
 823         if (*name == '!')
 824                 return backgndpid != -1;
 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                 int num = atoi(name);
 840
 841                 if (num > shellparam.nparam)
 842                         return 0;
 843
 844                 if (num == 0)
 845                         ap = arg0;
 846                 else
 847                         ap = shellparam.p[num - 1];
 848
 849                 if (nulok && (ap == NULL || *ap == '\0'))
 850                         return 0;
 851         }
 852         return 1;
 853 }
 854
 855
 856
 857 /*
 858  * Add the value of a specialized variable to the stack string.
 859  */
 860
 861 static void
 862 varvalue(char *name, int quoted, int subtype, int flag)
 863 {
 864         int num;
 865         char *p;
 866         int i;
 867         char sep;
 868         char **ap;
 869         char const *syntax;
 870
 871 #define STRTODEST(p) \
 872         do {\
 873         if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) { \
 874                 syntax = quoted? DQSYNTAX : BASESYNTAX; \
 875                 while (*p) { \
 876                         if (syntax[(int)*p] == CCTL) \
 877                                 STPUTC(CTLESC, expdest); \
 878                         STPUTC(*p++, expdest); \
 879                 } \
 880         } else \
 881                 while (*p) \
 882                         STPUTC(*p++, expdest); \
 883         } while (0)
 884
 885
 886         switch (*name) {
 887         case '$':
 888                 num = rootpid;
 889                 goto numvar;
 890         case '?':
 891                 num = oexitstatus;
 892                 goto numvar;
 893         case '#':
 894                 num = shellparam.nparam;
 895                 goto numvar;
 896         case '!':
 897                 num = backgndpid;
 898 numvar:
 899                 expdest = cvtnum(num, expdest);
 900                 break;
 901         case '-':
 902                 for (i = 0 ; i < NOPTS ; i++) {
 903                         if (optlist[i].val)
 904                                 STPUTC(optlist[i].letter, expdest);
 905                 }
 906                 break;
 907         case '@':
 908                 if (flag & EXP_FULL && quoted) {
 909                         for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 910                                 STRTODEST(p);
 911                                 if (*ap)
 912                                         STPUTC('\0', expdest);
 913                         }
 914                         break;
 915                 }
 916                 /* FALLTHROUGH */
 917         case '*':
 918                 if (ifsset())
 919                         sep = ifsval()[0];
 920                 else
 921                         sep = ' ';
 922                 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 923                         STRTODEST(p);
 924                         if (*ap && sep)
 925                                 STPUTC(sep, expdest);
 926                 }
 927                 break;
 928         case '0':
 929                 p = arg0;
 930                 STRTODEST(p);
 931                 break;
 932         default:
 933                 if (is_digit(*name)) {
 934                         num = atoi(name);
 935                         if (num > 0 && num <= shellparam.nparam) {
 936                                 p = shellparam.p[num - 1];
 937                                 STRTODEST(p);
 938                         }
 939                 }
 940                 break;
 941         }
 942 }
 943
 944
 945
 946 /*
 947  * Record the the fact that we have to scan this region of the
 948  * string for IFS characters.
 949  */
 950
 951 static void
 952 recordregion(int start, int end, int inquotes)
 953 {
 954         struct ifsregion *ifsp;
 955
 956         if (ifslastp == NULL) {
 957                 ifsp = &ifsfirst;
 958         } else {
 959                 if (ifslastp->endoff == start
 960                     && ifslastp->inquotes == inquotes) {
 961                         /* extend previous area */
 962                         ifslastp->endoff = end;
 963                         return;
 964                 }
 965                 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
 966                 ifslastp->next = ifsp;
 967         }
 968         ifslastp = ifsp;
 969         ifslastp->next = NULL;
 970         ifslastp->begoff = start;
 971         ifslastp->endoff = end;
 972         ifslastp->inquotes = inquotes;
 973 }
 974
 975
 976
 977 /*
 978  * Break the argument string into pieces based upon IFS and add the
 979  * strings to the argument list.  The regions of the string to be
 980  * searched for IFS characters have been stored by recordregion.
 981  * CTLESC characters are preserved but have little effect in this pass
 982  * other than escaping CTL* characters.  In particular, they do not escape
 983  * IFS characters: that should be done with the ifsregion mechanism.
 984  * CTLQUOTEMARK characters are used to preserve empty quoted strings.
 985  * This pass treats them as a regular character, making the string non-empty.
 986  * Later, they are removed along with the other CTL* characters.
 987  */
 988 static void
 989 ifsbreakup(char *string, struct arglist *arglist)
 990 {
 991         struct ifsregion *ifsp;
 992         struct strlist *sp;
 993         char *start;
 994         char *p;
 995         char *q;
 996         const char *ifs;
 997         const char *ifsspc;
 998         int had_param_ch = 0;
 999
1000         start = string;
1001
1002         if (ifslastp == NULL) {
1003                 /* Return entire argument, IFS doesn't apply to any of it */
1004                 sp = (struct strlist *)stalloc(sizeof *sp);
1005                 sp->text = start;
1006                 *arglist->lastp = sp;
1007                 arglist->lastp = &sp->next;
1008                 return;
1009         }
1010
1011         ifs = ifsset() ? ifsval() : " \t\n";
1012
1013         for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) {
1014                 p = string + ifsp->begoff;
1015                 while (p < string + ifsp->endoff) {
1016                         q = p;
1017                         if (*p == CTLESC)
1018                                 p++;
1019                         if (ifsp->inquotes) {
1020                                 /* Only NULs (should be from "$@") end args */
1021                                 had_param_ch = 1;
1022                                 if (*p != 0) {
1023                                         p++;
1024                                         continue;
1025                                 }
1026                                 ifsspc = NULL;
1027                         } else {
1028                                 if (!strchr(ifs, *p)) {
1029                                         had_param_ch = 1;
1030                                         p++;
1031                                         continue;
1032                                 }
1033                                 ifsspc = strchr(" \t\n", *p);
1034
1035                                 /* Ignore IFS whitespace at start */
1036                                 if (q == start && ifsspc != NULL) {
1037                                         p++;
1038                                         start = p;
1039                                         continue;
1040                                 }
1041                                 had_param_ch = 0;
1042                         }
1043
1044                         /* Save this argument... */
1045                         *q = '\0';
1046                         sp = (struct strlist *)stalloc(sizeof *sp);
1047                         sp->text = start;
1048                         *arglist->lastp = sp;
1049                         arglist->lastp = &sp->next;
1050                         p++;
1051
1052                         if (ifsspc != NULL) {
1053                                 /* Ignore further trailing IFS whitespace */
1054                                 for (; p < string + ifsp->endoff; p++) {
1055                                         q = p;
1056                                         if (*p == CTLESC)
1057                                                 p++;
1058                                         if (strchr(ifs, *p) == NULL) {
1059                                                 p = q;
1060                                                 break;
1061                                         }
1062                                         if (strchr(" \t\n", *p) == NULL) {
1063                                                 p++;
1064                                                 break;
1065                                         }
1066                                 }
1067                         }
1068                         start = p;
1069                 }
1070         }
1071
1072         /*
1073          * Save anything left as an argument.
1074          * Traditionally we have treated 'IFS=':'; set -- x$IFS' as
1075          * generating 2 arguments, the second of which is empty.
1076          * Some recent clarification of the Posix spec say that it
1077          * should only generate one....
1078          */
1079         if (had_param_ch || *start != 0) {
1080                 sp = (struct strlist *)stalloc(sizeof *sp);
1081                 sp->text = start;
1082                 *arglist->lastp = sp;
1083                 arglist->lastp = &sp->next;
1084         }
1085 }
1086
1087
1088 static char expdir[PATH_MAX];
1089 #define expdir_end (expdir + sizeof(expdir))
1090
1091 /*
1092  * Perform pathname generation and remove control characters.
1093  * At this point, the only control characters should be CTLESC and CTLQUOTEMARK.
1094  * The results are stored in the list exparg.
1095  */
1096 static void
1097 expandmeta(struct strlist *str, int flag __unused)
1098 {
1099         char *p;
1100         struct strlist **savelastp;
1101         struct strlist *sp;
1102         char c;
1103         /* TODO - EXP_REDIR */
1104
1105         while (str) {
1106                 if (fflag)
1107                         goto nometa;
1108                 p = str->text;
1109                 for (;;) {                      /* fast check for meta chars */
1110                         if ((c = *p++) == '\0')
1111                                 goto nometa;
1112                         if (c == '*' || c == '?' || c == '[' || c == '!')
1113                                 break;
1114                 }
1115                 savelastp = exparg.lastp;
1116                 INTOFF;
1117                 expmeta(expdir, str->text);
1118                 INTON;
1119                 if (exparg.lastp == savelastp) {
1120                         /*
1121                          * no matches
1122                          */
1123 nometa:
1124                         *exparg.lastp = str;
1125                         rmescapes(str->text);
1126                         exparg.lastp = &str->next;
1127                 } else {
1128                         *exparg.lastp = NULL;
1129                         *savelastp = sp = expsort(*savelastp);
1130                         while (sp->next != NULL)
1131                                 sp = sp->next;
1132                         exparg.lastp = &sp->next;
1133                 }
1134                 str = str->next;
1135         }
1136 }
1137
1138
1139 /*
1140  * Do metacharacter (i.e. *, ?, [...]) expansion.
1141  */
1142
1143 static void
1144 expmeta(char *enddir, char *name)
1145 {
1146         char *p;
1147         char *q;
1148         char *start;
1149         char *endname;
1150         int metaflag;
1151         struct stat statb;
1152         DIR *dirp;
1153         struct dirent *dp;
1154         int atend;
1155         int matchdot;
1156         int esc;
1157
1158         metaflag = 0;
1159         start = name;
1160         for (p = name; esc = 0, *p; p += esc + 1) {
1161                 if (*p == '*' || *p == '?')
1162                         metaflag = 1;
1163                 else if (*p == '[') {
1164                         q = p + 1;
1165                         if (*q == '!' || *q == '^')
1166                                 q++;
1167                         for (;;) {
1168                                 while (*q == CTLQUOTEMARK)
1169                                         q++;
1170                                 if (*q == CTLESC)
1171                                         q++;
1172                                 if (*q == '/' || *q == '\0')
1173                                         break;
1174                                 if (*++q == ']') {
1175                                         metaflag = 1;
1176                                         break;
1177                                 }
1178                         }
1179                 } else if (*p == '!' && p[1] == '!'     && (p == name || p[-1] == '/')) {
1180                         metaflag = 1;
1181                 } else if (*p == '\0')
1182                         break;
1183                 else if (*p == CTLQUOTEMARK)
1184                         continue;
1185                 else {
1186                         if (*p == CTLESC)
1187                                 esc++;
1188                         if (p[esc] == '/') {
1189                                 if (metaflag)
1190                                         break;
1191                                 start = p + esc + 1;
1192                         }
1193                 }
1194         }
1195         if (metaflag == 0) {    /* we've reached the end of the file name */
1196                 if (enddir != expdir)
1197                         metaflag++;
1198                 for (p = name ; ; p++) {
1199                         if (*p == CTLQUOTEMARK)
1200                                 continue;
1201                         if (*p == CTLESC)
1202                                 p++;
1203                         *enddir++ = *p;
1204                         if (*p == '\0')
1205                                 break;
1206                         if (enddir == expdir_end)
1207                                 return;
1208                 }
1209                 if (metaflag == 0 || lstat(expdir, &statb) >= 0)
1210                         addfname(expdir);
1211                 return;
1212         }
1213         endname = p;
1214         if (start != name) {
1215                 p = name;
1216                 while (p < start) {
1217                         while (*p == CTLQUOTEMARK)
1218                                 p++;
1219                         if (*p == CTLESC)
1220                                 p++;
1221                         *enddir++ = *p++;
1222                         if (enddir == expdir_end)
1223                                 return;
1224                 }
1225         }
1226         if (enddir == expdir) {
1227                 p = ".";
1228         } else if (enddir == expdir + 1 && *expdir == '/') {
1229                 p = "/";
1230         } else {
1231                 p = expdir;
1232                 enddir[-1] = '\0';
1233         }
1234         if ((dirp = opendir(p)) == NULL)
1235                 return;
1236         if (enddir != expdir)
1237                 enddir[-1] = '/';
1238         if (*endname == 0) {
1239                 atend = 1;
1240         } else {
1241                 atend = 0;
1242                 *endname = '\0';
1243                 endname += esc + 1;
1244         }
1245         matchdot = 0;
1246         p = start;
1247         while (*p == CTLQUOTEMARK)
1248                 p++;
1249         if (*p == CTLESC)
1250                 p++;
1251         if (*p == '.')
1252                 matchdot++;
1253         while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1254                 if (dp->d_name[0] == '.' && ! matchdot)
1255                         continue;
1256                 if (patmatch(start, dp->d_name, 0)) {
1257                         if (enddir + dp->d_namlen + 1 > expdir_end)
1258                                 continue;
1259                         memcpy(enddir, dp->d_name, dp->d_namlen + 1);
1260                         if (atend)
1261                                 addfname(expdir);
1262                         else {
1263                                 if (enddir + dp->d_namlen + 2 > expdir_end)
1264                                         continue;
1265                                 enddir[dp->d_namlen] = '/';
1266                                 enddir[dp->d_namlen + 1] = '\0';
1267                                 expmeta(enddir + dp->d_namlen + 1, endname);
1268                         }
1269                 }
1270         }
1271         closedir(dirp);
1272         if (! atend)
1273                 endname[-esc - 1] = esc ? CTLESC : '/';
1274 }
1275
1276
1277 /*
1278  * Add a file name to the list.
1279  */
1280
1281 static void
1282 addfname(char *name)
1283 {
1284         char *p;
1285         struct strlist *sp;
1286
1287         p = stalloc(strlen(name) + 1);
1288         scopy(name, p);
1289         sp = (struct strlist *)stalloc(sizeof *sp);
1290         sp->text = p;
1291         *exparg.lastp = sp;
1292         exparg.lastp = &sp->next;
1293 }
1294
1295
1296 /*
1297  * Sort the results of file name expansion.  It calculates the number of
1298  * strings to sort and then calls msort (short for merge sort) to do the
1299  * work.
1300  */
1301
1302 static struct strlist *
1303 expsort(struct strlist *str)
1304 {
1305         int len;
1306         struct strlist *sp;
1307
1308         len = 0;
1309         for (sp = str ; sp ; sp = sp->next)
1310                 len++;
1311         return msort(str, len);
1312 }
1313
1314
1315 static struct strlist *
1316 msort(struct strlist *list, int len)
1317 {
1318         struct strlist *p, *q = NULL;
1319         struct strlist **lpp;
1320         int half;
1321         int n;
1322
1323         if (len <= 1)
1324                 return list;
1325         half = len >> 1;
1326         p = list;
1327         for (n = half ; --n >= 0 ; ) {
1328                 q = p;
1329                 p = p->next;
1330         }
1331         q->next = NULL;                 /* terminate first half of list */
1332         q = msort(list, half);          /* sort first half of list */
1333         p = msort(p, len - half);               /* sort second half */
1334         lpp = &list;
1335         for (;;) {
1336                 if (strcmp(p->text, q->text) < 0) {
1337                         *lpp = p;
1338                         lpp = &p->next;
1339                         if ((p = *lpp) == NULL) {
1340                                 *lpp = q;
1341                                 break;
1342                         }
1343                 } else {
1344                         *lpp = q;
1345                         lpp = &q->next;
1346                         if ((q = *lpp) == NULL) {
1347                                 *lpp = p;
1348                                 break;
1349                         }
1350                 }
1351         }
1352         return list;
1353 }
1354
1355
1356
1357 /*
1358  * Returns true if the pattern matches the string.
1359  */
1360
1361 int
1362 patmatch(const char *pattern, const char *string, int squoted)
1363 {
1364 #ifdef notdef
1365         if (pattern[0] == '!' && pattern[1] == '!')
1366                 return 1 - pmatch(pattern + 2, string);
1367         else
1368 #endif
1369                 return pmatch(pattern, string, squoted);
1370 }
1371
1372
1373 static int
1374 pmatch(const char *pattern, const char *string, int squoted)
1375 {
1376         const char *p, *q;
1377         char c;
1378
1379         p = pattern;
1380         q = string;
1381         for (;;) {
1382                 switch (c = *p++) {
1383                 case '\0':
1384                         goto breakloop;
1385                 case CTLESC:
1386                         if (squoted && *q == CTLESC)
1387                                 q++;
1388                         if (*q++ != *p++)
1389                                 return 0;
1390                         break;
1391                 case CTLQUOTEMARK:
1392                         continue;
1393                 case '?':
1394                         if (squoted && *q == CTLESC)
1395                                 q++;
1396                         if (*q++ == '\0')
1397                                 return 0;
1398                         break;
1399                 case '*':
1400                         c = *p;
1401                         while (c == CTLQUOTEMARK || c == '*')
1402                                 c = *++p;
1403                         if (c != CTLESC &&  c != CTLQUOTEMARK &&
1404                             c != '?' && c != '*' && c != '[') {
1405                                 while (*q != c) {
1406                                         if (squoted && *q == CTLESC &&
1407                                             q[1] == c)
1408                                                 break;
1409                                         if (*q == '\0')
1410                                                 return 0;
1411                                         if (squoted && *q == CTLESC)
1412                                                 q++;
1413                                         q++;
1414                                 }
1415                         }
1416                         do {
1417                                 if (pmatch(p, q, squoted))
1418                                         return 1;
1419                                 if (squoted && *q == CTLESC)
1420                                         q++;
1421                         } while (*q++ != '\0');
1422                         return 0;
1423                 case '[': {
1424                         const char *endp;
1425                         int invert, found;
1426                         char chr;
1427
1428                         endp = p;
1429                         if (*endp == '!' || *endp == '^')
1430                                 endp++;
1431                         for (;;) {
1432                                 while (*endp == CTLQUOTEMARK)
1433                                         endp++;
1434                                 if (*endp == '\0')
1435                                         goto dft;               /* no matching ] */
1436                                 if (*endp == CTLESC)
1437                                         endp++;
1438                                 if (*++endp == ']')
1439                                         break;
1440                         }
1441                         invert = 0;
1442                         if (*p == '!' || *p == '^') {
1443                                 invert++;
1444                                 p++;
1445                         }
1446                         found = 0;
1447                         chr = *q++;
1448                         if (squoted && chr == CTLESC)
1449                                 chr = *q++;
1450                         if (chr == '\0')
1451                                 return 0;
1452                         c = *p++;
1453                         do {
1454                                 if (c == CTLQUOTEMARK)
1455                                         continue;
1456                                 if (c == CTLESC)
1457                                         c = *p++;
1458                                 if (*p == '-' && p[1] != ']') {
1459                                         p++;
1460                                         while (*p == CTLQUOTEMARK)
1461                                                 p++;
1462                                         if (*p == CTLESC)
1463                                                 p++;
1464                                         if (   collate_range_cmp(chr, c) >= 0
1465                                             && collate_range_cmp(chr, *p) <= 0
1466                                            )
1467                                                 found = 1;
1468                                         p++;
1469                                 } else {
1470                                         if (chr == c)
1471                                                 found = 1;
1472                                 }
1473                         } while ((c = *p++) != ']');
1474                         if (found == invert)
1475                                 return 0;
1476                         break;
1477                 }
1478 dft:            default:
1479                         if (squoted && *q == CTLESC)
1480                                 q++;
1481                         if (*q++ != c)
1482                                 return 0;
1483                         break;
1484                 }
1485         }
1486 breakloop:
1487         if (*q != '\0')
1488                 return 0;
1489         return 1;
1490 }
1491
1492
1493
1494 /*
1495  * Remove any CTLESC and CTLQUOTEMARK characters from a string.
1496  */
1497
1498 void
1499 rmescapes(char *str)
1500 {
1501         char *p, *q;
1502
1503         p = str;
1504         while (*p != CTLESC && *p != CTLQUOTEMARK) {
1505                 if (*p++ == '\0')
1506                         return;
1507         }
1508         q = p;
1509         while (*p) {
1510                 if (*p == CTLQUOTEMARK) {
1511                         p++;
1512                         continue;
1513                 }
1514                 if (*p == CTLESC)
1515                         p++;
1516                 *q++ = *p++;
1517         }
1518         *q = '\0';
1519 }
1520
1521
1522
1523 /*
1524  * See if a pattern matches in a case statement.
1525  */
1526
1527 int
1528 casematch(union node *pattern, const char *val)
1529 {
1530         struct stackmark smark;
1531         int result;
1532         char *p;
1533
1534         setstackmark(&smark);
1535         argbackq = pattern->narg.backquote;
1536         STARTSTACKSTR(expdest);
1537         ifslastp = NULL;
1538         argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
1539         STPUTC('\0', expdest);
1540         p = grabstackstr(expdest);
1541         result = patmatch(p, val, 0);
1542         popstackmark(&smark);
1543         return result;
1544 }
1545
1546 /*
1547  * Our own itoa().
1548  */
1549
1550 static char *
1551 cvtnum(int num, char *buf)
1552 {
1553         char temp[32];
1554         int neg = num < 0;
1555         char *p = temp + 31;
1556
1557         temp[31] = '\0';
1558
1559         do {
1560                 *--p = num % 10 + '0';
1561         } while ((num /= 10) != 0);
1562
1563         if (neg)
1564                 *--p = '-';
1565
1566         while (*p)
1567                 STPUTC(*p++, buf);
1568         return buf;
1569 }
1570
1571 /*
1572  * Do most of the work for wordexp(3).
1573  */
1574
1575 int
1576 wordexpcmd(int argc, char **argv)
1577 {
1578         size_t len;
1579         int i;
1580
1581         out1fmt("%08x", argc - 1);
1582         for (i = 1, len = 0; i < argc; i++)
1583                 len += strlen(argv[i]);
1584         out1fmt("%08x", (int)len);
1585         for (i = 1; i < argc; i++) {
1586                 out1str(argv[i]);
1587                 out1c('\0');
1588         }
1589         return (0);
1590 }