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 <errno.h>
  47 #include <dirent.h>
  48 #include <unistd.h>
  49 #include <pwd.h>
  50 #include <stdlib.h>
  51 #include <limits.h>
  52 #include <stdio.h>
  53 #include <string.h>
  54
  55 /*
  56  * Routines to expand arguments to commands.  We have to deal with
  57  * backquotes, shell variables, and file metacharacters.
  58  */
  59
  60 #include "shell.h"
  61 #include "main.h"
  62 #include "nodes.h"
  63 #include "eval.h"
  64 #include "expand.h"
  65 #include "syntax.h"
  66 #include "parser.h"
  67 #include "jobs.h"
  68 #include "options.h"
  69 #include "var.h"
  70 #include "input.h"
  71 #include "output.h"
  72 #include "memalloc.h"
  73 #include "error.h"
  74 #include "mystring.h"
  75 #include "arith.h"
  76 #include "show.h"
  77
  78 /*
  79  * Structure specifying which parts of the string should be searched
  80  * for IFS characters.
  81  */
  82
  83 struct ifsregion {
  84         struct ifsregion *next; /* next region in list */
  85         int begoff;             /* offset of start of region */
  86         int endoff;             /* offset of end of region */
  87         int inquotes;           /* search for nul bytes only */
  88 };
  89
  90
  91 STATIC char *expdest;                   /* output of current string */
  92 STATIC struct nodelist *argbackq;       /* list of back quote expressions */
  93 STATIC struct ifsregion ifsfirst;       /* first struct in list of ifs regions */
  94 STATIC struct ifsregion *ifslastp;      /* last struct in list */
  95 STATIC struct arglist exparg;           /* holds expanded arg list */
  96
  97 STATIC void argstr(char *, int);
  98 STATIC char *exptilde(char *, int);
  99 STATIC void expbackq(union node *, int, int);
 100 STATIC int subevalvar(char *, char *, int, int, int, int);
 101 STATIC char *evalvar(char *, int);
 102 STATIC int varisset(char *, int);
 103 STATIC void varvalue(char *, int, int, int);
 104 STATIC void recordregion(int, int, int);
 105 STATIC void removerecordregions(int);
 106 STATIC void ifsbreakup(char *, struct arglist *);
 107 STATIC void expandmeta(struct strlist *, int);
 108 STATIC void expmeta(char *, char *);
 109 STATIC void addfname(char *);
 110 STATIC struct strlist *expsort(struct strlist *);
 111 STATIC struct strlist *msort(struct strlist *, int);
 112 STATIC int pmatch(const char *, const char *, int);
 113 STATIC char *cvtnum(int, char *);
 114 STATIC int collate_range_cmp(int, int);
 115
 116 STATIC int
 117 collate_range_cmp(int c1, int c2)
 118 {
 119         static char s1[2], s2[2];
 120
 121         s1[0] = c1;
 122         s2[0] = c2;
 123         return (strcoll(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         herefd = fd;
 136         expandarg(arg, (struct arglist *)NULL, 0);
 137         xwrite(fd, stackblock(), expdest - stackblock());
 138 }
 139
 140
 141 /*
 142  * Perform variable substitution and command substitution on an argument,
 143  * placing the resulting list of arguments in arglist.  If EXP_FULL is true,
 144  * perform splitting and file name expansion.  When arglist is NULL, perform
 145  * here document expansion.
 146  */
 147
 148 void
 149 expandarg(union node *arg, struct arglist *arglist, int flag)
 150 {
 151         struct strlist *sp;
 152         char *p;
 153
 154         argbackq = arg->narg.backquote;
 155         STARTSTACKSTR(expdest);
 156         ifsfirst.next = NULL;
 157         ifslastp = NULL;
 158         argstr(arg->narg.text, flag);
 159         if (arglist == NULL) {
 160                 return;                 /* here document expanded */
 161         }
 162         STPUTC('\0', expdest);
 163         p = grabstackstr(expdest);
 164         exparg.lastp = &exparg.list;
 165         /*
 166          * TODO - EXP_REDIR
 167          */
 168         if (flag & EXP_FULL) {
 169                 ifsbreakup(p, &exparg);
 170                 *exparg.lastp = NULL;
 171                 exparg.lastp = &exparg.list;
 172                 expandmeta(exparg.list, flag);
 173         } else {
 174                 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
 175                         rmescapes(p);
 176                 sp = (struct strlist *)stalloc(sizeof (struct strlist));
 177                 sp->text = p;
 178                 *exparg.lastp = sp;
 179                 exparg.lastp = &sp->next;
 180         }
 181         while (ifsfirst.next != NULL) {
 182                 struct ifsregion *ifsp;
 183                 INTOFF;
 184                 ifsp = ifsfirst.next->next;
 185                 ckfree(ifsfirst.next);
 186                 ifsfirst.next = ifsp;
 187                 INTON;
 188         }
 189         *exparg.lastp = NULL;
 190         if (exparg.list) {
 191                 *arglist->lastp = exparg.list;
 192                 arglist->lastp = exparg.lastp;
 193         }
 194 }
 195
 196
 197
 198 /*
 199  * Perform variable and command substitution.  If EXP_FULL is set, output CTLESC
 200  * characters to allow for further processing.  Otherwise treat
 201  * $@ like $* since no splitting will be performed.
 202  */
 203
 204 STATIC void
 205 argstr(char *p, int flag)
 206 {
 207         char c;
 208         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);  /* do CTLESC */
 209         int firsteq = 1;
 210
 211         if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
 212                 p = exptilde(p, flag);
 213         for (;;) {
 214                 switch (c = *p++) {
 215                 case '\0':
 216                 case CTLENDVAR: /* ??? */
 217                         goto breakloop;
 218                 case CTLQUOTEMARK:
 219                         /* "$@" syntax adherence hack */
 220                         if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
 221                                 break;
 222                         if ((flag & EXP_FULL) != 0)
 223                                 STPUTC(c, expdest);
 224                         break;
 225                 case CTLESC:
 226                         if (quotes)
 227                                 STPUTC(c, expdest);
 228                         c = *p++;
 229                         STPUTC(c, expdest);
 230                         break;
 231                 case CTLVAR:
 232                         p = evalvar(p, flag);
 233                         break;
 234                 case CTLBACKQ:
 235                 case CTLBACKQ|CTLQUOTE:
 236                         expbackq(argbackq->n, c & CTLQUOTE, flag);
 237                         argbackq = argbackq->next;
 238                         break;
 239                 case CTLENDARI:
 240                         expari(flag);
 241                         break;
 242                 case ':':
 243                 case '=':
 244                         /*
 245                          * sort of a hack - expand tildes in variable
 246                          * assignments (after the first '=' and after ':'s).
 247                          */
 248                         STPUTC(c, expdest);
 249                         if (flag & EXP_VARTILDE && *p == '~') {
 250                                 if (c == '=') {
 251                                         if (firsteq)
 252                                                 firsteq = 0;
 253                                         else
 254                                                 break;
 255                                 }
 256                                 p = exptilde(p, flag);
 257                         }
 258                         break;
 259                 default:
 260                         STPUTC(c, expdest);
 261                 }
 262         }
 263 breakloop:;
 264 }
 265
 266 STATIC char *
 267 exptilde(char *p, int flag)
 268 {
 269         char c, *startp = p;
 270         struct passwd *pw;
 271         char *home;
 272         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 273
 274         while ((c = *p) != '\0') {
 275                 switch(c) {
 276                 case CTLESC:
 277                         return (startp);
 278                 case CTLQUOTEMARK:
 279                         return (startp);
 280                 case ':':
 281                         if (flag & EXP_VARTILDE)
 282                                 goto done;
 283                         break;
 284                 case '/':
 285                         goto done;
 286                 }
 287                 p++;
 288         }
 289 done:
 290         *p = '\0';
 291         if (*(startp+1) == '\0') {
 292                 if ((home = lookupvar("HOME")) == NULL)
 293                         goto lose;
 294         } else {
 295                 if ((pw = getpwnam(startp+1)) == NULL)
 296                         goto lose;
 297                 home = pw->pw_dir;
 298         }
 299         if (*home == '\0')
 300                 goto lose;
 301         *p = c;
 302         while ((c = *home++) != '\0') {
 303                 if (quotes && SQSYNTAX[(int)c] == CCTL)
 304                         STPUTC(CTLESC, expdest);
 305                 STPUTC(c, expdest);
 306         }
 307         return (p);
 308 lose:
 309         *p = c;
 310         return (startp);
 311 }
 312
 313
 314 STATIC void
 315 removerecordregions(int endoff)
 316 {
 317         if (ifslastp == NULL)
 318                 return;
 319
 320         if (ifsfirst.endoff > endoff) {
 321                 while (ifsfirst.next != NULL) {
 322                         struct ifsregion *ifsp;
 323                         INTOFF;
 324                         ifsp = ifsfirst.next->next;
 325                         ckfree(ifsfirst.next);
 326                         ifsfirst.next = ifsp;
 327                         INTON;
 328                 }
 329                 if (ifsfirst.begoff > endoff)
 330                         ifslastp = NULL;
 331                 else {
 332                         ifslastp = &ifsfirst;
 333                         ifsfirst.endoff = endoff;
 334                 }
 335                 return;
 336         }
 337
 338         ifslastp = &ifsfirst;
 339         while (ifslastp->next && ifslastp->next->begoff < endoff)
 340                 ifslastp=ifslastp->next;
 341         while (ifslastp->next != NULL) {
 342                 struct ifsregion *ifsp;
 343                 INTOFF;
 344                 ifsp = ifslastp->next->next;
 345                 ckfree(ifslastp->next);
 346                 ifslastp->next = ifsp;
 347                 INTON;
 348         }
 349         if (ifslastp->endoff > endoff)
 350                 ifslastp->endoff = endoff;
 351 }
 352
 353 /*
 354  * Expand arithmetic expression.  Backup to start of expression,
 355  * evaluate, place result in (backed up) result, adjust string position.
 356  */
 357 void
 358 expari(int flag)
 359 {
 360         char *p, *start;
 361         arith_t result;
 362         int begoff;
 363         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 364         int quoted;
 365
 366
 367         /*
 368          * This routine is slightly over-complicated for
 369          * efficiency.  First we make sure there is
 370          * enough space for the result, which may be bigger
 371          * than the expression if we add exponentiation.  Next we
 372          * scan backwards looking for the start of arithmetic.  If the
 373          * next previous character is a CTLESC character, then we
 374          * have to rescan starting from the beginning since CTLESC
 375          * characters have to be processed left to right.
 376          */
 377         CHECKSTRSPACE(DIGITS(result) - 2, expdest);
 378         USTPUTC('\0', expdest);
 379         start = stackblock();
 380         p = expdest - 2;
 381         while (p >= start && *p != CTLARI)
 382                 --p;
 383         if (p < start || *p != CTLARI)
 384                 error("missing CTLARI (shouldn't happen)");
 385         if (p > start && *(p - 1) == CTLESC)
 386                 for (p = start; *p != CTLARI; p++)
 387                         if (*p == CTLESC)
 388                                 p++;
 389
 390         if (p[1] == '"')
 391                 quoted=1;
 392         else
 393                 quoted=0;
 394         begoff = p - start;
 395         removerecordregions(begoff);
 396         if (quotes)
 397                 rmescapes(p+2);
 398         result = arith(p+2);
 399         fmtstr(p, DIGITS(result), ARITH_FORMAT_STR, result);
 400         while (*p++)
 401                 ;
 402         if (quoted == 0)
 403                 recordregion(begoff, p - 1 - start, 0);
 404         result = expdest - p + 1;
 405         STADJUST(-result, expdest);
 406 }
 407
 408
 409 /*
 410  * Expand stuff in backwards quotes.
 411  */
 412
 413 STATIC void
 414 expbackq(union node *cmd, int quoted, int flag)
 415 {
 416         struct backcmd in;
 417         int i;
 418         char buf[128];
 419         char *p;
 420         char *dest = expdest;
 421         struct ifsregion saveifs, *savelastp;
 422         struct nodelist *saveargbackq;
 423         char lastc;
 424         int startloc = dest - stackblock();
 425         char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
 426         int saveherefd;
 427         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 428         int nnl;
 429
 430         INTOFF;
 431         saveifs = ifsfirst;
 432         savelastp = ifslastp;
 433         saveargbackq = argbackq;
 434         saveherefd = herefd;
 435         herefd = -1;
 436         p = grabstackstr(dest);
 437         evalbackcmd(cmd, &in);
 438         ungrabstackstr(p, dest);
 439         ifsfirst = saveifs;
 440         ifslastp = savelastp;
 441         argbackq = saveargbackq;
 442         herefd = saveherefd;
 443
 444         p = in.buf;
 445         lastc = '\0';
 446         nnl = 0;
 447         /* Don't copy trailing newlines */
 448         for (;;) {
 449                 if (--in.nleft < 0) {
 450                         if (in.fd < 0)
 451                                 break;
 452                         while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR);
 453                         TRACE(("expbackq: read returns %d\n", i));
 454                         if (i <= 0)
 455                                 break;
 456                         p = buf;
 457                         in.nleft = i - 1;
 458                 }
 459                 lastc = *p++;
 460                 if (lastc != '\0') {
 461                         if (quotes && syntax[(int)lastc] == CCTL)
 462                                 STPUTC(CTLESC, dest);
 463                         if (lastc == '\n') {
 464                                 nnl++;
 465                         } else {
 466                                 while (nnl > 0) {
 467                                         nnl--;
 468                                         STPUTC('\n', dest);
 469                                 }
 470                                 STPUTC(lastc, dest);
 471                         }
 472                 }
 473         }
 474
 475         if (in.fd >= 0)
 476                 close(in.fd);
 477         if (in.buf)
 478                 ckfree(in.buf);
 479         if (in.jp)
 480                 exitstatus = waitforjob(in.jp, (int *)NULL);
 481         if (quoted == 0)
 482                 recordregion(startloc, dest - stackblock(), 0);
 483         TRACE(("evalbackq: size=%d: \"%.*s\"\n",
 484                 (dest - stackblock()) - startloc,
 485                 (dest - stackblock()) - startloc,
 486                 stackblock() + startloc));
 487         expdest = dest;
 488         INTON;
 489 }
 490
 491
 492
 493 STATIC int
 494 subevalvar(char *p, char *str, int strloc, int subtype, int startloc,
 495   int varflags)
 496 {
 497         char *startp;
 498         char *loc = NULL;
 499         char *q;
 500         int c = 0;
 501         int saveherefd = herefd;
 502         struct nodelist *saveargbackq = argbackq;
 503         int amount;
 504
 505         herefd = -1;
 506         argstr(p, 0);
 507         STACKSTRNUL(expdest);
 508         herefd = saveherefd;
 509         argbackq = saveargbackq;
 510         startp = stackblock() + startloc;
 511         if (str == NULL)
 512             str = stackblock() + strloc;
 513
 514         switch (subtype) {
 515         case VSASSIGN:
 516                 setvar(str, startp, 0);
 517                 amount = startp - expdest;
 518                 STADJUST(amount, expdest);
 519                 varflags &= ~VSNUL;
 520                 if (c != 0)
 521                         *loc = c;
 522                 return 1;
 523
 524         case VSQUESTION:
 525                 if (*p != CTLENDVAR) {
 526                         outfmt(&errout, "%s\n", startp);
 527                         error((char *)NULL);
 528                 }
 529                 error("%.*s: parameter %snot set", (int)(p - str - 1),
 530                       str, (varflags & VSNUL) ? "null or "
 531                                               : nullstr);
 532                 return 0;
 533
 534         case VSTRIMLEFT:
 535                 for (loc = startp; loc < str; loc++) {
 536                         c = *loc;
 537                         *loc = '\0';
 538                         if (patmatch(str, startp, varflags & VSQUOTE)) {
 539                                 *loc = c;
 540                                 goto recordleft;
 541                         }
 542                         *loc = c;
 543                         if ((varflags & VSQUOTE) && *loc == CTLESC)
 544                                 loc++;
 545                 }
 546                 return 0;
 547
 548         case VSTRIMLEFTMAX:
 549                 for (loc = str - 1; loc >= startp;) {
 550                         c = *loc;
 551                         *loc = '\0';
 552                         if (patmatch(str, startp, varflags & VSQUOTE)) {
 553                                 *loc = c;
 554                                 goto recordleft;
 555                         }
 556                         *loc = c;
 557                         loc--;
 558                         if ((varflags & VSQUOTE) && loc > startp &&
 559                             *(loc - 1) == CTLESC) {
 560                                 for (q = startp; q < loc; q++)
 561                                         if (*q == CTLESC)
 562                                                 q++;
 563                                 if (q > loc)
 564                                         loc--;
 565                         }
 566                 }
 567                 return 0;
 568
 569         case VSTRIMRIGHT:
 570                 for (loc = str - 1; loc >= startp;) {
 571                         if (patmatch(str, loc, varflags & VSQUOTE)) {
 572                                 amount = loc - expdest;
 573                                 STADJUST(amount, expdest);
 574                                 return 1;
 575                         }
 576                         loc--;
 577                         if ((varflags & VSQUOTE) && loc > startp &&
 578                             *(loc - 1) == CTLESC) {
 579                                 for (q = startp; q < loc; q++)
 580                                         if (*q == CTLESC)
 581                                                 q++;
 582                                 if (q > loc)
 583                                         loc--;
 584                         }
 585                 }
 586                 return 0;
 587
 588         case VSTRIMRIGHTMAX:
 589                 for (loc = startp; loc < str - 1; loc++) {
 590                         if (patmatch(str, loc, varflags & VSQUOTE)) {
 591                                 amount = loc - expdest;
 592                                 STADJUST(amount, expdest);
 593                                 return 1;
 594                         }
 595                         if ((varflags & VSQUOTE) && *loc == CTLESC)
 596                                 loc++;
 597                 }
 598                 return 0;
 599
 600
 601         default:
 602                 abort();
 603         }
 604
 605 recordleft:
 606         amount = ((str - 1) - (loc - startp)) - expdest;
 607         STADJUST(amount, expdest);
 608         while (loc != str - 1)
 609                 *startp++ = *loc++;
 610         return 1;
 611 }
 612
 613
 614 /*
 615  * Expand a variable, and return a pointer to the next character in the
 616  * input string.
 617  */
 618
 619 STATIC char *
 620 evalvar(char *p, int flag)
 621 {
 622         int subtype;
 623         int varflags;
 624         char *var;
 625         char *val;
 626         int patloc;
 627         int c;
 628         int set;
 629         int special;
 630         int startloc;
 631         int varlen;
 632         int easy;
 633         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 634
 635         varflags = (unsigned char)*p++;
 636         subtype = varflags & VSTYPE;
 637         var = p;
 638         special = 0;
 639         if (! is_name(*p))
 640                 special = 1;
 641         p = strchr(p, '=') + 1;
 642 again: /* jump here after setting a variable with ${var=text} */
 643         if (varflags & VSLINENO) {
 644                 set = 1;
 645                 special = 0;
 646                 val = var;
 647                 p[-1] = '\0';   /* temporarily overwrite '=' to have \0
 648                                    terminated string */
 649         } else if (special) {
 650                 set = varisset(var, varflags & VSNUL);
 651                 val = NULL;
 652         } else {
 653                 val = bltinlookup(var, 1);
 654                 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
 655                         val = NULL;
 656                         set = 0;
 657                 } else
 658                         set = 1;
 659         }
 660         varlen = 0;
 661         startloc = expdest - stackblock();
 662         if (!set && uflag) {
 663                 switch (subtype) {
 664                 case VSNORMAL:
 665                 case VSTRIMLEFT:
 666                 case VSTRIMLEFTMAX:
 667                 case VSTRIMRIGHT:
 668                 case VSTRIMRIGHTMAX:
 669                 case VSLENGTH:
 670                         error("%.*s: parameter not set", (int)(p - var - 1),
 671                             var);
 672                 }
 673         }
 674         if (set && subtype != VSPLUS) {
 675                 /* insert the value of the variable */
 676                 if (special) {
 677                         varvalue(var, varflags & VSQUOTE, subtype, flag);
 678                         if (subtype == VSLENGTH) {
 679                                 varlen = expdest - stackblock() - startloc;
 680                                 STADJUST(-varlen, expdest);
 681                         }
 682                 } else {
 683                         char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX
 684                                                                   : BASESYNTAX;
 685
 686                         if (subtype == VSLENGTH) {
 687                                 for (;*val; val++)
 688                                         varlen++;
 689                         }
 690                         else {
 691                                 while (*val) {
 692                                         if (quotes &&
 693                                             syntax[(int)*val] == CCTL)
 694                                                 STPUTC(CTLESC, expdest);
 695                                         STPUTC(*val++, expdest);
 696                                 }
 697
 698                         }
 699                 }
 700         }
 701
 702         if (subtype == VSPLUS)
 703                 set = ! set;
 704
 705         easy = ((varflags & VSQUOTE) == 0 ||
 706                 (*var == '@' && shellparam.nparam != 1));
 707
 708
 709         switch (subtype) {
 710         case VSLENGTH:
 711                 expdest = cvtnum(varlen, expdest);
 712                 goto record;
 713
 714         case VSNORMAL:
 715                 if (!easy)
 716                         break;
 717 record:
 718                 recordregion(startloc, expdest - stackblock(),
 719                              varflags & VSQUOTE);
 720                 break;
 721
 722         case VSPLUS:
 723         case VSMINUS:
 724                 if (!set) {
 725                         argstr(p, flag);
 726                         break;
 727                 }
 728                 if (easy)
 729                         goto record;
 730                 break;
 731
 732         case VSTRIMLEFT:
 733         case VSTRIMLEFTMAX:
 734         case VSTRIMRIGHT:
 735         case VSTRIMRIGHTMAX:
 736                 if (!set)
 737                         break;
 738                 /*
 739                  * Terminate the string and start recording the pattern
 740                  * right after it
 741                  */
 742                 STPUTC('\0', expdest);
 743                 patloc = expdest - stackblock();
 744                 if (subevalvar(p, NULL, patloc, subtype,
 745                                startloc, varflags) == 0) {
 746                         int amount = (expdest - stackblock() - patloc) + 1;
 747                         STADJUST(-amount, expdest);
 748                 }
 749                 /* Remove any recorded regions beyond start of variable */
 750                 removerecordregions(startloc);
 751                 goto record;
 752
 753         case VSASSIGN:
 754         case VSQUESTION:
 755                 if (!set) {
 756                         if (subevalvar(p, var, 0, subtype, startloc, varflags)) {
 757                                 varflags &= ~VSNUL;
 758                                 /*
 759                                  * Remove any recorded regions beyond
 760                                  * start of variable
 761                                  */
 762                                 removerecordregions(startloc);
 763                                 goto again;
 764                         }
 765                         break;
 766                 }
 767                 if (easy)
 768                         goto record;
 769                 break;
 770
 771         case VSERROR:
 772                 c = p - var - 1;
 773                 error("${%.*s%s}: Bad substitution", c, var,
 774                     (c > 0 && *p != CTLENDVAR) ? "..." : "");
 775
 776         default:
 777                 abort();
 778         }
 779         p[-1] = '=';    /* recover overwritten '=' */
 780
 781         if (subtype != VSNORMAL) {      /* skip to end of alternative */
 782                 int nesting = 1;
 783                 for (;;) {
 784                         if ((c = *p++) == CTLESC)
 785                                 p++;
 786                         else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
 787                                 if (set)
 788                                         argbackq = argbackq->next;
 789                         } else if (c == CTLVAR) {
 790                                 if ((*p++ & VSTYPE) != VSNORMAL)
 791                                         nesting++;
 792                         } else if (c == CTLENDVAR) {
 793                                 if (--nesting == 0)
 794                                         break;
 795                         }
 796                 }
 797         }
 798         return p;
 799 }
 800
 801
 802
 803 /*
 804  * Test whether a specialized variable is set.
 805  */
 806
 807 STATIC int
 808 varisset(char *name, int nulok)
 809 {
 810
 811         if (*name == '!')
 812                 return backgndpid != -1;
 813         else if (*name == '@' || *name == '*') {
 814                 if (*shellparam.p == NULL)
 815                         return 0;
 816
 817                 if (nulok) {
 818                         char **av;
 819
 820                         for (av = shellparam.p; *av; av++)
 821                                 if (**av != '\0')
 822                                         return 1;
 823                         return 0;
 824                 }
 825         } else if (is_digit(*name)) {
 826                 char *ap;
 827                 int num = atoi(name);
 828
 829                 if (num > shellparam.nparam)
 830                         return 0;
 831
 832                 if (num == 0)
 833                         ap = arg0;
 834                 else
 835                         ap = shellparam.p[num - 1];
 836
 837                 if (nulok && (ap == NULL || *ap == '\0'))
 838                         return 0;
 839         }
 840         return 1;
 841 }
 842
 843
 844
 845 /*
 846  * Add the value of a specialized variable to the stack string.
 847  */
 848
 849 STATIC void
 850 varvalue(char *name, int quoted, int subtype, int flag)
 851 {
 852         int num;
 853         char *p;
 854         int i;
 855         char sep;
 856         char **ap;
 857         char const *syntax;
 858
 859 #define STRTODEST(p) \
 860         do {\
 861         if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) { \
 862                 syntax = quoted? DQSYNTAX : BASESYNTAX; \
 863                 while (*p) { \
 864                         if (syntax[(int)*p] == CCTL) \
 865                                 STPUTC(CTLESC, expdest); \
 866                         STPUTC(*p++, expdest); \
 867                 } \
 868         } else \
 869                 while (*p) \
 870                         STPUTC(*p++, expdest); \
 871         } while (0)
 872
 873
 874         switch (*name) {
 875         case '$':
 876                 num = rootpid;
 877                 goto numvar;
 878         case '?':
 879                 num = oexitstatus;
 880                 goto numvar;
 881         case '#':
 882                 num = shellparam.nparam;
 883                 goto numvar;
 884         case '!':
 885                 num = backgndpid;
 886 numvar:
 887                 expdest = cvtnum(num, expdest);
 888                 break;
 889         case '-':
 890                 for (i = 0 ; i < NOPTS ; i++) {
 891                         if (optlist[i].val)
 892                                 STPUTC(optlist[i].letter, expdest);
 893                 }
 894                 break;
 895         case '@':
 896                 if (flag & EXP_FULL && quoted) {
 897                         for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 898                                 STRTODEST(p);
 899                                 if (*ap)
 900                                         STPUTC('\0', expdest);
 901                         }
 902                         break;
 903                 }
 904                 /* FALLTHROUGH */
 905         case '*':
 906                 if (ifsset())
 907                         sep = ifsval()[0];
 908                 else
 909                         sep = ' ';
 910                 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 911                         STRTODEST(p);
 912                         if (*ap && sep)
 913                                 STPUTC(sep, expdest);
 914                 }
 915                 break;
 916         case '0':
 917                 p = arg0;
 918                 STRTODEST(p);
 919                 break;
 920         default:
 921                 if (is_digit(*name)) {
 922                         num = atoi(name);
 923                         if (num > 0 && num <= shellparam.nparam) {
 924                                 p = shellparam.p[num - 1];
 925                                 STRTODEST(p);
 926                         }
 927                 }
 928                 break;
 929         }
 930 }
 931
 932
 933
 934 /*
 935  * Record the the fact that we have to scan this region of the
 936  * string for IFS characters.
 937  */
 938
 939 STATIC void
 940 recordregion(int start, int end, int inquotes)
 941 {
 942         struct ifsregion *ifsp;
 943
 944         if (ifslastp == NULL) {
 945                 ifsp = &ifsfirst;
 946         } else {
 947                 if (ifslastp->endoff == start
 948                     && ifslastp->inquotes == inquotes) {
 949                         /* extend previous area */
 950                         ifslastp->endoff = end;
 951                         return;
 952                 }
 953                 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
 954                 ifslastp->next = ifsp;
 955         }
 956         ifslastp = ifsp;
 957         ifslastp->next = NULL;
 958         ifslastp->begoff = start;
 959         ifslastp->endoff = end;
 960         ifslastp->inquotes = inquotes;
 961 }
 962
 963
 964
 965 /*
 966  * Break the argument string into pieces based upon IFS and add the
 967  * strings to the argument list.  The regions of the string to be
 968  * searched for IFS characters have been stored by recordregion.
 969  */
 970 STATIC void
 971 ifsbreakup(char *string, struct arglist *arglist)
 972 {
 973         struct ifsregion *ifsp;
 974         struct strlist *sp;
 975         char *start;
 976         char *p;
 977         char *q;
 978         const char *ifs;
 979         const char *ifsspc;
 980         int had_param_ch = 0;
 981
 982         start = string;
 983
 984         if (ifslastp == NULL) {
 985                 /* Return entire argument, IFS doesn't apply to any of it */
 986                 sp = (struct strlist *)stalloc(sizeof *sp);
 987                 sp->text = start;
 988                 *arglist->lastp = sp;
 989                 arglist->lastp = &sp->next;
 990                 return;
 991         }
 992
 993         ifs = ifsset() ? ifsval() : " \t\n";
 994
 995         for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) {
 996                 p = string + ifsp->begoff;
 997                 while (p < string + ifsp->endoff) {
 998                         q = p;
 999                         if (*p == CTLESC)
1000                                 p++;
1001                         if (ifsp->inquotes) {
1002                                 /* Only NULs (should be from "$@") end args */
1003                                 had_param_ch = 1;
1004                                 if (*p != 0) {
1005                                         p++;
1006                                         continue;
1007                                 }
1008                                 ifsspc = NULL;
1009                         } else {
1010                                 if (!strchr(ifs, *p)) {
1011                                         had_param_ch = 1;
1012                                         p++;
1013                                         continue;
1014                                 }
1015                                 ifsspc = strchr(" \t\n", *p);
1016
1017                                 /* Ignore IFS whitespace at start */
1018                                 if (q == start && ifsspc != NULL) {
1019                                         p++;
1020                                         start = p;
1021                                         continue;
1022                                 }
1023                                 had_param_ch = 0;
1024                         }
1025
1026                         /* Save this argument... */
1027                         *q = '\0';
1028                         sp = (struct strlist *)stalloc(sizeof *sp);
1029                         sp->text = start;
1030                         *arglist->lastp = sp;
1031                         arglist->lastp = &sp->next;
1032                         p++;
1033
1034                         if (ifsspc != NULL) {
1035                                 /* Ignore further trailing IFS whitespace */
1036                                 for (; p < string + ifsp->endoff; p++) {
1037                                         q = p;
1038                                         if (*p == CTLESC)
1039                                                 p++;
1040                                         if (strchr(ifs, *p) == NULL) {
1041                                                 p = q;
1042                                                 break;
1043                                         }
1044                                         if (strchr(" \t\n", *p) == NULL) {
1045                                                 p++;
1046                                                 break;
1047                                         }
1048                                 }
1049                         }
1050                         start = p;
1051                 }
1052         }
1053
1054         /*
1055          * Save anything left as an argument.
1056          * Traditionally we have treated 'IFS=':'; set -- x$IFS' as
1057          * generating 2 arguments, the second of which is empty.
1058          * Some recent clarification of the Posix spec say that it
1059          * should only generate one....
1060          */
1061         if (had_param_ch || *start != 0) {
1062                 sp = (struct strlist *)stalloc(sizeof *sp);
1063                 sp->text = start;
1064                 *arglist->lastp = sp;
1065                 arglist->lastp = &sp->next;
1066         }
1067 }
1068
1069
1070
1071 /*
1072  * Expand shell metacharacters.  At this point, the only control characters
1073  * should be escapes.  The results are stored in the list exparg.
1074  */
1075
1076 STATIC char expdir[PATH_MAX];
1077 #define expdir_end (expdir + sizeof(expdir))
1078
1079 STATIC void
1080 expandmeta(struct strlist *str, int flag __unused)
1081 {
1082         char *p;
1083         struct strlist **savelastp;
1084         struct strlist *sp;
1085         char c;
1086         /* TODO - EXP_REDIR */
1087
1088         while (str) {
1089                 if (fflag)
1090                         goto nometa;
1091                 p = str->text;
1092                 for (;;) {                      /* fast check for meta chars */
1093                         if ((c = *p++) == '\0')
1094                                 goto nometa;
1095                         if (c == '*' || c == '?' || c == '[' || c == '!')
1096                                 break;
1097                 }
1098                 savelastp = exparg.lastp;
1099                 INTOFF;
1100                 expmeta(expdir, str->text);
1101                 INTON;
1102                 if (exparg.lastp == savelastp) {
1103                         /*
1104                          * no matches
1105                          */
1106 nometa:
1107                         *exparg.lastp = str;
1108                         rmescapes(str->text);
1109                         exparg.lastp = &str->next;
1110                 } else {
1111                         *exparg.lastp = NULL;
1112                         *savelastp = sp = expsort(*savelastp);
1113                         while (sp->next != NULL)
1114                                 sp = sp->next;
1115                         exparg.lastp = &sp->next;
1116                 }
1117                 str = str->next;
1118         }
1119 }
1120
1121
1122 /*
1123  * Do metacharacter (i.e. *, ?, [...]) expansion.
1124  */
1125
1126 STATIC void
1127 expmeta(char *enddir, char *name)
1128 {
1129         char *p;
1130         char *q;
1131         char *start;
1132         char *endname;
1133         int metaflag;
1134         struct stat statb;
1135         DIR *dirp;
1136         struct dirent *dp;
1137         int atend;
1138         int matchdot;
1139         int esc;
1140
1141         metaflag = 0;
1142         start = name;
1143         for (p = name; esc = 0, *p; p += esc + 1) {
1144                 if (*p == '*' || *p == '?')
1145                         metaflag = 1;
1146                 else if (*p == '[') {
1147                         q = p + 1;
1148                         if (*q == '!' || *q == '^')
1149                                 q++;
1150                         for (;;) {
1151                                 while (*q == CTLQUOTEMARK)
1152                                         q++;
1153                                 if (*q == CTLESC)
1154                                         q++;
1155                                 if (*q == '/' || *q == '\0')
1156                                         break;
1157                                 if (*++q == ']') {
1158                                         metaflag = 1;
1159                                         break;
1160                                 }
1161                         }
1162                 } else if (*p == '!' && p[1] == '!'     && (p == name || p[-1] == '/')) {
1163                         metaflag = 1;
1164                 } else if (*p == '\0')
1165                         break;
1166                 else if (*p == CTLQUOTEMARK)
1167                         continue;
1168                 else {
1169                         if (*p == CTLESC)
1170                                 esc++;
1171                         if (p[esc] == '/') {
1172                                 if (metaflag)
1173                                         break;
1174                                 start = p + esc + 1;
1175                         }
1176                 }
1177         }
1178         if (metaflag == 0) {    /* we've reached the end of the file name */
1179                 if (enddir != expdir)
1180                         metaflag++;
1181                 for (p = name ; ; p++) {
1182                         if (*p == CTLQUOTEMARK)
1183                                 continue;
1184                         if (*p == CTLESC)
1185                                 p++;
1186                         *enddir++ = *p;
1187                         if (*p == '\0')
1188                                 break;
1189                         if (enddir == expdir_end)
1190                                 return;
1191                 }
1192                 if (metaflag == 0 || lstat(expdir, &statb) >= 0)
1193                         addfname(expdir);
1194                 return;
1195         }
1196         endname = p;
1197         if (start != name) {
1198                 p = name;
1199                 while (p < start) {
1200                         while (*p == CTLQUOTEMARK)
1201                                 p++;
1202                         if (*p == CTLESC)
1203                                 p++;
1204                         *enddir++ = *p++;
1205                         if (enddir == expdir_end)
1206                                 return;
1207                 }
1208         }
1209         if (enddir == expdir) {
1210                 p = ".";
1211         } else if (enddir == expdir + 1 && *expdir == '/') {
1212                 p = "/";
1213         } else {
1214                 p = expdir;
1215                 enddir[-1] = '\0';
1216         }
1217         if ((dirp = opendir(p)) == NULL)
1218                 return;
1219         if (enddir != expdir)
1220                 enddir[-1] = '/';
1221         if (*endname == 0) {
1222                 atend = 1;
1223         } else {
1224                 atend = 0;
1225                 *endname = '\0';
1226                 endname += esc + 1;
1227         }
1228         matchdot = 0;
1229         p = start;
1230         while (*p == CTLQUOTEMARK)
1231                 p++;
1232         if (*p == CTLESC)
1233                 p++;
1234         if (*p == '.')
1235                 matchdot++;
1236         while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1237                 if (dp->d_name[0] == '.' && ! matchdot)
1238                         continue;
1239                 if (patmatch(start, dp->d_name, 0)) {
1240                         if (enddir + dp->d_namlen + 1 > expdir_end)
1241                                 continue;
1242                         memcpy(enddir, dp->d_name, dp->d_namlen + 1);
1243                         if (atend)
1244                                 addfname(expdir);
1245                         else {
1246                                 if (enddir + dp->d_namlen + 2 > expdir_end)
1247                                         continue;
1248                                 enddir[dp->d_namlen] = '/';
1249                                 enddir[dp->d_namlen + 1] = '\0';
1250                                 expmeta(enddir + dp->d_namlen + 1, endname);
1251                         }
1252                 }
1253         }
1254         closedir(dirp);
1255         if (! atend)
1256                 endname[-esc - 1] = esc ? CTLESC : '/';
1257 }
1258
1259
1260 /*
1261  * Add a file name to the list.
1262  */
1263
1264 STATIC void
1265 addfname(char *name)
1266 {
1267         char *p;
1268         struct strlist *sp;
1269
1270         p = stalloc(strlen(name) + 1);
1271         scopy(name, p);
1272         sp = (struct strlist *)stalloc(sizeof *sp);
1273         sp->text = p;
1274         *exparg.lastp = sp;
1275         exparg.lastp = &sp->next;
1276 }
1277
1278
1279 /*
1280  * Sort the results of file name expansion.  It calculates the number of
1281  * strings to sort and then calls msort (short for merge sort) to do the
1282  * work.
1283  */
1284
1285 STATIC struct strlist *
1286 expsort(struct strlist *str)
1287 {
1288         int len;
1289         struct strlist *sp;
1290
1291         len = 0;
1292         for (sp = str ; sp ; sp = sp->next)
1293                 len++;
1294         return msort(str, len);
1295 }
1296
1297
1298 STATIC struct strlist *
1299 msort(struct strlist *list, int len)
1300 {
1301         struct strlist *p, *q = NULL;
1302         struct strlist **lpp;
1303         int half;
1304         int n;
1305
1306         if (len <= 1)
1307                 return list;
1308         half = len >> 1;
1309         p = list;
1310         for (n = half ; --n >= 0 ; ) {
1311                 q = p;
1312                 p = p->next;
1313         }
1314         q->next = NULL;                 /* terminate first half of list */
1315         q = msort(list, half);          /* sort first half of list */
1316         p = msort(p, len - half);               /* sort second half */
1317         lpp = &list;
1318         for (;;) {
1319                 if (strcmp(p->text, q->text) < 0) {
1320                         *lpp = p;
1321                         lpp = &p->next;
1322                         if ((p = *lpp) == NULL) {
1323                                 *lpp = q;
1324                                 break;
1325                         }
1326                 } else {
1327                         *lpp = q;
1328                         lpp = &q->next;
1329                         if ((q = *lpp) == NULL) {
1330                                 *lpp = p;
1331                                 break;
1332                         }
1333                 }
1334         }
1335         return list;
1336 }
1337
1338
1339
1340 /*
1341  * Returns true if the pattern matches the string.
1342  */
1343
1344 int
1345 patmatch(const char *pattern, const char *string, int squoted)
1346 {
1347 #ifdef notdef
1348         if (pattern[0] == '!' && pattern[1] == '!')
1349                 return 1 - pmatch(pattern + 2, string);
1350         else
1351 #endif
1352                 return pmatch(pattern, string, squoted);
1353 }
1354
1355
1356 STATIC int
1357 pmatch(const char *pattern, const char *string, int squoted)
1358 {
1359         const char *p, *q;
1360         char c;
1361
1362         p = pattern;
1363         q = string;
1364         for (;;) {
1365                 switch (c = *p++) {
1366                 case '\0':
1367                         goto breakloop;
1368                 case CTLESC:
1369                         if (squoted && *q == CTLESC)
1370                                 q++;
1371                         if (*q++ != *p++)
1372                                 return 0;
1373                         break;
1374                 case CTLQUOTEMARK:
1375                         continue;
1376                 case '?':
1377                         if (squoted && *q == CTLESC)
1378                                 q++;
1379                         if (*q++ == '\0')
1380                                 return 0;
1381                         break;
1382                 case '*':
1383                         c = *p;
1384                         while (c == CTLQUOTEMARK || c == '*')
1385                                 c = *++p;
1386                         if (c != CTLESC &&  c != CTLQUOTEMARK &&
1387                             c != '?' && c != '*' && c != '[') {
1388                                 while (*q != c) {
1389                                         if (squoted && *q == CTLESC &&
1390                                             q[1] == c)
1391                                                 break;
1392                                         if (*q == '\0')
1393                                                 return 0;
1394                                         if (squoted && *q == CTLESC)
1395                                                 q++;
1396                                         q++;
1397                                 }
1398                         }
1399                         do {
1400                                 if (pmatch(p, q, squoted))
1401                                         return 1;
1402                                 if (squoted && *q == CTLESC)
1403                                         q++;
1404                         } while (*q++ != '\0');
1405                         return 0;
1406                 case '[': {
1407                         const char *endp;
1408                         int invert, found;
1409                         char chr;
1410
1411                         endp = p;
1412                         if (*endp == '!' || *endp == '^')
1413                                 endp++;
1414                         for (;;) {
1415                                 while (*endp == CTLQUOTEMARK)
1416                                         endp++;
1417                                 if (*endp == '\0')
1418                                         goto dft;               /* no matching ] */
1419                                 if (*endp == CTLESC)
1420                                         endp++;
1421                                 if (*++endp == ']')
1422                                         break;
1423                         }
1424                         invert = 0;
1425                         if (*p == '!' || *p == '^') {
1426                                 invert++;
1427                                 p++;
1428                         }
1429                         found = 0;
1430                         chr = *q++;
1431                         if (squoted && chr == CTLESC)
1432                                 chr = *q++;
1433                         if (chr == '\0')
1434                                 return 0;
1435                         c = *p++;
1436                         do {
1437                                 if (c == CTLQUOTEMARK)
1438                                         continue;
1439                                 if (c == CTLESC)
1440                                         c = *p++;
1441                                 if (*p == '-' && p[1] != ']') {
1442                                         p++;
1443                                         while (*p == CTLQUOTEMARK)
1444                                                 p++;
1445                                         if (*p == CTLESC)
1446                                                 p++;
1447                                         if (   collate_range_cmp(chr, c) >= 0
1448                                             && collate_range_cmp(chr, *p) <= 0
1449                                            )
1450                                                 found = 1;
1451                                         p++;
1452                                 } else {
1453                                         if (chr == c)
1454                                                 found = 1;
1455                                 }
1456                         } while ((c = *p++) != ']');
1457                         if (found == invert)
1458                                 return 0;
1459                         break;
1460                 }
1461 dft:            default:
1462                         if (squoted && *q == CTLESC)
1463                                 q++;
1464                         if (*q++ != c)
1465                                 return 0;
1466                         break;
1467                 }
1468         }
1469 breakloop:
1470         if (*q != '\0')
1471                 return 0;
1472         return 1;
1473 }
1474
1475
1476
1477 /*
1478  * Remove any CTLESC characters from a string.
1479  */
1480
1481 void
1482 rmescapes(char *str)
1483 {
1484         char *p, *q;
1485
1486         p = str;
1487         while (*p != CTLESC && *p != CTLQUOTEMARK) {
1488                 if (*p++ == '\0')
1489                         return;
1490         }
1491         q = p;
1492         while (*p) {
1493                 if (*p == CTLQUOTEMARK) {
1494                         p++;
1495                         continue;
1496                 }
1497                 if (*p == CTLESC)
1498                         p++;
1499                 *q++ = *p++;
1500         }
1501         *q = '\0';
1502 }
1503
1504
1505
1506 /*
1507  * See if a pattern matches in a case statement.
1508  */
1509
1510 int
1511 casematch(union node *pattern, const char *val)
1512 {
1513         struct stackmark smark;
1514         int result;
1515         char *p;
1516
1517         setstackmark(&smark);
1518         argbackq = pattern->narg.backquote;
1519         STARTSTACKSTR(expdest);
1520         ifslastp = NULL;
1521         argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
1522         STPUTC('\0', expdest);
1523         p = grabstackstr(expdest);
1524         result = patmatch(p, val, 0);
1525         popstackmark(&smark);
1526         return result;
1527 }
1528
1529 /*
1530  * Our own itoa().
1531  */
1532
1533 STATIC char *
1534 cvtnum(int num, char *buf)
1535 {
1536         char temp[32];
1537         int neg = num < 0;
1538         char *p = temp + 31;
1539
1540         temp[31] = '\0';
1541
1542         do {
1543                 *--p = num % 10 + '0';
1544         } while ((num /= 10) != 0);
1545
1546         if (neg)
1547                 *--p = '-';
1548
1549         while (*p)
1550                 STPUTC(*p++, buf);
1551         return buf;
1552 }
1553
1554 /*
1555  * Do most of the work for wordexp(3).
1556  */
1557
1558 int
1559 wordexpcmd(int argc, char **argv)
1560 {
1561         size_t len;
1562         int i;
1563
1564         out1fmt("%08x", argc - 1);
1565         for (i = 1, len = 0; i < argc; i++)
1566                 len += strlen(argv[i]);
1567         out1fmt("%08x", (int)len);
1568         for (i = 1; i < argc; i++) {
1569                 out1str(argv[i]);
1570                 out1c('\0');
1571         }
1572         return (0);
1573 }