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  * Copyright (c) 2010-2015
   7  *      Jilles Tjoelker <jilles@stack.nl>.  All rights reserved.
   8  *
   9  * This code is derived from software contributed to Berkeley by
  10  * Kenneth Almquist.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  */
  36
  37 #ifndef lint
  38 #if 0
  39 static char sccsid[] = "@(#)expand.c    8.5 (Berkeley) 5/15/95";
  40 #endif
  41 #endif /* not lint */
  42 #include <sys/cdefs.h>
  43 __FBSDID("$FreeBSD: head/bin/sh/expand.c 303586 2016-07-31 13:11:34Z jilles $");
  44
  45 #include <sys/types.h>
  46 #include <sys/time.h>
  47 #include <sys/stat.h>
  48 #include <dirent.h>
  49 #include <errno.h>
  50 #include <inttypes.h>
  51 #include <limits.h>
  52 #include <pwd.h>
  53 #include <stdio.h>
  54 #include <stdlib.h>
  55 #include <string.h>
  56 #include <unistd.h>
  57 #include <wchar.h>
  58 #include <wctype.h>
  59
  60 /*
  61  * Routines to expand arguments to commands.  We have to deal with
  62  * backquotes, shell variables, and file metacharacters.
  63  */
  64
  65 #include "shell.h"
  66 #include "main.h"
  67 #include "nodes.h"
  68 #include "eval.h"
  69 #include "expand.h"
  70 #include "syntax.h"
  71 #include "parser.h"
  72 #include "jobs.h"
  73 #include "options.h"
  74 #include "var.h"
  75 #include "input.h"
  76 #include "output.h"
  77 #include "memalloc.h"
  78 #include "error.h"
  79 #include "mystring.h"
  80 #include "arith.h"
  81 #include "show.h"
  82 #include "builtins.h"
  83
  84 enum wordstate { WORD_IDLE, WORD_WS_DELIMITED, WORD_QUOTEMARK };
  85
  86 struct worddest {
  87         struct arglist *list;
  88         enum wordstate state;
  89 };
  90
  91 static char *expdest;                   /* output of current string */
  92 static struct nodelist *argbackq;       /* list of back quote expressions */
  93
  94 static const char *argstr(const char *, int, struct worddest *);
  95 static const char *exptilde(const char *, int);
  96 static const char *expari(const char *, int, struct worddest *);
  97 static void expbackq(union node *, int, int, struct worddest *);
  98 static void subevalvar_trim(const char *, int, int, int);
  99 static int subevalvar_misc(const char *, const char *, int, int, int);
 100 static const char *evalvar(const char *, int, struct worddest *);
 101 static int varisset(const char *, int);
 102 static void strtodest(const char *, int, int, int, struct worddest *);
 103 static void reprocess(int, int, int, int, struct worddest *);
 104 static void varvalue(const char *, int, int, int, struct worddest *);
 105 static void expandmeta(char *, struct arglist *);
 106 static void expmeta(char *, char *, struct arglist *);
 107 static int expsortcmp(const void *, const void *);
 108 static int patmatch(const char *, const char *);
 109 static void cvtnum(int, char *);
 110 static int collate_range_cmp(wchar_t, wchar_t);
 111
 112 void
 113 emptyarglist(struct arglist *list)
 114 {
 115
 116         list->args = list->smallarg;
 117         list->count = 0;
 118         list->capacity = sizeof(list->smallarg) / sizeof(list->smallarg[0]);
 119 }
 120
 121 void
 122 appendarglist(struct arglist *list, char *str)
 123 {
 124         char **newargs;
 125         int newcapacity;
 126
 127         if (list->count >= list->capacity) {
 128                 newcapacity = list->capacity * 2;
 129                 if (newcapacity < 16)
 130                         newcapacity = 16;
 131                 if (newcapacity > INT_MAX / (int)sizeof(newargs[0]))
 132                         error("Too many entries in arglist");
 133                 newargs = stalloc(newcapacity * sizeof(newargs[0]));
 134                 memcpy(newargs, list->args, list->count * sizeof(newargs[0]));
 135                 list->args = newargs;
 136                 list->capacity = newcapacity;
 137         }
 138         list->args[list->count++] = str;
 139 }
 140
 141 static int
 142 collate_range_cmp(wchar_t c1, wchar_t c2)
 143 {
 144         static wchar_t s1[2], s2[2];
 145
 146         s1[0] = c1;
 147         s2[0] = c2;
 148         return (wcscoll(s1, s2));
 149 }
 150
 151 static char *
 152 stputs_quotes(const char *data, const char *syntax, char *p)
 153 {
 154         while (*data) {
 155                 CHECKSTRSPACE(2, p);
 156                 if (syntax[(int)*data] == CCTL)
 157                         USTPUTC(CTLESC, p);
 158                 USTPUTC(*data++, p);
 159         }
 160         return (p);
 161 }
 162 #define STPUTS_QUOTES(data, syntax, p) p = stputs_quotes((data), syntax, p)
 163
 164 static char *
 165 nextword(char c, int flag, char *p, struct worddest *dst)
 166 {
 167         int is_ws;
 168
 169         is_ws = c == '\t' || c == '\n' || c == ' ';
 170         if (p != stackblock() || (is_ws ? dst->state == WORD_QUOTEMARK :
 171             dst->state != WORD_WS_DELIMITED) || c == '\0') {
 172                 STPUTC('\0', p);
 173                 if (flag & EXP_GLOB)
 174                         expandmeta(grabstackstr(p), dst->list);
 175                 else
 176                         appendarglist(dst->list, grabstackstr(p));
 177                 dst->state = is_ws ? WORD_WS_DELIMITED : WORD_IDLE;
 178         } else if (!is_ws && dst->state == WORD_WS_DELIMITED)
 179                 dst->state = WORD_IDLE;
 180         /* Reserve space while the stack string is empty. */
 181         appendarglist(dst->list, NULL);
 182         dst->list->count--;
 183         STARTSTACKSTR(p);
 184         return p;
 185 }
 186 #define NEXTWORD(c, flag, p, dstlist) p = nextword(c, flag, p, dstlist)
 187
 188 static char *
 189 stputs_split(const char *data, const char *syntax, int flag, char *p,
 190     struct worddest *dst)
 191 {
 192         const char *ifs;
 193         char c;
 194
 195         ifs = ifsset() ? ifsval() : " \t\n";
 196         while (*data) {
 197                 CHECKSTRSPACE(2, p);
 198                 c = *data++;
 199                 if (strchr(ifs, c) != NULL) {
 200                         NEXTWORD(c, flag, p, dst);
 201                         continue;
 202                 }
 203                 if (flag & EXP_GLOB && syntax[(int)c] == CCTL)
 204                         USTPUTC(CTLESC, p);
 205                 USTPUTC(c, p);
 206         }
 207         return (p);
 208 }
 209 #define STPUTS_SPLIT(data, syntax, flag, p, dst) p = stputs_split((data), syntax, flag, p, dst)
 210
 211 /*
 212  * Perform expansions on an argument, placing the resulting list of arguments
 213  * in arglist.  Parameter expansion, command substitution and arithmetic
 214  * expansion are always performed; additional expansions can be requested
 215  * via flag (EXP_*).
 216  * The result is left in the stack string.
 217  * When arglist is NULL, perform here document expansion.
 218  *
 219  * Caution: this function uses global state and is not reentrant.
 220  * However, a new invocation after an interrupted invocation is safe
 221  * and will reset the global state for the new call.
 222  */
 223 void
 224 expandarg(union node *arg, struct arglist *arglist, int flag)
 225 {
 226         struct worddest exparg;
 227
 228         if (fflag)
 229                 flag &= ~EXP_GLOB;
 230         argbackq = arg->narg.backquote;
 231         exparg.list = arglist;
 232         exparg.state = WORD_IDLE;
 233         STARTSTACKSTR(expdest);
 234         argstr(arg->narg.text, flag, &exparg);
 235         if (arglist == NULL) {
 236                 STACKSTRNUL(expdest);
 237                 return;                 /* here document expanded */
 238         }
 239         if ((flag & EXP_SPLIT) == 0 || expdest != stackblock() ||
 240             exparg.state == WORD_QUOTEMARK) {
 241                 STPUTC('\0', expdest);
 242                 if (flag & EXP_SPLIT) {
 243                         if (flag & EXP_GLOB)
 244                                 expandmeta(grabstackstr(expdest), exparg.list);
 245                         else
 246                                 appendarglist(exparg.list, grabstackstr(expdest));
 247                 }
 248         }
 249         if ((flag & EXP_SPLIT) == 0)
 250                 appendarglist(arglist, grabstackstr(expdest));
 251 }
 252
 253
 254
 255 /*
 256  * Perform parameter expansion, command substitution and arithmetic
 257  * expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE.
 258  * Processing ends at a CTLENDVAR or CTLENDARI character as well as '\0'.
 259  * This is used to expand word in ${var+word} etc.
 260  * If EXP_GLOB or EXP_CASE are set, keep and/or generate CTLESC
 261  * characters to allow for further processing.
 262  *
 263  * If EXP_SPLIT is set, dst receives any complete words produced.
 264  */
 265 static const char *
 266 argstr(const char *p, int flag, struct worddest *dst)
 267 {
 268         char c;
 269         int quotes = flag & (EXP_GLOB | EXP_CASE);      /* do CTLESC */
 270         int firsteq = 1;
 271         int split_lit;
 272         int lit_quoted;
 273
 274         split_lit = flag & EXP_SPLIT_LIT;
 275         lit_quoted = flag & EXP_LIT_QUOTED;
 276         flag &= ~(EXP_SPLIT_LIT | EXP_LIT_QUOTED);
 277         if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
 278                 p = exptilde(p, flag);
 279         for (;;) {
 280                 CHECKSTRSPACE(2, expdest);
 281                 switch (c = *p++) {
 282                 case '\0':
 283                         return (p - 1);
 284                 case CTLENDVAR:
 285                 case CTLENDARI:
 286                         return (p);
 287                 case CTLQUOTEMARK:
 288                         lit_quoted = 1;
 289                         /* "$@" syntax adherence hack */
 290                         if (p[0] == CTLVAR && (p[1] & VSQUOTE) != 0 &&
 291                             p[2] == '@' && p[3] == '=')
 292                                 break;
 293                         if ((flag & EXP_SPLIT) != 0 && expdest == stackblock())
 294                                 dst->state = WORD_QUOTEMARK;
 295                         break;
 296                 case CTLQUOTEEND:
 297                         lit_quoted = 0;
 298                         break;
 299                 case CTLESC:
 300                         c = *p++;
 301                         if (split_lit && !lit_quoted &&
 302                             strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
 303                                 NEXTWORD(c, flag, expdest, dst);
 304                                 break;
 305                         }
 306                         if (quotes)
 307                                 USTPUTC(CTLESC, expdest);
 308                         USTPUTC(c, expdest);
 309                         break;
 310                 case CTLVAR:
 311                         p = evalvar(p, flag, dst);
 312                         break;
 313                 case CTLBACKQ:
 314                 case CTLBACKQ|CTLQUOTE:
 315                         expbackq(argbackq->n, c & CTLQUOTE, flag, dst);
 316                         argbackq = argbackq->next;
 317                         break;
 318                 case CTLARI:
 319                         p = expari(p, flag, dst);
 320                         break;
 321                 case ':':
 322                 case '=':
 323                         /*
 324                          * sort of a hack - expand tildes in variable
 325                          * assignments (after the first '=' and after ':'s).
 326                          */
 327                         if (split_lit && !lit_quoted &&
 328                             strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
 329                                 NEXTWORD(c, flag, expdest, dst);
 330                                 break;
 331                         }
 332                         USTPUTC(c, expdest);
 333                         if (flag & EXP_VARTILDE && *p == '~' &&
 334                             (c != '=' || firsteq)) {
 335                                 if (c == '=')
 336                                         firsteq = 0;
 337                                 p = exptilde(p, flag);
 338                         }
 339                         break;
 340                 default:
 341                         if (split_lit && !lit_quoted &&
 342                             strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
 343                                 NEXTWORD(c, flag, expdest, dst);
 344                                 break;
 345                         }
 346                         USTPUTC(c, expdest);
 347                 }
 348         }
 349 }
 350
 351 /*
 352  * Perform tilde expansion, placing the result in the stack string and
 353  * returning the next position in the input string to process.
 354  */
 355 static const char *
 356 exptilde(const char *p, int flag)
 357 {
 358         char c;
 359         const char *startp = p;
 360         const char *user;
 361         struct passwd *pw;
 362         char *home;
 363         int len;
 364
 365         for (;;) {
 366                 c = *p;
 367                 switch(c) {
 368                 case CTLESC: /* This means CTL* are always considered quoted. */
 369                 case CTLVAR:
 370                 case CTLBACKQ:
 371                 case CTLBACKQ | CTLQUOTE:
 372                 case CTLARI:
 373                 case CTLENDARI:
 374                 case CTLQUOTEMARK:
 375                         return (startp);
 376                 case ':':
 377                         if ((flag & EXP_VARTILDE) == 0)
 378                                 break;
 379                         /* FALLTHROUGH */
 380                 case '\0':
 381                 case '/':
 382                 case CTLENDVAR:
 383                         len = p - startp - 1;
 384                         STPUTBIN(startp + 1, len, expdest);
 385                         STACKSTRNUL(expdest);
 386                         user = expdest - len;
 387                         if (*user == '\0') {
 388                                 home = lookupvar("HOME");
 389                         } else {
 390                                 pw = getpwnam(user);
 391                                 home = pw != NULL ? pw->pw_dir : NULL;
 392                         }
 393                         STADJUST(-len, expdest);
 394                         if (home == NULL || *home == '\0')
 395                                 return (startp);
 396                         strtodest(home, flag, VSNORMAL, 1, NULL);
 397                         return (p);
 398                 }
 399                 p++;
 400         }
 401 }
 402
 403
 404 /*
 405  * Expand arithmetic expression.
 406  */
 407 static const char *
 408 expari(const char *p, int flag, struct worddest *dst)
 409 {
 410         char *q, *start;
 411         arith_t result;
 412         int begoff;
 413         int quoted;
 414         int adj;
 415
 416         quoted = *p++ == '"';
 417         begoff = expdest - stackblock();
 418         p = argstr(p, 0, NULL);
 419         STPUTC('\0', expdest);
 420         start = stackblock() + begoff;
 421
 422         q = grabstackstr(expdest);
 423         result = arith(start);
 424         ungrabstackstr(q, expdest);
 425
 426         start = stackblock() + begoff;
 427         adj = start - expdest;
 428         STADJUST(adj, expdest);
 429
 430         CHECKSTRSPACE((int)(DIGITS(result) + 1), expdest);
 431         fmtstr(expdest, DIGITS(result), ARITH_FORMAT_STR, result);
 432         adj = strlen(expdest);
 433         STADJUST(adj, expdest);
 434         if (!quoted)
 435                 reprocess(expdest - adj - stackblock(), flag, VSNORMAL, 0, dst);
 436         return p;
 437 }
 438
 439
 440 /*
 441  * Perform command substitution.
 442  */
 443 static void
 444 expbackq(union node *cmd, int quoted, int flag, struct worddest *dst)
 445 {
 446         struct backcmd in;
 447         int i;
 448         char buf[128];
 449         char *p;
 450         char *dest = expdest;
 451         struct nodelist *saveargbackq;
 452         char lastc;
 453         char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
 454         int quotes = flag & (EXP_GLOB | EXP_CASE);
 455         size_t nnl;
 456         const char *ifs;
 457
 458         INTOFF;
 459         saveargbackq = argbackq;
 460         p = grabstackstr(dest);
 461         evalbackcmd(cmd, &in);
 462         ungrabstackstr(p, dest);
 463         argbackq = saveargbackq;
 464
 465         p = in.buf;
 466         nnl = 0;
 467         if (!quoted && flag & EXP_SPLIT)
 468                 ifs = ifsset() ? ifsval() : " \t\n";
 469         else
 470                 ifs = "";
 471         /* Don't copy trailing newlines */
 472         for (;;) {
 473                 if (--in.nleft < 0) {
 474                         if (in.fd < 0)
 475                                 break;
 476                         while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR)
 477                                 ;
 478                         TRACE(("expbackq: read returns %d\n", i));
 479                         if (i <= 0)
 480                                 break;
 481                         p = buf;
 482                         in.nleft = i - 1;
 483                 }
 484                 lastc = *p++;
 485                 if (lastc == '\0')
 486                         continue;
 487                 if (lastc == '\n') {
 488                         nnl++;
 489                 } else {
 490                         if (nnl > 0) {
 491                                 if (strchr(ifs, '\n') != NULL) {
 492                                         NEXTWORD('\n', flag, dest, dst);
 493                                         nnl = 0;
 494                                 } else {
 495                                         CHECKSTRSPACE(nnl + 2, dest);
 496                                         while (nnl > 0) {
 497                                                 nnl--;
 498                                                 USTPUTC('\n', dest);
 499                                         }
 500                                 }
 501                         }
 502                         if (strchr(ifs, lastc) != NULL)
 503                                 NEXTWORD(lastc, flag, dest, dst);
 504                         else {
 505                                 CHECKSTRSPACE(2, dest);
 506                                 if (quotes && syntax[(int)lastc] == CCTL)
 507                                         USTPUTC(CTLESC, dest);
 508                                 USTPUTC(lastc, dest);
 509                         }
 510                 }
 511         }
 512
 513         if (in.fd >= 0)
 514                 close(in.fd);
 515         if (in.buf)
 516                 ckfree(in.buf);
 517         if (in.jp)
 518                 exitstatus = waitforjob(in.jp, (int *)NULL);
 519         TRACE(("expbackq: size=%td: \"%.*s\"\n",
 520                 ((dest - stackblock()) - startloc),
 521                 (int)((dest - stackblock()) - startloc),
 522                 stackblock() + startloc));
 523         expdest = dest;
 524         INTON;
 525 }
 526
 527
 528
 529 static void
 530 recordleft(const char *str, const char *loc, char *startp)
 531 {
 532         int amount;
 533
 534         amount = ((str - 1) - (loc - startp)) - expdest;
 535         STADJUST(amount, expdest);
 536         while (loc != str - 1)
 537                 *startp++ = *loc++;
 538 }
 539
 540 static void
 541 subevalvar_trim(const char *p, int strloc, int subtype, int startloc)
 542 {
 543         char *startp;
 544         char *loc = NULL;
 545         char *str;
 546         int c = 0;
 547         struct nodelist *saveargbackq = argbackq;
 548         int amount;
 549
 550         argstr(p, EXP_CASE | EXP_TILDE, NULL);
 551         STACKSTRNUL(expdest);
 552         argbackq = saveargbackq;
 553         startp = stackblock() + startloc;
 554         str = stackblock() + strloc;
 555
 556         switch (subtype) {
 557         case VSTRIMLEFT:
 558                 for (loc = startp; loc < str; loc++) {
 559                         c = *loc;
 560                         *loc = '\0';
 561                         if (patmatch(str, startp)) {
 562                                 *loc = c;
 563                                 recordleft(str, loc, startp);
 564                                 return;
 565                         }
 566                         *loc = c;
 567                 }
 568                 break;
 569
 570         case VSTRIMLEFTMAX:
 571                 for (loc = str - 1; loc >= startp;) {
 572                         c = *loc;
 573                         *loc = '\0';
 574                         if (patmatch(str, startp)) {
 575                                 *loc = c;
 576                                 recordleft(str, loc, startp);
 577                                 return;
 578                         }
 579                         *loc = c;
 580                         loc--;
 581                 }
 582                 break;
 583
 584         case VSTRIMRIGHT:
 585                 for (loc = str - 1; loc >= startp;) {
 586                         if (patmatch(str, loc)) {
 587                                 amount = loc - expdest;
 588                                 STADJUST(amount, expdest);
 589                                 return;
 590                         }
 591                         loc--;
 592                 }
 593                 break;
 594
 595         case VSTRIMRIGHTMAX:
 596                 for (loc = startp; loc < str - 1; loc++) {
 597                         if (patmatch(str, loc)) {
 598                                 amount = loc - expdest;
 599                                 STADJUST(amount, expdest);
 600                                 return;
 601                         }
 602                 }
 603                 break;
 604
 605
 606         default:
 607                 abort();
 608         }
 609         amount = (expdest - stackblock() - strloc) + 1;
 610         STADJUST(-amount, expdest);
 611 }
 612
 613
 614 static int
 615 subevalvar_misc(const char *p, const char *var, int subtype, int startloc,
 616   int varflags)
 617 {
 618         char *startp;
 619         struct nodelist *saveargbackq = argbackq;
 620         int amount;
 621
 622         argstr(p, EXP_TILDE, NULL);
 623         STACKSTRNUL(expdest);
 624         argbackq = saveargbackq;
 625         startp = stackblock() + startloc;
 626
 627         switch (subtype) {
 628         case VSASSIGN:
 629                 setvar(var, startp, 0);
 630                 amount = startp - expdest;
 631                 STADJUST(amount, expdest);
 632                 return 1;
 633
 634         case VSQUESTION:
 635                 if (*p != CTLENDVAR) {
 636                         outfmt(out2, "%s\n", startp);
 637                         error((char *)NULL);
 638                 }
 639                 error("%.*s: parameter %snot set", (int)(p - var - 1),
 640                       var, (varflags & VSNUL) ? "null or " : "");
 641                 return 0;
 642
 643         default:
 644                 abort();
 645         }
 646 }
 647
 648
 649 /*
 650  * Expand a variable, and return a pointer to the next character in the
 651  * input string.
 652  */
 653
 654 static const char *
 655 evalvar(const char *p, int flag, struct worddest *dst)
 656 {
 657         int subtype;
 658         int varflags;
 659         const char *var;
 660         const char *val;
 661         int patloc;
 662         int c;
 663         int set;
 664         int special;
 665         int startloc;
 666         int varlen;
 667         int varlenb;
 668         char buf[21];
 669
 670         varflags = (unsigned char)*p++;
 671         subtype = varflags & VSTYPE;
 672         var = p;
 673         special = 0;
 674         if (! is_name(*p))
 675                 special = 1;
 676         p = strchr(p, '=') + 1;
 677 again: /* jump here after setting a variable with ${var=text} */
 678         if (varflags & VSLINENO) {
 679                 set = 1;
 680                 special = 1;
 681                 val = NULL;
 682         } else if (special) {
 683                 set = varisset(var, varflags & VSNUL);
 684                 val = NULL;
 685         } else {
 686                 val = bltinlookup(var, 1);
 687                 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
 688                         val = NULL;
 689                         set = 0;
 690                 } else
 691                         set = 1;
 692         }
 693         varlen = 0;
 694         startloc = expdest - stackblock();
 695         if (!set && uflag && *var != '@' && *var != '*') {
 696                 switch (subtype) {
 697                 case VSNORMAL:
 698                 case VSTRIMLEFT:
 699                 case VSTRIMLEFTMAX:
 700                 case VSTRIMRIGHT:
 701                 case VSTRIMRIGHTMAX:
 702                 case VSLENGTH:
 703                         error("%.*s: parameter not set", (int)(p - var - 1),
 704                             var);
 705                 }
 706         }
 707         if (set && subtype != VSPLUS) {
 708                 /* insert the value of the variable */
 709                 if (special) {
 710                         if (varflags & VSLINENO) {
 711                                 if (p - var > (ptrdiff_t)sizeof(buf))
 712                                         abort();
 713                                 memcpy(buf, var, p - var - 1);
 714                                 buf[p - var - 1] = '\0';
 715                                 strtodest(buf, flag, subtype,
 716                                     varflags & VSQUOTE, dst);
 717                         } else
 718                                 varvalue(var, varflags & VSQUOTE, subtype, flag,
 719                                     dst);
 720                         if (subtype == VSLENGTH) {
 721                                 varlenb = expdest - stackblock() - startloc;
 722                                 varlen = varlenb;
 723                                 if (localeisutf8) {
 724                                         val = stackblock() + startloc;
 725                                         for (;val != expdest; val++)
 726                                                 if ((*val & 0xC0) == 0x80)
 727                                                         varlen--;
 728                                 }
 729                                 STADJUST(-varlenb, expdest);
 730                         }
 731                 } else {
 732                         if (subtype == VSLENGTH) {
 733                                 for (;*val; val++)
 734                                         if (!localeisutf8 ||
 735                                             (*val & 0xC0) != 0x80)
 736                                                 varlen++;
 737                         }
 738                         else
 739                                 strtodest(val, flag, subtype,
 740                                     varflags & VSQUOTE, dst);
 741                 }
 742         }
 743
 744         if (subtype == VSPLUS)
 745                 set = ! set;
 746
 747         switch (subtype) {
 748         case VSLENGTH:
 749                 cvtnum(varlen, buf);
 750                 strtodest(buf, flag, VSNORMAL, varflags & VSQUOTE, dst);
 751                 break;
 752
 753         case VSNORMAL:
 754                 break;
 755
 756         case VSPLUS:
 757         case VSMINUS:
 758                 if (!set) {
 759                         argstr(p, flag | (flag & EXP_SPLIT ? EXP_SPLIT_LIT : 0) |
 760                             (varflags & VSQUOTE ? EXP_LIT_QUOTED : 0), dst);
 761                         break;
 762                 }
 763                 break;
 764
 765         case VSTRIMLEFT:
 766         case VSTRIMLEFTMAX:
 767         case VSTRIMRIGHT:
 768         case VSTRIMRIGHTMAX:
 769                 if (!set)
 770                         break;
 771                 /*
 772                  * Terminate the string and start recording the pattern
 773                  * right after it
 774                  */
 775                 STPUTC('\0', expdest);
 776                 patloc = expdest - stackblock();
 777                 subevalvar_trim(p, patloc, subtype, startloc);
 778                 reprocess(startloc, flag, VSNORMAL, varflags & VSQUOTE, dst);
 779                 if (flag & EXP_SPLIT && *var == '@' && varflags & VSQUOTE)
 780                         dst->state = WORD_QUOTEMARK;
 781                 break;
 782
 783         case VSASSIGN:
 784         case VSQUESTION:
 785                 if (!set) {
 786                         if (subevalvar_misc(p, var, subtype, startloc,
 787                             varflags)) {
 788                                 varflags &= ~VSNUL;
 789                                 goto again;
 790                         }
 791                         break;
 792                 }
 793                 break;
 794
 795         case VSERROR:
 796                 c = p - var - 1;
 797                 error("${%.*s%s}: Bad substitution", c, var,
 798                     (c > 0 && *p != CTLENDVAR) ? "..." : "");
 799
 800         default:
 801                 abort();
 802         }
 803
 804         if (subtype != VSNORMAL) {      /* skip to end of alternative */
 805                 int nesting = 1;
 806                 for (;;) {
 807                         if ((c = *p++) == CTLESC)
 808                                 p++;
 809                         else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
 810                                 if (set)
 811                                         argbackq = argbackq->next;
 812                         } else if (c == CTLVAR) {
 813                                 if ((*p++ & VSTYPE) != VSNORMAL)
 814                                         nesting++;
 815                         } else if (c == CTLENDVAR) {
 816                                 if (--nesting == 0)
 817                                         break;
 818                         }
 819                 }
 820         }
 821         return p;
 822 }
 823
 824
 825
 826 /*
 827  * Test whether a specialized variable is set.
 828  */
 829
 830 static int
 831 varisset(const char *name, int nulok)
 832 {
 833
 834         if (*name == '!')
 835                 return backgndpidset();
 836         else if (*name == '@' || *name == '*') {
 837                 if (*shellparam.p == NULL)
 838                         return 0;
 839
 840                 if (nulok) {
 841                         char **av;
 842
 843                         for (av = shellparam.p; *av; av++)
 844                                 if (**av != '\0')
 845                                         return 1;
 846                         return 0;
 847                 }
 848         } else if (is_digit(*name)) {
 849                 char *ap;
 850                 long num;
 851
 852                 errno = 0;
 853                 num = strtol(name, NULL, 10);
 854                 if (errno != 0 || num > shellparam.nparam)
 855                         return 0;
 856
 857                 if (num == 0)
 858                         ap = arg0;
 859                 else
 860                         ap = shellparam.p[num - 1];
 861
 862                 if (nulok && (ap == NULL || *ap == '\0'))
 863                         return 0;
 864         }
 865         return 1;
 866 }
 867
 868 static void
 869 strtodest(const char *p, int flag, int subtype, int quoted,
 870     struct worddest *dst)
 871 {
 872         if (subtype == VSLENGTH || subtype == VSTRIMLEFT ||
 873             subtype == VSTRIMLEFTMAX || subtype == VSTRIMRIGHT ||
 874             subtype == VSTRIMRIGHTMAX)
 875                 STPUTS(p, expdest);
 876         else if (flag & EXP_SPLIT && !quoted && dst != NULL)
 877                 STPUTS_SPLIT(p, BASESYNTAX, flag, expdest, dst);
 878         else if (flag & (EXP_GLOB | EXP_CASE))
 879                 STPUTS_QUOTES(p, quoted ? DQSYNTAX : BASESYNTAX, expdest);
 880         else
 881                 STPUTS(p, expdest);
 882 }
 883
 884 static void
 885 reprocess(int startloc, int flag, int subtype, int quoted,
 886     struct worddest *dst)
 887 {
 888         static char *buf = NULL;
 889         static size_t buflen = 0;
 890         char *startp;
 891         size_t len, zpos, zlen;
 892
 893         startp = stackblock() + startloc;
 894         len = expdest - startp;
 895         if (len >= SIZE_MAX / 2)
 896                 abort();
 897         INTOFF;
 898         if (len >= buflen) {
 899                 ckfree(buf);
 900                 buf = NULL;
 901         }
 902         if (buflen < 128)
 903                 buflen = 128;
 904         while (len >= buflen)
 905                 buflen <<= 1;
 906         if (buf == NULL)
 907                 buf = ckmalloc(buflen);
 908         INTON;
 909         memcpy(buf, startp, len);
 910         buf[len] = '\0';
 911         STADJUST(-len, expdest);
 912         for (zpos = 0;;) {
 913                 zlen = strlen(buf + zpos);
 914                 strtodest(buf + zpos, flag, subtype, quoted, dst);
 915                 zpos += zlen + 1;
 916                 if (zpos == len + 1)
 917                         break;
 918                 if (flag & EXP_SPLIT && (quoted || (zlen > 0 && zpos < len)))
 919                         NEXTWORD('\0', flag, expdest, dst);
 920         }
 921 }
 922
 923 /*
 924  * Add the value of a specialized variable to the stack string.
 925  */
 926
 927 static void
 928 varvalue(const char *name, int quoted, int subtype, int flag,
 929     struct worddest *dst)
 930 {
 931         int num;
 932         char *p;
 933         int i;
 934         int splitlater;
 935         char sep[2];
 936         char **ap;
 937         char buf[(NSHORTOPTS > 10 ? NSHORTOPTS : 10) + 1];
 938
 939         if (subtype == VSLENGTH)
 940                 flag &= ~EXP_FULL;
 941         splitlater = subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX ||
 942                 subtype == VSTRIMRIGHT || subtype == VSTRIMRIGHTMAX;
 943
 944         switch (*name) {
 945         case '$':
 946                 num = rootpid;
 947                 break;
 948         case '?':
 949                 num = oexitstatus;
 950                 break;
 951         case '#':
 952                 num = shellparam.nparam;
 953                 break;
 954         case '!':
 955                 num = backgndpidval();
 956                 break;
 957         case '-':
 958                 p = buf;
 959                 for (i = 0 ; i < NSHORTOPTS ; i++) {
 960                         if (optval[i])
 961                                 *p++ = optletter[i];
 962                 }
 963                 *p = '\0';
 964                 strtodest(buf, flag, subtype, quoted, dst);
 965                 return;
 966         case '@':
 967                 if (flag & EXP_SPLIT && quoted) {
 968                         for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 969                                 strtodest(p, flag, subtype, quoted, dst);
 970                                 if (*ap) {
 971                                         if (splitlater)
 972                                                 STPUTC('\0', expdest);
 973                                         else
 974                                                 NEXTWORD('\0', flag, expdest,
 975                                                     dst);
 976                                 }
 977                         }
 978                         if (shellparam.nparam > 0)
 979                                 dst->state = WORD_QUOTEMARK;
 980                         return;
 981                 }
 982                 /* FALLTHROUGH */
 983         case '*':
 984                 if (ifsset())
 985                         sep[0] = ifsval()[0];
 986                 else
 987                         sep[0] = ' ';
 988                 sep[1] = '\0';
 989                 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 990                         strtodest(p, flag, subtype, quoted, dst);
 991                         if (!*ap)
 992                                 break;
 993                         if (sep[0])
 994                                 strtodest(sep, flag, subtype, quoted, dst);
 995                         else if (flag & EXP_SPLIT && !quoted && **ap != '\0') {
 996                                 if (splitlater)
 997                                         STPUTC('\0', expdest);
 998                                 else
 999                                         NEXTWORD('\0', flag, expdest, dst);
1000                         }
1001                 }
1002                 return;
1003         default:
1004                 if (is_digit(*name)) {
1005                         num = atoi(name);
1006                         if (num == 0)
1007                                 p = arg0;
1008                         else if (num > 0 && num <= shellparam.nparam)
1009                                 p = shellparam.p[num - 1];
1010                         else
1011                                 return;
1012                         strtodest(p, flag, subtype, quoted, dst);
1013                 }
1014                 return;
1015         }
1016         cvtnum(num, buf);
1017         strtodest(buf, flag, subtype, quoted, dst);
1018 }
1019
1020
1021
1022 static char expdir[PATH_MAX];
1023 #define expdir_end (expdir + sizeof(expdir))
1024
1025 /*
1026  * Perform pathname generation and remove control characters.
1027  * At this point, the only control characters should be CTLESC.
1028  * The results are stored in the list dstlist.
1029  */
1030 static void
1031 expandmeta(char *pattern, struct arglist *dstlist)
1032 {
1033         char *p;
1034         int firstmatch;
1035         char c;
1036
1037         firstmatch = dstlist->count;
1038         p = pattern;
1039         for (; (c = *p) != '\0'; p++) {
1040                 /* fast check for meta chars */
1041                 if (c == '*' || c == '?' || c == '[') {
1042                         INTOFF;
1043                         expmeta(expdir, pattern, dstlist);
1044                         INTON;
1045                         break;
1046                 }
1047         }
1048         if (dstlist->count == firstmatch) {
1049                 /*
1050                  * no matches
1051                  */
1052                 rmescapes(pattern);
1053                 appendarglist(dstlist, pattern);
1054         } else {
1055                 qsort(&dstlist->args[firstmatch],
1056                     dstlist->count - firstmatch,
1057                     sizeof(dstlist->args[0]), expsortcmp);
1058         }
1059 }
1060
1061
1062 /*
1063  * Do metacharacter (i.e. *, ?, [...]) expansion.
1064  */
1065
1066 static void
1067 expmeta(char *enddir, char *name, struct arglist *arglist)
1068 {
1069         const char *p;
1070         const char *q;
1071         const char *start;
1072         char *endname;
1073         int metaflag;
1074         struct stat statb;
1075         DIR *dirp;
1076         struct dirent *dp;
1077         int atend;
1078         int matchdot;
1079         int esc;
1080         int namlen;
1081
1082         metaflag = 0;
1083         start = name;
1084         for (p = name; esc = 0, *p; p += esc + 1) {
1085                 if (*p == '*' || *p == '?')
1086                         metaflag = 1;
1087                 else if (*p == '[') {
1088                         q = p + 1;
1089                         if (*q == '!' || *q == '^')
1090                                 q++;
1091                         for (;;) {
1092                                 if (*q == CTLESC)
1093                                         q++;
1094                                 if (*q == '/' || *q == '\0')
1095                                         break;
1096                                 if (*++q == ']') {
1097                                         metaflag = 1;
1098                                         break;
1099                                 }
1100                         }
1101                 } else if (*p == '\0')
1102                         break;
1103                 else {
1104                         if (*p == CTLESC)
1105                                 esc++;
1106                         if (p[esc] == '/') {
1107                                 if (metaflag)
1108                                         break;
1109                                 start = p + esc + 1;
1110                         }
1111                 }
1112         }
1113         if (metaflag == 0) {    /* we've reached the end of the file name */
1114                 if (enddir != expdir)
1115                         metaflag++;
1116                 for (p = name ; ; p++) {
1117                         if (*p == CTLESC)
1118                                 p++;
1119                         *enddir++ = *p;
1120                         if (*p == '\0')
1121                                 break;
1122                         if (enddir == expdir_end)
1123                                 return;
1124                 }
1125                 if (metaflag == 0 || lstat(expdir, &statb) >= 0)
1126                         appendarglist(arglist, stsavestr(expdir));
1127                 return;
1128         }
1129         endname = name + (p - name);
1130         if (start != name) {
1131                 p = name;
1132                 while (p < start) {
1133                         if (*p == CTLESC)
1134                                 p++;
1135                         *enddir++ = *p++;
1136                         if (enddir == expdir_end)
1137                                 return;
1138                 }
1139         }
1140         if (enddir == expdir) {
1141                 p = ".";
1142         } else if (enddir == expdir + 1 && *expdir == '/') {
1143                 p = "/";
1144         } else {
1145                 p = expdir;
1146                 enddir[-1] = '\0';
1147         }
1148         if ((dirp = opendir(p)) == NULL)
1149                 return;
1150         if (enddir != expdir)
1151                 enddir[-1] = '/';
1152         if (*endname == 0) {
1153                 atend = 1;
1154         } else {
1155                 atend = 0;
1156                 *endname = '\0';
1157                 endname += esc + 1;
1158         }
1159         matchdot = 0;
1160         p = start;
1161         if (*p == CTLESC)
1162                 p++;
1163         if (*p == '.')
1164                 matchdot++;
1165         while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1166                 if (dp->d_name[0] == '.' && ! matchdot)
1167                         continue;
1168                 if (patmatch(start, dp->d_name)) {
1169                         namlen = dp->d_namlen;
1170                         if (enddir + namlen + 1 > expdir_end)
1171                                 continue;
1172                         memcpy(enddir, dp->d_name, namlen + 1);
1173                         if (atend)
1174                                 appendarglist(arglist, stsavestr(expdir));
1175                         else {
1176                                 if (dp->d_type != DT_UNKNOWN &&
1177                                     dp->d_type != DT_DIR &&
1178                                     dp->d_type != DT_LNK)
1179                                         continue;
1180                                 if (enddir + namlen + 2 > expdir_end)
1181                                         continue;
1182                                 enddir[namlen] = '/';
1183                                 enddir[namlen + 1] = '\0';
1184                                 expmeta(enddir + namlen + 1, endname, arglist);
1185                         }
1186                 }
1187         }
1188         closedir(dirp);
1189         if (! atend)
1190                 endname[-esc - 1] = esc ? CTLESC : '/';
1191 }
1192
1193
1194 static int
1195 expsortcmp(const void *p1, const void *p2)
1196 {
1197         const char *s1 = *(const char * const *)p1;
1198         const char *s2 = *(const char * const *)p2;
1199
1200         return (strcoll(s1, s2));
1201 }
1202
1203
1204
1205 static wchar_t
1206 get_wc(const char **p)
1207 {
1208         wchar_t c;
1209         int chrlen;
1210
1211         chrlen = mbtowc(&c, *p, 4);
1212         if (chrlen == 0)
1213                 return 0;
1214         else if (chrlen == -1)
1215                 c = 0;
1216         else
1217                 *p += chrlen;
1218         return c;
1219 }
1220
1221
1222 /*
1223  * See if a character matches a character class, starting at the first colon
1224  * of "[:class:]".
1225  * If a valid character class is recognized, a pointer to the next character
1226  * after the final closing bracket is stored into *end, otherwise a null
1227  * pointer is stored into *end.
1228  */
1229 static int
1230 match_charclass(const char *p, wchar_t chr, const char **end)
1231 {
1232         char name[20];
1233         const char *nameend;
1234         wctype_t cclass;
1235
1236         *end = NULL;
1237         p++;
1238         nameend = strstr(p, ":]");
1239         if (nameend == NULL || (size_t)(nameend - p) >= sizeof(name) ||
1240             nameend == p)
1241                 return 0;
1242         memcpy(name, p, nameend - p);
1243         name[nameend - p] = '\0';
1244         *end = nameend + 2;
1245         cclass = wctype(name);
1246         /* An unknown class matches nothing but is valid nevertheless. */
1247         if (cclass == 0)
1248                 return 0;
1249         return iswctype(chr, cclass);
1250 }
1251
1252
1253 /*
1254  * Returns true if the pattern matches the string.
1255  */
1256
1257 static int
1258 patmatch(const char *pattern, const char *string)
1259 {
1260         const char *p, *q, *end;
1261         const char *bt_p, *bt_q;
1262         char c;
1263         wchar_t wc, wc2;
1264
1265         p = pattern;
1266         q = string;
1267         bt_p = NULL;
1268         bt_q = NULL;
1269         for (;;) {
1270                 switch (c = *p++) {
1271                 case '\0':
1272                         if (*q != '\0')
1273                                 goto backtrack;
1274                         return 1;
1275                 case CTLESC:
1276                         if (*q++ != *p++)
1277                                 goto backtrack;
1278                         break;
1279                 case '?':
1280                         if (*q == '\0')
1281                                 return 0;
1282                         if (localeisutf8) {
1283                                 wc = get_wc(&q);
1284                                 /*
1285                                  * A '?' does not match invalid UTF-8 but a
1286                                  * '*' does, so backtrack.
1287                                  */
1288                                 if (wc == 0)
1289                                         goto backtrack;
1290                         } else
1291                                 q++;
1292                         break;
1293                 case '*':
1294                         c = *p;
1295                         while (c == '*')
1296                                 c = *++p;
1297                         /*
1298                          * If the pattern ends here, we know the string
1299                          * matches without needing to look at the rest of it.
1300                          */
1301                         if (c == '\0')
1302                                 return 1;
1303                         /*
1304                          * First try the shortest match for the '*' that
1305                          * could work. We can forget any earlier '*' since
1306                          * there is no way having it match more characters
1307                          * can help us, given that we are already here.
1308                          */
1309                         bt_p = p;
1310                         bt_q = q;
1311                         break;
1312                 case '[': {
1313                         const char *savep, *saveq;
1314                         int invert, found;
1315                         wchar_t chr;
1316
1317                         savep = p, saveq = q;
1318                         invert = 0;
1319                         if (*p == '!' || *p == '^') {
1320                                 invert++;
1321                                 p++;
1322                         }
1323                         found = 0;
1324                         if (*q == '\0')
1325                                 return 0;
1326                         if (localeisutf8) {
1327                                 chr = get_wc(&q);
1328                                 if (chr == 0)
1329                                         goto backtrack;
1330                         } else
1331                                 chr = (unsigned char)*q++;
1332                         c = *p++;
1333                         do {
1334                                 if (c == '\0') {
1335                                         p = savep, q = saveq;
1336                                         c = '[';
1337                                         goto dft;
1338                                 }
1339                                 if (c == '[' && *p == ':') {
1340                                         found |= match_charclass(p, chr, &end);
1341                                         if (end != NULL)
1342                                                 p = end;
1343                                 }
1344                                 if (c == CTLESC)
1345                                         c = *p++;
1346                                 if (localeisutf8 && c & 0x80) {
1347                                         p--;
1348                                         wc = get_wc(&p);
1349                                         if (wc == 0) /* bad utf-8 */
1350                                                 return 0;
1351                                 } else
1352                                         wc = (unsigned char)c;
1353                                 if (*p == '-' && p[1] != ']') {
1354                                         p++;
1355                                         if (*p == CTLESC)
1356                                                 p++;
1357                                         if (localeisutf8) {
1358                                                 wc2 = get_wc(&p);
1359                                                 if (wc2 == 0) /* bad utf-8 */
1360                                                         return 0;
1361                                         } else
1362                                                 wc2 = (unsigned char)*p++;
1363                                         if (   collate_range_cmp(chr, wc) >= 0
1364                                             && collate_range_cmp(chr, wc2) <= 0
1365                                            )
1366                                                 found = 1;
1367                                 } else {
1368                                         if (chr == wc)
1369                                                 found = 1;
1370                                 }
1371                         } while ((c = *p++) != ']');
1372                         if (found == invert)
1373                                 goto backtrack;
1374                         break;
1375                 }
1376 dft:            default:
1377                         if (*q == '\0')
1378                                 return 0;
1379                         if (*q++ == c)
1380                                 break;
1381 backtrack:
1382                         /*
1383                          * If we have a mismatch (other than hitting the end
1384                          * of the string), go back to the last '*' seen and
1385                          * have it match one additional character.
1386                          */
1387                         if (bt_p == NULL)
1388                                 return 0;
1389                         if (*bt_q == '\0')
1390                                 return 0;
1391                         bt_q++;
1392                         p = bt_p;
1393                         q = bt_q;
1394                         break;
1395                 }
1396         }
1397 }
1398
1399
1400
1401 /*
1402  * Remove any CTLESC and CTLQUOTEMARK characters from a string.
1403  */
1404
1405 void
1406 rmescapes(char *str)
1407 {
1408         char *p, *q;
1409
1410         p = str;
1411         while (*p != CTLESC && *p != CTLQUOTEMARK && *p != CTLQUOTEEND) {
1412                 if (*p++ == '\0')
1413                         return;
1414         }
1415         q = p;
1416         while (*p) {
1417                 if (*p == CTLQUOTEMARK || *p == CTLQUOTEEND) {
1418                         p++;
1419                         continue;
1420                 }
1421                 if (*p == CTLESC)
1422                         p++;
1423                 *q++ = *p++;
1424         }
1425         *q = '\0';
1426 }
1427
1428
1429
1430 /*
1431  * See if a pattern matches in a case statement.
1432  */
1433
1434 int
1435 casematch(union node *pattern, const char *val)
1436 {
1437         struct stackmark smark;
1438         int result;
1439         char *p;
1440
1441         setstackmark(&smark);
1442         argbackq = pattern->narg.backquote;
1443         STARTSTACKSTR(expdest);
1444         argstr(pattern->narg.text, EXP_TILDE | EXP_CASE, NULL);
1445         STPUTC('\0', expdest);
1446         p = grabstackstr(expdest);
1447         result = patmatch(p, val);
1448         popstackmark(&smark);
1449         return result;
1450 }
1451
1452 /*
1453  * Our own itoa().
1454  */
1455
1456 static void
1457 cvtnum(int num, char *buf)
1458 {
1459         char temp[32];
1460         int neg = num < 0;
1461         char *p = temp + 31;
1462
1463         temp[31] = '\0';
1464
1465         do {
1466                 *--p = num % 10 + '0';
1467         } while ((num /= 10) != 0);
1468
1469         if (neg)
1470                 *--p = '-';
1471
1472         memcpy(buf, p, temp + 32 - p);
1473 }
1474
1475 /*
1476  * Do most of the work for wordexp(3).
1477  */
1478
1479 int
1480 wordexpcmd(int argc, char **argv)
1481 {
1482         size_t len;
1483         int i;
1484
1485         out1fmt("%08x", argc - 1);
1486         for (i = 1, len = 0; i < argc; i++)
1487                 len += strlen(argv[i]);
1488         out1fmt("%08x", (int)len);
1489         for (i = 1; i < argc; i++)
1490                 outbin(argv[i], strlen(argv[i]) + 1, out1);
1491         return (0);
1492 }
1493
1494 /*
1495  * Do most of the work for wordexp(3), new version.
1496  */
1497
1498 int
1499 freebsd_wordexpcmd(int argc __unused, char **argv __unused)
1500 {
1501         struct arglist arglist;
1502         union node *args, *n;
1503         size_t len;
1504         int ch;
1505         int protected = 0;
1506         int fd = -1;
1507         int i;
1508
1509         while ((ch = nextopt("f:p")) != '\0') {
1510                 switch (ch) {
1511                 case 'f':
1512                         fd = number(shoptarg);
1513                         break;
1514                 case 'p':
1515                         protected = 1;
1516                         break;
1517                 }
1518         }
1519         if (*argptr != NULL)
1520                 error("wrong number of arguments");
1521         if (fd < 0)
1522                 error("missing fd");
1523         INTOFF;
1524         setinputfd(fd, 1);
1525         INTON;
1526         args = parsewordexp();
1527         popfile(); /* will also close fd */
1528         if (protected)
1529                 for (n = args; n != NULL; n = n->narg.next) {
1530                         if (n->narg.backquote != NULL) {
1531                                 outcslow('C', out1);
1532                                 error("command substitution disabled");
1533                         }
1534                 }
1535         outcslow(' ', out1);
1536         emptyarglist(&arglist);
1537         for (n = args; n != NULL; n = n->narg.next)
1538                 expandarg(n, &arglist, EXP_FULL | EXP_TILDE);
1539         for (i = 0, len = 0; i < arglist.count; i++)
1540                 len += strlen(arglist.args[i]);
1541         out1fmt("%016x %016zx", arglist.count, len);
1542         for (i = 0; i < arglist.count; i++)
1543                 outbin(arglist.args[i], strlen(arglist.args[i]) + 1, out1);
1544         return (0);
1545 }