bin/sh/expand.c

   1 /*      $NetBSD: expand.c,v 1.82 2009/01/18 00:30:54 lukem Exp $        */
   2
   3 /*-
   4  * Copyright (c) 1991, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Kenneth Almquist.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. 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 #include <sys/cdefs.h>
  36 #ifndef lint
  37 #if 0
  38 static char sccsid[] = "@(#)expand.c    8.5 (Berkeley) 5/15/95";
  39 #else
  40 __RCSID("$NetBSD: expand.c,v 1.82 2009/01/18 00:30:54 lukem Exp $");
  41 #endif
  42 #endif /* not lint */
  43
  44 #include <sys/types.h>
  45 #include <sys/time.h>
  46 #include <sys/stat.h>
  47 #include <errno.h>
  48 #include <dirent.h>
  49 #include <unistd.h>
  50 #include <pwd.h>
  51 #include <stdlib.h>
  52 #include <stdio.h>
  53
  54 /*
  55  * Routines to expand arguments to commands.  We have to deal with
  56  * backquotes, shell variables, and file metacharacters.
  57  */
  58
  59 #include "shell.h"
  60 #include "main.h"
  61 #include "nodes.h"
  62 #include "eval.h"
  63 #include "expand.h"
  64 #include "syntax.h"
  65 #include "parser.h"
  66 #include "jobs.h"
  67 #include "options.h"
  68 #include "var.h"
  69 #include "input.h"
  70 #include "output.h"
  71 #include "memalloc.h"
  72 #include "error.h"
  73 #include "mystring.h"
  74 #include "show.h"
  75
  76 /*
  77  * Structure specifying which parts of the string should be searched
  78  * for IFS characters.
  79  */
  80
  81 struct ifsregion {
  82         struct ifsregion *next; /* next region in list */
  83         int begoff;             /* offset of start of region */
  84         int endoff;             /* offset of end of region */
  85         int inquotes;           /* search for nul bytes only */
  86 };
  87
  88
  89 char *expdest;                  /* output of current string */
  90 struct nodelist *argbackq;      /* list of back quote expressions */
  91 struct ifsregion ifsfirst;      /* first struct in list of ifs regions */
  92 struct ifsregion *ifslastp;     /* last struct in list */
  93 struct arglist exparg;          /* holds expanded arg list */
  94
  95 STATIC void argstr(char *, int);
  96 STATIC char *exptilde(char *, int);
  97 STATIC void expbackq(union node *, int, int);
  98 STATIC int subevalvar(char *, char *, int, int, int, int);
  99 STATIC char *evalvar(char *, int);
 100 STATIC int varisset(char *, int);
 101 STATIC void varvalue(char *, int, int, int);
 102 STATIC void recordregion(int, int, int);
 103 STATIC void removerecordregions(int);
 104 STATIC void ifsbreakup(char *, struct arglist *);
 105 STATIC void ifsfree(void);
 106 STATIC void expandmeta(struct strlist *, int);
 107 STATIC void expmeta(char *, char *);
 108 STATIC void addfname(char *);
 109 STATIC struct strlist *expsort(struct strlist *);
 110 STATIC struct strlist *msort(struct strlist *, int);
 111 STATIC int pmatch(char *, char *, int);
 112 STATIC char *cvtnum(int, char *);
 113
 114 /*
 115  * Expand shell variables and backquotes inside a here document.
 116  */
 117
 118 void
 119 expandhere(union node *arg, int fd)
 120 {
 121         herefd = fd;
 122         expandarg(arg, (struct arglist *)NULL, 0);
 123         xwrite(fd, stackblock(), expdest - stackblock());
 124 }
 125
 126
 127 /*
 128  * Perform variable substitution and command substitution on an argument,
 129  * placing the resulting list of arguments in arglist.  If EXP_FULL is true,
 130  * perform splitting and file name expansion.  When arglist is NULL, perform
 131  * here document expansion.
 132  */
 133
 134 void
 135 expandarg(union node *arg, struct arglist *arglist, int flag)
 136 {
 137         struct strlist *sp;
 138         char *p;
 139
 140         argbackq = arg->narg.backquote;
 141         STARTSTACKSTR(expdest);
 142         ifsfirst.next = NULL;
 143         ifslastp = NULL;
 144         argstr(arg->narg.text, flag);
 145         if (arglist == NULL) {
 146                 return;                 /* here document expanded */
 147         }
 148         STPUTC('\0', expdest);
 149         p = grabstackstr(expdest);
 150         exparg.lastp = &exparg.list;
 151         /*
 152          * TODO - EXP_REDIR
 153          */
 154         if (flag & EXP_FULL) {
 155                 ifsbreakup(p, &exparg);
 156                 *exparg.lastp = NULL;
 157                 exparg.lastp = &exparg.list;
 158                 expandmeta(exparg.list, flag);
 159         } else {
 160                 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
 161                         rmescapes(p);
 162                 sp = (struct strlist *)stalloc(sizeof (struct strlist));
 163                 sp->text = p;
 164                 *exparg.lastp = sp;
 165                 exparg.lastp = &sp->next;
 166         }
 167         ifsfree();
 168         *exparg.lastp = NULL;
 169         if (exparg.list) {
 170                 *arglist->lastp = exparg.list;
 171                 arglist->lastp = exparg.lastp;
 172         }
 173 }
 174
 175
 176
 177 /*
 178  * Perform variable and command substitution.
 179  * If EXP_FULL is set, output CTLESC characters to allow for further processing.
 180  * Otherwise treat $@ like $* since no splitting will be performed.
 181  */
 182
 183 STATIC void
 184 argstr(char *p, int flag)
 185 {
 186         char c;
 187         int quotes = flag & (EXP_FULL | EXP_CASE);      /* do CTLESC */
 188         int firsteq = 1;
 189         const char *ifs = NULL;
 190         int ifs_split = EXP_IFS_SPLIT;
 191
 192         if (flag & EXP_IFS_SPLIT)
 193                 ifs = ifsset() ? ifsval() : " \t\n";
 194
 195         if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
 196                 p = exptilde(p, flag);
 197         for (;;) {
 198                 switch (c = *p++) {
 199                 case '\0':
 200                 case CTLENDVAR: /* end of expanding yyy in ${xxx-yyy} */
 201                         return;
 202                 case CTLQUOTEMARK:
 203                         /* "$@" syntax adherence hack */
 204                         if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
 205                                 break;
 206                         if ((flag & EXP_FULL) != 0)
 207                                 STPUTC(c, expdest);
 208                         ifs_split = 0;
 209                         break;
 210                 case CTLQUOTEEND:
 211                         ifs_split = EXP_IFS_SPLIT;
 212                         break;
 213                 case CTLESC:
 214                         if (quotes)
 215                                 STPUTC(c, expdest);
 216                         c = *p++;
 217                         STPUTC(c, expdest);
 218                         break;
 219                 case CTLVAR:
 220                         p = evalvar(p, (flag & ~EXP_IFS_SPLIT) | (flag & ifs_split));
 221                         break;
 222                 case CTLBACKQ:
 223                 case CTLBACKQ|CTLQUOTE:
 224                         expbackq(argbackq->n, c & CTLQUOTE, flag);
 225                         argbackq = argbackq->next;
 226                         break;
 227                 case CTLENDARI:
 228                         expari(flag);
 229                         break;
 230                 case ':':
 231                 case '=':
 232                         /*
 233                          * sort of a hack - expand tildes in variable
 234                          * assignments (after the first '=' and after ':'s).
 235                          */
 236                         STPUTC(c, expdest);
 237                         if (flag & EXP_VARTILDE && *p == '~') {
 238                                 if (c == '=') {
 239                                         if (firsteq)
 240                                                 firsteq = 0;
 241                                         else
 242                                                 break;
 243                                 }
 244                                 p = exptilde(p, flag);
 245                         }
 246                         break;
 247                 default:
 248                         STPUTC(c, expdest);
 249                         if (flag & EXP_IFS_SPLIT & ifs_split && strchr(ifs, c) != NULL) {
 250                                 /* We need to get the output split here... */
 251                                 recordregion(expdest - stackblock() - 1,
 252                                                 expdest - stackblock(), 0);
 253                         }
 254                         break;
 255                 }
 256         }
 257 }
 258
 259 STATIC char *
 260 exptilde(char *p, int flag)
 261 {
 262         char c, *startp = p;
 263         struct passwd *pw;
 264         const char *home;
 265         int quotes = flag & (EXP_FULL | EXP_CASE);
 266
 267         while ((c = *p) != '\0') {
 268                 switch(c) {
 269                 case CTLESC:
 270                         return (startp);
 271                 case CTLQUOTEMARK:
 272                         return (startp);
 273                 case ':':
 274                         if (flag & EXP_VARTILDE)
 275                                 goto done;
 276                         break;
 277                 case '/':
 278                         goto done;
 279                 }
 280                 p++;
 281         }
 282 done:
 283         *p = '\0';
 284         if (*(startp+1) == '\0') {
 285                 if ((home = lookupvar("HOME")) == NULL)
 286                         goto lose;
 287         } else {
 288                 if ((pw = getpwnam(startp+1)) == NULL)
 289                         goto lose;
 290                 home = pw->pw_dir;
 291         }
 292         if (*home == '\0')
 293                 goto lose;
 294         *p = c;
 295         while ((c = *home++) != '\0') {
 296                 if (quotes && SQSYNTAX[(int)c] == CCTL)
 297                         STPUTC(CTLESC, expdest);
 298                 STPUTC(c, expdest);
 299         }
 300         return (p);
 301 lose:
 302         *p = c;
 303         return (startp);
 304 }
 305
 306
 307 STATIC void
 308 removerecordregions(int endoff)
 309 {
 310         if (ifslastp == NULL)
 311                 return;
 312
 313         if (ifsfirst.endoff > endoff) {
 314                 while (ifsfirst.next != NULL) {
 315                         struct ifsregion *ifsp;
 316                         INTOFF;
 317                         ifsp = ifsfirst.next->next;
 318                         ckfree(ifsfirst.next);
 319                         ifsfirst.next = ifsp;
 320                         INTON;
 321                 }
 322                 if (ifsfirst.begoff > endoff)
 323                         ifslastp = NULL;
 324                 else {
 325                         ifslastp = &ifsfirst;
 326                         ifsfirst.endoff = endoff;
 327                 }
 328                 return;
 329         }
 330
 331         ifslastp = &ifsfirst;
 332         while (ifslastp->next && ifslastp->next->begoff < endoff)
 333                 ifslastp=ifslastp->next;
 334         while (ifslastp->next != NULL) {
 335                 struct ifsregion *ifsp;
 336                 INTOFF;
 337                 ifsp = ifslastp->next->next;
 338                 ckfree(ifslastp->next);
 339                 ifslastp->next = ifsp;
 340                 INTON;
 341         }
 342         if (ifslastp->endoff > endoff)
 343                 ifslastp->endoff = endoff;
 344 }
 345
 346
 347 /*
 348  * Expand arithmetic expression.  Backup to start of expression,
 349  * evaluate, place result in (backed up) result, adjust string position.
 350  */
 351 void
 352 expari(int flag)
 353 {
 354         char *p, *start;
 355         intmax_t result;
 356         int adjustment;
 357         int begoff;
 358         int quotes = flag & (EXP_FULL | EXP_CASE);
 359         int quoted;
 360
 361         /*      ifsfree(); */
 362
 363         /*
 364          * This routine is slightly over-complicated for
 365          * efficiency.  First we make sure there is
 366          * enough space for the result, which may be bigger
 367          * than the expression if we add exponentation.  Next we
 368          * scan backwards looking for the start of arithmetic.  If the
 369          * next previous character is a CTLESC character, then we
 370          * have to rescan starting from the beginning since CTLESC
 371          * characters have to be processed left to right.
 372          */
 373 /* SPACE_NEEDED is enough for all digits, plus possible "-", plus 2 (why?) */
 374 #define SPACE_NEEDED ((sizeof(intmax_t) * CHAR_BIT + 2) / 3 + 1 + 2)
 375         CHECKSTRSPACE((int)(SPACE_NEEDED - 2), expdest);
 376         USTPUTC('\0', expdest);
 377         start = stackblock();
 378         p = expdest - 1;
 379         while (*p != CTLARI && p >= start)
 380                 --p;
 381         if (*p != CTLARI)
 382                 error("missing CTLARI (shouldn't happen)");
 383         if (p > start && *(p-1) == CTLESC)
 384                 for (p = start; *p != CTLARI; p++)
 385                         if (*p == CTLESC)
 386                                 p++;
 387
 388         if (p[1] == '"')
 389                 quoted=1;
 390         else
 391                 quoted=0;
 392         begoff = p - start;
 393         removerecordregions(begoff);
 394         if (quotes)
 395                 rmescapes(p+2);
 396         result = arith(p+2);
 397         fmtstr(p, SPACE_NEEDED, "%"PRIdMAX, result);
 398
 399         while (*p++)
 400                 ;
 401
 402         if (quoted == 0)
 403                 recordregion(begoff, p - 1 - start, 0);
 404         adjustment = expdest - p + 1;
 405         STADJUST(-adjustment, 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);
 428
 429         INTOFF;
 430         saveifs = ifsfirst;
 431         savelastp = ifslastp;
 432         saveargbackq = argbackq;
 433         saveherefd = herefd;
 434         herefd = -1;
 435         p = grabstackstr(dest);
 436         evalbackcmd(cmd, &in);
 437         ungrabstackstr(p, dest);
 438         ifsfirst = saveifs;
 439         ifslastp = savelastp;
 440         argbackq = saveargbackq;
 441         herefd = saveherefd;
 442
 443         p = in.buf;
 444         lastc = '\0';
 445         for (;;) {
 446                 if (--in.nleft < 0) {
 447                         if (in.fd < 0)
 448                                 break;
 449                         while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR);
 450                         TRACE(("expbackq: read returns %d\n", i));
 451                         if (i <= 0)
 452                                 break;
 453                         p = buf;
 454                         in.nleft = i - 1;
 455                 }
 456                 lastc = *p++;
 457                 if (lastc != '\0') {
 458                         if (quotes && syntax[(int)lastc] == CCTL)
 459                                 STPUTC(CTLESC, dest);
 460                         STPUTC(lastc, dest);
 461                 }
 462         }
 463
 464         /* Eat all trailing newlines */
 465         p = stackblock() + startloc;
 466         while (dest > p && dest[-1] == '\n')
 467                 STUNPUTC(dest);
 468
 469         if (in.fd >= 0)
 470                 close(in.fd);
 471         if (in.buf)
 472                 ckfree(in.buf);
 473         if (in.jp)
 474                 back_exitstatus = waitforjob(in.jp);
 475         if (quoted == 0)
 476                 recordregion(startloc, dest - stackblock(), 0);
 477         TRACE(("evalbackq: size=%d: \"%.*s\"\n",
 478                 (int)((dest - stackblock()) - startloc),
 479                 (int)((dest - stackblock()) - startloc),
 480                 stackblock() + startloc));
 481         expdest = dest;
 482         INTON;
 483 }
 484
 485
 486
 487 STATIC int
 488 subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varflags)
 489 {
 490         char *startp;
 491         char *loc = NULL;
 492         char *q;
 493         int c = 0;
 494         int saveherefd = herefd;
 495         struct nodelist *saveargbackq = argbackq;
 496         int amount, how;
 497
 498         herefd = -1;
 499         switch (subtype) {
 500         case VSTRIMLEFT:
 501         case VSTRIMLEFTMAX:
 502         case VSTRIMRIGHT:
 503         case VSTRIMRIGHTMAX:
 504                 how = (varflags & VSQUOTE) ? 0 : EXP_CASE;
 505                 break;
 506         default:
 507                 how = 0;
 508                 break;
 509         }
 510         argstr(p, how);
 511         STACKSTRNUL(expdest);
 512         herefd = saveherefd;
 513         argbackq = saveargbackq;
 514         startp = stackblock() + startloc;
 515         if (str == NULL)
 516             str = stackblock() + strloc;
 517
 518         switch (subtype) {
 519         case VSASSIGN:
 520                 setvar(str, startp, 0);
 521                 amount = startp - expdest;
 522                 STADJUST(amount, expdest);
 523                 varflags &= ~VSNUL;
 524                 return 1;
 525
 526         case VSQUESTION:
 527                 if (*p != CTLENDVAR) {
 528                         outfmt(&errout, "%s\n", startp);
 529                         error((char *)NULL);
 530                 }
 531                 error("%.*s: parameter %snot set",
 532                       (int)(p - str - 1),
 533                       str, (varflags & VSNUL) ? "null or "
 534                                               : nullstr);
 535                 /* NOTREACHED */
 536
 537         case VSTRIMLEFT:
 538                 for (loc = startp; loc < str; loc++) {
 539                         c = *loc;
 540                         *loc = '\0';
 541                         if (patmatch(str, startp, varflags & VSQUOTE))
 542                                 goto recordleft;
 543                         *loc = c;
 544                         if ((varflags & VSQUOTE) && *loc == CTLESC)
 545                                 loc++;
 546                 }
 547                 return 0;
 548
 549         case VSTRIMLEFTMAX:
 550                 for (loc = str - 1; loc >= startp;) {
 551                         c = *loc;
 552                         *loc = '\0';
 553                         if (patmatch(str, startp, varflags & VSQUOTE))
 554                                 goto recordleft;
 555                         *loc = c;
 556                         loc--;
 557                         if ((varflags & VSQUOTE) && loc > startp &&
 558                             *(loc - 1) == CTLESC) {
 559                                 for (q = startp; q < loc; q++)
 560                                         if (*q == CTLESC)
 561                                                 q++;
 562                                 if (q > loc)
 563                                         loc--;
 564                         }
 565                 }
 566                 return 0;
 567
 568         case VSTRIMRIGHT:
 569                 for (loc = str - 1; loc >= startp;) {
 570                         if (patmatch(str, loc, varflags & VSQUOTE))
 571                                 goto recordright;
 572                         loc--;
 573                         if ((varflags & VSQUOTE) && loc > startp &&
 574                             *(loc - 1) == CTLESC) {
 575                                 for (q = startp; q < loc; q++)
 576                                         if (*q == CTLESC)
 577                                                 q++;
 578                                 if (q > loc)
 579                                         loc--;
 580                         }
 581                 }
 582                 return 0;
 583
 584         case VSTRIMRIGHTMAX:
 585                 for (loc = startp; loc < str - 1; loc++) {
 586                         if (patmatch(str, loc, varflags & VSQUOTE))
 587                                 goto recordright;
 588                         if ((varflags & VSQUOTE) && *loc == CTLESC)
 589                                 loc++;
 590                 }
 591                 return 0;
 592
 593         default:
 594                 abort();
 595         }
 596
 597 recordleft:
 598         *loc = c;
 599         amount = ((str - 1) - (loc - startp)) - expdest;
 600         STADJUST(amount, expdest);
 601         while (loc != str - 1)
 602                 *startp++ = *loc++;
 603         return 1;
 604
 605 recordright:
 606         amount = loc - expdest;
 607         STADJUST(amount, expdest);
 608         STPUTC('\0', expdest);
 609         STADJUST(-1, expdest);
 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 apply_ifs;
 633         int quotes = flag & (EXP_FULL | EXP_CASE);
 634
 635         varflags = (unsigned char)*p++;
 636         subtype = varflags & VSTYPE;
 637         var = p;
 638         special = !is_name(*p);
 639         p = strchr(p, '=') + 1;
 640
 641 again: /* jump here after setting a variable with ${var=text} */
 642         if (special) {
 643                 set = varisset(var, varflags & VSNUL);
 644                 val = NULL;
 645         } else {
 646                 val = lookupvar(var);
 647                 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
 648                         val = NULL;
 649                         set = 0;
 650                 } else
 651                         set = 1;
 652         }
 653
 654         varlen = 0;
 655         startloc = expdest - stackblock();
 656
 657         if (!set && uflag) {
 658                 switch (subtype) {
 659                 case VSNORMAL:
 660                 case VSTRIMLEFT:
 661                 case VSTRIMLEFTMAX:
 662                 case VSTRIMRIGHT:
 663                 case VSTRIMRIGHTMAX:
 664                 case VSLENGTH:
 665                         error("%.*s: parameter not set",
 666                             (int)(p - var - 1), var);
 667                         /* NOTREACHED */
 668                 }
 669         }
 670
 671         if (set && subtype != VSPLUS) {
 672                 /* insert the value of the variable */
 673                 if (special) {
 674                         varvalue(var, varflags & VSQUOTE, subtype, flag);
 675                         if (subtype == VSLENGTH) {
 676                                 varlen = expdest - stackblock() - startloc;
 677                                 STADJUST(-varlen, expdest);
 678                         }
 679                 } else {
 680                         char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX
 681                                                                   : BASESYNTAX;
 682
 683                         if (subtype == VSLENGTH) {
 684                                 for (;*val; val++)
 685                                         varlen++;
 686                         } else {
 687                                 while (*val) {
 688                                         if (quotes && syntax[(int)*val] == CCTL)
 689                                                 STPUTC(CTLESC, expdest);
 690                                         STPUTC(*val++, expdest);
 691                                 }
 692
 693                         }
 694                 }
 695         }
 696
 697
 698         apply_ifs = ((varflags & VSQUOTE) == 0 ||
 699                 (*var == '@' && shellparam.nparam != 1));
 700
 701         switch (subtype) {
 702         case VSLENGTH:
 703                 expdest = cvtnum(varlen, expdest);
 704                 break;
 705
 706         case VSNORMAL:
 707                 break;
 708
 709         case VSPLUS:
 710                 set = !set;
 711                 /* FALLTHROUGH */
 712         case VSMINUS:
 713                 if (!set) {
 714                         argstr(p, flag | (apply_ifs ? EXP_IFS_SPLIT : 0));
 715                         /*
 716                          * ${x-a b c} doesn't get split, but removing the
 717                          * 'apply_ifs = 0' apparently breaks ${1+"$@"}..
 718                          * ${x-'a b' c} should generate 2 args.
 719                          */
 720                         /* We should have marked stuff already */
 721                         apply_ifs = 0;
 722                 }
 723                 break;
 724
 725         case VSTRIMLEFT:
 726         case VSTRIMLEFTMAX:
 727         case VSTRIMRIGHT:
 728         case VSTRIMRIGHTMAX:
 729                 if (!set)
 730                         break;
 731                 /*
 732                  * Terminate the string and start recording the pattern
 733                  * right after it
 734                  */
 735                 STPUTC('\0', expdest);
 736                 patloc = expdest - stackblock();
 737                 if (subevalvar(p, NULL, patloc, subtype,
 738                                startloc, varflags) == 0) {
 739                         int amount = (expdest - stackblock() - patloc) + 1;
 740                         STADJUST(-amount, expdest);
 741                 }
 742                 /* Remove any recorded regions beyond start of variable */
 743                 removerecordregions(startloc);
 744                 apply_ifs = 1;
 745                 break;
 746
 747         case VSASSIGN:
 748         case VSQUESTION:
 749                 if (set)
 750                         break;
 751                 if (subevalvar(p, var, 0, subtype, startloc, varflags)) {
 752                         varflags &= ~VSNUL;
 753                         /*
 754                          * Remove any recorded regions beyond
 755                          * start of variable
 756                          */
 757                         removerecordregions(startloc);
 758                         goto again;
 759                 }
 760                 apply_ifs = 0;
 761                 break;
 762
 763         default:
 764                 abort();
 765         }
 766
 767         if (apply_ifs)
 768                 recordregion(startloc, expdest - stackblock(),
 769                              varflags & VSQUOTE);
 770
 771         if (subtype != VSNORMAL) {      /* skip to end of alternative */
 772                 int nesting = 1;
 773                 for (;;) {
 774                         if ((c = *p++) == CTLESC)
 775                                 p++;
 776                         else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
 777                                 if (set)
 778                                         argbackq = argbackq->next;
 779                         } else if (c == CTLVAR) {
 780                                 if ((*p++ & VSTYPE) != VSNORMAL)
 781                                         nesting++;
 782                         } else if (c == CTLENDVAR) {
 783                                 if (--nesting == 0)
 784                                         break;
 785                         }
 786                 }
 787         }
 788         return p;
 789 }
 790
 791
 792
 793 /*
 794  * Test whether a specialized variable is set.
 795  */
 796
 797 STATIC int
 798 varisset(char *name, int nulok)
 799 {
 800         if (*name == '!')
 801                 return backgndpid != -1;
 802         else if (*name == '@' || *name == '*') {
 803                 if (*shellparam.p == NULL)
 804                         return 0;
 805
 806                 if (nulok) {
 807                         char **av;
 808
 809                         for (av = shellparam.p; *av; av++)
 810                                 if (**av != '\0')
 811                                         return 1;
 812                         return 0;
 813                 }
 814         } else if (is_digit(*name)) {
 815                 char *ap;
 816                 int num = atoi(name);
 817
 818                 if (num > shellparam.nparam)
 819                         return 0;
 820
 821                 if (num == 0)
 822                         ap = arg0;
 823                 else
 824                         ap = shellparam.p[num - 1];
 825
 826                 if (nulok && (ap == NULL || *ap == '\0'))
 827                         return 0;
 828         }
 829         return 1;
 830 }
 831
 832
 833
 834 /*
 835  * Add the value of a specialized variable to the stack string.
 836  */
 837
 838 STATIC void
 839 varvalue(char *name, int quoted, int subtype, int flag)
 840 {
 841         int num;
 842         char *p;
 843         int i;
 844         char sep;
 845         char **ap;
 846         char const *syntax;
 847
 848 #define STRTODEST(p) \
 849         do {\
 850         if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) { \
 851                 syntax = quoted? DQSYNTAX : BASESYNTAX; \
 852                 while (*p) { \
 853                         if (syntax[(int)*p] == CCTL) \
 854                                 STPUTC(CTLESC, expdest); \
 855                         STPUTC(*p++, expdest); \
 856                 } \
 857         } else \
 858                 while (*p) \
 859                         STPUTC(*p++, expdest); \
 860         } while (0)
 861
 862
 863         switch (*name) {
 864         case '$':
 865                 num = rootpid;
 866                 goto numvar;
 867         case '?':
 868                 num = exitstatus;
 869                 goto numvar;
 870         case '#':
 871                 num = shellparam.nparam;
 872                 goto numvar;
 873         case '!':
 874                 num = backgndpid;
 875 numvar:
 876                 expdest = cvtnum(num, expdest);
 877                 break;
 878         case '-':
 879                 for (i = 0; optlist[i].name; i++) {
 880                         if (optlist[i].val && optlist[i].letter)
 881                                 STPUTC(optlist[i].letter, expdest);
 882                 }
 883                 break;
 884         case '@':
 885                 if (flag & EXP_FULL && quoted) {
 886                         for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 887                                 STRTODEST(p);
 888                                 if (*ap)
 889                                         /* A NUL separates args inside "" */
 890                                         STPUTC('\0', expdest);
 891                         }
 892                         break;
 893                 }
 894                 /* fall through */
 895         case '*':
 896                 if (ifsset() != 0)
 897                         sep = ifsval()[0];
 898                 else
 899                         sep = ' ';
 900                 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 901                         STRTODEST(p);
 902                         if (*ap && sep)
 903                                 STPUTC(sep, expdest);
 904                 }
 905                 break;
 906         case '0':
 907                 p = arg0;
 908                 STRTODEST(p);
 909                 break;
 910         default:
 911                 if (is_digit(*name)) {
 912                         num = atoi(name);
 913                         if (num > 0 && num <= shellparam.nparam) {
 914                                 p = shellparam.p[num - 1];
 915                                 STRTODEST(p);
 916                         }
 917                 }
 918                 break;
 919         }
 920 }
 921
 922
 923
 924 /*
 925  * Record the fact that we have to scan this region of the
 926  * string for IFS characters.
 927  */
 928
 929 STATIC void
 930 recordregion(int start, int end, int inquotes)
 931 {
 932         struct ifsregion *ifsp;
 933
 934         if (ifslastp == NULL) {
 935                 ifsp = &ifsfirst;
 936         } else {
 937                 if (ifslastp->endoff == start
 938                     && ifslastp->inquotes == inquotes) {
 939                         /* extend previous area */
 940                         ifslastp->endoff = end;
 941                         return;
 942                 }
 943                 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
 944                 ifslastp->next = ifsp;
 945         }
 946         ifslastp = ifsp;
 947         ifslastp->next = NULL;
 948         ifslastp->begoff = start;
 949         ifslastp->endoff = end;
 950         ifslastp->inquotes = inquotes;
 951 }
 952
 953
 954
 955 /*
 956  * Break the argument string into pieces based upon IFS and add the
 957  * strings to the argument list.  The regions of the string to be
 958  * searched for IFS characters have been stored by recordregion.
 959  */
 960 STATIC void
 961 ifsbreakup(char *string, struct arglist *arglist)
 962 {
 963         struct ifsregion *ifsp;
 964         struct strlist *sp;
 965         char *start;
 966         char *p;
 967         char *q;
 968         const char *ifs;
 969         const char *ifsspc;
 970         int had_param_ch = 0;
 971
 972         start = string;
 973
 974         if (ifslastp == NULL) {
 975                 /* Return entire argument, IFS doesn't apply to any of it */
 976                 sp = (struct strlist *)stalloc(sizeof *sp);
 977                 sp->text = start;
 978                 *arglist->lastp = sp;
 979                 arglist->lastp = &sp->next;
 980                 return;
 981         }
 982
 983         ifs = ifsset() ? ifsval() : " \t\n";
 984
 985         for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) {
 986                 p = string + ifsp->begoff;
 987                 while (p < string + ifsp->endoff) {
 988                         had_param_ch = 1;
 989                         q = p;
 990                         if (*p == CTLESC)
 991                                 p++;
 992                         if (ifsp->inquotes) {
 993                                 /* Only NULs (should be from "$@") end args */
 994                                 if (*p != 0) {
 995                                         p++;
 996                                         continue;
 997                                 }
 998                                 ifsspc = NULL;
 999                         } else {
1000                                 if (!strchr(ifs, *p)) {
1001                                         p++;
1002                                         continue;
1003                                 }
1004                                 had_param_ch = 0;
1005                                 ifsspc = strchr(" \t\n", *p);
1006
1007                                 /* Ignore IFS whitespace at start */
1008                                 if (q == start && ifsspc != NULL) {
1009                                         p++;
1010                                         start = p;
1011                                         continue;
1012                                 }
1013                         }
1014
1015                         /* Save this argument... */
1016                         *q = '\0';
1017                         sp = (struct strlist *)stalloc(sizeof *sp);
1018                         sp->text = start;
1019                         *arglist->lastp = sp;
1020                         arglist->lastp = &sp->next;
1021                         p++;
1022
1023                         if (ifsspc != NULL) {
1024                                 /* Ignore further trailing IFS whitespace */
1025                                 for (; p < string + ifsp->endoff; p++) {
1026                                         q = p;
1027                                         if (*p == CTLESC)
1028                                                 p++;
1029                                         if (strchr(ifs, *p) == NULL) {
1030                                                 p = q;
1031                                                 break;
1032                                         }
1033                                         if (strchr(" \t\n", *p) == NULL) {
1034                                                 p++;
1035                                                 break;
1036                                         }
1037                                 }
1038                         }
1039                         start = p;
1040                 }
1041         }
1042
1043         /*
1044          * Save anything left as an argument.
1045          * Traditionally we have treated 'IFS=':'; set -- x$IFS' as
1046          * generating 2 arguments, the second of which is empty.
1047          * Some recent clarification of the Posix spec say that it
1048          * should only generate one....
1049          */
1050         if (had_param_ch || *start != 0) {
1051                 sp = (struct strlist *)stalloc(sizeof *sp);
1052                 sp->text = start;
1053                 *arglist->lastp = sp;
1054                 arglist->lastp = &sp->next;
1055         }
1056 }
1057
1058 STATIC void
1059 ifsfree(void)
1060 {
1061         while (ifsfirst.next != NULL) {
1062                 struct ifsregion *ifsp;
1063                 INTOFF;
1064                 ifsp = ifsfirst.next->next;
1065                 ckfree(ifsfirst.next);
1066                 ifsfirst.next = ifsp;
1067                 INTON;
1068         }
1069         ifslastp = NULL;
1070         ifsfirst.next = NULL;
1071 }
1072
1073
1074
1075 /*
1076  * Expand shell metacharacters.  At this point, the only control characters
1077  * should be escapes.  The results are stored in the list exparg.
1078  */
1079
1080 char *expdir;
1081
1082
1083 STATIC void
1084 expandmeta(struct strlist *str, int flag)
1085 {
1086         char *p;
1087         struct strlist **savelastp;
1088         struct strlist *sp;
1089         char c;
1090         /* TODO - EXP_REDIR */
1091
1092         while (str) {
1093                 if (fflag)
1094                         goto nometa;
1095                 p = str->text;
1096                 for (;;) {                      /* fast check for meta chars */
1097                         if ((c = *p++) == '\0')
1098                                 goto nometa;
1099                         if (c == '*' || c == '?' || c == '[' || c == '!')
1100                                 break;
1101                 }
1102                 savelastp = exparg.lastp;
1103                 INTOFF;
1104                 if (expdir == NULL) {
1105                         int i = strlen(str->text);
1106                         expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */
1107                 }
1108
1109                 expmeta(expdir, str->text);
1110                 ckfree(expdir);
1111                 expdir = NULL;
1112                 INTON;
1113                 if (exparg.lastp == savelastp) {
1114                         /*
1115                          * no matches
1116                          */
1117 nometa:
1118                         *exparg.lastp = str;
1119                         rmescapes(str->text);
1120                         exparg.lastp = &str->next;
1121                 } else {
1122                         *exparg.lastp = NULL;
1123                         *savelastp = sp = expsort(*savelastp);
1124                         while (sp->next != NULL)
1125                                 sp = sp->next;
1126                         exparg.lastp = &sp->next;
1127                 }
1128                 str = str->next;
1129         }
1130 }
1131
1132
1133 /*
1134  * Do metacharacter (i.e. *, ?, [...]) expansion.
1135  */
1136
1137 STATIC void
1138 expmeta(char *enddir, char *name)
1139 {
1140         char *p;
1141         const char *cp;
1142         char *q;
1143         char *start;
1144         char *endname;
1145         int metaflag;
1146         struct stat statb;
1147         DIR *dirp;
1148         struct dirent *dp;
1149         int atend;
1150         int matchdot;
1151
1152         metaflag = 0;
1153         start = name;
1154         for (p = name ; ; p++) {
1155                 if (*p == '*' || *p == '?')
1156                         metaflag = 1;
1157                 else if (*p == '[') {
1158                         q = p + 1;
1159                         if (*q == '!')
1160                                 q++;
1161                         for (;;) {
1162                                 while (*q == CTLQUOTEMARK)
1163                                         q++;
1164                                 if (*q == CTLESC)
1165                                         q++;
1166                                 if (*q == '/' || *q == '\0')
1167                                         break;
1168                                 if (*++q == ']') {
1169                                         metaflag = 1;
1170                                         break;
1171                                 }
1172                         }
1173                 } else if (*p == '!' && p[1] == '!'     && (p == name || p[-1] == '/')) {
1174                         metaflag = 1;
1175                 } else if (*p == '\0')
1176                         break;
1177                 else if (*p == CTLQUOTEMARK)
1178                         continue;
1179                 else if (*p == CTLESC)
1180                         p++;
1181                 if (*p == '/') {
1182                         if (metaflag)
1183                                 break;
1184                         start = p + 1;
1185                 }
1186         }
1187         if (metaflag == 0) {    /* we've reached the end of the file name */
1188                 if (enddir != expdir)
1189                         metaflag++;
1190                 for (p = name ; ; p++) {
1191                         if (*p == CTLQUOTEMARK)
1192                                 continue;
1193                         if (*p == CTLESC)
1194                                 p++;
1195                         *enddir++ = *p;
1196                         if (*p == '\0')
1197                                 break;
1198                 }
1199                 if (metaflag == 0 || lstat(expdir, &statb) >= 0)
1200                         addfname(expdir);
1201                 return;
1202         }
1203         endname = p;
1204         if (start != name) {
1205                 p = name;
1206                 while (p < start) {
1207                         while (*p == CTLQUOTEMARK)
1208                                 p++;
1209                         if (*p == CTLESC)
1210                                 p++;
1211                         *enddir++ = *p++;
1212                 }
1213         }
1214         if (enddir == expdir) {
1215                 cp = ".";
1216         } else if (enddir == expdir + 1 && *expdir == '/') {
1217                 cp = "/";
1218         } else {
1219                 cp = expdir;
1220                 enddir[-1] = '\0';
1221         }
1222         if ((dirp = opendir(cp)) == NULL)
1223                 return;
1224         if (enddir != expdir)
1225                 enddir[-1] = '/';
1226         if (*endname == 0) {
1227                 atend = 1;
1228         } else {
1229                 atend = 0;
1230                 *endname++ = '\0';
1231         }
1232         matchdot = 0;
1233         p = start;
1234         while (*p == CTLQUOTEMARK)
1235                 p++;
1236         if (*p == CTLESC)
1237                 p++;
1238         if (*p == '.')
1239                 matchdot++;
1240         while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1241                 if (dp->d_name[0] == '.' && ! matchdot)
1242                         continue;
1243                 if (patmatch(start, dp->d_name, 0)) {
1244                         if (atend) {
1245                                 scopy(dp->d_name, enddir);
1246                                 addfname(expdir);
1247                         } else {
1248                                 for (p = enddir, cp = dp->d_name;
1249                                      (*p++ = *cp++) != '\0';)
1250                                         continue;
1251                                 p[-1] = '/';
1252                                 expmeta(p, endname);
1253                         }
1254                 }
1255         }
1256         closedir(dirp);
1257         if (! atend)
1258                 endname[-1] = '/';
1259 }
1260
1261
1262 /*
1263  * Add a file name to the list.
1264  */
1265
1266 STATIC void
1267 addfname(char *name)
1268 {
1269         char *p;
1270         struct strlist *sp;
1271
1272         p = stalloc(strlen(name) + 1);
1273         scopy(name, p);
1274         sp = (struct strlist *)stalloc(sizeof *sp);
1275         sp->text = p;
1276         *exparg.lastp = sp;
1277         exparg.lastp = &sp->next;
1278 }
1279
1280
1281 /*
1282  * Sort the results of file name expansion.  It calculates the number of
1283  * strings to sort and then calls msort (short for merge sort) to do the
1284  * work.
1285  */
1286
1287 STATIC struct strlist *
1288 expsort(struct strlist *str)
1289 {
1290         int len;
1291         struct strlist *sp;
1292
1293         len = 0;
1294         for (sp = str ; sp ; sp = sp->next)
1295                 len++;
1296         return msort(str, len);
1297 }
1298
1299
1300 STATIC struct strlist *
1301 msort(struct strlist *list, int len)
1302 {
1303         struct strlist *p, *q = NULL;
1304         struct strlist **lpp;
1305         int half;
1306         int n;
1307
1308         if (len <= 1)
1309                 return list;
1310         half = len >> 1;
1311         p = list;
1312         for (n = half ; --n >= 0 ; ) {
1313                 q = p;
1314                 p = p->next;
1315         }
1316         q->next = NULL;                 /* terminate first half of list */
1317         q = msort(list, half);          /* sort first half of list */
1318         p = msort(p, len - half);               /* sort second half */
1319         lpp = &list;
1320         for (;;) {
1321                 if (strcmp(p->text, q->text) < 0) {
1322                         *lpp = p;
1323                         lpp = &p->next;
1324                         if ((p = *lpp) == NULL) {
1325                                 *lpp = q;
1326                                 break;
1327                         }
1328                 } else {
1329                         *lpp = q;
1330                         lpp = &q->next;
1331                         if ((q = *lpp) == NULL) {
1332                                 *lpp = p;
1333                                 break;
1334                         }
1335                 }
1336         }
1337         return list;
1338 }
1339
1340
1341
1342 /*
1343  * Returns true if the pattern matches the string.
1344  */
1345
1346 int
1347 patmatch(char *pattern, char *string, int squoted)
1348 {
1349 #ifdef notdef
1350         if (pattern[0] == '!' && pattern[1] == '!')
1351                 return 1 - pmatch(pattern + 2, string);
1352         else
1353 #endif
1354                 return pmatch(pattern, string, squoted);
1355 }
1356
1357
1358 STATIC int
1359 pmatch(char *pattern, char *string, int squoted)
1360 {
1361         char *p, *q;
1362         char c;
1363
1364         p = pattern;
1365         q = string;
1366         for (;;) {
1367                 switch (c = *p++) {
1368                 case '\0':
1369                         goto breakloop;
1370                 case CTLESC:
1371                         if (squoted && *q == CTLESC)
1372                                 q++;
1373                         if (*q++ != *p++)
1374                                 return 0;
1375                         break;
1376                 case CTLQUOTEMARK:
1377                         continue;
1378                 case '?':
1379                         if (squoted && *q == CTLESC)
1380                                 q++;
1381                         if (*q++ == '\0')
1382                                 return 0;
1383                         break;
1384                 case '*':
1385                         c = *p;
1386                         while (c == CTLQUOTEMARK || c == '*')
1387                                 c = *++p;
1388                         if (c != CTLESC &&  c != CTLQUOTEMARK &&
1389                             c != '?' && c != '*' && c != '[') {
1390                                 while (*q != c) {
1391                                         if (squoted && *q == CTLESC &&
1392                                             q[1] == c)
1393                                                 break;
1394                                         if (*q == '\0')
1395                                                 return 0;
1396                                         if (squoted && *q == CTLESC)
1397                                                 q++;
1398                                         q++;
1399                                 }
1400                         }
1401                         do {
1402                                 if (pmatch(p, q, squoted))
1403                                         return 1;
1404                                 if (squoted && *q == CTLESC)
1405                                         q++;
1406                         } while (*q++ != '\0');
1407                         return 0;
1408                 case '[': {
1409                         char *endp;
1410                         int invert, found;
1411                         char chr;
1412
1413                         endp = p;
1414                         if (*endp == '!')
1415                                 endp++;
1416                         for (;;) {
1417                                 while (*endp == CTLQUOTEMARK)
1418                                         endp++;
1419                                 if (*endp == '\0')
1420                                         goto dft;               /* no matching ] */
1421                                 if (*endp == CTLESC)
1422                                         endp++;
1423                                 if (*++endp == ']')
1424                                         break;
1425                         }
1426                         invert = 0;
1427                         if (*p == '!') {
1428                                 invert++;
1429                                 p++;
1430                         }
1431                         found = 0;
1432                         chr = *q++;
1433                         if (squoted && chr == CTLESC)
1434                                 chr = *q++;
1435                         if (chr == '\0')
1436                                 return 0;
1437                         c = *p++;
1438                         do {
1439                                 if (c == CTLQUOTEMARK)
1440                                         continue;
1441                                 if (c == CTLESC)
1442                                         c = *p++;
1443                                 if (*p == '-' && p[1] != ']') {
1444                                         p++;
1445                                         while (*p == CTLQUOTEMARK)
1446                                                 p++;
1447                                         if (*p == CTLESC)
1448                                                 p++;
1449                                         if (chr >= c && chr <= *p)
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, 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("%d", argc - 1);
1565         out1c('\0');
1566         for (i = 1, len = 0; i < argc; i++)
1567                 len += strlen(argv[i]);
1568         out1fmt("%zu", len);
1569         out1c('\0');
1570         for (i = 1; i < argc; i++) {
1571                 out1str(argv[i]);
1572                 out1c('\0');
1573         }
1574         return (0);
1575 }