bin/sh/expand.c

   1 /*-
   2  * Copyright (c) 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Kenneth Almquist.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  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  * @(#)expand.c 8.5 (Berkeley) 5/15/95
  37  * $FreeBSD: src/bin/sh/expand.c,v 1.51 2006/11/07 22:46:13 stefanf Exp $
  38  * $DragonFly: src/bin/sh/expand.c,v 1.9 2007/01/07 16:58:30 pavalos Exp $
  39  */
  40
  41 #include <sys/types.h>
  42 #include <sys/time.h>
  43 #include <sys/stat.h>
  44 #include <errno.h>
  45 #include <dirent.h>
  46 #include <unistd.h>
  47 #include <pwd.h>
  48 #include <stdlib.h>
  49 #include <limits.h>
  50 #include <stdio.h>
  51 #include <string.h>
  52
  53 /*
  54  * Routines to expand arguments to commands.  We have to deal with
  55  * backquotes, shell variables, and file metacharacters.
  56  */
  57
  58 #include "shell.h"
  59 #include "main.h"
  60 #include "nodes.h"
  61 #include "eval.h"
  62 #include "expand.h"
  63 #include "syntax.h"
  64 #include "parser.h"
  65 #include "jobs.h"
  66 #include "options.h"
  67 #include "var.h"
  68 #include "input.h"
  69 #include "output.h"
  70 #include "memalloc.h"
  71 #include "error.h"
  72 #include "mystring.h"
  73 #include "arith.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 nulonly;            /* search for nul bytes only */
  86 };
  87
  88
  89 STATIC char *expdest;                   /* output of current string */
  90 STATIC struct nodelist *argbackq;       /* list of back quote expressions */
  91 STATIC struct ifsregion ifsfirst;       /* first struct in list of ifs regions */
  92 STATIC struct ifsregion *ifslastp;      /* last struct in list */
  93 STATIC 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 expandmeta(struct strlist *, int);
 106 STATIC void expmeta(char *, char *);
 107 STATIC void addfname(char *);
 108 STATIC struct strlist *expsort(struct strlist *);
 109 STATIC struct strlist *msort(struct strlist *, int);
 110 STATIC int pmatch(char *, char *, int);
 111 STATIC char *cvtnum(int, char *);
 112 STATIC int collate_range_cmp(int, int);
 113
 114 STATIC int
 115 collate_range_cmp(int c1, int c2)
 116 {
 117         static char s1[2], s2[2];
 118
 119         s1[0] = c1;
 120         s2[0] = c2;
 121         return (strcoll(s1, s2));
 122 }
 123
 124 extern int oexitstatus;
 125
 126 /*
 127  * Expand shell variables and backquotes inside a here document.
 128  *      union node *arg         the document
 129  *      int fd;                 where to write the expanded version
 130  */
 131
 132 void
 133 expandhere(union node *arg, int fd)
 134 {
 135         herefd = fd;
 136         expandarg(arg, NULL, 0);
 137         xwrite(fd, stackblock(), expdest - stackblock());
 138 }
 139
 140
 141 /*
 142  * Perform variable substitution and command substitution on an argument,
 143  * placing the resulting list of arguments in arglist.  If EXP_FULL is true,
 144  * perform splitting and file name expansion.  When arglist is NULL, perform
 145  * here document expansion.
 146  */
 147
 148 void
 149 expandarg(union node *arg, struct arglist *arglist, int flag)
 150 {
 151         struct strlist *sp;
 152         char *p;
 153
 154         argbackq = arg->narg.backquote;
 155         STARTSTACKSTR(expdest);
 156         ifsfirst.next = NULL;
 157         ifslastp = NULL;
 158         argstr(arg->narg.text, flag);
 159         if (arglist == NULL) {
 160                 return;                 /* here document expanded */
 161         }
 162         STPUTC('\0', expdest);
 163         p = grabstackstr(expdest);
 164         exparg.lastp = &exparg.list;
 165         /*
 166          * TODO - EXP_REDIR
 167          */
 168         if (flag & EXP_FULL) {
 169                 ifsbreakup(p, &exparg);
 170                 *exparg.lastp = NULL;
 171                 exparg.lastp = &exparg.list;
 172                 expandmeta(exparg.list, flag);
 173         } else {
 174                 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
 175                         rmescapes(p);
 176                 sp = (struct strlist *)stalloc(sizeof (struct strlist));
 177                 sp->text = p;
 178                 *exparg.lastp = sp;
 179                 exparg.lastp = &sp->next;
 180         }
 181         while (ifsfirst.next != NULL) {
 182                 struct ifsregion *ifsp;
 183                 INTOFF;
 184                 ifsp = ifsfirst.next->next;
 185                 ckfree(ifsfirst.next);
 186                 ifsfirst.next = ifsp;
 187                 INTON;
 188         }
 189         *exparg.lastp = NULL;
 190         if (exparg.list) {
 191                 *arglist->lastp = exparg.list;
 192                 arglist->lastp = exparg.lastp;
 193         }
 194 }
 195
 196
 197
 198 /*
 199  * Perform variable and command substitution.  If EXP_FULL is set, output CTLESC
 200  * characters to allow for further processing.  Otherwise treat
 201  * $@ like $* since no splitting will be performed.
 202  */
 203
 204 STATIC void
 205 argstr(char *p, int flag)
 206 {
 207         char c;
 208         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);  /* do CTLESC */
 209         int firsteq = 1;
 210
 211         if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
 212                 p = exptilde(p, flag);
 213         for (;;) {
 214                 switch (c = *p++) {
 215                 case '\0':
 216                 case CTLENDVAR: /* ??? */
 217                         goto breakloop;
 218                 case CTLQUOTEMARK:
 219                         /* "$@" syntax adherence hack */
 220                         if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
 221                                 break;
 222                         if ((flag & EXP_FULL) != 0)
 223                                 STPUTC(c, expdest);
 224                         break;
 225                 case CTLESC:
 226                         if (quotes)
 227                                 STPUTC(c, expdest);
 228                         c = *p++;
 229                         STPUTC(c, expdest);
 230                         break;
 231                 case CTLVAR:
 232                         p = evalvar(p, flag);
 233                         break;
 234                 case CTLBACKQ:
 235                 case CTLBACKQ|CTLQUOTE:
 236                         expbackq(argbackq->n, c & CTLQUOTE, flag);
 237                         argbackq = argbackq->next;
 238                         break;
 239                 case CTLENDARI:
 240                         expari(flag);
 241                         break;
 242                 case ':':
 243                 case '=':
 244                         /*
 245                          * sort of a hack - expand tildes in variable
 246                          * assignments (after the first '=' and after ':'s).
 247                          */
 248                         STPUTC(c, expdest);
 249                         if (flag & EXP_VARTILDE && *p == '~') {
 250                                 if (c == '=') {
 251                                         if (firsteq)
 252                                                 firsteq = 0;
 253                                         else
 254                                                 break;
 255                                 }
 256                                 p = exptilde(p, flag);
 257                         }
 258                         break;
 259                 default:
 260                         STPUTC(c, expdest);
 261                 }
 262         }
 263 breakloop:;
 264 }
 265
 266 STATIC char *
 267 exptilde(char *p, int flag)
 268 {
 269         char c, *startp = p;
 270         struct passwd *pw;
 271         char *home;
 272         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 273
 274         while ((c = *p) != '\0') {
 275                 switch(c) {
 276                 case CTLESC:
 277                         return (startp);
 278                 case CTLQUOTEMARK:
 279                         return (startp);
 280                 case ':':
 281                         if (flag & EXP_VARTILDE)
 282                                 goto done;
 283                         break;
 284                 case '/':
 285                         goto done;
 286                 }
 287                 p++;
 288         }
 289 done:
 290         *p = '\0';
 291         if (*(startp+1) == '\0') {
 292                 if ((home = lookupvar("HOME")) == NULL)
 293                         goto lose;
 294         } else {
 295                 if ((pw = getpwnam(startp+1)) == NULL)
 296                         goto lose;
 297                 home = pw->pw_dir;
 298         }
 299         if (*home == '\0')
 300                 goto lose;
 301         *p = c;
 302         while ((c = *home++) != '\0') {
 303                 if (quotes && SQSYNTAX[(int)c] == CCTL)
 304                         STPUTC(CTLESC, expdest);
 305                 STPUTC(c, expdest);
 306         }
 307         return (p);
 308 lose:
 309         *p = c;
 310         return (startp);
 311 }
 312
 313
 314 STATIC void
 315 removerecordregions(int endoff)
 316 {
 317         if (ifslastp == NULL)
 318                 return;
 319
 320         if (ifsfirst.endoff > endoff) {
 321                 while (ifsfirst.next != NULL) {
 322                         struct ifsregion *ifsp;
 323                         INTOFF;
 324                         ifsp = ifsfirst.next->next;
 325                         ckfree(ifsfirst.next);
 326                         ifsfirst.next = ifsp;
 327                         INTON;
 328                 }
 329                 if (ifsfirst.begoff > endoff)
 330                         ifslastp = NULL;
 331                 else {
 332                         ifslastp = &ifsfirst;
 333                         ifsfirst.endoff = endoff;
 334                 }
 335                 return;
 336         }
 337
 338         ifslastp = &ifsfirst;
 339         while (ifslastp->next && ifslastp->next->begoff < endoff)
 340                 ifslastp=ifslastp->next;
 341         while (ifslastp->next != NULL) {
 342                 struct ifsregion *ifsp;
 343                 INTOFF;
 344                 ifsp = ifslastp->next->next;
 345                 ckfree(ifslastp->next);
 346                 ifslastp->next = ifsp;
 347                 INTON;
 348         }
 349         if (ifslastp->endoff > endoff)
 350                 ifslastp->endoff = endoff;
 351 }
 352
 353 /*
 354  * Expand arithmetic expression.  Backup to start of expression,
 355  * evaluate, place result in (backed up) result, adjust string position.
 356  */
 357 void
 358 expari(int flag)
 359 {
 360         char *p, *start;
 361         int result;
 362         int begoff;
 363         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 364         int quoted;
 365
 366
 367         /*
 368          * This routine is slightly over-complicated for
 369          * efficiency.  First we make sure there is
 370          * enough space for the result, which may be bigger
 371          * than the expression if we add exponentiation.  Next we
 372          * scan backwards looking for the start of arithmetic.  If the
 373          * next previous character is a CTLESC character, then we
 374          * have to rescan starting from the beginning since CTLESC
 375          * characters have to be processed left to right.
 376          */
 377 #if INT_MAX / 1000000000 >= 10 || INT_MIN / 1000000000 <= -10
 378 #error "integers with more than 10 digits are not supported"
 379 #endif
 380         CHECKSTRSPACE(12 - 2, expdest);
 381         USTPUTC('\0', expdest);
 382         start = stackblock();
 383         p = expdest - 2;
 384         while (p >= start && *p != CTLARI)
 385                 --p;
 386         if (p < start || *p != CTLARI)
 387                 error("missing CTLARI (shouldn't happen)");
 388         if (p > start && *(p - 1) == CTLESC)
 389                 for (p = start; *p != CTLARI; p++)
 390                         if (*p == CTLESC)
 391                                 p++;
 392
 393         if (p[1] == '"')
 394                 quoted=1;
 395         else
 396                 quoted=0;
 397         begoff = p - start;
 398         removerecordregions(begoff);
 399         if (quotes)
 400                 rmescapes(p+2);
 401         result = arith(p+2);
 402         fmtstr(p, 12, "%d", result);
 403         while (*p++)
 404                 ;
 405         if (quoted == 0)
 406                 recordregion(begoff, p - 1 - start, 0);
 407         result = expdest - p + 1;
 408         STADJUST(-result, expdest);
 409 }
 410
 411
 412 /*
 413  * Expand stuff in backwards quotes.
 414  */
 415
 416 STATIC void
 417 expbackq(union node *cmd, int quoted, int flag)
 418 {
 419         struct backcmd in;
 420         int i;
 421         char buf[128];
 422         char *p;
 423         char *dest = expdest;
 424         struct ifsregion saveifs, *savelastp;
 425         struct nodelist *saveargbackq;
 426         char lastc;
 427         int startloc = dest - stackblock();
 428         char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
 429         int saveherefd;
 430         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 431         int nnl;
 432
 433         INTOFF;
 434         saveifs = ifsfirst;
 435         savelastp = ifslastp;
 436         saveargbackq = argbackq;
 437         saveherefd = herefd;
 438         herefd = -1;
 439         p = grabstackstr(dest);
 440         evalbackcmd(cmd, &in);
 441         ungrabstackstr(p, dest);
 442         ifsfirst = saveifs;
 443         ifslastp = savelastp;
 444         argbackq = saveargbackq;
 445         herefd = saveherefd;
 446
 447         p = in.buf;
 448         lastc = '\0';
 449         nnl = 0;
 450         /* Don't copy trailing newlines */
 451         for (;;) {
 452                 if (--in.nleft < 0) {
 453                         if (in.fd < 0)
 454                                 break;
 455                         while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR);
 456                         TRACE(("expbackq: read returns %d\n", i));
 457                         if (i <= 0)
 458                                 break;
 459                         p = buf;
 460                         in.nleft = i - 1;
 461                 }
 462                 lastc = *p++;
 463                 if (lastc != '\0') {
 464                         if (quotes && syntax[(int)lastc] == CCTL)
 465                                 STPUTC(CTLESC, dest);
 466                         if (lastc == '\n') {
 467                                 nnl++;
 468                         } else {
 469                                 while (nnl > 0) {
 470                                         nnl--;
 471                                         STPUTC('\n', dest);
 472                                 }
 473                                 STPUTC(lastc, dest);
 474                         }
 475                 }
 476         }
 477
 478         if (in.fd >= 0)
 479                 close(in.fd);
 480         if (in.buf)
 481                 ckfree(in.buf);
 482         if (in.jp)
 483                 exitstatus = waitforjob(in.jp, NULL);
 484         if (quoted == 0)
 485                 recordregion(startloc, dest - stackblock(), 0);
 486         TRACE(("evalbackq: size=%d: \"%.*s\"\n",
 487                 (dest - stackblock()) - startloc,
 488                 (dest - stackblock()) - startloc,
 489                 stackblock() + startloc));
 490         expdest = dest;
 491         INTON;
 492 }
 493
 494
 495
 496 STATIC int
 497 subevalvar(char *p, char *str, int strloc, int subtype, int startloc,
 498   int varflags)
 499 {
 500         char *startp;
 501         char *loc = NULL;
 502         char *q;
 503         int c = 0;
 504         int saveherefd = herefd;
 505         struct nodelist *saveargbackq = argbackq;
 506         int amount;
 507
 508         herefd = -1;
 509         argstr(p, 0);
 510         STACKSTRNUL(expdest);
 511         herefd = saveherefd;
 512         argbackq = saveargbackq;
 513         startp = stackblock() + startloc;
 514         if (str == NULL)
 515             str = stackblock() + strloc;
 516
 517         switch (subtype) {
 518         case VSASSIGN:
 519                 setvar(str, startp, 0);
 520                 amount = startp - expdest;
 521                 STADJUST(amount, expdest);
 522                 varflags &= ~VSNUL;
 523                 if (c != 0)
 524                         *loc = c;
 525                 return 1;
 526
 527         case VSQUESTION:
 528                 if (*p != CTLENDVAR) {
 529                         outfmt(&errout, "%s\n", startp);
 530                         error(NULL);
 531                 }
 532                 error("%.*s: parameter %snot set", (int)(p - str - 1),
 533                       str, (varflags & VSNUL) ? "null or "
 534                                               : nullstr);
 535                 return 0;
 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                                 *loc = c;
 543                                 goto recordleft;
 544                         }
 545                         *loc = c;
 546                         if ((varflags & VSQUOTE) && *loc == CTLESC)
 547                                 loc++;
 548                 }
 549                 return 0;
 550
 551         case VSTRIMLEFTMAX:
 552                 for (loc = str - 1; loc >= startp;) {
 553                         c = *loc;
 554                         *loc = '\0';
 555                         if (patmatch(str, startp, varflags & VSQUOTE)) {
 556                                 *loc = c;
 557                                 goto recordleft;
 558                         }
 559                         *loc = c;
 560                         loc--;
 561                         if ((varflags & VSQUOTE) && loc > startp &&
 562                             *(loc - 1) == CTLESC) {
 563                                 for (q = startp; q < loc; q++)
 564                                         if (*q == CTLESC)
 565                                                 q++;
 566                                 if (q > loc)
 567                                         loc--;
 568                         }
 569                 }
 570                 return 0;
 571
 572         case VSTRIMRIGHT:
 573                 for (loc = str - 1; loc >= startp;) {
 574                         if (patmatch(str, loc, varflags & VSQUOTE)) {
 575                                 amount = loc - expdest;
 576                                 STADJUST(amount, expdest);
 577                                 return 1;
 578                         }
 579                         loc--;
 580                         if ((varflags & VSQUOTE) && loc > startp &&
 581                             *(loc - 1) == CTLESC) {
 582                                 for (q = startp; q < loc; q++)
 583                                         if (*q == CTLESC)
 584                                                 q++;
 585                                 if (q > loc)
 586                                         loc--;
 587                         }
 588                 }
 589                 return 0;
 590
 591         case VSTRIMRIGHTMAX:
 592                 for (loc = startp; loc < str - 1; loc++) {
 593                         if (patmatch(str, loc, varflags & VSQUOTE)) {
 594                                 amount = loc - expdest;
 595                                 STADJUST(amount, expdest);
 596                                 return 1;
 597                         }
 598                         if ((varflags & VSQUOTE) && *loc == CTLESC)
 599                                 loc++;
 600                 }
 601                 return 0;
 602
 603
 604         default:
 605                 abort();
 606         }
 607
 608 recordleft:
 609         amount = ((str - 1) - (loc - startp)) - expdest;
 610         STADJUST(amount, expdest);
 611         while (loc != str - 1)
 612                 *startp++ = *loc++;
 613         return 1;
 614 }
 615
 616
 617 /*
 618  * Expand a variable, and return a pointer to the next character in the
 619  * input string.
 620  */
 621
 622 STATIC char *
 623 evalvar(char *p, int flag)
 624 {
 625         int subtype;
 626         int varflags;
 627         char *var;
 628         char *val;
 629         int patloc;
 630         int c;
 631         int set;
 632         int special;
 633         int startloc;
 634         int varlen;
 635         int easy;
 636         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 637
 638         varflags = (unsigned char)*p++;
 639         subtype = varflags & VSTYPE;
 640         var = p;
 641         special = 0;
 642         if (! is_name(*p))
 643                 special = 1;
 644         p = strchr(p, '=') + 1;
 645 again: /* jump here after setting a variable with ${var=text} */
 646         if (varflags & VSLINENO) {
 647                 set = 1;
 648                 special = 0;
 649                 val = var;
 650                 p[-1] = '\0';   /* temporarily overwrite '=' to have \0
 651                                    terminated string */
 652         } else if (special) {
 653                 set = varisset(var, varflags & VSNUL);
 654                 val = NULL;
 655         } else {
 656                 val = bltinlookup(var, 1);
 657                 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
 658                         val = NULL;
 659                         set = 0;
 660                 } else
 661                         set = 1;
 662         }
 663         varlen = 0;
 664         startloc = expdest - stackblock();
 665         if (!set && uflag) {
 666                 switch (subtype) {
 667                 case VSNORMAL:
 668                 case VSTRIMLEFT:
 669                 case VSTRIMLEFTMAX:
 670                 case VSTRIMRIGHT:
 671                 case VSTRIMRIGHTMAX:
 672                 case VSLENGTH:
 673                         error("%.*s: parameter not set", (int)(p - var - 1),
 674                             var);
 675                 }
 676         }
 677         if (set && subtype != VSPLUS) {
 678                 /* insert the value of the variable */
 679                 if (special) {
 680                         varvalue(var, varflags & VSQUOTE, subtype, flag);
 681                         if (subtype == VSLENGTH) {
 682                                 varlen = expdest - stackblock() - startloc;
 683                                 STADJUST(-varlen, expdest);
 684                         }
 685                 } else {
 686                         char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX
 687                                                                   : BASESYNTAX;
 688
 689                         if (subtype == VSLENGTH) {
 690                                 for (;*val; val++)
 691                                         varlen++;
 692                         }
 693                         else {
 694                                 while (*val) {
 695                                         if (quotes &&
 696                                             syntax[(int)*val] == CCTL)
 697                                                 STPUTC(CTLESC, expdest);
 698                                         STPUTC(*val++, expdest);
 699                                 }
 700
 701                         }
 702                 }
 703         }
 704
 705         if (subtype == VSPLUS)
 706                 set = ! set;
 707
 708         easy = ((varflags & VSQUOTE) == 0 ||
 709                 (*var == '@' && shellparam.nparam != 1));
 710
 711
 712         switch (subtype) {
 713         case VSLENGTH:
 714                 expdest = cvtnum(varlen, expdest);
 715                 goto record;
 716
 717         case VSNORMAL:
 718                 if (!easy)
 719                         break;
 720 record:
 721                 recordregion(startloc, expdest - stackblock(),
 722                              varflags & VSQUOTE);
 723                 break;
 724
 725         case VSPLUS:
 726         case VSMINUS:
 727                 if (!set) {
 728                         argstr(p, flag);
 729                         break;
 730                 }
 731                 if (easy)
 732                         goto record;
 733                 break;
 734
 735         case VSTRIMLEFT:
 736         case VSTRIMLEFTMAX:
 737         case VSTRIMRIGHT:
 738         case VSTRIMRIGHTMAX:
 739                 if (!set)
 740                         break;
 741                 /*
 742                  * Terminate the string and start recording the pattern
 743                  * right after it
 744                  */
 745                 STPUTC('\0', expdest);
 746                 patloc = expdest - stackblock();
 747                 if (subevalvar(p, NULL, patloc, subtype,
 748                                startloc, varflags) == 0) {
 749                         int amount = (expdest - stackblock() - patloc) + 1;
 750                         STADJUST(-amount, expdest);
 751                 }
 752                 /* Remove any recorded regions beyond start of variable */
 753                 removerecordregions(startloc);
 754                 goto record;
 755
 756         case VSASSIGN:
 757         case VSQUESTION:
 758                 if (!set) {
 759                         if (subevalvar(p, var, 0, subtype, startloc, varflags)) {
 760                                 varflags &= ~VSNUL;
 761                                 /*
 762                                  * Remove any recorded regions beyond
 763                                  * start of variable
 764                                  */
 765                                 removerecordregions(startloc);
 766                                 goto again;
 767                         }
 768                         break;
 769                 }
 770                 if (easy)
 771                         goto record;
 772                 break;
 773
 774         case VSERROR:
 775                 c = p - var - 1;
 776                 error("${%.*s%s}: Bad substitution", c, var,
 777                     (c > 0 && *p != CTLENDVAR) ? "..." : "");
 778
 779         default:
 780                 abort();
 781         }
 782         p[-1] = '=';    /* recover overwritten '=' */
 783
 784         if (subtype != VSNORMAL) {      /* skip to end of alternative */
 785                 int nesting = 1;
 786                 for (;;) {
 787                         if ((c = *p++) == CTLESC)
 788                                 p++;
 789                         else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
 790                                 if (set)
 791                                         argbackq = argbackq->next;
 792                         } else if (c == CTLVAR) {
 793                                 if ((*p++ & VSTYPE) != VSNORMAL)
 794                                         nesting++;
 795                         } else if (c == CTLENDVAR) {
 796                                 if (--nesting == 0)
 797                                         break;
 798                         }
 799                 }
 800         }
 801         return p;
 802 }
 803
 804
 805
 806 /*
 807  * Test whether a specialized variable is set.
 808  */
 809
 810 STATIC int
 811 varisset(char *name, int nulok)
 812 {
 813
 814         if (*name == '!')
 815                 return backgndpid != -1;
 816         else if (*name == '@' || *name == '*') {
 817                 if (*shellparam.p == NULL)
 818                         return 0;
 819
 820                 if (nulok) {
 821                         char **av;
 822
 823                         for (av = shellparam.p; *av; av++)
 824                                 if (**av != '\0')
 825                                         return 1;
 826                         return 0;
 827                 }
 828         } else if (is_digit(*name)) {
 829                 char *ap;
 830                 int num = atoi(name);
 831
 832                 if (num > shellparam.nparam)
 833                         return 0;
 834
 835                 if (num == 0)
 836                         ap = arg0;
 837                 else
 838                         ap = shellparam.p[num - 1];
 839
 840                 if (nulok && (ap == NULL || *ap == '\0'))
 841                         return 0;
 842         }
 843         return 1;
 844 }
 845
 846
 847
 848 /*
 849  * Add the value of a specialized variable to the stack string.
 850  */
 851
 852 STATIC void
 853 varvalue(char *name, int quoted, int subtype, int flag)
 854 {
 855         int num;
 856         char *p;
 857         int i;
 858         char sep;
 859         char **ap;
 860         char const *syntax;
 861
 862 #define STRTODEST(p) \
 863         do {\
 864         if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) { \
 865                 syntax = quoted? DQSYNTAX : BASESYNTAX; \
 866                 while (*p) { \
 867                         if (syntax[(int)*p] == CCTL) \
 868                                 STPUTC(CTLESC, expdest); \
 869                         STPUTC(*p++, expdest); \
 870                 } \
 871         } else \
 872                 while (*p) \
 873                         STPUTC(*p++, expdest); \
 874         } while (0)
 875
 876
 877         switch (*name) {
 878         case '$':
 879                 num = rootpid;
 880                 goto numvar;
 881         case '?':
 882                 num = oexitstatus;
 883                 goto numvar;
 884         case '#':
 885                 num = shellparam.nparam;
 886                 goto numvar;
 887         case '!':
 888                 num = backgndpid;
 889 numvar:
 890                 expdest = cvtnum(num, expdest);
 891                 break;
 892         case '-':
 893                 for (i = 0 ; i < NOPTS ; i++) {
 894                         if (optlist[i].val)
 895                                 STPUTC(optlist[i].letter, expdest);
 896                 }
 897                 break;
 898         case '@':
 899                 if (flag & EXP_FULL && quoted) {
 900                         for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 901                                 STRTODEST(p);
 902                                 if (*ap)
 903                                         STPUTC('\0', expdest);
 904                         }
 905                         break;
 906                 }
 907                 /* FALLTHROUGH */
 908         case '*':
 909                 if (ifsset())
 910                         sep = ifsval()[0];
 911                 else
 912                         sep = ' ';
 913                 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 914                         STRTODEST(p);
 915                         if (*ap && sep)
 916                                 STPUTC(sep, expdest);
 917                 }
 918                 break;
 919         case '0':
 920                 p = arg0;
 921                 STRTODEST(p);
 922                 break;
 923         default:
 924                 if (is_digit(*name)) {
 925                         num = atoi(name);
 926                         if (num > 0 && num <= shellparam.nparam) {
 927                                 p = shellparam.p[num - 1];
 928                                 STRTODEST(p);
 929                         }
 930                 }
 931                 break;
 932         }
 933 }
 934
 935
 936
 937 /*
 938  * Record the the fact that we have to scan this region of the
 939  * string for IFS characters.
 940  */
 941
 942 STATIC void
 943 recordregion(int start, int end, int nulonly)
 944 {
 945         struct ifsregion *ifsp;
 946
 947         if (ifslastp == NULL) {
 948                 ifsp = &ifsfirst;
 949         } else {
 950                 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
 951                 ifslastp->next = ifsp;
 952         }
 953         ifslastp = ifsp;
 954         ifslastp->next = NULL;
 955         ifslastp->begoff = start;
 956         ifslastp->endoff = end;
 957         ifslastp->nulonly = nulonly;
 958 }
 959
 960
 961
 962 /*
 963  * Break the argument string into pieces based upon IFS and add the
 964  * strings to the argument list.  The regions of the string to be
 965  * searched for IFS characters have been stored by recordregion.
 966  */
 967 STATIC void
 968 ifsbreakup(char *string, struct arglist *arglist)
 969 {
 970         struct ifsregion *ifsp;
 971         struct strlist *sp;
 972         char *start;
 973         char *p;
 974         char *q;
 975         const char *ifs;
 976         int ifsspc;
 977         int nulonly;
 978
 979
 980         start = string;
 981         ifsspc = 0;
 982         nulonly = 0;
 983         if (ifslastp != NULL) {
 984                 ifsp = &ifsfirst;
 985                 do {
 986                         p = string + ifsp->begoff;
 987                         nulonly = ifsp->nulonly;
 988                         ifs = nulonly ? nullstr :
 989                                 ( ifsset() ? ifsval() : " \t\n" );
 990                         ifsspc = 0;
 991                         while (p < string + ifsp->endoff) {
 992                                 q = p;
 993                                 if (*p == CTLESC)
 994                                         p++;
 995                                 if (strchr(ifs, *p)) {
 996                                         if (!nulonly)
 997                                                 ifsspc = (strchr(" \t\n", *p) != NULL);
 998                                         /* Ignore IFS whitespace at start */
 999                                         if (q == start && ifsspc) {
1000                                                 p++;
1001                                                 start = p;
1002                                                 continue;
1003                                         }
1004                                         *q = '\0';
1005                                         sp = (struct strlist *)stalloc(sizeof *sp);
1006                                         sp->text = start;
1007                                         *arglist->lastp = sp;
1008                                         arglist->lastp = &sp->next;
1009                                         p++;
1010                                         if (!nulonly) {
1011                                                 for (;;) {
1012                                                         if (p >= string + ifsp->endoff) {
1013                                                                 break;
1014                                                         }
1015                                                         q = p;
1016                                                         if (*p == CTLESC)
1017                                                                 p++;
1018                                                         if (strchr(ifs, *p) == NULL ) {
1019                                                                 p = q;
1020                                                                 break;
1021                                                         } else if (strchr(" \t\n",*p) == NULL) {
1022                                                                 if (ifsspc) {
1023                                                                         p++;
1024                                                                         ifsspc = 0;
1025                                                                 } else {
1026                                                                         p = q;
1027                                                                         break;
1028                                                                 }
1029                                                         } else
1030                                                                 p++;
1031                                                 }
1032                                         }
1033                                         start = p;
1034                                 } else
1035                                         p++;
1036                         }
1037                 } while ((ifsp = ifsp->next) != NULL);
1038                 if (*start || (!ifsspc && start > string)) {
1039                         sp = (struct strlist *)stalloc(sizeof *sp);
1040                         sp->text = start;
1041                         *arglist->lastp = sp;
1042                         arglist->lastp = &sp->next;
1043                 }
1044         } else {
1045                 sp = (struct strlist *)stalloc(sizeof *sp);
1046                 sp->text = start;
1047                 *arglist->lastp = sp;
1048                 arglist->lastp = &sp->next;
1049         }
1050 }
1051
1052
1053
1054 /*
1055  * Expand shell metacharacters.  At this point, the only control characters
1056  * should be escapes.  The results are stored in the list exparg.
1057  */
1058
1059 STATIC char *expdir;
1060
1061
1062 STATIC void
1063 expandmeta(struct strlist *str, int flag __unused)
1064 {
1065         char *p;
1066         struct strlist **savelastp;
1067         struct strlist *sp;
1068         char c;
1069         /* TODO - EXP_REDIR */
1070
1071         while (str) {
1072                 if (fflag)
1073                         goto nometa;
1074                 p = str->text;
1075                 for (;;) {                      /* fast check for meta chars */
1076                         if ((c = *p++) == '\0')
1077                                 goto nometa;
1078                         if (c == '*' || c == '?' || c == '[' || c == '!')
1079                                 break;
1080                 }
1081                 savelastp = exparg.lastp;
1082                 INTOFF;
1083                 if (expdir == NULL) {
1084                         int i = strlen(str->text);
1085                         expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */
1086                 }
1087
1088                 expmeta(expdir, str->text);
1089                 ckfree(expdir);
1090                 expdir = NULL;
1091                 INTON;
1092                 if (exparg.lastp == savelastp) {
1093                         /*
1094                          * no matches
1095                          */
1096 nometa:
1097                         *exparg.lastp = str;
1098                         rmescapes(str->text);
1099                         exparg.lastp = &str->next;
1100                 } else {
1101                         *exparg.lastp = NULL;
1102                         *savelastp = sp = expsort(*savelastp);
1103                         while (sp->next != NULL)
1104                                 sp = sp->next;
1105                         exparg.lastp = &sp->next;
1106                 }
1107                 str = str->next;
1108         }
1109 }
1110
1111
1112 /*
1113  * Do metacharacter (i.e. *, ?, [...]) expansion.
1114  */
1115
1116 STATIC void
1117 expmeta(char *enddir, char *name)
1118 {
1119         char *p;
1120         const char *q;
1121         char *start;
1122         char *endname;
1123         int metaflag;
1124         struct stat statb;
1125         DIR *dirp;
1126         struct dirent *dp;
1127         int atend;
1128         int matchdot;
1129
1130         metaflag = 0;
1131         start = name;
1132         for (p = name ; ; p++) {
1133                 if (*p == '*' || *p == '?')
1134                         metaflag = 1;
1135                 else if (*p == '[') {
1136                         q = p + 1;
1137                         if (*q == '!' || *q == '^')
1138                                 q++;
1139                         for (;;) {
1140                                 while (*q == CTLQUOTEMARK)
1141                                         q++;
1142                                 if (*q == CTLESC)
1143                                         q++;
1144                                 if (*q == '/' || *q == '\0')
1145                                         break;
1146                                 if (*++q == ']') {
1147                                         metaflag = 1;
1148                                         break;
1149                                 }
1150                         }
1151                 } else if (*p == '!' && p[1] == '!'     && (p == name || p[-1] == '/')) {
1152                         metaflag = 1;
1153                 } else if (*p == '\0')
1154                         break;
1155                 else if (*p == CTLQUOTEMARK)
1156                         continue;
1157                 else if (*p == CTLESC)
1158                         p++;
1159                 if (*p == '/') {
1160                         if (metaflag)
1161                                 break;
1162                         start = p + 1;
1163                 }
1164         }
1165         if (metaflag == 0) {    /* we've reached the end of the file name */
1166                 if (enddir != expdir)
1167                         metaflag++;
1168                 for (p = name ; ; p++) {
1169                         if (*p == CTLQUOTEMARK)
1170                                 continue;
1171                         if (*p == CTLESC)
1172                                 p++;
1173                         *enddir++ = *p;
1174                         if (*p == '\0')
1175                                 break;
1176                 }
1177                 if (metaflag == 0 || lstat(expdir, &statb) >= 0)
1178                         addfname(expdir);
1179                 return;
1180         }
1181         endname = p;
1182         if (start != name) {
1183                 p = name;
1184                 while (p < start) {
1185                         while (*p == CTLQUOTEMARK)
1186                                 p++;
1187                         if (*p == CTLESC)
1188                                 p++;
1189                         *enddir++ = *p++;
1190                 }
1191         }
1192         if (enddir == expdir) {
1193                 q = ".";
1194         } else if (enddir == expdir + 1 && *expdir == '/') {
1195                 q = "/";
1196         } else {
1197                 q = expdir;
1198                 enddir[-1] = '\0';
1199         }
1200         if ((dirp = opendir(q)) == NULL)
1201                 return;
1202         if (enddir != expdir)
1203                 enddir[-1] = '/';
1204         if (*endname == 0) {
1205                 atend = 1;
1206         } else {
1207                 atend = 0;
1208                 *endname++ = '\0';
1209         }
1210         matchdot = 0;
1211         p = start;
1212         while (*p == CTLQUOTEMARK)
1213                 p++;
1214         if (*p == CTLESC)
1215                 p++;
1216         if (*p == '.')
1217                 matchdot++;
1218         while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1219                 if (dp->d_name[0] == '.' && ! matchdot)
1220                         continue;
1221                 if (patmatch(start, dp->d_name, 0)) {
1222                         if (atend) {
1223                                 scopy(dp->d_name, enddir);
1224                                 addfname(expdir);
1225                         } else {
1226                                 char *t;
1227                                 for (t = enddir, q = dp->d_name;
1228                                      (*t++ = *q++) != '\0';)
1229                                         continue;
1230                                 t[-1] = '/';
1231                                 expmeta(t, endname);
1232                         }
1233                 }
1234         }
1235         closedir(dirp);
1236         if (! atend)
1237                 endname[-1] = '/';
1238 }
1239
1240
1241 /*
1242  * Add a file name to the list.
1243  */
1244
1245 STATIC void
1246 addfname(char *name)
1247 {
1248         char *p;
1249         struct strlist *sp;
1250
1251         p = stalloc(strlen(name) + 1);
1252         scopy(name, p);
1253         sp = (struct strlist *)stalloc(sizeof *sp);
1254         sp->text = p;
1255         *exparg.lastp = sp;
1256         exparg.lastp = &sp->next;
1257 }
1258
1259
1260 /*
1261  * Sort the results of file name expansion.  It calculates the number of
1262  * strings to sort and then calls msort (short for merge sort) to do the
1263  * work.
1264  */
1265
1266 STATIC struct strlist *
1267 expsort(struct strlist *str)
1268 {
1269         int len;
1270         struct strlist *sp;
1271
1272         len = 0;
1273         for (sp = str ; sp ; sp = sp->next)
1274                 len++;
1275         return msort(str, len);
1276 }
1277
1278
1279 STATIC struct strlist *
1280 msort(struct strlist *list, int len)
1281 {
1282         struct strlist *p, *q = NULL;
1283         struct strlist **lpp;
1284         int half;
1285         int n;
1286
1287         if (len <= 1)
1288                 return list;
1289         half = len >> 1;
1290         p = list;
1291         for (n = half ; --n >= 0 ; ) {
1292                 q = p;
1293                 p = p->next;
1294         }
1295         q->next = NULL;                 /* terminate first half of list */
1296         q = msort(list, half);          /* sort first half of list */
1297         p = msort(p, len - half);               /* sort second half */
1298         lpp = &list;
1299         for (;;) {
1300                 if (strcmp(p->text, q->text) < 0) {
1301                         *lpp = p;
1302                         lpp = &p->next;
1303                         if ((p = *lpp) == NULL) {
1304                                 *lpp = q;
1305                                 break;
1306                         }
1307                 } else {
1308                         *lpp = q;
1309                         lpp = &q->next;
1310                         if ((q = *lpp) == NULL) {
1311                                 *lpp = p;
1312                                 break;
1313                         }
1314                 }
1315         }
1316         return list;
1317 }
1318
1319
1320
1321 /*
1322  * Returns true if the pattern matches the string.
1323  */
1324
1325 int
1326 patmatch(char *pattern, char *string, int squoted)
1327 {
1328 #ifdef notdef
1329         if (pattern[0] == '!' && pattern[1] == '!')
1330                 return 1 - pmatch(pattern + 2, string);
1331         else
1332 #endif
1333                 return pmatch(pattern, string, squoted);
1334 }
1335
1336
1337 STATIC int
1338 pmatch(char *pattern, char *string, int squoted)
1339 {
1340         char *p, *q;
1341         char c;
1342
1343         p = pattern;
1344         q = string;
1345         for (;;) {
1346                 switch (c = *p++) {
1347                 case '\0':
1348                         goto breakloop;
1349                 case CTLESC:
1350                         if (squoted && *q == CTLESC)
1351                                 q++;
1352                         if (*q++ != *p++)
1353                                 return 0;
1354                         break;
1355                 case CTLQUOTEMARK:
1356                         continue;
1357                 case '?':
1358                         if (squoted && *q == CTLESC)
1359                                 q++;
1360                         if (*q++ == '\0')
1361                                 return 0;
1362                         break;
1363                 case '*':
1364                         c = *p;
1365                         while (c == CTLQUOTEMARK || c == '*')
1366                                 c = *++p;
1367                         if (c != CTLESC &&  c != CTLQUOTEMARK &&
1368                             c != '?' && c != '*' && c != '[') {
1369                                 while (*q != c) {
1370                                         if (squoted && *q == CTLESC &&
1371                                             q[1] == c)
1372                                                 break;
1373                                         if (*q == '\0')
1374                                                 return 0;
1375                                         if (squoted && *q == CTLESC)
1376                                                 q++;
1377                                         q++;
1378                                 }
1379                         }
1380                         do {
1381                                 if (pmatch(p, q, squoted))
1382                                         return 1;
1383                                 if (squoted && *q == CTLESC)
1384                                         q++;
1385                         } while (*q++ != '\0');
1386                         return 0;
1387                 case '[': {
1388                         char *endp;
1389                         int invert, found;
1390                         char chr;
1391
1392                         endp = p;
1393                         if (*endp == '!' || *endp == '^')
1394                                 endp++;
1395                         for (;;) {
1396                                 while (*endp == CTLQUOTEMARK)
1397                                         endp++;
1398                                 if (*endp == '\0')
1399                                         goto dft;               /* no matching ] */
1400                                 if (*endp == CTLESC)
1401                                         endp++;
1402                                 if (*++endp == ']')
1403                                         break;
1404                         }
1405                         invert = 0;
1406                         if (*p == '!' || *p == '^') {
1407                                 invert++;
1408                                 p++;
1409                         }
1410                         found = 0;
1411                         chr = *q++;
1412                         if (squoted && chr == CTLESC)
1413                                 chr = *q++;
1414                         if (chr == '\0')
1415                                 return 0;
1416                         c = *p++;
1417                         do {
1418                                 if (c == CTLQUOTEMARK)
1419                                         continue;
1420                                 if (c == CTLESC)
1421                                         c = *p++;
1422                                 if (*p == '-' && p[1] != ']') {
1423                                         p++;
1424                                         while (*p == CTLQUOTEMARK)
1425                                                 p++;
1426                                         if (*p == CTLESC)
1427                                                 p++;
1428                                         if (   collate_range_cmp(chr, c) >= 0
1429                                             && collate_range_cmp(chr, *p) <= 0
1430                                            )
1431                                                 found = 1;
1432                                         p++;
1433                                 } else {
1434                                         if (chr == c)
1435                                                 found = 1;
1436                                 }
1437                         } while ((c = *p++) != ']');
1438                         if (found == invert)
1439                                 return 0;
1440                         break;
1441                 }
1442 dft:            default:
1443                         if (squoted && *q == CTLESC)
1444                                 q++;
1445                         if (*q++ != c)
1446                                 return 0;
1447                         break;
1448                 }
1449         }
1450 breakloop:
1451         if (*q != '\0')
1452                 return 0;
1453         return 1;
1454 }
1455
1456
1457
1458 /*
1459  * Remove any CTLESC characters from a string.
1460  */
1461
1462 void
1463 rmescapes(char *str)
1464 {
1465         char *p, *q;
1466
1467         p = str;
1468         while (*p != CTLESC && *p != CTLQUOTEMARK) {
1469                 if (*p++ == '\0')
1470                         return;
1471         }
1472         q = p;
1473         while (*p) {
1474                 if (*p == CTLQUOTEMARK) {
1475                         p++;
1476                         continue;
1477                 }
1478                 if (*p == CTLESC)
1479                         p++;
1480                 *q++ = *p++;
1481         }
1482         *q = '\0';
1483 }
1484
1485
1486
1487 /*
1488  * See if a pattern matches in a case statement.
1489  */
1490
1491 int
1492 casematch(union node *pattern, char *val)
1493 {
1494         struct stackmark smark;
1495         int result;
1496         char *p;
1497
1498         setstackmark(&smark);
1499         argbackq = pattern->narg.backquote;
1500         STARTSTACKSTR(expdest);
1501         ifslastp = NULL;
1502         argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
1503         STPUTC('\0', expdest);
1504         p = grabstackstr(expdest);
1505         result = patmatch(p, val, 0);
1506         popstackmark(&smark);
1507         return result;
1508 }
1509
1510 /*
1511  * Our own itoa().
1512  */
1513
1514 STATIC char *
1515 cvtnum(int num, char *buf)
1516 {
1517         char temp[32];
1518         int neg = num < 0;
1519         char *p = temp + 31;
1520
1521         temp[31] = '\0';
1522
1523         do {
1524                 *--p = num % 10 + '0';
1525         } while ((num /= 10) != 0);
1526
1527         if (neg)
1528                 *--p = '-';
1529
1530         while (*p)
1531                 STPUTC(*p++, buf);
1532         return buf;
1533 }
1534
1535 /*
1536  * Do most of the work for wordexp(3).
1537  */
1538
1539 int
1540 wordexpcmd(int argc, char **argv)
1541 {
1542         size_t len;
1543         int i;
1544
1545         out1fmt("%08x", argc - 1);
1546         for (i = 1, len = 0; i < argc; i++)
1547                 len += strlen(argv[i]);
1548         out1fmt("%08x", (int)len);
1549         for (i = 1; i < argc; i++) {
1550                 out1str(argv[i]);
1551                 out1c('\0');
1552         }
1553         return (0);
1554 }