io/ftw.c

   1 /* File tree walker functions.
   2    Copyright (C) 1996-2004, 2006-2008, 2010 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #ifdef HAVE_CONFIG_H
  22 # include <config.h>
  23 #endif
  24
  25 #if __GNUC__
  26 # define alloca __builtin_alloca
  27 #else
  28 # if HAVE_ALLOCA_H
  29 #  include <alloca.h>
  30 # else
  31 #  ifdef _AIX
  32  #  pragma alloca
  33 #  else
  34 char *alloca ();
  35 #  endif
  36 # endif
  37 #endif
  38
  39 #ifdef _LIBC
  40 # include <dirent.h>
  41 # define NAMLEN(dirent) _D_EXACT_NAMLEN (dirent)
  42 #else
  43 # if HAVE_DIRENT_H
  44 #  include <dirent.h>
  45 #  define NAMLEN(dirent) strlen ((dirent)->d_name)
  46 # else
  47 #  define dirent direct
  48 #  define NAMLEN(dirent) (dirent)->d_namlen
  49 #  if HAVE_SYS_NDIR_H
  50 #   include <sys/ndir.h>
  51 #  endif
  52 #  if HAVE_SYS_DIR_H
  53 #   include <sys/dir.h>
  54 #  endif
  55 #  if HAVE_NDIR_H
  56 #   include <ndir.h>
  57 #  endif
  58 # endif
  59 #endif
  60
  61 #include <errno.h>
  62 #include <fcntl.h>
  63 #include <ftw.h>
  64 #include <limits.h>
  65 #include <search.h>
  66 #include <stdlib.h>
  67 #include <string.h>
  68 #include <unistd.h>
  69 #include <not-cancel.h>
  70 #if HAVE_SYS_PARAM_H || defined _LIBC
  71 # include <sys/param.h>
  72 #endif
  73 #ifdef _LIBC
  74 # include <include/sys/stat.h>
  75 #else
  76 # include <sys/stat.h>
  77 #endif
  78
  79 #if ! _LIBC && !HAVE_DECL_STPCPY && !defined stpcpy
  80 char *stpcpy ();
  81 #endif
  82
  83 #if ! _LIBC && ! defined HAVE_MEMPCPY && ! defined mempcpy
  84 /* Be CAREFUL that there are no side effects in N.  */
  85 # define mempcpy(D, S, N) ((void *) ((char *) memcpy (D, S, N) + (N)))
  86 #endif
  87
  88 /* #define NDEBUG 1 */
  89 #include <assert.h>
  90
  91 #ifndef _LIBC
  92 # undef __chdir
  93 # define __chdir chdir
  94 # undef __closedir
  95 # define __closedir closedir
  96 # undef __fchdir
  97 # define __fchdir fchdir
  98 # undef __getcwd
  99 # define __getcwd(P, N) xgetcwd ()
 100 extern char *xgetcwd (void);
 101 # undef __mempcpy
 102 # define __mempcpy mempcpy
 103 # undef __opendir
 104 # define __opendir opendir
 105 # undef __readdir64
 106 # define __readdir64 readdir
 107 # undef __stpcpy
 108 # define __stpcpy stpcpy
 109 # undef __tdestroy
 110 # define __tdestroy tdestroy
 111 # undef __tfind
 112 # define __tfind tfind
 113 # undef __tsearch
 114 # define __tsearch tsearch
 115 # undef internal_function
 116 # define internal_function /* empty */
 117 # undef dirent64
 118 # define dirent64 dirent
 119 # undef MAX
 120 # define MAX(a, b) ((a) > (b) ? (a) : (b))
 121 #endif
 122
 123 /* Arrange to make lstat calls go through the wrapper function
 124    on systems with an lstat function that does not dereference symlinks
 125    that are specified with a trailing slash.  */
 126 #if ! _LIBC && ! LSTAT_FOLLOWS_SLASHED_SYMLINK
 127 int rpl_lstat (const char *, struct stat *);
 128 # undef lstat
 129 # define lstat(Name, Stat_buf) rpl_lstat(Name, Stat_buf)
 130 #endif
 131
 132 #ifndef __set_errno
 133 # define __set_errno(Val) errno = (Val)
 134 #endif
 135
 136 /* Support for the LFS API version.  */
 137 #ifndef FTW_NAME
 138 # define FTW_NAME ftw
 139 # define NFTW_NAME nftw
 140 # define NFTW_OLD_NAME __old_nftw
 141 # define NFTW_NEW_NAME __new_nftw
 142 # define INO_T ino_t
 143 # define STAT stat
 144 # ifdef _LIBC
 145 #  define LXSTAT __lxstat
 146 #  define XSTAT __xstat
 147 #  define FXSTATAT __fxstatat
 148 # else
 149 #  define LXSTAT(V,f,sb) lstat (f,sb)
 150 #  define XSTAT(V,f,sb) stat (f,sb)
 151 #  define FXSTATAT(V,d,f,sb,m) fstatat (d, f, sb, m)
 152 # endif
 153 # define FTW_FUNC_T __ftw_func_t
 154 # define NFTW_FUNC_T __nftw_func_t
 155 #endif
 156
 157 /* We define PATH_MAX if the system does not provide a definition.
 158    This does not artificially limit any operation.  PATH_MAX is simply
 159    used as a guesstimate for the expected maximal path length.
 160    Buffers will be enlarged if necessary.  */
 161 #ifndef PATH_MAX
 162 # define PATH_MAX 1024
 163 #endif
 164
 165 struct dir_data
 166 {
 167   DIR *stream;
 168   int streamfd;
 169   char *content;
 170 };
 171
 172 struct known_object
 173 {
 174   dev_t dev;
 175   INO_T ino;
 176 };
 177
 178 struct ftw_data
 179 {
 180   /* Array with pointers to open directory streams.  */
 181   struct dir_data **dirstreams;
 182   size_t actdir;
 183   size_t maxdir;
 184
 185   /* Buffer containing name of currently processed object.  */
 186   char *dirbuf;
 187   size_t dirbufsize;
 188
 189   /* Passed as fourth argument to `nftw' callback.  The `base' member
 190      tracks the content of the `dirbuf'.  */
 191   struct FTW ftw;
 192
 193   /* Flags passed to `nftw' function.  0 for `ftw'.  */
 194   int flags;
 195
 196   /* Conversion array for flag values.  It is the identity mapping for
 197      `nftw' calls, otherwise it maps the values to those known by
 198      `ftw'.  */
 199   const int *cvt_arr;
 200
 201   /* Callback function.  We always use the `nftw' form.  */
 202   NFTW_FUNC_T func;
 203
 204   /* Device of starting point.  Needed for FTW_MOUNT.  */
 205   dev_t dev;
 206
 207   /* Data structure for keeping fingerprints of already processed
 208      object.  This is needed when not using FTW_PHYS.  */
 209   void *known_objects;
 210 };
 211
 212
 213 /* Internally we use the FTW_* constants used for `nftw'.  When invoked
 214    as `ftw', map each flag to the subset of values used by `ftw'.  */
 215 static const int nftw_arr[] =
 216 {
 217   FTW_F, FTW_D, FTW_DNR, FTW_NS, FTW_SL, FTW_DP, FTW_SLN
 218 };
 219
 220 static const int ftw_arr[] =
 221 {
 222   FTW_F, FTW_D, FTW_DNR, FTW_NS, FTW_F, FTW_D, FTW_NS
 223 };
 224
 225
 226 /* Forward declarations of local functions.  */
 227 static int ftw_dir (struct ftw_data *data, struct STAT *st,
 228                     struct dir_data *old_dir) internal_function;
 229
 230
 231 static int
 232 object_compare (const void *p1, const void *p2)
 233 {
 234   /* We don't need a sophisticated and useful comparison.  We are only
 235      interested in equality.  However, we must be careful not to
 236      accidentally compare `holes' in the structure.  */
 237   const struct known_object *kp1 = p1, *kp2 = p2;
 238   int cmp1;
 239   cmp1 = (kp1->ino > kp2->ino) - (kp1->ino < kp2->ino);
 240   if (cmp1 != 0)
 241     return cmp1;
 242   return (kp1->dev > kp2->dev) - (kp1->dev < kp2->dev);
 243 }
 244
 245
 246 static int
 247 add_object (struct ftw_data *data, struct STAT *st)
 248 {
 249   struct known_object *newp = malloc (sizeof (struct known_object));
 250   if (newp == NULL)
 251     return -1;
 252   newp->dev = st->st_dev;
 253   newp->ino = st->st_ino;
 254   return __tsearch (newp, &data->known_objects, object_compare) ? 0 : -1;
 255 }
 256
 257
 258 static inline int
 259 find_object (struct ftw_data *data, struct STAT *st)
 260 {
 261   struct known_object obj;
 262   obj.dev = st->st_dev;
 263   obj.ino = st->st_ino;
 264   return __tfind (&obj, &data->known_objects, object_compare) != NULL;
 265 }
 266
 267
 268 static inline int
 269 __attribute ((always_inline))
 270 open_dir_stream (int *dfdp, struct ftw_data *data, struct dir_data *dirp)
 271 {
 272   int result = 0;
 273
 274   if (data->dirstreams[data->actdir] != NULL)
 275     {
 276       /* Oh, oh.  We must close this stream.  Get all remaining
 277          entries and store them as a list in the `content' member of
 278          the `struct dir_data' variable.  */
 279       size_t bufsize = 1024;
 280       char *buf = malloc (bufsize);
 281
 282       if (buf == NULL)
 283         result = -1;
 284       else
 285         {
 286           DIR *st = data->dirstreams[data->actdir]->stream;
 287           struct dirent64 *d;
 288           size_t actsize = 0;
 289
 290           while ((d = __readdir64 (st)) != NULL)
 291             {
 292               size_t this_len = NAMLEN (d);
 293               if (actsize + this_len + 2 >= bufsize)
 294                 {
 295                   char *newp;
 296                   bufsize += MAX (1024, 2 * this_len);
 297                   newp = (char *) realloc (buf, bufsize);
 298                   if (newp == NULL)
 299                     {
 300                       /* No more memory.  */
 301                       int save_err = errno;
 302                       free (buf);
 303                       __set_errno (save_err);
 304                       return -1;
 305                     }
 306                   buf = newp;
 307                 }
 308
 309               *((char *) __mempcpy (buf + actsize, d->d_name, this_len))
 310                 = '\0';
 311               actsize += this_len + 1;
 312             }
 313
 314           /* Terminate the list with an additional NUL byte.  */
 315           buf[actsize++] = '\0';
 316
 317           /* Shrink the buffer to what we actually need.  */
 318           data->dirstreams[data->actdir]->content = realloc (buf, actsize);
 319           if (data->dirstreams[data->actdir]->content == NULL)
 320             {
 321               int save_err = errno;
 322               free (buf);
 323               __set_errno (save_err);
 324               result = -1;
 325             }
 326           else
 327             {
 328               __closedir (st);
 329               data->dirstreams[data->actdir]->stream = NULL;
 330               data->dirstreams[data->actdir]->streamfd = -1;
 331               data->dirstreams[data->actdir] = NULL;
 332             }
 333         }
 334     }
 335
 336   /* Open the new stream.  */
 337   if (result == 0)
 338     {
 339       assert (data->dirstreams[data->actdir] == NULL);
 340
 341       if (dfdp != NULL && *dfdp != -1)
 342         {
 343           int fd = openat64_not_cancel_3 (*dfdp, data->dirbuf + data->ftw.base,
 344                                           O_RDONLY | O_DIRECTORY | O_NDELAY);
 345           dirp->stream = NULL;
 346           if (fd != -1 && (dirp->stream = __fdopendir (fd)) == NULL)
 347             close_not_cancel_no_status (fd);
 348         }
 349       else
 350         {
 351           const char *name;
 352
 353           if (data->flags & FTW_CHDIR)
 354             {
 355               name = data->dirbuf + data->ftw.base;
 356               if (name[0] == '\0')
 357                 name = ".";
 358             }
 359           else
 360             name = data->dirbuf;
 361
 362           dirp->stream = __opendir (name);
 363         }
 364
 365       if (dirp->stream == NULL)
 366         result = -1;
 367       else
 368         {
 369           dirp->streamfd = dirfd (dirp->stream);
 370           dirp->content = NULL;
 371           data->dirstreams[data->actdir] = dirp;
 372
 373           if (++data->actdir == data->maxdir)
 374             data->actdir = 0;
 375         }
 376     }
 377
 378   return result;
 379 }
 380
 381
 382 static int
 383 internal_function
 384 process_entry (struct ftw_data *data, struct dir_data *dir, const char *name,
 385                size_t namlen, int d_type)
 386 {
 387   struct STAT st;
 388   int result = 0;
 389   int flag = 0;
 390   size_t new_buflen;
 391
 392   if (name[0] == '.' && (name[1] == '\0'
 393                          || (name[1] == '.' && name[2] == '\0')))
 394     /* Don't process the "." and ".." entries.  */
 395     return 0;
 396
 397   new_buflen = data->ftw.base + namlen + 2;
 398   if (data->dirbufsize < new_buflen)
 399     {
 400       /* Enlarge the buffer.  */
 401       char *newp;
 402
 403       data->dirbufsize = 2 * new_buflen;
 404       newp = (char *) realloc (data->dirbuf, data->dirbufsize);
 405       if (newp == NULL)
 406         return -1;
 407       data->dirbuf = newp;
 408     }
 409
 410   *((char *) __mempcpy (data->dirbuf + data->ftw.base, name, namlen)) = '\0';
 411
 412   int statres;
 413   if (dir->streamfd != -1)
 414     statres = FXSTATAT (_STAT_VER, dir->streamfd, name, &st,
 415                         (data->flags & FTW_PHYS) ? AT_SYMLINK_NOFOLLOW : 0);
 416   else
 417     {
 418       if ((data->flags & FTW_CHDIR) == 0)
 419         name = data->dirbuf;
 420
 421       statres = ((data->flags & FTW_PHYS)
 422                  ? LXSTAT (_STAT_VER, name, &st)
 423                  : XSTAT (_STAT_VER, name, &st));
 424     }
 425
 426   if (statres < 0)
 427     {
 428       if (errno != EACCES && errno != ENOENT)
 429         result = -1;
 430       else if (data->flags & FTW_PHYS)
 431         flag = FTW_NS;
 432       else if (d_type == DT_LNK)
 433         flag = FTW_SLN;
 434       else
 435         {
 436           if (dir->streamfd != -1)
 437             statres = FXSTATAT (_STAT_VER, dir->streamfd, name, &st,
 438                                 AT_SYMLINK_NOFOLLOW);
 439           else
 440             statres = LXSTAT (_STAT_VER, name, &st);
 441           if (statres == 0 && S_ISLNK (st.st_mode))
 442             flag = FTW_SLN;
 443           else
 444             flag = FTW_NS;
 445         }
 446     }
 447   else
 448     {
 449       if (S_ISDIR (st.st_mode))
 450         flag = FTW_D;
 451       else if (S_ISLNK (st.st_mode))
 452         flag = FTW_SL;
 453       else
 454         flag = FTW_F;
 455     }
 456
 457   if (result == 0
 458       && (flag == FTW_NS
 459           || !(data->flags & FTW_MOUNT) || st.st_dev == data->dev))
 460     {
 461       if (flag == FTW_D)
 462         {
 463           if ((data->flags & FTW_PHYS)
 464               || (!find_object (data, &st)
 465                   /* Remember the object.  */
 466                   && (result = add_object (data, &st)) == 0))
 467             result = ftw_dir (data, &st, dir);
 468         }
 469       else
 470         result = (*data->func) (data->dirbuf, &st, data->cvt_arr[flag],
 471                                 &data->ftw);
 472     }
 473
 474   if ((data->flags & FTW_ACTIONRETVAL) && result == FTW_SKIP_SUBTREE)
 475     result = 0;
 476
 477   return result;
 478 }
 479
 480
 481 static int
 482 __attribute ((noinline))
 483 internal_function
 484 ftw_dir (struct ftw_data *data, struct STAT *st, struct dir_data *old_dir)
 485 {
 486   struct dir_data dir;
 487   struct dirent64 *d;
 488   int previous_base = data->ftw.base;
 489   int result;
 490   char *startp;
 491
 492   /* Open the stream for this directory.  This might require that
 493      another stream has to be closed.  */
 494   result = open_dir_stream (old_dir == NULL ? NULL : &old_dir->streamfd,
 495                             data, &dir);
 496   if (result != 0)
 497     {
 498       if (errno == EACCES)
 499         /* We cannot read the directory.  Signal this with a special flag.  */
 500         result = (*data->func) (data->dirbuf, st, FTW_DNR, &data->ftw);
 501
 502       return result;
 503     }
 504
 505   /* First, report the directory (if not depth-first).  */
 506   if (!(data->flags & FTW_DEPTH))
 507     {
 508       result = (*data->func) (data->dirbuf, st, FTW_D, &data->ftw);
 509       if (result != 0)
 510         {
 511           int save_err;
 512 fail:
 513           save_err = errno;
 514           __closedir (dir.stream);
 515           dir.streamfd = -1;
 516           __set_errno (save_err);
 517
 518           if (data->actdir-- == 0)
 519             data->actdir = data->maxdir - 1;
 520           data->dirstreams[data->actdir] = NULL;
 521           return result;
 522         }
 523     }
 524
 525   /* If necessary, change to this directory.  */
 526   if (data->flags & FTW_CHDIR)
 527     {
 528       if (__fchdir (dirfd (dir.stream)) < 0)
 529         {
 530           result = -1;
 531           goto fail;
 532         }
 533     }
 534
 535   /* Next, update the `struct FTW' information.  */
 536   ++data->ftw.level;
 537   startp = __rawmemchr (data->dirbuf, '\0');
 538   /* There always must be a directory name.  */
 539   assert (startp != data->dirbuf);
 540   if (startp[-1] != '/')
 541     *startp++ = '/';
 542   data->ftw.base = startp - data->dirbuf;
 543
 544   while (dir.stream != NULL && (d = __readdir64 (dir.stream)) != NULL)
 545     {
 546       result = process_entry (data, &dir, d->d_name, NAMLEN (d), d->d_type);
 547       if (result != 0)
 548         break;
 549     }
 550
 551   if (dir.stream != NULL)
 552     {
 553       /* The stream is still open.  I.e., we did not need more
 554          descriptors.  Simply close the stream now.  */
 555       int save_err = errno;
 556
 557       assert (dir.content == NULL);
 558
 559       __closedir (dir.stream);
 560       dir.streamfd = -1;
 561       __set_errno (save_err);
 562
 563       if (data->actdir-- == 0)
 564         data->actdir = data->maxdir - 1;
 565       data->dirstreams[data->actdir] = NULL;
 566     }
 567   else
 568     {
 569       int save_err;
 570       char *runp = dir.content;
 571
 572       while (result == 0 && *runp != '\0')
 573         {
 574           char *endp = strchr (runp, '\0');
 575
 576           // XXX Should store the d_type values as well?!
 577           result = process_entry (data, &dir, runp, endp - runp, DT_UNKNOWN);
 578
 579           runp = endp + 1;
 580         }
 581
 582       save_err = errno;
 583       free (dir.content);
 584       __set_errno (save_err);
 585     }
 586
 587   if ((data->flags & FTW_ACTIONRETVAL) && result == FTW_SKIP_SIBLINGS)
 588     result = 0;
 589
 590   /* Prepare the return, revert the `struct FTW' information.  */
 591   data->dirbuf[data->ftw.base - 1] = '\0';
 592   --data->ftw.level;
 593   data->ftw.base = previous_base;
 594
 595   /* Finally, if we process depth-first report the directory.  */
 596   if (result == 0 && (data->flags & FTW_DEPTH))
 597     result = (*data->func) (data->dirbuf, st, FTW_DP, &data->ftw);
 598
 599   if (old_dir
 600       && (data->flags & FTW_CHDIR)
 601       && (result == 0
 602           || ((data->flags & FTW_ACTIONRETVAL)
 603               && (result != -1 && result != FTW_STOP))))
 604     {
 605       /* Change back to the parent directory.  */
 606       int done = 0;
 607       if (old_dir->stream != NULL)
 608         if (__fchdir (dirfd (old_dir->stream)) == 0)
 609           done = 1;
 610
 611       if (!done)
 612         {
 613           if (data->ftw.base == 1)
 614             {
 615               if (__chdir ("/") < 0)
 616                 result = -1;
 617             }
 618           else
 619             if (__chdir ("..") < 0)
 620               result = -1;
 621         }
 622     }
 623
 624   return result;
 625 }
 626
 627
 628 static int
 629 __attribute ((noinline))
 630 internal_function
 631 ftw_startup (const char *dir, int is_nftw, void *func, int descriptors,
 632              int flags)
 633 {
 634   struct ftw_data data;
 635   struct STAT st;
 636   int result = 0;
 637   int save_err;
 638   int cwdfd = -1;
 639   char *cwd = NULL;
 640   char *cp;
 641
 642   /* First make sure the parameters are reasonable.  */
 643   if (dir[0] == '\0')
 644     {
 645       __set_errno (ENOENT);
 646       return -1;
 647     }
 648
 649   data.maxdir = descriptors < 1 ? 1 : descriptors;
 650   data.actdir = 0;
 651   data.dirstreams = (struct dir_data **) alloca (data.maxdir
 652                                                  * sizeof (struct dir_data *));
 653   memset (data.dirstreams, '\0', data.maxdir * sizeof (struct dir_data *));
 654
 655   /* PATH_MAX is always defined when we get here.  */
 656   data.dirbufsize = MAX (2 * strlen (dir), PATH_MAX);
 657   data.dirbuf = (char *) malloc (data.dirbufsize);
 658   if (data.dirbuf == NULL)
 659     return -1;
 660   cp = __stpcpy (data.dirbuf, dir);
 661   /* Strip trailing slashes.  */
 662   while (cp > data.dirbuf + 1 && cp[-1] == '/')
 663     --cp;
 664   *cp = '\0';
 665
 666   data.ftw.level = 0;
 667
 668   /* Find basename.  */
 669   while (cp > data.dirbuf && cp[-1] != '/')
 670     --cp;
 671   data.ftw.base = cp - data.dirbuf;
 672
 673   data.flags = flags;
 674
 675   /* This assignment might seem to be strange but it is what we want.
 676      The trick is that the first three arguments to the `ftw' and
 677      `nftw' callback functions are equal.  Therefore we can call in
 678      every case the callback using the format of the `nftw' version
 679      and get the correct result since the stack layout for a function
 680      call in C allows this.  */
 681   data.func = (NFTW_FUNC_T) func;
 682
 683   /* Since we internally use the complete set of FTW_* values we need
 684      to reduce the value range before calling a `ftw' callback.  */
 685   data.cvt_arr = is_nftw ? nftw_arr : ftw_arr;
 686
 687   /* No object known so far.  */
 688   data.known_objects = NULL;
 689
 690   /* Now go to the directory containing the initial file/directory.  */
 691   if (flags & FTW_CHDIR)
 692     {
 693       /* We have to be able to go back to the current working
 694          directory.  The best way to do this is to use a file
 695          descriptor.  */
 696       cwdfd = __open (".", O_RDONLY | O_DIRECTORY);
 697       if (cwdfd == -1)
 698         {
 699           /* Try getting the directory name.  This can be needed if
 700              the current directory is executable but not readable.  */
 701           if (errno == EACCES)
 702             /* GNU extension ahead.  */
 703             cwd =  __getcwd (NULL, 0);
 704
 705           if (cwd == NULL)
 706             goto out_fail;
 707         }
 708       else if (data.maxdir > 1)
 709         /* Account for the file descriptor we use here.  */
 710         --data.maxdir;
 711
 712       if (data.ftw.base > 0)
 713         {
 714           /* Change to the directory the file is in.  In data.dirbuf
 715              we have a writable copy of the file name.  Just NUL
 716              terminate it for now and change the directory.  */
 717           if (data.ftw.base == 1)
 718             /* I.e., the file is in the root directory.  */
 719             result = __chdir ("/");
 720           else
 721             {
 722               char ch = data.dirbuf[data.ftw.base - 1];
 723               data.dirbuf[data.ftw.base - 1] = '\0';
 724               result = __chdir (data.dirbuf);
 725               data.dirbuf[data.ftw.base - 1] = ch;
 726             }
 727         }
 728     }
 729
 730   /* Get stat info for start directory.  */
 731   if (result == 0)
 732     {
 733       const char *name;
 734
 735       if (data.flags & FTW_CHDIR)
 736         {
 737           name = data.dirbuf + data.ftw.base;
 738           if (name[0] == '\0')
 739             name = ".";
 740         }
 741       else
 742         name = data.dirbuf;
 743
 744       if (((flags & FTW_PHYS)
 745            ? LXSTAT (_STAT_VER, name, &st)
 746            : XSTAT (_STAT_VER, name, &st)) < 0)
 747         {
 748           if (!(flags & FTW_PHYS)
 749               && errno == ENOENT
 750               && LXSTAT (_STAT_VER, name, &st) == 0
 751               && S_ISLNK (st.st_mode))
 752             result = (*data.func) (data.dirbuf, &st, data.cvt_arr[FTW_SLN],
 753                                    &data.ftw);
 754           else
 755             /* No need to call the callback since we cannot say anything
 756                about the object.  */
 757             result = -1;
 758         }
 759       else
 760         {
 761           if (S_ISDIR (st.st_mode))
 762             {
 763               /* Remember the device of the initial directory in case
 764                  FTW_MOUNT is given.  */
 765               data.dev = st.st_dev;
 766
 767               /* We know this directory now.  */
 768               if (!(flags & FTW_PHYS))
 769                 result = add_object (&data, &st);
 770
 771               if (result == 0)
 772                 result = ftw_dir (&data, &st, NULL);
 773             }
 774           else
 775             {
 776               int flag = S_ISLNK (st.st_mode) ? FTW_SL : FTW_F;
 777
 778               result = (*data.func) (data.dirbuf, &st, data.cvt_arr[flag],
 779                                      &data.ftw);
 780             }
 781         }
 782
 783       if ((flags & FTW_ACTIONRETVAL)
 784           && (result == FTW_SKIP_SUBTREE || result == FTW_SKIP_SIBLINGS))
 785         result = 0;
 786     }
 787
 788   /* Return to the start directory (if necessary).  */
 789   if (cwdfd != -1)
 790     {
 791       int save_err = errno;
 792       __fchdir (cwdfd);
 793       close_not_cancel_no_status (cwdfd);
 794       __set_errno (save_err);
 795     }
 796   else if (cwd != NULL)
 797     {
 798       int save_err = errno;
 799       __chdir (cwd);
 800       free (cwd);
 801       __set_errno (save_err);
 802     }
 803
 804   /* Free all memory.  */
 805  out_fail:
 806   save_err = errno;
 807   __tdestroy (data.known_objects, free);
 808   free (data.dirbuf);
 809   __set_errno (save_err);
 810
 811   return result;
 812 }
 813
 814
 815
 816 /* Entry points.  */
 817
 818 int
 819 FTW_NAME (path, func, descriptors)
 820      const char *path;
 821      FTW_FUNC_T func;
 822      int descriptors;
 823 {
 824   return ftw_startup (path, 0, func, descriptors, 0);
 825 }
 826
 827 #ifndef _LIBC
 828 int
 829 NFTW_NAME (path, func, descriptors, flags)
 830      const char *path;
 831      NFTW_FUNC_T func;
 832      int descriptors;
 833      int flags;
 834 {
 835   return ftw_startup (path, 1, func, descriptors, flags);
 836 }
 837 #else
 838
 839 # include <shlib-compat.h>
 840
 841 int NFTW_NEW_NAME (const char *, NFTW_FUNC_T, int, int);
 842
 843 int
 844 NFTW_NEW_NAME (path, func, descriptors, flags)
 845      const char *path;
 846      NFTW_FUNC_T func;
 847      int descriptors;
 848      int flags;
 849 {
 850   if (flags
 851       & ~(FTW_PHYS | FTW_MOUNT | FTW_CHDIR | FTW_DEPTH | FTW_ACTIONRETVAL))
 852     {
 853       __set_errno (EINVAL);
 854       return -1;
 855     }
 856   return ftw_startup (path, 1, func, descriptors, flags);
 857 }
 858
 859 versioned_symbol (libc, NFTW_NEW_NAME, NFTW_NAME, GLIBC_2_3_3);
 860
 861 # if SHLIB_COMPAT(libc, GLIBC_2_1, GLIBC_2_3_3)
 862
 863 /* Older nftw* version just ignored all unknown flags.  */
 864
 865 int NFTW_OLD_NAME (const char *, NFTW_FUNC_T, int, int);
 866
 867 int
 868 attribute_compat_text_section
 869 NFTW_OLD_NAME (path, func, descriptors, flags)
 870      const char *path;
 871      NFTW_FUNC_T func;
 872      int descriptors;
 873      int flags;
 874 {
 875   flags &= (FTW_PHYS | FTW_MOUNT | FTW_CHDIR | FTW_DEPTH);
 876   return ftw_startup (path, 1, func, descriptors, flags);
 877 }
 878
 879 compat_symbol (libc, NFTW_OLD_NAME, NFTW_NAME, GLIBC_2_1);
 880 # endif
 881 #endif