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