io/ftw.c

   1 /* Copyright (C) 1992, 1995, 1996, 1997 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ian Lance Taylor (ian@airs.com).
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <errno.h>
  21 #include <limits.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <dirent.h>
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27 #include <ftw.h>
  28
  29
  30 #ifndef PATH_MAX
  31 #define PATH_MAX 1024           /* XXX */
  32 #endif
  33
  34
  35 /* Traverse one level of a directory tree.  */
  36
  37 static int
  38 ftw_dir (DIR **dirs, int level, int descriptors, char *dir, size_t len,
  39          int (*func) (const char *file, const struct stat *status, int flag))
  40 {
  41   int got;
  42   struct dirent *entry;
  43
  44   got = 0;
  45
  46   __set_errno (0);
  47
  48   while ((entry = readdir (dirs[level])) != NULL)
  49     {
  50       struct stat s;
  51       int flag, retval, newlev;
  52       size_t namlen;
  53
  54       ++got;
  55
  56       if (entry->d_name[0] == '.'
  57           && (entry->d_name[1] == '\0' ||
  58               (entry->d_name[1] == '.' && entry->d_name[2] == '\0')))
  59         {
  60           __set_errno (0);
  61           continue;
  62         }
  63
  64       namlen = _D_EXACT_NAMLEN (entry);
  65
  66       if (namlen + len + 1 > PATH_MAX)
  67         {
  68 #ifdef ENAMETOOLONG
  69           __set_errno (ENAMETOOLONG);
  70 #else
  71           __set_errno (ENOMEM);
  72 #endif
  73           return -1;
  74         }
  75
  76       dir[len] = '/';
  77       memcpy ((void *) (dir + len + 1), (void *) entry->d_name,
  78               namlen + 1);
  79
  80       if (stat (dir, &s) < 0)
  81         {
  82           if (errno != EACCES && errno != ENOENT)
  83             return -1;
  84           flag = FTW_NS;
  85         }
  86       else if (S_ISDIR (s.st_mode))
  87         {
  88           newlev = (level + 1) % descriptors;
  89
  90           if (dirs[newlev] != NULL)
  91             closedir (dirs[newlev]);
  92
  93           dirs[newlev] = opendir (dir);
  94           if (dirs[newlev] != NULL)
  95             flag = FTW_D;
  96           else
  97             {
  98               if (errno != EACCES)
  99                 return -1;
 100               flag = FTW_DNR;
 101             }
 102         }
 103       else
 104         flag = FTW_F;
 105
 106       retval = (*func) (dir, &s, flag);
 107
 108       if (flag == FTW_D)
 109         {
 110           if (retval == 0)
 111             retval = ftw_dir (dirs, newlev, descriptors, dir,
 112                               namlen + len + 1, func);
 113           if (dirs[newlev] != NULL)
 114             {
 115               int save;
 116
 117               save = errno;
 118               closedir (dirs[newlev]);
 119               __set_errno (save);
 120               dirs[newlev] = NULL;
 121             }
 122         }
 123
 124       if (retval != 0)
 125         return retval;
 126
 127       if (dirs[level] == NULL)
 128         {
 129           int skip;
 130
 131           dir[len] = '\0';
 132           dirs[level] = opendir (dir);
 133           if (dirs[level] == NULL)
 134             return -1;
 135           skip = got;
 136           while (skip-- != 0)
 137             {
 138               __set_errno (0);
 139               if (readdir (dirs[level]) == NULL)
 140                 return errno == 0 ? 0 : -1;
 141             }
 142         }
 143
 144       __set_errno (0);
 145     }
 146
 147   return errno == 0 ? 0 : -1;
 148 }
 149
 150 /* Call a function on every element in a directory tree.  */
 151
 152 int
 153 ftw (const char *dir,
 154      int (*func) (const char *file, const struct stat *status, int flag),
 155      int descriptors)
 156 {
 157   DIR **dirs;
 158   size_t len;
 159   char buf[PATH_MAX + 1];
 160   struct stat s;
 161   int flag, retval;
 162   int i;
 163
 164   if (descriptors <= 0)
 165     descriptors = 1;
 166
 167   dirs = (DIR **) __alloca (descriptors * sizeof (DIR *));
 168   i = descriptors;
 169   while (i-- > 0)
 170     dirs[i] = NULL;
 171
 172   if (stat (dir, &s) < 0)
 173     {
 174       if (errno != EACCES && errno != ENOENT)
 175         return -1;
 176       flag = FTW_NS;
 177     }
 178   else if (S_ISDIR (s.st_mode))
 179     {
 180       dirs[0] = opendir (dir);
 181       if (dirs[0] != NULL)
 182         flag = FTW_D;
 183       else
 184         {
 185           if (errno != EACCES)
 186             return -1;
 187           flag = FTW_DNR;
 188         }
 189     }
 190   else
 191     flag = FTW_F;
 192
 193   len = strlen (dir);
 194   memcpy ((void *) buf, (void *) dir, len + 1);
 195
 196   retval = (*func) (buf, &s, flag);
 197
 198   if (flag == FTW_D)
 199     {
 200       if (retval == 0)
 201         retval = ftw_dir (dirs, 0, descriptors, buf, len, func);
 202       if (dirs[0] != NULL)
 203         {
 204           int save;
 205
 206           save = errno;
 207           closedir (dirs[0]);
 208           __set_errno (save);
 209         }
 210     }
 211
 212   return retval;
 213 }