lib/savedirinfo.c

   1 /* savedirinfo.c -- Save the list of files in a directory, with additional information.
   2
   3    Copyright 1990, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005 Free
   4    Software Foundation, Inc.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    This program 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
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software Foundation,
  18    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  19
  20 /* Written by James Youngman, <jay@gnu.org>. */
  21 /* Derived from savedir.c, written by David MacKenzie <djm@gnu.org>. */
  22
  23 #if HAVE_CONFIG_H
  24 # include <config.h>
  25 #endif
  26
  27 #if HAVE_SYS_STAT_H
  28 # include <sys/stat.h>
  29 #endif
  30
  31 #if HAVE_SYS_TYPES_H
  32 # include <sys/types.h>
  33 #endif
  34
  35 #if HAVE_UNISTD_H
  36 # include <unistd.h>
  37 #endif
  38
  39 #include <errno.h>
  40
  41 #if HAVE_DIRENT_H
  42 # include <dirent.h>
  43 #else
  44 # define dirent direct
  45 # if HAVE_SYS_NDIR_H
  46 #  include <sys/ndir.h>
  47 # endif
  48 # if HAVE_SYS_DIR_H
  49 #  include <sys/dir.h>
  50 # endif
  51 # if HAVE_NDIR_H
  52 #  include <ndir.h>
  53 # endif
  54 #endif
  55
  56 #ifdef CLOSEDIR_VOID
  57 /* Fake a return value. */
  58 # define CLOSEDIR(d) (closedir (d), 0)
  59 #else
  60 # define CLOSEDIR(d) closedir (d)
  61 #endif
  62
  63 #include <stddef.h>
  64 #include <stdlib.h>
  65 #include <string.h>
  66
  67 #include "xalloc.h"
  68 #include "extendbuf.h"
  69 #include "savedirinfo.h"
  70
  71 /* In order to use struct dirent.d_type, it has to be enabled on the
  72  * configure command line, and we have to have a d_type member in
  73  * 'struct dirent'.
  74  */
  75 #if !defined(USE_STRUCT_DIRENT_D_TYPE)
  76 /* Not enabled, hence pretend it is absent. */
  77 #undef HAVE_STRUCT_DIRENT_D_TYPE
  78 #endif
  79 #if !defined(HAVE_STRUCT_DIRENT_D_TYPE)
  80 /* Not present, so cannot use it. */
  81 #undef USE_STRUCT_DIRENT_D_TYPE
  82 #endif
  83
  84
  85 #if defined(HAVE_STRUCT_DIRENT_D_TYPE) && defined(USE_STRUCT_DIRENT_D_TYPE)
  86 /* Convert the value of struct dirent.d_type into a value for
  87  * struct stat.st_mode (at least the file type bits), or zero
  88  * if the type is DT_UNKNOWN or is a value we don't know about.
  89  */
  90 static mode_t
  91 type_to_mode(unsigned type)
  92 {
  93   mode_t result = 0;
  94
  95   switch (type)
  96     {
  97 #ifdef DT_FIFO
  98     case DT_FIFO: return S_IFIFO;
  99 #endif
 100 #ifdef DT_CHR
 101     case DT_CHR:  return S_IFCHR;
 102 #endif
 103 #ifdef DT_DIR
 104     case DT_DIR:  return S_IFDIR;
 105 #endif
 106 #ifdef DT_BLK
 107     case DT_BLK:  return S_IFBLK;
 108 #endif
 109 #ifdef DT_REG
 110     case DT_REG:  return S_IFREG;
 111 #endif
 112 #ifdef DT_LNK
 113     case DT_LNK:  return S_IFLNK;
 114 #endif
 115 #ifdef DT_SOCK
 116     case DT_SOCK: return S_IFSOCK;
 117 #endif
 118     default:
 119       return 0;                 /* Unknown. */
 120     }
 121 }
 122
 123 #endif
 124
 125
 126 /* Return a freshly allocated string containing the filenames
 127    in directory DIR, separated by '\0' characters;
 128    the end is marked by two '\0' characters in a row.
 129    Return NULL (setting errno) if DIR cannot be opened, read, or closed.  */
 130
 131 char *
 132 savedirinfo (const char *dir, struct savedir_dirinfo **extra)
 133 {
 134   DIR *dirp;
 135   struct dirent *dp;
 136   char *name_space;
 137   size_t namebuf_allocated = 0u, namebuf_used = 0u;
 138 #if defined(HAVE_STRUCT_DIRENT_D_TYPE) && defined(USE_STRUCT_DIRENT_D_TYPE)
 139   size_t extra_allocated = 0u, extra_used = 0u;
 140   struct savedir_dirinfo *info = NULL;
 141 #endif
 142   int save_errno;
 143
 144   if (extra)
 145     *extra = NULL;
 146
 147   dirp = opendir (dir);
 148   if (dirp == NULL)
 149     return NULL;
 150
 151   errno = 0;
 152   name_space = NULL;
 153   while ((dp = readdir (dirp)) != NULL)
 154     {
 155       /* Skip "", ".", and "..".  "" is returned by at least one buggy
 156          implementation: Solaris 2.4 readdir on NFS file systems.  */
 157       char const *entry = dp->d_name;
 158       if (entry[entry[0] != '.' ? 0 : entry[1] != '.' ? 1 : 2] != '\0')
 159         {
 160           /* Remember the name. */
 161           size_t entry_size = strlen (entry) + 1;
 162           name_space = extendbuf(name_space, namebuf_used+entry_size, &namebuf_allocated);
 163           memcpy (name_space + namebuf_used, entry, entry_size);
 164           namebuf_used += entry_size;
 165
 166
 167 #if defined(HAVE_STRUCT_DIRENT_D_TYPE) && defined(USE_STRUCT_DIRENT_D_TYPE)
 168           /* Remember the type. */
 169           if (extra)
 170             {
 171               info = extendbuf(info,
 172                                (extra_used+1) * sizeof(struct savedir_dirinfo),
 173                                &extra_allocated);
 174               info[extra_used].type_info = type_to_mode(dp->d_type);
 175               ++extra_used;
 176             }
 177 #endif
 178         }
 179     }
 180
 181   name_space = extendbuf(name_space, namebuf_used+1, &namebuf_allocated);
 182   name_space[namebuf_used] = '\0';
 183
 184   save_errno = errno;
 185   if (CLOSEDIR (dirp) != 0)
 186     save_errno = errno;
 187   if (save_errno != 0)
 188     {
 189       free (name_space);
 190       errno = save_errno;
 191       return NULL;
 192     }
 193
 194 #if defined(HAVE_STRUCT_DIRENT_D_TYPE) && defined(USE_STRUCT_DIRENT_D_TYPE)
 195   if (extra && info)
 196     *extra = info;
 197 #endif
 198
 199   return name_space;
 200 }