gnulib/import/opendir.c

   1 /* Start reading the entries of a directory.
   2    Copyright (C) 2006-2022 Free Software Foundation, Inc.
   3
   4    This file is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU Lesser General Public License as
   6    published by the Free Software Foundation; either version 2.1 of the
   7    License, or (at your option) any later version.
   8
   9    This file is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 #include <config.h>
  18
  19 /* Specification.  */
  20 #include <dirent.h>
  21
  22 #include <errno.h>
  23 #include <stddef.h>
  24
  25 #if HAVE_OPENDIR
  26
  27 /* Override opendir(), to keep track of the open file descriptors.
  28    Needed because there is a function dirfd().  */
  29
  30 #else
  31
  32 # include <stdlib.h>
  33
  34 # include "dirent-private.h"
  35 # include "filename.h"
  36
  37 #endif
  38
  39 #if REPLACE_FCHDIR
  40 # include <unistd.h>
  41 #endif
  42
  43 #ifdef __KLIBC__
  44 # include <io.h>
  45 # include <fcntl.h>
  46 #endif
  47
  48 #if defined _WIN32 && ! defined __CYGWIN__
  49 /* Don't assume that UNICODE is not defined.  */
  50 # undef WIN32_FIND_DATA
  51 # define WIN32_FIND_DATA WIN32_FIND_DATAA
  52 # undef GetFullPathName
  53 # define GetFullPathName GetFullPathNameA
  54 # undef FindFirstFile
  55 # define FindFirstFile FindFirstFileA
  56 #endif
  57
  58 DIR *
  59 opendir (const char *dir_name)
  60 {
  61 #if HAVE_OPENDIR
  62 # undef opendir
  63   DIR *dirp;
  64
  65   dirp = opendir (dir_name);
  66   if (dirp == NULL)
  67     return NULL;
  68
  69 # ifdef __KLIBC__
  70   {
  71     int fd = open (dir_name, O_RDONLY);
  72     if (fd == -1 || _gl_register_dirp_fd (fd, dirp))
  73       {
  74         int saved_errno = errno;
  75
  76         close (fd);
  77         closedir (dirp);
  78
  79         errno = saved_errno;
  80
  81         return NULL;
  82       }
  83   }
  84 # endif
  85 #else
  86
  87   char dir_name_mask[MAX_PATH + 1 + 1 + 1];
  88   int status;
  89   HANDLE current;
  90   WIN32_FIND_DATA entry;
  91   struct gl_directory *dirp;
  92
  93   if (dir_name[0] == '\0')
  94     {
  95       errno = ENOENT;
  96       return NULL;
  97     }
  98
  99   /* Make the dir_name absolute, so that we continue reading the same
 100      directory if the current directory changed between this opendir()
 101      call and a subsequent rewinddir() call.  */
 102   if (!GetFullPathName (dir_name, MAX_PATH, dir_name_mask, NULL))
 103     {
 104       errno = EINVAL;
 105       return NULL;
 106     }
 107
 108   /* Append the mask.
 109      "*" and "*.*" appear to be equivalent.  */
 110   {
 111     char *p;
 112
 113     p = dir_name_mask + strlen (dir_name_mask);
 114     if (p > dir_name_mask && !ISSLASH (p[-1]))
 115       *p++ = '\\';
 116     *p++ = '*';
 117     *p = '\0';
 118   }
 119
 120   /* Start searching the directory.  */
 121   status = -1;
 122   current = FindFirstFile (dir_name_mask, &entry);
 123   if (current == INVALID_HANDLE_VALUE)
 124     {
 125       switch (GetLastError ())
 126         {
 127         case ERROR_FILE_NOT_FOUND:
 128           status = -2;
 129           break;
 130         case ERROR_PATH_NOT_FOUND:
 131           errno = ENOENT;
 132           return NULL;
 133         case ERROR_DIRECTORY:
 134           errno = ENOTDIR;
 135           return NULL;
 136         case ERROR_ACCESS_DENIED:
 137           errno = EACCES;
 138           return NULL;
 139         default:
 140           errno = EIO;
 141           return NULL;
 142         }
 143     }
 144
 145   /* Allocate the result.  */
 146   dirp =
 147     (struct gl_directory *)
 148     malloc (offsetof (struct gl_directory, dir_name_mask[0])
 149             + strlen (dir_name_mask) + 1);
 150   if (dirp == NULL)
 151     {
 152       if (current != INVALID_HANDLE_VALUE)
 153         FindClose (current);
 154       errno = ENOMEM;
 155       return NULL;
 156     }
 157   dirp->status = status;
 158   dirp->current = current;
 159   if (status == -1)
 160     memcpy (&dirp->entry, &entry, sizeof (WIN32_FIND_DATA));
 161   strcpy (dirp->dir_name_mask, dir_name_mask);
 162
 163 #endif
 164
 165 #if REPLACE_FCHDIR
 166   {
 167     int fd = dirfd (dirp);
 168     if (0 <= fd && _gl_register_fd (fd, dir_name) != fd)
 169       {
 170         int saved_errno = errno;
 171         closedir (dirp);
 172         errno = saved_errno;
 173         return NULL;
 174       }
 175   }
 176 #endif
 177
 178   return dirp;
 179 }