/* GLIB - Library of useful routines for C programming

 * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald

 *

 * gdir.c: Simplified wrapper around the DIRENT functions.

 *

 * Copyright 2001 Hans Breuer

 * Copyright 2004 Tor Lillqvist

 *

 * SPDX-License-Identifier: LGPL-2.1-or-later

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, see <http://www.gnu.org/licenses/>.

 */

#include "config.h"

#include <errno.h>

#include <string.h>

#include <stdio.h>

#include <sys/stat.h>

#ifdef HAVE_DIRENT_H

#include <sys/types.h>

#include <dirent.h>

#endif

#include "gdir.h"

#include "gconvert.h"

#include "gfileutils.h"

#include "gstrfuncs.h"

#include "gtestutils.h"

#include "glibintl.h"

#if defined (_MSC_VER) && !defined (HAVE_DIRENT_H)

#include "dirent/dirent.h"

#endif

#include "glib-private.h" /* g_dir_open_with_errno, g_dir_new_from_dirp */

/**

 * GDir:

 *

 * An opaque structure representing an opened directory.

 */

struct _GDir

{

  gatomicrefcount ref_count;

#ifdef G_OS_WIN32

  _WDIR *wdirp;

#else

  DIR *dirp;

#endif

#ifdef G_OS_WIN32

  /* maximum encoding of FILENAME_MAX UTF-8 characters, plus a nul terminator

   * (FILENAME_MAX is not guaranteed to include one) */

  gchar utf8_buf[FILENAME_MAX*4 + 1];

#endif

};

/*< private >

 * g_dir_open_with_errno:

 * @path: the path to the directory you are interested in.

 * @flags: Currently must be set to 0. Reserved for future use.

 *

 * Opens a directory for reading.

 *

 * This function is equivalent to g_dir_open() except in the error case,

 * errno will be set accordingly.

 *

 * This is useful if you want to construct your own error message.

 *

 * Returns: a newly allocated #GDir on success, or %NULL on failure,

 *   with errno set accordingly.

 *

 * Since: 2.38

 */

GDir *

g_dir_open_with_errno (const gchar *path,

                       guint        flags)

{

#ifdef G_OS_WIN32

  GDir *dir;

  _WDIR *wdirp;

  gint saved_errno;

  wchar_t *wpath;

#else

  DIR *dirp;

#endif

  g_return_val_if_fail (path != NULL, NULL);

#ifdef G_OS_WIN32

  wpath = g_utf8_to_utf16 (path, -1, NULL, NULL, NULL);

  g_return_val_if_fail (wpath != NULL, NULL);

  wdirp = _wopendir (wpath);

  saved_errno = errno;

  g_free (wpath);

  errno = saved_errno;

  if (wdirp == NULL)

    return NULL;

  dir = g_new0 (GDir, 1);

  g_atomic_ref_count_init (&dir->ref_count);

  dir->wdirp = wdirp;

  return g_steal_pointer (&dir);

#else

  dirp = opendir (path);

  if (dirp == NULL)

    return NULL;

  return g_dir_new_from_dirp (dirp);

#endif

}

/**

 * g_dir_open: (constructor)

 * @path: the path to the directory you are interested in. On Unix

 *         in the on-disk encoding. On Windows in UTF-8

 * @flags: Currently must be set to 0. Reserved for future use.

 * @error: return location for a #GError, or %NULL.

 *         If non-%NULL, an error will be set if and only if

 *         g_dir_open() fails.

 *

 * Opens a directory for reading. The names of the files in the

 * directory can then be retrieved using g_dir_read_name().  Note

 * that the ordering is not defined.

 *

 * Returns: (transfer full): a newly allocated #GDir on success, %NULL on failure.

 *   If non-%NULL, you must free the result with g_dir_close()

 *   when you are finished with it.

 **/

GDir *

g_dir_open (const gchar  *path,

            guint         flags,

            GError      **error)

{

  gint saved_errno;

  GDir *dir;

  dir = g_dir_open_with_errno (path, flags);

  if (dir == NULL)

    {

      gchar *utf8_path;

      saved_errno = errno;

      utf8_path = g_filename_to_utf8 (path, -1, NULL, NULL, NULL);

      g_set_error (error, G_FILE_ERROR, g_file_error_from_errno (saved_errno),

                   _("Error opening directory “%s”: %s"), utf8_path, g_strerror (saved_errno));

      g_free (utf8_path);

    }

  return dir;

}

/*< private >

 * g_dir_new_from_dirp:

 * @dirp: a #DIR* created by opendir() or fdopendir()

 *

 * Creates a #GDir object from the DIR object that is created using

 * opendir() or fdopendir().  The created #GDir assumes ownership of the

 * passed-in #DIR pointer.

 *

 * @dirp must not be %NULL.

 *

 * This function never fails.

 *

 * Returns: a newly allocated #GDir, which should be closed using

 *     g_dir_close().

 *

 * Since: 2.38

 **/

GDir *

g_dir_new_from_dirp (gpointer dirp)

{

#ifdef G_OS_UNIX

  GDir *dir;

  g_return_val_if_fail (dirp != NULL, NULL);

  dir = g_new0 (GDir, 1);

  g_atomic_ref_count_init (&dir->ref_count);

  dir->dirp = dirp;

  return dir;

#else

  g_assert_not_reached ();

  return NULL;

#endif

}

/**

 * g_dir_read_name:

 * @dir: a #GDir* created by g_dir_open()

 *

 * Retrieves the name of another entry in the directory, or %NULL.

 * The order of entries returned from this function is not defined,

 * and may vary by file system or other operating-system dependent

 * factors.

 *

 * %NULL may also be returned in case of errors. On Unix, you can

 * check `errno` to find out if %NULL was returned because of an error.

 *

 * On Unix, the '.' and '..' entries are omitted, and the returned

 * name is in the on-disk encoding.

 *

 * On Windows, as is true of all GLib functions which operate on

 * filenames, the returned name is in UTF-8.

 *

 * Returns: (type filename): The entry's name or %NULL if there are no

 *   more entries. The return value is owned by GLib and

 *   must not be modified or freed.

 **/

const gchar *

g_dir_read_name (GDir *dir)

{

#ifdef G_OS_WIN32

  gchar *utf8_name;

  struct _wdirent *wentry;

#else

  struct dirent *entry;

#endif

  g_return_val_if_fail (dir != NULL, NULL);

#ifdef G_OS_WIN32

  while (1)

    {

      wentry = _wreaddir (dir->wdirp);

      while (wentry 

       && (0 == wcscmp (wentry->d_name, L".") ||

     0 == wcscmp (wentry->d_name, L"..")))

  wentry = _wreaddir (dir->wdirp);

      if (wentry == NULL)

  return NULL;

      utf8_name = g_utf16_to_utf8 (wentry->d_name, -1, NULL, NULL, NULL);

      if (utf8_name == NULL)

  continue;   /* Huh, impossible? Skip it anyway */

      strcpy (dir->utf8_buf, utf8_name);

      g_free (utf8_name);

      return dir->utf8_buf;

    }

#else

  entry = readdir (dir->dirp);

  while (entry 

         && (0 == strcmp (entry->d_name, ".") ||

             0 == strcmp (entry->d_name, "..")))

    entry = readdir (dir->dirp);

  if (entry)

    return entry->d_name;

  else

    return NULL;

#endif

}

/**

 * g_dir_rewind:

 * @dir: a #GDir* created by g_dir_open()

 *

 * Resets the given directory. The next call to g_dir_read_name()

 * will return the first entry again.

 **/

void

g_dir_rewind (GDir *dir)

{

  g_return_if_fail (dir != NULL);

#ifdef G_OS_WIN32

  _wrewinddir (dir->wdirp);

#else

  rewinddir (dir->dirp);

#endif

}

static void

g_dir_actually_close (GDir *dir)

{

#ifdef G_OS_WIN32

  g_clear_pointer (&dir->wdirp, _wclosedir);

#else

  g_clear_pointer (&dir->dirp, closedir);

#endif

}

/**

 * g_dir_close:

 * @dir: (transfer full): a #GDir* created by g_dir_open()

 *

 * Closes the directory immediately and decrements the reference count.

 *

 * Once the reference count reaches zero, the `GDir` structure itself will be

 * freed. Prior to GLib 2.80, `GDir` was not reference counted.

 *

 * It is an error to call any of the `GDir` methods other than

 * [method@GLib.Dir.ref] and [method@GLib.Dir.unref] on a `GDir` after calling

 * [method@GLib.Dir.close] on it.

 **/

void

g_dir_close (GDir *dir)

{

  g_return_if_fail (dir != NULL);

  g_dir_actually_close (dir);

  g_dir_unref (dir);

}

/**

 * g_dir_ref:

 * @dir: (transfer none): a `GDir`

 *

 * Increment the reference count of `dir`.

 *

 * Returns: (transfer full): the same pointer as `dir`

 * Since: 2.80

 */

GDir *

g_dir_ref (GDir *dir)

{

  g_return_val_if_fail (dir != NULL, NULL);

  g_atomic_ref_count_inc (&dir->ref_count);

  return dir;

}

/**

 * g_dir_unref:

 * @dir: (transfer full): a `GDir`

 *

 * Decrements the reference count of `dir`.

 *

 * Once the reference count reaches zero, the directory will be closed and all

 * resources associated with it will be freed. If [method@GLib.Dir.close] is

 * called when the reference count is greater than zero, the directory is closed

 * but the `GDir` structure will not be freed until its reference count reaches

 * zero.

 *

 * It is an error to call any of the `GDir` methods other than

 * [method@GLib.Dir.ref] and [method@GLib.Dir.unref] on a `GDir` after calling

 * [method@GLib.Dir.close] on it.

 *

 * Since: 2.80

 */

void

g_dir_unref (GDir *dir)

{

  g_return_if_fail (dir != NULL);

  if (g_atomic_ref_count_dec (&dir->ref_count))

    {

      g_dir_actually_close (dir);

      g_free (dir);

    }

}

#ifdef G_OS_WIN32

/* Binary compatibility versions. Not for newly compiled code. */

_GLIB_EXTERN GDir        *g_dir_open_utf8      (const gchar  *path,

                                                guint         flags,

                                                GError      **error);

_GLIB_EXTERN const gchar *g_dir_read_name_utf8 (GDir         *dir);

GDir *

g_dir_open_utf8 (const gchar  *path,

                 guint         flags,

                 GError      **error)

{

  return g_dir_open (path, flags, error);

}

const gchar *

g_dir_read_name_utf8 (GDir *dir)

{

  return g_dir_read_name (dir);

}

#endif