fs_rewinddir.c

/****************************************************************************
 * fs/dirent/fs_rewinddir.c
 *
 *   Copyright (C) 2007-2009, 2011, 2014 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include "vfs_config.h"
#include "dirent.h"
#include "errno.h"
#include "fs/dirent_fs.h"
#include "vnode.h"

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: rewinddir
 *
 * Description:
 *   The  rewinddir() function resets the position of the
 *   directory stream dir to the beginning of the directory.
 *
 * Input Parameters:
 *   dirp -- An instance of type DIR created by a previous
 *     call to opendir();
 *
 * Returned Value:
 *   None
 *
 ****************************************************************************/

void rewinddir(DIR *dirp)
{
  struct fs_dirent_s *idir = (struct fs_dirent_s *)dirp;
  struct Vnode *vnode_ptr = NULL;

  if (!idir || !idir->fd_root || idir->fd_status != DIRENT_MAGIC)
    {
      set_errno(EBADF);
      return;
    }

  /* The way we handle the readdir depends on the type of vnode
   * that we are dealing with.
   */

  vnode_ptr = idir->fd_root;
  if (vnode_ptr->vop != NULL && vnode_ptr->vop->Rewinddir != NULL)
    {
      /* Perform the rewinddir() operation */

      vnode_ptr->vop->Rewinddir(vnode_ptr, idir);
    }
  else
    {
      set_errno(ENOSYS);
    }

  /* Reset position for telldir() */

  idir->fd_position = 0;
}