px4-firmware/nuttx/lib/dirent/lib_telldir.c

92 lines
3.3 KiB
C

/****************************************************************************
* lib/dirent/fs_telldir.c
*
* Copyright (C) 2007-2008, 2011-2012 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 <nuttx/config.h>
#include <sys/types.h>
#include <dirent.h>
#include <errno.h>
#include <nuttx/fs.h>
#include <nuttx/dirent.h>
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: telldir
*
* Description:
* The telldir() function returns the current location
* associated with the directory stream dirp.
*
* Inputs:
* dirp -- An instance of type DIR created by a previous
* call to opendir();
*
* Return:
* On success, the telldir() function returns the current
* location in the directory stream. On error, -1 is
* returned, and errno is set appropriately.
*
* EBADF - Invalid directory stream descriptor dir
*
****************************************************************************/
off_t telldir(FAR DIR *dirp)
{
struct fs_dirent_s *idir = (struct fs_dirent_s *)dirp;
if (!idir || !idir->fd_root)
{
set_errno(EBADF);
return (off_t)-1;
}
/* Just return the current position */
return idir->fd_position;
}