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/****************************************************************************
* fs/fs_filedup.c
*
* Copyright (C) 2007-2009, 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 <sched.h>
#include <errno.h>
#include <nuttx/fs/fs.h>
#include "fs_internal.h"
#if CONFIG_NFILE_DESCRIPTORS > 0
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define DUP_ISOPEN(fd, list) \
((unsigned int)fd < CONFIG_NFILE_DESCRIPTORS && \
list->fl_files[fd].f_inode != NULL)
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Global Functions
****************************************************************************/
/****************************************************************************
* Name: file_dup OR dup
*
* Description:
* Clone a file descriptor 'fd' to an arbitray descriptor number (any value
* greater than or equal to 'minfd'). If socket descriptors are
* implemented, then this is called by dup() for the case of file
* descriptors. If socket descriptors are not implemented, then this
* function IS dup().
*
****************************************************************************/
int file_dup(int fildes, int minfd)
{
FAR struct filelist *list;
int fildes2;
/* Get the thread-specific file list */
list = sched_getfiles();
if (!list)
{
set_errno(EMFILE);
return ERROR;
}
/* Verify that fildes is a valid, open file descriptor */
if (!DUP_ISOPEN(fildes, list))
{
set_errno(EBADF);
return ERROR;
}
/* Increment the reference count on the contained inode */
inode_addref(list->fl_files[fildes].f_inode);
/* Then allocate a new file descriptor for the inode */
fildes2 = files_allocate(list->fl_files[fildes].f_inode,
list->fl_files[fildes].f_oflags,
list->fl_files[fildes].f_pos,
minfd);
if (fildes2 < 0)
{
set_errno(EMFILE);
inode_release(list->fl_files[fildes].f_inode);
return ERROR;
}
return fildes2;
}
#endif /* CONFIG_NFILE_DESCRIPTORS > 0 */
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