incubator-nuttx/libc/stdio/lib_wrflush.c

115 lines
3.7 KiB
C

/****************************************************************************
* libc/stdio/lib_wrflush.c
*
* Copyright (C) 2008-2009, 2011-2012, 2017 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 <stdbool.h>
#include <fcntl.h>
#include <errno.h>
#include "libc.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: lib_wrflush
*
* Description:
* This is simply a version of fflush that does not report an error if
* the file is not open for writing.
*
****************************************************************************/
int lib_wrflush(FAR FILE *stream)
{
#ifndef CONFIG_STDIO_DISABLE_BUFFERING
/* Verify that we were passed a valid (i.e., non-NULL) stream */
#ifdef CONFIG_DEBUG_FEATURES
if (stream == NULL)
{
return -EINVAL;
}
#endif
/* Do nothing if there is no I/O buffer */
if (stream->fs_bufstart == NULL)
{
return OK;
}
/* Verify that the stream is opened for writing... lib_fflush will
* return an error if it is called for a stream that is not opened for
* writing. Check that first so that this function will not fail in
* that case.
*/
if ((stream->fs_oflags & O_WROK) == 0)
{
/* Report that the success was successful if we attempt to flush a
* read-only stream.
*/
return OK;
}
/* Flush the stream. Return success if there is no buffered write data
* -- i.e., that the stream is opened for writing and that all of the
* buffered write data was successfully flushed by lib_fflush().
*/
return lib_fflush(stream, true);
#else
/* Verify that we were passed a valid (i.e., non-NULL) stream */
#ifdef CONFIG_DEBUG_FEATURES
if (!stream)
{
return -EINVAL;
}
#endif
return OK;
#endif
}