5cb8226727
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5331 42af7a65-404d-4744-a932-0658087f49c3
122 lines
4.6 KiB
C
122 lines
4.6 KiB
C
/****************************************************************************
|
|
* libc/stdio/lib_ungetc.c
|
|
*
|
|
* Copyright (C) 2007, 2008, 2011 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.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Compilation Switches
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
#include <stdio.h>
|
|
#include <fcntl.h>
|
|
#include <errno.h>
|
|
#include <nuttx/fs/fs.h>
|
|
#include "lib_internal.h"
|
|
|
|
/****************************************************************************
|
|
* Definitions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Type Declarations
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Function Prototypes
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Global Function Prototypes
|
|
****************************************************************************/
|
|
|
|
/**************************************************************************
|
|
* Global Constant Data
|
|
**************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Global Variables
|
|
****************************************************************************/
|
|
|
|
/**************************************************************************
|
|
* Private Constant Data
|
|
**************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Variables
|
|
**************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
**************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: ungetc
|
|
**************************************************************************/
|
|
|
|
int ungetc(int c, FAR FILE *stream)
|
|
{
|
|
#if CONFIG_NUNGET_CHARS > 0
|
|
int nungotten;
|
|
#endif
|
|
|
|
/* Stream must be open for read access */
|
|
|
|
if ((stream && stream->fs_filedes < 0) ||
|
|
((stream->fs_oflags & O_RDOK) == 0))
|
|
{
|
|
set_errno(EBADF);
|
|
return EOF;
|
|
}
|
|
|
|
#if CONFIG_NUNGET_CHARS > 0
|
|
nungotten = stream->fs_nungotten;
|
|
if (stream->fs_nungotten < CONFIG_NUNGET_CHARS)
|
|
{
|
|
stream->fs_ungotten[nungotten] = c;
|
|
stream->fs_nungotten = nungotten + 1;
|
|
return c;
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
set_errno(ENOMEM);
|
|
return EOF;
|
|
}
|
|
}
|
|
|