nuttx/libs/libc/stdio/lib_vfscanf.c
2019-02-15 18:26:06 -06:00

92 lines
3.2 KiB
C

/****************************************************************************
* libs/libc/stdio/lib_vfscanf.c
*
* Copyright (C) 2019 Gregory Nutt. All rights reserved.
* Author: Johannes Shock
*
* 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 <stdio.h>
#include <semaphore.h>
#include <nuttx/streams.h>
#include "libc.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: vfscanf
****************************************************************************/
int vfscanf(FAR FILE *stream, FAR const IPTR char *fmt, va_list ap)
{
struct lib_stdinstream_s stdinstream;
int n = ERROR;
int lastc;
if (stream)
{
/* Wrap the stream in a stream object and let lib_vscanf do the work. */
lib_stdinstream(&stdinstream, stream);
/* Hold the stream semaphore throughout the lib_vscanf call so that
* this thread can get its entire message out before being pre-empted by
* the next thread.
*/
lib_take_semaphore(stream);
n = lib_vscanf(&stdinstream.public, &lastc, fmt, ap);
/* The lib_vscanf function reads always one character more, this
* character needs to be written back.
*/
if (lastc != EOF)
{
ungetc(lastc, stream);
}
lib_give_semaphore(stream);
}
return n;
}