incubator-nuttx/libs/libc/stdio/lib_vfscanf.c

76 lines
2.4 KiB
C

/****************************************************************************
* libs/libc/stdio/lib_vfscanf.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdio.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.
*/
flockfile(stream);
n = lib_vscanf(&stdinstream.common, &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);
}
funlockfile(stream);
}
return n;
}