nuttx/libs/libc/stdio/lib_printf.c
Gregory Nutt 4935ab5243 printf() and vprintf() must use C buffered I/O if available.
This backs out a part of PR 1179 which has a very serious error:  If C buffered I/O is available, then printf() and vprintf MUST use it.  Otherwise, the ordering of the I/O will be screwed up.  They must not use direct file descriptor I/O UNLESS C buffered I/O is disabled.
2020-06-03 18:38:19 +01:00

52 lines
1.8 KiB
C

/****************************************************************************
* libs/libc/stdio/lib_printf.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 <stdio.h>
#include <stdarg.h>
#include <unistd.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: printf
****************************************************************************/
int printf(FAR const IPTR char *fmt, ...)
{
va_list ap;
int ret;
va_start(ap, fmt);
#if CONFIG_NFILE_STREAMS > 0
ret = vfprintf(stdout, fmt, ap);
#else
ret = vdprintf(STDOUT_FILENO, fmt, ap);
#endif
va_end(ap);
return ret;
}