incubator-nuttx/libc/stdio/lib_rawsistream.c

107 lines
3.9 KiB
C

/****************************************************************************
* libc/stdio/lib_rawinstream.c
*
* Copyright (C) 2007-2009, 2011-2012, 2014 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 <unistd.h>
#include <assert.h>
#include <errno.h>
#include "lib_internal.h"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: rawinstream_getc
****************************************************************************/
static int rawinstream_getc(FAR struct lib_instream_s *this)
{
FAR struct lib_rawinstream_s *rthis = (FAR struct lib_rawinstream_s *)this;
int nwritten;
char ch;
DEBUGASSERT(this && rthis->fd >= 0);
/* Attempt to read one character */
nwritten = read(rthis->fd, &ch, 1);
if (nwritten == 1)
{
this->nget++;
return ch;
}
/* Return EOF on any failure to read from the incoming byte stream. The
* only expected error is EINTR meaning that the read was interrupted
* by a signal. A Zero return value would indicated an end-of-file
* confition.
*/
return EOF;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: lib_rawinstream
*
* Description:
* Initializes a stream for use with a file descriptor.
*
* Input parameters:
* instream - User allocated, uninitialized instance of struct
* lib_rawinstream_s to be initialized.
* fd - User provided file/socket descriptor (must have been opened
* for the correct access).
*
* Returned Value:
* None (User allocated instance initialized).
*
****************************************************************************/
void lib_rawinstream(FAR struct lib_rawinstream_s *instream, int fd)
{
instream->public.get = rawinstream_getc;
instream->public.nget = 0;
instream->fd = fd;
}