121 lines
4.4 KiB
C
121 lines
4.4 KiB
C
/****************************************************************************
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* libc/stdio/lib_rawsistream.c
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*
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* Copyright (C) 2014 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <unistd.h>
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#include <assert.h>
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#include <errno.h>
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#include "lib_internal.h"
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Name: rawsistream_getc
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****************************************************************************/
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static int rawsistream_getc(FAR struct lib_sistream_s *this)
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{
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FAR struct lib_rawsistream_s *rthis = (FAR struct lib_rawsistream_s *)this;
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int nwritten;
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char ch;
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DEBUGASSERT(this && rthis->fd >= 0);
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/* Attempt to read one character */
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nwritten = read(rthis->fd, &ch, 1);
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if (nwritten == 1)
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{
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this->nget++;
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return ch;
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}
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/* Return EOF on any failure to read from the incoming byte stream. The
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* only expected error is EINTR meaning that the read was interrupted
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* by a signal. A Zero return value would indicated an end-of-file
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* confition.
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*/
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return EOF;
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}
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/****************************************************************************
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* Name: rawsistream_seek
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****************************************************************************/
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static off_t rawsistream_seek(FAR struct lib_sistream_s *this, off_t offset,
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int whence)
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{
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FAR struct lib_rawsistream_s *mthis = (FAR struct lib_rawsistream_s *)this;
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DEBUGASSERT(this);
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return lseek(mthis->fd, offset, whence);
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}
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: lib_rawsistream
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*
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* Description:
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* Initializes a stream for use with a file descriptor.
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*
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* Input parameters:
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* instream - User allocated, uninitialized instance of struct
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* lib_rawsistream_s to be initialized.
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* fd - User provided file/socket descriptor (must have been opened
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* for the correct access).
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*
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* Returned Value:
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* None (User allocated instance initialized).
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*
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****************************************************************************/
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void lib_rawsistream(FAR struct lib_rawsistream_s *instream, int fd)
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{
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instream->public.get = rawsistream_getc;
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instream->public.seek = rawsistream_seek;
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instream->public.nget = 0;
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instream->fd = fd;
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}
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