incubator-nuttx/include/nuttx/fs/uio.h

66 lines
2.3 KiB
C

/****************************************************************************
* include/nuttx/fs/uio.h
*
* 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.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_FS_UIO_H
#define __INCLUDE_NUTTX_FS_UIO_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <sys/types.h>
/****************************************************************************
* Public Type Definitions
****************************************************************************/
/* The structure to describe an user I/O operation.
*
* At this point, this is a bare minimum for readv/writev.
* In the future, we might extend this for other things like
* the file offset for pread/pwrite.
*
* This structure was inspired by BSDs.
* (Thus it doesn't have the NuttX-style "_s" suffix.)
*/
struct uio
{
FAR const struct iovec *uio_iov;
int uio_iovcnt;
};
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: uio_total_len
*
* Description:
* Return the total length of data in bytes.
* Or -EOVERFLOW.
*
****************************************************************************/
ssize_t uio_total_len(FAR const struct uio *uio);
#endif /* __INCLUDE_NUTTX_FS_UIO_H */