aio_write

AIO_WRITE(3)               Linux Programmer's Manual              AIO_WRITE(3)



NAME
       aio_write - asynchronous write

SYNOPSIS
       #include <aio.h>

       int aio_write(struct aiocb *aiocbp);


DESCRIPTION
       The  aio_write  function  requests  an asynchronous "n = write(fd, buf,
       count)"   with   fd,   buf,   count   given   by    aiocbp->aio_fildes,
       aiocbp->aio_buf,  aiocbp->aio_nbytes, respectively. The return status n
       can be retrieved upon completion using aio_return(3).

       If O_APPEND is not set, the data is written starting  at  the  absolute
       file  offset  aiocbp->aio_offset,  regardless of the current file posi-
       tion.  If O_APPEND is set, the data is written at the end of the  file.
       After  this request, the value of the current file position is unspeci-
       fied.

       The "asynchronous" means that this call returns as soon as the  request
       has  been  enqueued;  the  write may or may not have completed when the
       call returns. One tests for completion using aio_error(3).

       If _POSIX_PRIORITIZED_IO is defined, and this file  supports  it,  then
       the  asynchronous operation is submitted at a priority equal to that of
       the calling process minus aiocbp->aio_reqprio.

       The field aiocbp->aio_lio_opcode is ignored.

       No data is written to a regular file beyond its maximum offset.

RETURN VALUE
       On success, 0 is returned. On error the request is not enqueued, -1  is
       returned, and errno is set appropriately. If an error is first detected
       later, it will be reported via aio_return(3) (returns  status  -1)  and
       aio_error(3)  (error  status  whatever  one would have gotten in errno,
       such as EBADF).

ERRORS
       EAGAIN Out of resources.

       EBADF  aio_fildes is not a valid file descriptor open for writing.

       EINVAL One or more of aio_offset, aio_reqprio, aio_nbytes are  invalid.

       EFBIG  The  file is a regular file, we want to write at least one byte,
              but the starting position is at or beyond the maximum offset for
              this file.

       ENOSYS This function is not supported.


NOTES
       It  is a good idea to zero out the control block before use.  This con-
       trol block must  not  be  changed  while  the  write  operation  is  in
       progress.   The buffer area being written out must not be accessed dur-
       ing the operation or undefined results  may  occur.  The  memory  areas
       involved must remain valid.


CONFORMING TO
       POSIX 1003.1-2003

SEE ALSO
       aio_cancel(3),  aio_error(3), aio_fsync(3), aio_read(3), aio_return(3),
       aio_suspend(3)



                                  2003-11-14                      AIO_WRITE(3)