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)