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);

       Link with -lrt.

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 comple-
       tion 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 position.  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 unspecified.

       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  prior-
       ity 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.

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

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

       ENOSYS This function is not supported.

CONFORMING TO
       POSIX.1-2001.

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

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

COLOPHON
       This page is part of release 3.25 of the Linux man-pages project.  A description of the project,  and  information  about
       reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.



                                                           2003-11-14                                               AIO_WRITE(3)