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 queues the I/O request described by the buffer pointed to by aiocbp.  This function is the asynchronous analog of
       write(2).  The arguments of the call

	   write(fd, buf, count)

       correspond (in order) to the fields aio_fildes, aio_buf, and aio_nbytes of the structure pointed to by aiocbp.  (See aio(7) for a  descrip-
       tion of the aiocb structure.)

       If O_APPEND is not set, the data is written starting at the absolute file offset aiocbp->aio_offset, regardless of the current file offset.
       If O_APPEND is set, data is written at the end of the file in the same order as aio_write() calls are made.  After the call, the  value	of
       the current file offset 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).  The return status of a completed I/O operation can be obtained  aio_return(3).
       Asynchronous notification of I/O completion can be obtained by setting aiocbp->aio_sigevent appropriately; see sigevent(7) for details.

       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  only
       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  maximum  offset  for
	      this file.

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

       ENOSYS aio_write() is not implemented.

VERSIONS

       The aio_write() function is available since glibc 2.1.

CONFORMING TO

       POSIX.1-2001, POSIX.1-2008.

NOTES

       It  is  a  good	idea  to  zero	out  the  control block before use.  The control block must not be changed while the write operation 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.

       Simultaneous I/O operations specifying the same aiocb structure produce undefined results.

SEE ALSO

       aio_cancel(3), aio_error(3), aio_fsync(3), aio_read(3), aio_return(3), aio_suspend(3), lio_listio(3), aio(7)

COLOPHON

       This  page is part of release 3.44 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/.

								    2012-05-08							      AIO_WRITE(3)