.Sh SYNOPSIS
.In aio.h
.Ft int
-.Fn aio_read "struct aiocb *iocb"
+.Fo aio_read
+.Fa "struct aiocb *aiocbp"
+.Fc
.Sh DESCRIPTION
The
.Fn aio_read
system call allows the calling process to read
-.Fa iocb->aio_nbytes
+.Fa aiocbp->aio_nbytes
from the descriptor
-.Fa iocb->aio_fildes
+.Fa aiocbp->aio_fildes ,
beginning at the offset
-.Fa iocb->aio_offset
+.Fa aiocbp->aio_offset ,
into the buffer pointed to by
-.Fa iocb->aio_buf .
+.Fa aiocbp->aio_buf .
The call returns immediately after the read request has
-been enqueued to the descriptor; the read may or may not have
-completed at the time the call returns.
+been enqueued to the descriptor;
+the read may or may not have completed at the time the call returns.
.Pp
If _POSIX_PRIORITIZED_IO is defined, and the descriptor supports it,
then the enqueued operation is submitted at a priority equal to that
of the calling process minus
-.Fa iocb->aio_reqprio .
+.Fa aiocbp->aio_reqprio .
.Pp
The
-.Fa iocb->aio_lio_opcode
+.Fa aiocbp->aio_lio_opcode
argument
is ignored by the
.Fn aio_read
system call.
.Pp
The
-.Fa iocb
+.Fa aiocbp
pointer may be subsequently used as an argument to
.Fn aio_return
and
then the call returns without having enqueued the request.
.Pp
If the request is successfully enqueued, the value of
-.Fa iocb->aio_offset
+.Fa aiocbp->aio_offset
can be modified during the request as context, so this value must
not be referenced after the request is enqueued.
.Sh RESTRICTIONS
The Asynchronous I/O Control Block structure pointed to by
-.Fa iocb
+.Fa aiocbp
and the buffer that the
-.Fa iocb->aio_buf
+.Fa aiocbp->aio_buf
member of that structure references must remain valid until the
operation has completed. For this reason, use of auto (stack) variables
for these objects is discouraged.
.Pp
The asynchronous I/O control buffer
-.Fa iocb
+.Fa aiocbp
should be zeroed before the
.Fn aio_read
call to avoid passing bogus context information to the kernel.
request has completed, are not allowed.
.Pp
If the file offset in
-.Fa iocb->aio_offset
+.Fa aiocbp->aio_offset
is past the offset maximum for
-.Fa iocb->aio_fildes ,
+.Fa aiocbp->aio_fildes ,
no I/O will occur.
.Sh RETURN VALUES
.Rv -std aio_read
.Fn aio_read
system call will fail if:
.Bl -tag -width Er
+.\" ==========
.It Bq Er EAGAIN
-The request was not queued because of system resource limitations.
+Because of system resource limitations,
+the request was not queued.
+.\" ==========
.It Bq Er ENOSYS
The
.Fn aio_read
.Pp
The following conditions may be synchronously detected when the
.Fn aio_read
-system call is made, or asynchronously, at any time thereafter. If they
-are detected at call time,
+system call is made, or asynchronously, at any time thereafter.
+If they are detected at call time,
.Fn aio_read
returns -1 and sets
.Va errno
-appropriately; otherwise the
+appropriately.
+Otherwise, the
.Fn aio_return
-system call must be called, and will return -1, and
+system call must be called.
+It will return -1;
.Fn aio_error
-must be called to determine the actual value that would have been
-returned in
+must then be called to determine the actual value
+that would have been returned in
.Va errno .
.Pp
.Bl -tag -width Er
+.\" ==========
.It Bq Er EBADF
The
-.Fa iocb->aio_fildes
+.Fa aiocbp->aio_fildes
argument
is invalid.
+.\" ==========
.It Bq Er EINVAL
The offset
-.Fa iocb->aio_offset
+.Fa aiocbp->aio_offset
is not valid, the priority specified by
-.Fa iocb->aio_reqprio
+.Fa aiocbp->aio_reqprio
is not a valid priority, or the number of bytes specified by
-.Fa iocb->aio_nbytes
+.Fa aiocbp->aio_nbytes
is not valid.
+.\" ==========
.It Bq Er EOVERFLOW
The file is a regular file,
-.Fa iocb->aio_nbytes
+.Fa aiocbp->aio_nbytes
is greater than zero, the starting offset in
-.Fa iocb->aio_offset
+.Fa aiocbp->aio_offset
is before the end of the file, but is at or beyond the
-.Fa iocb->aio_fildes
+.Fa aiocbp->aio_fildes
offset maximum.
.El
.Pp
.Xr read 2
system call, or one of:
.Bl -tag -width Er
+.\" ==========
.It Bq Er EBADF
The
-.Fa iocb->aio_fildes
+.Fa aiocbp->aio_fildes
argument
is invalid for reading.
+.\" ==========
.It Bq Er ECANCELED
The request was explicitly cancelled via a call to
.Fn aio_cancel .
+.\" ==========
.It Bq Er EINVAL
The offset
-.Fa iocb->aio_offset
+.Fa aiocbp->aio_offset
would be invalid.
.El
.Sh SEE ALSO
.An Terry Lambert Aq terry@whistle.com .
.Sh BUGS
Invalid information in
-.Fa iocb->_aiocb_private
+.Fa aiocbp->_aiocb_private
may confuse the kernel.