Module Name: src
Committed By: jruoho
Date: Mon Apr 26 07:36:33 UTC 2010
Modified Files:
src/share/man/man9: uiomove.9
Log Message:
Small markup improvements.
To generate a diff of this commit:
cvs rdiff -u -r1.15 -r1.16 src/share/man/man9/uiomove.9
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/share/man/man9/uiomove.9
diff -u src/share/man/man9/uiomove.9:1.15 src/share/man/man9/uiomove.9:1.16
--- src/share/man/man9/uiomove.9:1.15 Mon Mar 22 18:58:33 2010
+++ src/share/man/man9/uiomove.9 Mon Apr 26 07:36:33 2010
@@ -1,4 +1,4 @@
-.\" $NetBSD: uiomove.9,v 1.15 2010/03/22 18:58:33 joerg Exp $
+.\" $NetBSD: uiomove.9,v 1.16 2010/04/26 07:36:33 jruoho Exp $
.\"
.\" Copyright (c) 1996 The NetBSD Foundation, Inc.
.\" All rights reserved.
@@ -24,7 +24,7 @@
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
-.Dd March 7, 2007
+.Dd April 26, 2010
.Dt UIOMOVE 9
.Os
.Sh NAME
@@ -36,7 +36,7 @@
.Fn uiomove "void *buf" "size_t n" "struct uio *uio"
.Sh DESCRIPTION
The
-.Nm
+.Fn uiomove
function copies up to
.Fa n
bytes between the kernel-space address pointed
@@ -49,53 +49,61 @@
The
.Fa uio
argument is a pointer to a
-.Fa struct uio
+.Va struct uio
as defined by
.In sys/uio.h :
-.Bd -literal
+.Bd -literal -offset indent
struct uio {
- struct iovec *uio_iov; /* pointer to array of iovecs */
- int uio_iovcnt; /* number of iovecs in array */
- off_t uio_offset; /* offset into file this uio corresponds to */
- size_t uio_resid; /* residual i/o count */
+ struct iovec *uio_iov;
+ int uio_iovcnt;
+ off_t uio_offset;
+ size_t uio_resid;
enum uio_rw uio_rw;
struct vmspace *uio_vmspace;
};
.Ed
.Pp
A
-.Fa struct uio
+.Va struct uio
typically describes data in motion.
Several of the fields described below reflect that expectation.
.Pp
-.Bl -tag -width uio_xxxxxx
-.It uio_iov
+.Bl -tag -width "uio_vmspace "
+.It Va uio_iov
Pointer to array of
-.Fa struct iovecs :
+.Tn I/O
+vectors to be processed.
+The
+.Va struct iovec
+is defined to be:
.Bd -literal
struct iovec {
void *iov_base; /* Base address. */
size_t iov_len; /* Length. */
};
.Ed
-.It uio_iovcnt
-The number of iovecs in the array.
-.It uio_offset
+.It Va uio_iovcnt
+The number of
+.Tn I/O
+vectors in the
+.Va uio_iov
+array.
+.It Va uio_offset
An offset into the corresponding object.
-.It uio_resid
+.It Va uio_resid
The amount of space described by the structure; notionally, the amount
of data remaining to be transferred.
-.It uio_rw
+.It Va uio_rw
A flag indicating whether data should be read into the space
(UIO_READ) or written from the space (UIO_WRITE).
-.It uio_vmspace
+.It Va uio_vmspace
A pointer to the address space which is being transferred to or from.
.El
.Pp
The value of
-.Fa uio-\*[Gt]uio_rw
+.Va uio-\*[Gt]uio_rw
controls whether
-.Nm
+.Fn uiomove
copies data from
.Fa buf
to
@@ -105,24 +113,28 @@
The lesser of
.Fa n
or
-.Fa uio-\*[Gt]uio_resid
+.Va uio-\*[Gt]uio_resid
bytes are copied.
.Pp
-.Nm
+.Fn uiomove
changes fields of the structure pointed to by
.Fa uio ,
such that
-.Fa uio-\*[Gt]uio_resid
+.Va uio-\*[Gt]uio_resid
is decremented by the amount of data moved,
-.Fa uio-\*[Gt]uio_offset
+.Va uio-\*[Gt]uio_offset
is incremented by the same amount, and the array of iovecs is adjusted
to point that much farther into the region described.
This allows multiple calls to
-.Nm
+.Fn uiomove
to easily be used to fill or drain the region of data.
.Sh RETURN VALUES
-.Nm
-returns 0 on success or EFAULT if a bad address is encountered.
+Upon successful completion,
+.Fn uiomove
+returns 0.
+If a bad address is encountered,
+.Er EFAULT
+is returned.
.Sh SEE ALSO
.Xr copy 9 ,
.Xr fetch 9 ,
