Add an operand to /bin/dd that suppresses the status lines printed

to stderr after transfer.  Use the GNU syntax status=noxfer and
status=none to make dd quiet.  The output is annoying in some
situations, so people redirect stderr to /dev/null.  This approach
also suppresses the error messages and bugs in shell scripts remain
undetected.  The new feature status=none is the better alternative.
OK mpf@

1 files changed, 17 insertions, 2 deletions

diff --git a/bin/dd/dd.1 b/bin/dd/dd.1
index 4721e1572ee..ae9d81ad00a 100644
--- a/bin/dd/dd.1
+++ b/bin/dd/dd.1
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: dd.1,v 1.26 2014/02/02 22:43:40 jmc Exp $
+.\"	$OpenBSD: dd.1,v 1.27 2014/02/12 01:18:36 bluhm Exp $
 .\"	$NetBSD: dd.1,v 1.5 1995/03/21 09:04:04 cgd Exp $
 .\"
 .\" Copyright (c) 1990, 1993
@@ -33,7 +33,7 @@
 .\"
 .\"	@(#)dd.1	8.2 (Berkeley) 1/13/94
 .\"
-.Dd $Mdocdate: February 2 2014 $
+.Dd $Mdocdate: February 12 2014 $
 .Dt DD 1
 .Os
 .Sh NAME
@@ -139,6 +139,21 @@ For all other devices, the correct number of blocks is read without
 distinguishing between a partial or complete block being read.
 .It Xo
 .Sm off
+.Cm status= Ar value
+.Sm on
+.Xc
+Where
+.Ar value
+is one of the symbols from the following list.
+.Bl -tag -width unblock
+.It Cm noxfer
+Do not print the transfer statistics as the last line of status output.
+.It Cm none
+Do not print the status output.
+Error messages are shown, but no informational messages.
+.El
+.It Xo
+.Sm off
 .Cm conv= Ar value Oo ,
 .Sm on
 .Ar value ... Oc