===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/tmux/tmux.1,v
retrieving revision 1.590
retrieving revision 1.591
diff -u -r1.590 -r1.591
--- src/usr.bin/tmux/tmux.1	2017/12/22 10:16:36	1.590
+++ src/usr.bin/tmux/tmux.1	2018/01/16 09:00:38	1.591
@@ -1,4 +1,4 @@
-.\" $OpenBSD: tmux.1,v 1.590 2017/12/22 10:16:36 nicm Exp $
+.\" $OpenBSD: tmux.1,v 1.591 2018/01/16 09:00:38 nicm Exp $
 .\"
 .\" Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
 .\"
@@ -14,7 +14,7 @@
 .\" IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 .\" OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: December 22 2017 $
+.Dd $Mdocdate: January 16 2018 $
 .Dt TMUX 1
 .Os
 .Sh NAME
@@ -1800,15 +1800,15 @@
 .Fl a
 is used, move to the next window with an alert.
 .It Xo Ic pipe-pane
-.Op Fl o
+.Op Fl IOo
 .Op Fl t Ar target-pane
 .Op Ar shell-command
 .Xc
 .D1 (alias: Ic pipep )
-Pipe any output sent by the program in
+Pipe output sent by the program in
 .Ar target-pane
-to a shell command.
-A pane may only be piped to one command at a time, any existing pipe is
+to a shell command or vice versa.
+A pane may only be connected to one command at a time, any existing pipe is
 closed before
 .Ar shell-command
 is executed.
@@ -1820,6 +1820,25 @@
 If no
 .Ar shell-command
 is given, the current pipe (if any) is closed.
+.Pp
+.Fl I
+and
+.Fl O
+specify which of the
+.Ar shell-command
+output streams are connected to the pane:
+with
+.Fl I
+stdout is connected (so anything
+.Ar shell-command
+prints is written to the pane as if it were typed);
+with
+.Fl O
+stdin is connected (so any output in the pane is piped to
+.Ar shell-command ) .
+Both may be used together and if neither are specified,
+.Fl O
+is used.
 .Pp
 The
 .Fl o