[GRASSweb-list]scott: web/platforms macgrass.php,1.6,1.7

[grass at intevation.de]

Author: scott

Update of /grassrepository/web/platforms
In directory doto:/tmp/cvs-serv30324

Modified Files:
	macgrass.php 
Log Message:
Added instructions for TclTk graphics to make it through an SSH connection

Index: macgrass.php
===================================================================
RCS file: /grassrepository/web/platforms/macgrass.php,v
retrieving revision 1.6
retrieving revision 1.7
diff -u -d -r1.6 -r1.7
--- macgrass.php	23 Jul 2005 17:19:20 -0000	1.6
+++ macgrass.php	14 Mar 2006 15:49:45 -0000	1.7
@@ -38,6 +38,9 @@
 <p>The Tcl/Tk Aqua method just takes minimal work (but work nonetheless) to make sure everything works well in the Aqua environment, and much progress has been made on this front.  The problem is that there is one module that still requires X11 - NVIZ.  Also, in Mac OS 10.3, Apple's Aqua Tcl is just Tcl, no Tk - you need a third-party installation of an Aqua Tcl/Tk.  Mac OS 10.4 &quot;Tiger&quot; does include an Aqua Tk (in fact, a subset of that third-party Tcl/Tk Aqua).</p>
 
 <p>So, the alternative approach is to stick with the X11 interface that is shared amongst other UNIX systems, in which case GRASS will look and behave pretty much the same as on other platforms.&nbsp; As of OS 10.3 "Panther", Apple includes X11 with the operating system, combining XFree86 with a window manager that is integrated with the Aqua graphics system.&nbsp; So if you have this version of the operating system, the windows that you run GRASS in can now all be part of the normal Mac windowing system, although if you want the graphical menuing system (which is an optional way to run GRASS), it will use standard X11-based Tcl/Tk, and requires that you have that installed separately.&nbsp; If you are still using OS 10.2 ("Jaguar"), you can install X11 separately a number of ways (see below).</p>
+<P>There is one other issue regarding Tcl/Tk under OS X.  At some point (OS 10.4?) the default configuration of SSH was changed by Apple to improve security, and it has implications for the use of GRASS between hosts on a network (i.e. running it on one machine but displaying it on another).  If you are interacting with GRASS on a Mac, but actually running it on a remote machine that you connect to with SSH, you will need to use the "trusted forwarding" mode of SSH in order for the Tcl/Tk generated graphics (d.m and the GUI versions of the initial mapset selection, plus the GUI versions of each GRASS module) to make it through your connection.  This can be done using the -Y flag when you start the ssh session:
+<tt>ssh -Y remotehost</tt>
+Using the -X flag, or simply turning on X11Forwarding in the SSH configuration files, is not enough:  the symptoms in this case are that a d.mon window will function fine, but none of the Tcl/Tk dialogues will work, failing with an error message complaining either about Wish not behaving as expected, or a "Bad Atom". </P>
 
 <h3>General Requirements</h3>