Tcl - Displaying on Another Computer

Author

Displaying on Another Computer

Duane A. Damiano

2004-10-27, 8:57 pm

Tclers,

On a network of Unix computers I am able to start a Tcl/Tk program on
one machine and have its graphical output display on another by using
the "-display" option on the command line. e.g.

../myscript.tcl -display A.B.C.D:0.0

where A.B.C.D is the IP address of the machine that receives the
display.

Also, from within a Tcl/Tk script, I can open a toplevel window on
another machine with a command like

toplevel .dwin -screen A.B.C.D:0.0

Does anyone know how to make these work on a network of MS Windows
computers? When answering this question, you may assume the
following:

A. There is no need for a script running on a Unix computer to send
output to a Windows computer or vice versa.

B. Cygwin is available on the Windows computers and can be used if
necessary. (Although, I would prefer a solution that does not require
Cygwin.)

Do I need to set some access control on the receiving Windows
computer, analogous to an xhost entry on a Unix machine?

Duane

---------------------------------------------------------
Duane A. Damiano duane@damiano.name
211 E. Lombard St. #356 Phone: 410-685-6221
Baltimore MD 21202-6102 U.S.A.

Bruce Hartweg

2004-10-28, 3:57 am

Duane A. Damiano wrote:

> Tclers,
>
> On a network of Unix computers I am able to start a Tcl/Tk program on
> one machine and have its graphical output display on another by using
> the "-display" option on the command line. e.g.
>
> ./myscript.tcl -display A.B.C.D:0.0
>
> where A.B.C.D is the IP address of the machine that receives the
> display.
>
> Also, from within a Tcl/Tk script, I can open a toplevel window on
> another machine with a command like
>
> toplevel .dwin -screen A.B.C.D:0.0
>
> Does anyone know how to make these work on a network of MS Windows
> computers? When answering this question, you may assume the
> following:
>
> A. There is no need for a script running on a Unix computer to send
> output to a Windows computer or vice versa.
>
> B. Cygwin is available on the Windows computers and can be used if
> necessary. (Although, I would prefer a solution that does not require
> Cygwin.)
>
> Do I need to set some access control on the receiving Windows
> computer, analogous to an xhost entry on a Unix machine?
>
> Duane
>
> ---------------------------------------------------------
> Duane A. Damiano duane@damiano.name
> 211 E. Lombard St. #356 Phone: 410-685-6221
> Baltimore MD 21202-6102 U.S.A.
>

That is a feature that was a core design of X - remote display.
There is no equivalent on windows. there are *other* ways to
do things that are somewhat similar, but take more work on the
programmers part. does Cygwin include an X server? if so then
use that and you're done. otherwise you have to do it a little
more yourself.

Bruce

Duane A. Damiano

2004-10-28, 3:57 am

On Wed, 27 Oct 2004, Darren New wrote:

> Duane A. Damiano wrote:
>
> Would not installing X servers on your windows machines do the trick?
>

Maybe, but I don't control the machines, so that is not an option.

I don't think it's that simple anyway. Cygwin does provide an X server.
I am able to run a Tcl/Tk script on a unix computer and send graphical
output to a Windows machine running the Cygwin X server. However, I can't
do the reverse. I think this is because the wish included with the Cygwin
package is a Windows executable (wish84.exe). Normally, this would be
convenient because it runs with or without the X server. However, in this
case, it behaves like a Windows program and doesn't send output to other X
servers. Yes, I could get the Tcl/Tk sources and compile them under
Cygwin. But, for reasons that I can't go into here, that is not a
practical idea for me.

What I really need is a way to do this entirely in an MS windows context.

Duane
---------------------------------------------------------
Duane A. Damiano duane@damiano.name
211 E. Lombard St. #356 Phone: 410-685-6221
Baltimore MD 21202-6102 U.S.A.

Darren New

2004-10-28, 3:57 am

Duane A. Damiano wrote:
> What I really need is a way to do this entirely in an MS windows context.

Then, if "Remote Desktop" isn't sufficient, you need to code it up
yourself. Put a simple program running just the Tk shell up on the
Windows machine, and have the UNIX machine sending it Tcl/Tk scripts to
run to generate the display. I'm pretty sure this is the easiest way to
do it.

Mac A. Cody

2004-10-28, 3:57 am

Duane A. Damiano wrote:
> Does anyone know how to make these work on a network of MS Windows
> computers? When answering this question, you may assume the
> following:
>
> A. There is no need for a script running on a Unix computer to send
> output to a Windows computer or vice versa.

You could set up a Tcl application running on one Windows
machine that can be communicated with using the comm
extension (see http://mini.net/tcl/comm ). It could then
recieve commands from a Tcl application running on another
machine that would send Tk commands through the comm interface
to generate the GUI. The main challenge would be in setting
up callbacks in the GUI to use the comm extension to talk back
to the originating machine.

>
> Do I need to set some access control on the receiving Windows
> computer, analogous to an xhost entry on a Unix machine?

No. MS Windows <lax> attitude towards security does not
have any access control issues (AFAIK).

Mac Cody

P.S. swap the "cast" and "com" to send email to me.

Darren New

2004-10-28, 3:57 am

Mac A. Cody wrote:
> No. MS Windows <lax> attitude towards security does not
> have any access control issues (AFAIK).

Actually, yeah, it does. :-)

Melissa Schrumpf

2004-10-28, 8:58 am

Duane A. Damiano wrote:

> I don't think it's that simple anyway. Cygwin does provide an X server.
> I am able to run a Tcl/Tk script on a unix computer and send graphical
> output to a Windows machine running the Cygwin X server. However, I can't
> do the reverse. I think this is because the wish included with the Cygwin
> package is a Windows executable (wish84.exe). Normally, this would be
> convenient because it runs with or without the X server. However, in this
> case, it behaves like a Windows program and doesn't send output to other X
> servers. Yes, I could get the Tcl/Tk sources and compile them under
> Cygwin. But, for reasons that I can't go into here, that is not a
> practical idea for me.

Just a minor nit pick: the Cygwin executables are "Windows executables"
in the sense that they are .exe files. For example, "xterm.exe,"
&c. It's just a matter that the Wish shipped with Cygwin is a Win32
application that uses the Windows resources for displaying windows
(unlike, e.g. xterm.exe).

I haven't done it, but I see no reason to believe that you couldn't
compile the Tcl/Tk unix tree under Cygwin to use X11 display instead of
Win32. (It can be done on OSX, but then. there's no compat layer there
like there is with Cygwin.)

--
MKS

Arjen Markus

2004-10-28, 8:58 am

Melissa Schrumpf wrote:
>
> Duane A. Damiano wrote:
>
>
> Just a minor nit pick: the Cygwin executables are "Windows executables"
> in the sense that they are .exe files. For example, "xterm.exe,"
> &c. It's just a matter that the Wish shipped with Cygwin is a Win32
> application that uses the Windows resources for displaying windows
> (unlike, e.g. xterm.exe).
>
> I haven't done it, but I see no reason to believe that you couldn't
> compile the Tcl/Tk unix tree under Cygwin to use X11 display instead of
> Win32. (It can be done on OSX, but then. there's no compat layer there
> like there is with Cygwin.)
>

I have no particular experience with Cygwin in these matters, but I
have seen programs compiled on Windows that use an X11 display. So
I guess there is no principal problem.

Regards,

Arjen

Ralf Fassel

2004-10-28, 4:00 pm

* "Duane A. Damiano" <dadamia@toad.net>
| ./myscript.tcl -display A.B.C.D:0.0
--<snip-snip>--
| Does anyone know how to make these work on a network of MS Windows
| computers?

As a workaround, you might consider VNC
http://www.tightvnc.com/

allows mirroring of the _complete_ desktop on another machine. You
can't open single windows with that solution on a different display.

R'

lvirden@gmail.com

2004-10-28, 4:00 pm

According to Duane A. Damiano <duane@damiano.name>:
:Does anyone know how to make these work on a network of MS Windows
:computers?

I don't know of a solution that is built into Tcl/Tk the way that
the X Windows system solution is built in. Other threads have
discussed work arounds such as separate programs like VNC, or modifying
your applications (using comm or you could perhaps use one of the
Windows extensions like tcom, etc.). However, none of these work
as nearly painlessly (ignoring the interaction with xauth... ;)
as does the X solution.

--
<URL: http://wiki.tcl.tk/> MP3 ID tag repair < http://www.fixtunes.com/?C=17038 >
Even if explicitly stated to the contrary, nothing in this posting
should be construed as representing my employer's opinions.
<URL: mailto:lvirden@gmail.com > <URL: http://www.purl.org/NET/lvirden/ >

Theo Verelst

2004-10-28, 4:00 pm

Arjen Markus wrote:
> Melissa Schrumpf wrote:
>
>
>
> I have no particular experience with Cygwin in these matters, but I
> have seen programs compiled on Windows that use an X11 display. So
> I guess there is no principal problem.
>
> Regards,
>
> Arjen

See http://mini.net/tcl/9403

Theo.

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