Mailing List Archive

Command line version of connecting to listening viewer doesn't work
Hi,

I am trying to create an icon for connecting to a listening viewer with the
information that I gathered about this subject, but it doesn't work.
All I can see, that a black DOS command line window pops up for a
millisecond in the left upper corner of the screen, but nothing else
happens.
The same computer has no problem connecting to the listening viewer by
having the user typing (copy/pasting) the IP address of the viewer in the
window.

(The port 5500 on the firewall of the listening viewer is forwarded to the
listening computer (otherwise the manual method wouldn't work either,
right?)

This is the command line that I think should work, but it doesn't: (IP
address here is a bogus one, of course)

"C:\Program Files\RealVNC\VNC4\winvnc4.exe" -connect 99.999.999.99:5500

Any idea why this command line doesn't work but manually the PC can connect
to the listening viewer without any problem?

Geza


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RE: Command line version of connecting to listening viewer doesn't work [ In reply to ]
To debug a thing like this, run it in a command window, so you can see any
error messages.

I believe the problem may be with the trailing :5500 - I've never needed to
specify this at the server end, only to set up port-forwarding on the
firewall at the receiving (client) end. Take that off and it should work.

You may be interested in a command script I've developed to keep checking
for an established connection and re-connect if it has dropped (something I
developed when trying to manage a system in Ghana from my location in
London). You can find it here:
http://cid-2e572770a3a5cd55.skydrive.live.com/self.aspx/Public/VNCloop.cmd

http://cid-2e572770a3a5cd55.skydrive.live.com/self.aspx/Public/VNCloop.cmd

Philip Herlihy

-----Original Message-----
From: vnc-list-bounces@realvnc.com [mailto:vnc-list-bounces@realvnc.com] On
Behalf Of Geza Levai
Sent: 25 February 2010 23:01
To: vnc-list@realvnc.com
Subject: Command line version of connecting to listening viewer doesn't work

Hi,

I am trying to create an icon for connecting to a listening viewer with the
information that I gathered about this subject, but it doesn't work.
All I can see, that a black DOS command line window pops up for a
millisecond in the left upper corner of the screen, but nothing else
happens.
The same computer has no problem connecting to the listening viewer by
having the user typing (copy/pasting) the IP address of the viewer in the
window.

(The port 5500 on the firewall of the listening viewer is forwarded to the
listening computer (otherwise the manual method wouldn't work either,
right?)

This is the command line that I think should work, but it doesn't: (IP
address here is a bogus one, of course)

"C:\Program Files\RealVNC\VNC4\winvnc4.exe" -connect 99.999.999.99:5500

Any idea why this command line doesn't work but manually the PC can connect
to the listening viewer without any problem?

Geza


_______________________________________________
VNC-List mailing list
VNC-List@realvnc.com
To remove yourself from the list visit:
http://www.realvnc.com/mailman/listinfo/vnc-list




_______________________________________________
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VNC-List@realvnc.com
To remove yourself from the list visit:
http://www.realvnc.com/mailman/listinfo/vnc-list
RE: Command line version of connecting to listening viewer doesn't work [ In reply to ]
Philip,

I am getting an error message "Unable to locate existing VNC Server". I
tried it with :5500, ::5500 and without any port designation. I am doing
these tests on my home network with two computers, both of them have XP Pro
sp3.

BUT THE MOST IMPORTANT FACT IS THAT THERE IS NO PROBLEM CONNECTING TO THE
LISTENING VIEWER COMPUTER BY RIGHT CLICKING ON THE VNC SERVER ICON IN THE
SYSTEM TRAY AND ADDING THE IP ADDRESS TO THE DIALOG WINDOW "Connect to
listening VNC Viewer".

I also tried to connect to the listening computer using telnet, the
connection was successful.

So, the bottom line is, that using the GUI interface there is no problem at
all, using the command line interface it gives the error message "Unable to
locate existing VNC Server".

"C:\Program Files\RealVNC\VNC4\winvnc4.exe" -connect computer2

I think either I am not using the correct syntax or RealVNC has a
programming error or bug in it and it cannot interpret its own command line
commands.

What is interesting is that I did a Google search on this problem, and I
found numerous postings about the same problem with RealVNC, but not one had
a solution to this problem.

About your cmd utility: did I understand it correctly that you supposed to
run it on the server end, so that if the connection gets lost, it will be
restored from the server end without human interaction? Will that work on
Windows Vista and Windows 7 if you get bumped out by the UAC?

Geza



-----Original Message-----
From: Philip Herlihy [mailto:philip@herlihy.eu.com]
Sent: Friday, February 26, 2010 5:45 AM
To: 'Geza Levai'; vnc-list@realvnc.com
Subject: RE: Command line version of connecting to listening viewer doesn't
work

To debug a thing like this, run it in a command window, so you can see any
error messages.

I believe the problem may be with the trailing :5500 - I've never needed to
specify this at the server end, only to set up port-forwarding on the
firewall at the receiving (client) end. Take that off and it should work.

You may be interested in a command script I've developed to keep checking
for an established connection and re-connect if it has dropped (something I
developed when trying to manage a system in Ghana from my location in
London). You can find it here:
http://cid-2e572770a3a5cd55.skydrive.live.com/self.aspx/Public/VNCloop.cmd

http://cid-2e572770a3a5cd55.skydrive.live.com/self.aspx/Public/VNCloop.cmd

Philip Herlihy

-----Original Message-----
From: vnc-list-bounces@realvnc.com [mailto:vnc-list-bounces@realvnc.com] On
Behalf Of Geza Levai
Sent: 25 February 2010 23:01
To: vnc-list@realvnc.com
Subject: Command line version of connecting to listening viewer doesn't work

Hi,

I am trying to create an icon for connecting to a listening viewer with the
information that I gathered about this subject, but it doesn't work.
All I can see, that a black DOS command line window pops up for a
millisecond in the left upper corner of the screen, but nothing else
happens.
The same computer has no problem connecting to the listening viewer by
having the user typing (copy/pasting) the IP address of the viewer in the
window.

(The port 5500 on the firewall of the listening viewer is forwarded to the
listening computer (otherwise the manual method wouldn't work either,
right?)

This is the command line that I think should work, but it doesn't: (IP
address here is a bogus one, of course)

"C:\Program Files\RealVNC\VNC4\winvnc4.exe" -connect 99.999.999.99:5500

Any idea why this command line doesn't work but manually the PC can connect
to the listening viewer without any problem?

Geza


_______________________________________________
VNC-List mailing list
VNC-List@realvnc.com
To remove yourself from the list visit:
http://www.realvnc.com/mailman/listinfo/vnc-list




_______________________________________________
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VNC-List@realvnc.com
To remove yourself from the list visit:
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RE: Command line version of connecting to listening viewer doesn't work [ In reply to ]
I found the cause of the problem.

When and if you want this command to work, the VNC server HAS TO BE ALREADY
RUNNING in "service" or "user" mode.

The 2nd important thing to keep in mind, that you have to launch the
matching command:

1. If you have the VNC Server service running, this is the command that will
work:

"C:\Program Files\RealVNC\VNC4\winvnc4.exe" -service -connect <ip address>


2. If you have the VNC server running in "User mode" this is the command
that will work:

"C:\Program Files\RealVNC\VNC4\winvnc4.exe" -connect <ip address>

Basically, when you launch either of the commands, you are not starting
another application, but a "sub-application of some sort" of winvnc4.exe
that is already running. Until now I (and probably many other folks with the
same problem) was assuming that running the command line version by itself
should work.

In my case the problem was caused by two things: I don't run VNC server on
my computers because I don't have the need for it. I told my friend not to
run it either, that's why the command line version never worked and even
after he turned on the VNC server service on his computer, the command line
still didn't work because he was trying to use the "user mode" version of
the command line that was looking for the "user mode" VNC server.

This stuff seems like a trivial one once you understand how it works, but in
fact it is not. In my opinion the trivial one would be if you could launch
it from the command line without the prerequisite of having the matching VNC
server running - this should have been part of the RealVNC manual for a long
time and the FAQs too.

Geza


-----Original Message-----
From: Philip Herlihy [mailto:philip@herlihy.eu.com]
Sent: Monday, March 01, 2010 4:03 AM
To: 'Geza Levai'
Subject: RE: Command line version of connecting to listening viewer doesn't
work

I'm afraid I can't shed any light on your connection problem - the
equivalent commands work for me. Do you have any security software on the
server box that might be interfering?

Yes, you're right in your understanding of what my script does. However,
the situation is certainly different on Vista and 7 and I haven't had a
chance to investigate.

Philip Herlihy

-----Original Message-----
From: Geza Levai [mailto:geza@pumi.org]
Sent: 28 February 2010 23:18
To: 'Philip Herlihy'
Subject: RE: Command line version of connecting to listening viewer doesn't
work

Philip,

I am getting an error message "Unable to locate existing VNC Server". I
tried it with :5500, ::5500 and without any port designation. I am doing
these tests on my home network with two computers, both of them have XP Pro
sp3.

BUT THE MOST IMPORTANT FACT IS THAT THERE IS NO PROBLEM CONNECTING TO THE
LISTENING VIEWER COMPUTER BY RIGHT CLICKING ON THE VNC SERVER ICON IN THE
SYSTEM TRAY AND ADDING THE IP ADDRESS TO THE DIALOG WINDOW "Connect to
listening VNC Viewer".

I also tried to connect to the listening computer using telnet, the
connection was successful.

So, the bottom line is, that using the GUI interface there is no problem at
all, using the command line interface it gives the error message "Unable to
locate existing VNC Server".

"C:\Program Files\RealVNC\VNC4\winvnc4.exe" -connect computer2

I think either I am not using the correct syntax or RealVNC has a
programming error or bug in it and it cannot interpret its own command line
commands.

What is interesting is that I did a Google search on this problem, and I
found numerous postings about the same problem with RealVNC, but not one had
a solution to this problem.

About your cmd utility: did I understand it correctly that you supposed to
run it on the server end, so that if the connection gets lost, it will be
restored from the server end without human interaction? Will that work on
Windows Vista and Windows 7 if you get bumped out by the UAC?

Geza



-----Original Message-----
From: Philip Herlihy [mailto:philip@herlihy.eu.com]
Sent: Friday, February 26, 2010 5:45 AM
To: 'Geza Levai'; vnc-list@realvnc.com
Subject: RE: Command line version of connecting to listening viewer doesn't
work

To debug a thing like this, run it in a command window, so you can see any
error messages.

I believe the problem may be with the trailing :5500 - I've never needed to
specify this at the server end, only to set up port-forwarding on the
firewall at the receiving (client) end. Take that off and it should work.

You may be interested in a command script I've developed to keep checking
for an established connection and re-connect if it has dropped (something I
developed when trying to manage a system in Ghana from my location in
London). You can find it here:
http://cid-2e572770a3a5cd55.skydrive.live.com/self.aspx/Public/VNCloop.cmd

http://cid-2e572770a3a5cd55.skydrive.live.com/self.aspx/Public/VNCloop.cmd

Philip Herlihy

-----Original Message-----
From: vnc-list-bounces@realvnc.com [mailto:vnc-list-bounces@realvnc.com] On
Behalf Of Geza Levai
Sent: 25 February 2010 23:01
To: vnc-list@realvnc.com
Subject: Command line version of connecting to listening viewer doesn't work

Hi,

I am trying to create an icon for connecting to a listening viewer with the
information that I gathered about this subject, but it doesn't work.
All I can see, that a black DOS command line window pops up for a
millisecond in the left upper corner of the screen, but nothing else
happens.
The same computer has no problem connecting to the listening viewer by
having the user typing (copy/pasting) the IP address of the viewer in the
window.

(The port 5500 on the firewall of the listening viewer is forwarded to the
listening computer (otherwise the manual method wouldn't work either,
right?)

This is the command line that I think should work, but it doesn't: (IP
address here is a bogus one, of course)

"C:\Program Files\RealVNC\VNC4\winvnc4.exe" -connect 99.999.999.99:5500

Any idea why this command line doesn't work but manually the PC can connect
to the listening viewer without any problem?

Geza


_______________________________________________
VNC-List mailing list
VNC-List@realvnc.com
To remove yourself from the list visit:
http://www.realvnc.com/mailman/listinfo/vnc-list






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