while( .... ) {
  # some non-blocking stuff
  
  if( Tk::MainWindow->Count ) {
    local $inMainLoop = 1;
    DoOneEvent(0); 
  } # if
  else {
    # no more mainwindows, finish somehow
  } # else

  # other non-blocking stuff

} # while
[download]

(not tested; see: Tk.pm -> MainLoop)

But that may (or may not) become dangerous if Tk.pm is changed in future

Sorry for the format of my last posting, I have two questions to the formatting.

How can I write a "general" reply, not a reply to a answer of a certain user ? Is it the "Comment on" link ??

How can I have the source code only as a download link like user strat or Errto has ? In each readmore section seems to be all of my source code sections. Is this normal or did I misunderstood something ?
Thanks for the help.

Tcl/Tk has fileevent which resolves the problem.

I have written bluetooth COM-keyboard driver this way, which works both for linux and windows. The essential part is

use Tcl::Tk;
my $int = new Tcl::Tk;

# .....
$int->fileevent($fhbt, readable => \&process_keyboard);
# ....
$int->MainLoop;
[download]

Write 3 simple applications.

1. Just sends every 5 seconds.
2. Just receives and does what it needs to do.
3. The Tk application that draws what you want to appear.

Test them individually.

When you are satisfied with them. come back, post the code and we can show you how easy it is to put the code from the each of the first two into its own thread, share whatever needs sharing and viola, you have your integrated application.

Hello, I'll post some code that I have at the moment.
The server accepting requests and responding immediately to the clients is here
Read more... (6 kB)
Normally the server reads from a mysql table and compares the request content to the table content, and updates eventually the mysql table.
This is at the moment comment.
The code for the client sending request after n seconds is here
Read more... (4 kB)
In the client I tried to let him receive the server-response with a timeout, but I did not succeed. Maybe some hints ? The client should continue to send every n seconds a request even if there is no server listening.
By the way, when using the client on a xp machine it stops at the first time he receives (server is listening) when the server includes $startzeit in his response.
If the client runs on ubuntu (vmware guest system) he receives the whole response if the response does not include $startzeit, but with the server code $sock->send("Zeitstempel: $startzeit : Du sagtest: ''$nachricht'' zu mir $/"); or   $sock->send("Zeitstempel: ''$startzeit'' : Du sagtest: ''$nachricht'' zu mir $/"); the client receives not the whole response or at least prints not the whole response to STDOUT. What could be here the problem ?

Here is the actual contents of meinfile.txt which corresponds to the request:

Read more... (295 Bytes)
A first Tk code is here:
Read more... (4 kB)
If I edit the contents of the meinfile.txt in an editor, the changes are displayed immediately in the listbox.
The listbox should later display the data of the mysql table which should be updated depending on the clients requests.

vkon, I tried to implement the Tk code with fileevent, but I did not succeed. Here is my code:

Read more... (4 kB)
BrowserUk, the client code could be used as the server "just sending every 5 seconds".
By the way, how could this be implemented,that the server listens to all UDP ports, not only to a specific. Later there are e.g. 5 clients, each sending on his on port (e.g. from 10001 to 10005) and the server should listen to all of these ports simultaneously, thats why I thought of listening to all UDP ports.

Okay. Here are three separate minimal programs, and one composite that joins them all together. I have used your Tk program, cleaned up a lot. Sorry that your comments are missing, but I don't read Gernman and they were just in the way of seeing what was going on. You should really try to be a little more consistant with your code layout also.

This is the standalone server that listens and responds to 5 different udp ports:

<Reveal this spoiler or all spoilers in this node or all in this thread>

And this is the standalone client. It talks to all of the ports on the server for testing and demo, but would normally only talk to one. When used as the heartbeat thread withing the combined app, it would also talk to all 5 clients.

<Reveal this spoiler>

And here is my cleaned up and working version of your Tk code. I am posting it separately because you should maintain all 3 standalone apps as testbeds and reference points, as well as the combined app. It is much easier to test changes in the individual apps and, once you are satisfied they are working, c&p the changes into the combined app. It make seem extra work, but think of the separate apps and testcases.

<Reveal this spoiler>

And finally, the combined, threaded app. The modifications are minimal. Each thread is a direct C&P from the standalone version.

In particular, there is very little shared data, as it is not clear what else you want to do or what else you need to share, but it should give you a starting point. My purpose is to demonstrate the simplicity of combining the code.

After that, you are responsible for adding whatever extras you need. I'm willing to help you make your additions, but please don't post reams and reams of code with huge chunks commented out and reams and reams of comments that I cannot understand--just delete them from the post--otherwise I am apt to be put off.

<Reveal this spoiler>

To answer your question from Re^2: Displaying text in columns, I've used spoiler tags, rather than readmore tags, despite this usage being frowned upon, because spoiler tags do not get expanded until you choose to click on them whereas readmore tags are expanded whenever you view the post directly. This way, you can read the text of the post as a coherent whole without having to scroll past loads of code.

---

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

"Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."

# setup MainWindow $mw
# setup socket with timeout
sub myloop {
   while (1) {
       #read from socket;
       #if anything read, deal with it;
       $mw->update();
   }
}
$mw->after(1, \&myloop);
MainLoop;
[download]