solution for fileevent on Win32 ???

cta has asked for the wisdom of the Perl Monks concerning the following question:

Hello everyone,

I really need your help about a problem that I'm having here.
My program supposes to wait permanently for an event that comes from other machine and integrates it to my Tk Canvas. Apparently 2 issues appear :

1. First of all, the event is represented by a Perl data structure. So, in order to send it to other machine, it has to be translated to another format. The solution that I think of is using JSON format.
Do you know any better way to do that ?

2. Second of all, I have to integrate that incoming event in real time to my GUI and I don't know how to do it yet. There is a command called fileevent solve that problem but It works only on Unix.
Any suggestion for this problem would help me alot.

Thanks in advance.
Christina--

Comment on solution for fileevent on Win32 ???

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Re: solution for fileevent on Win32 ??? by pc88mxer (Vicar) on Jul 10, 2008 at 17:03 UTC
This exact issue is discussed in the section "Polling Win32 Sockets" of the book "Mastering Perl/Tk: Graphical User Interfaces in Perl". The basic idea is to set up a timer event to poll the socket. As for other serialization formats, you might consider YAML or Storable.	[reply]
Re^2: solution for fileevent on Win32 ??? by cta (Acolyte) on Jul 10, 2008 at 17:55 UTC
thanks for your promptly responses. I did try to use the timer event but I don't see which method you can use to send data through the socket at the sender part. When you call the can_read method, can you get the event data or just the boolean value saying if there is any available data at the socket?	[reply]
Re^3: solution for fileevent on Win32 ??? by pc88mxer (Vicar) on Jul 10, 2008 at 20:15 UTC
A socket is just a file handle, so you can use `syswrite` or `print`. `can_read` (from IO::Select) only returns true or false. It is telling you that you will not block if you try to read from the file handle. You have to call `read` or `sysread` to get the data.	[reply] [d/l] [select]
Re^4: solution for fileevent on Win32 ??? by cta (Acolyte) on Jul 16, 2008 at 20:26 UTC
Re: solution for fileevent on Win32 ??? by zentara (Cardinal) on Jul 10, 2008 at 19:29 UTC
See Non-blocking socket read on Windows. I "think" that fileevent will work on Win32, did you try it? The problem with fileevent on Win32, is that it won't work on pipe filehandles( you need the Win32::Pipe module). But it should works on sockets. IPC::Run(which uses sockets)is often suggested as an IPC substitute for IPC::Open3 (which uses pipes), for use on Win32. Here is an example, see if it runs for you on Win32. Tk Realtime data aquisition I'm not really a human, but I play one on earth CandyGram for Mongo	[reply]
Re^2: solution for fileevent on Win32 ??? by cta (Acolyte) on Jul 11, 2008 at 14:12 UTC
I tried using fileevent command and it didn't work on Win32 and you were right about the handle. Thanks. I'm still working on the timer event to see if I could get around the problem. And hmm having error while trying to open the socket.	[reply]
Re^3: solution for fileevent on Win32 ??? by zentara (Cardinal) on Jul 11, 2008 at 16:04 UTC
See Re^2: Perl/Tk App and Interprocess Communication for setting up a timer on a filehandle. You may need to use sysread instead of <> on the filehandle. I wish I had windows going so I could test, but no. :-( I'm not really a human, but I play one on earth CandyGram for Mongo	[reply]
Re^4: solution for fileevent on Win32 ??? by cta (Acolyte) on Jul 16, 2008 at 19:25 UTC
Re: solution for fileevent on Win32 ??? by jethro (Monsignor) on Jul 10, 2008 at 16:44 UTC
2. You could make a timer event that checks for that incoming event. Depends on how real time your real time constraint really is. Second possibility could be to find an X event that could be hijacked to signify your event, but that sounds to me a bit like a hack.	[reply]