I don't see this documented in perlfunc, so I'd be interested in know how robust and portable this is. (I am using perl 5.8.7 in Win32) In case it is of help, here is a small library I wrote using TCP connections to transfer YAML-serialised data for basic RPC.

Wouldn't a UDP connection make more sense for editing a file? The server is easier to program because there is no connection that can break. The traffic is more suited to UPD because it is always a single keystroke between loooong pauses (at least for the computer)

UPDATE: Ah, I forgot that the changes have to be sent back to the client for display, which works better in a TCP connection.

Also read perldoc IO::Socket and look for the "connected" method.

Hi,

select kinda does the trick. I can now monitor the server. If the client disconnects, it is captured and the thread running the read/write is killed.

now I have another problem. Even though a new socket seems to be opened after reconnect, I can only write to it, when I have the print"$pid \n"; before cancelling the thread. If i comment that out, it just prints out:

SEND( TYPE q or Q to Quit):

RECIEVED:

SEND( TYPE q or Q to Quit):

RECIEVED:
SEND( TYPE q or Q to Quit):Use of uninitialized value $send_data in sc
+alar chop
at select_server.pl line 46, <STDIN> line 5.

RECIEVED:
SEND( TYPE q or Q to Quit):Terminating on signal SIGINT(2)
[download]

The error above shows up when hitting CTRL-C

What am I missing?

use IO::Select;
use IO::Socket();
use threads;
use threads::shared;
use Thread::Cancel ;
use strict;
use warnings;
my $Thread;
my $lsn = new IO::Socket::INET(Listen => 1, LocalPort => 5000);
my $sel = new IO::Select( $lsn );
my $tid : shared;
    while(my @ready = $sel->can_read) {
        foreach my $fh (@ready) {
           if($fh == $lsn) {
                # Create a new socket
                my $new = $lsn->accept;
                $sel->add($new);
                my $Thread = threads->create( "echoserver", $new);  #s
+tart the echo-server as a seperate thread
                #$Thread->detach();
                 }
            else {
                # Process socket
                # Maybe we have finished with the socket
                print "$tid\n";
                my $Thread = threads->object($tid);  #get handle of cu
+rrent echo-server thread
                $sel->remove($fh);
                $fh->close;
                threads->cancel($Thread);            #kill the thread.
+  a new one will get started when we reconnect
                }
        }
    }
    
sub echoserver {
   #Clienthandle
    my $session = shift;
    my $own_thread;
    # get our own thread-id and store it, so we can kill the thread fr
+om outside
    $own_thread=threads->self();
    $tid = threads->tid($own_thread);
    lock($tid);
    $session->autoflush(1);    #make sure the socket get read right aw
+ay
    while (1) {print "\n SEND( TYPE q or Q to Quit):";
        my $recieved_data;
        my $send_data = <STDIN>;
        STDIN->autoflush(1);
        chop($send_data); 
        $session->send($send_data);
        $session->recv($recieved_data,1024);print "\n RECIEVED: $recie
+ved_data";}
}
[download]

Thanks,

Sven

I now use a queue to pause the thread.