in reply to In perl socket programming how to send a data from client and receive it from server and how to get number of clients processes and client ID?


You can certainly track open connections as hippo mentions. But since as choroba mentions, it's possible for the connection to close at any time without notifying you, so at best it's an optimistic estimate.

With respect to the code you've shown, I can see the confusion: When I run it, the thread reports "clients-> 5" when I connect to it a single time. I found that changing the statement reporting the number of clients from:

print "clients-> @clients\n";

to the following, it reports the correct number of clients:

print "clients->", scalar(@clients), "\n";

I've whacked on your code a little to:

I thought about doing other stuff, like:

But I refrained, as I have other stuff to do and mostly to not deprive you of the fun of doing it yourself.

#!/usr/bin/perl #server use warnings; use strict; use IO::Socket; use threads; use threads::shared; $|++; print "$$ Server started\n";; # do a "top -p -H $$" to monitor server + threads our @clients : shared; @clients = (); my $server = new IO::Socket::INET( Timeout => 7200, Proto => "tcp", LocalPort => 9000, Reuse => 1, Listen => 3 ); my $num_of_client = -1; while (1) { my $client; do { $client = $server->accept; } until ( defined($client) ); my $peerhost = $client->peerhost(); print "accepted a client $client, $peerhost, id = ", ++$num_of_cli +ent, "\n"; my $fileno = fileno $client; # Build a hash of information about the client connection and # share it (deep copy) in @clients. Set it up *before* starting # the thread so it can access the data. my $hr = { ID=>$num_of_client, FILE=>$fileno, IP=>$peerhost }; push @clients, shared_clone($hr); #spawn a thread here for each client my $thr = threads->new( \&processit, $client, $fileno, $peerhost ) +->detach(); } # end of main thread sub processit { my ($lclient,$lfileno,$lpeer) = @_; #local client # Current client record my @tmp = grep { $_->{FILE} == $lfileno } @clients; my $ID = "UNKNOWN"; $ID = $tmp[0]{ID} if @tmp; if ($lclient->connected) { # Here you can do your stuff # I use have the server talk to the client # via print $client and while(<$lclient>) print $lclient "$lpeer (ID:$ID)->Welcome to server\n"; while (<$lclient>) { # print $lclient "$lpeer->$_\n"; print "clients->", scalar(@clients), ".\n"; foreach my $hr (@clients) { next if $hr->{ID} eq $ID; my $fn = $hr->{FILE}; open my $fh, ">&=$fn" or warn $! and die; print $fh "$ID says: $_"; } } } #close filehandle before detached thread dies out close( $lclient); #remove multi-echo-clients from echo list @clients = grep {$_->{FILE} !~ $lfileno} @clients; }


When your only tool is a hammer, all problems look like your thumb.