I seek the knowledge of the enlightened monks to help me reach the last leg of a forking server.

I have tried to read documentation available online, in cookbooks but I am not sure if it is the same as what I want.

The aim is to:

    1. Create a telnet server running on port 7070.
    2. Enable 5 clients at MAX to connect to it.
    3. When 1 client is connected and running a command, all commands from other clients should be queued.(There are only 5 possible commands that a client can invoke, 2 of which are "printhelp" and "quit")

I have managed to reach level 1 and partially level 2. Multiple clients are able to connect to the server.

The problems that I face are these

    A) When the first client dies, the server commits suicide. Advise is sought on this.
    B) How can I prevent more than 5 clients from connecting.
    C) How can I enable queuing of commands and ensuring the result of the commands are sent to the right client. 
#!/usr/bin/perl -w
use IO::Socket;
use strict;

$SIG{CHLD} = sub{ wait; };


my $inputLine;
my $new_sock;
my $main_sock;
my $pid;

    # Create Socket on port 7070
    $main_sock = new IO::Socket::INET (
                                        LocalHost => 'localhost',
                                        LocalPort => '7070',
                                        Proto => 'tcp',
                                        Listen => 1,
                                        Reuse => 1,
                                    );
    die "Could not create socket: $!\n" unless $main_sock;
    print "Telnet Server listening on 7070....\n";

    # Accept connection and fork child!
    while( $new_sock = $main_sock->accept() ){

            $pid = fork();
            unless( defined($pid) ){
               die "Cannot fork\n";
            }

            ##################
            # CHILD PROCESS 
            ##################
            if($pid == 0) {

                # Print Welcome message!
                welcomeClient($new_sock);

                while( defined( $inputLine=<$new_sock>) ) {
                    $inputLine =~ s/[\r\n]//g;

                    if( $inputLine eq "printhelp" ){
                           callPrintHelp($new_sock);

                    }elsif( $inputLine eq "quit" ){
                            callQuit($new_sock);
                            exit(0);
                    }else{
                            print $new_sock "INFO> Not implemented yet
+\n";
                    }

                 }#while

                 exit(0);
            }

            ##################
            # CHILD PROCESS 
            ##################



    }# while main_sock

    close($main_sock);




sub welcomeClient {

    # Show starting point for client and help messages
    my ($client_sock) = @_;

    print $client_sock "######################################\n";
    print $client_sock "         Telnet Interface         \n";
    print $client_sock "######################################\n\n";
    print $client_sock "INFO>  Type 'printhelp' for help\n\n";
    print $client_sock "READY:\n";
    print $client_sock ">";
}

sub callPrintHelp{
   my ($client_sock) = @_;
    ......
     .....

}

sub callQuit{
   my ($client_sock) = @_;
    ......
     .....

}

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In reply to A suicidal parent OR death of a forking server by MonkeyMonk

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