Since I am trying to learn, please do not recommend modules that do this for me. I have looked at Net::Server and it is way over my head at this point. Additionally, I have RTFM'd so if there is something I am missing in the docs, please be specific if you recommend further reading.

#!/usr/bin/perl
use strict;
use warnings;
use IO::Select;
use IO::Socket::INET;

my $hsock = IO::Socket::INET->new (
    Listen    => 5,
    LocalAddr => '0.0.0.0',
    LocalPort => 5885,
    Proto     => 'tcp',
    Type      => SOCK_STREAM,
    Reuse     => 1
);

my $handles = IO::Select->new($hsock);

my %user;
while (1) {
    last if keys %user > 4;
    my @ready = $handles->can_read(3);
    for my $sock (@ready) {
        if ($sock eq $hsock) {
            my $new_sock = $hsock->accept();
            $handles->add($new_sock);
            $new_sock->send("Welcome\r\n");
            $_->send("New user joined\r\n") for values %user;
            $user{$new_sock} = $new_sock;
        }
        else {
            my $buff = <$sock>;
            if ($buff) {
                $buff =~ tr/\r\n//d;
                next if $buff =~ /^\s*$/;
                $_->send("$buff\r\n") for values %user;
            }
            else {
                $handles->remove($sock);
                delete $user{$sock};
                $_->send("User left\r\n") for values %user;
            }
        }
    }
}
[download]

This code works - sorta. The timing of output is off. It seems as though the handles do not flush automatically even though auto-flush is on by default for socket handles. I considered forking the clients as I saw in other examples, but I want to understand why what I have doesn't work. It think I just have a stupid flow control problem between accept(), send(), and receive().

It seems to me that with just a listener and a couple of clients, even a single process should be able to keep up. I would prefer my existing code be modified to work with an explanation, but as always - all help/advice is appreciated.

Update: It may have been the client!
I received a /msg from BrowserUk indicating that from a windows telnet session it appeared to work just fine. I had been using Putty. When I changed the Putty protocol from "telnet" to "raw", it worked as BrowserUk described. I still welcome any/all advice!