handle firebird events asynchronously with perl - perl

Question

I'm creating an info board app with data taken from firebird 1.5 database.
I would like not to use polling but events.
I've created sample trigger which fires up an event in firebird database.
Now I need a client to listen for and handle the event.
I've decided to go with perl.
Here is the doc DBD::Firebird.
I'm trying to go with async events.
Here's the code, I give the skeleton which won't work anyway.
The event won't fire up in perl. What am I doing wrong. Please help, thanks!
#!/usr/bin/perl
use DBI;
$dsn =<< "DSN";
dbi:Firebird:dbname=/home/firebird/dev/db.gdb;
host=localhost;
port=3050;
ib_dialect=3;
DSN
$dbh = DBI->connect($dsn, "user", "password");
# events of interest
#event_names = ("schedule_event");
$evh = $dbh->func(#event_names, 'ib_init_event');
my $cb = sub {.
print "got event";
};
$dbh->func($evh, $cb, 'ib_register_callback');
while (1) {
}
UPDATE:
ok here's the php script I'm going with right now, just leave it here maybe it helps someone:
<?php
declare(ticks = 1);
$username = "user";
$password = "password";
$host = 'localhost:/home/firebird/base/base.gdb';
$sockets = array();
$dbh = ibase_connect($host, $username, $password);
function event_handler($event_name, $link) {
echo $event_name . "\n";
send_message($event_name);
}
# we need to unregister event in firebird before exit
function terminate($signal) {
global $event;
if (is_null($event)) {
die ( "no event has been registered yet, exiting" );
} else {
ibase_free_event_handler($event);
die ( "unregistered evented and exiting\n" );
}
}
function send_message($msg)
{
$localsocket = 'tcp://127.0.0.1:8010';
$instance = stream_socket_client ($localsocket, $errno, $errstr);
fwrite($instance, json_encode(['message' => $msg, 'userId' => 824]) . \n");
}
$event = ibase_set_event_handler($dbh, "event_handler", "schedule_update");
pcntl_signal(SIGTERM, "terminate");
while (true) {
sleep(1);
}
?>