gnu-social/vendor/diogocomposer/xmpphp/examples/sendmessage_example.php

<?php
/**
 * @file: XMPPHP Send message example
 *
 * @info: If this script doesn't work, are you running 64-bit PHP with < 5.2.6?
 */
/**
 * Activate full error reporting
 * error_reporting(E_ALL & E_STRICT);
 *
 * XMPPHP Log levels:
 *
 * LEVEL_ERROR   = 0;
 * LEVEL_WARNING = 1;
 * LEVEL_INFO    = 2;
 * LEVEL_DEBUG   = 3;
 * LEVEL_VERBOSE = 4;
 */

$conf = [
    'server' => 'jabber.domain.com',
    'port' => 5222,
    'username' => 'username',
    'password' => 'password',
    'proto' => 'xmpphp',
    'domain' => 'domain.net',
    'printlog' => true,
    'loglevel' => XMPPHP\Log::LEVEL_VERBOSE,
];

// Easy and simple for access to variables with their names
extract($conf);

$XMPP = new XMPPHP\XMPP($server, $port, $username, $password, $proto, $domain, $printlog, $loglevel);

try {
    $XMPP->connect();
    $XMPP->processUntil('session_start', 10);
    $XMPP->presence();
    $XMPP->message('target.user@jabber.domain.com', 'Hello, how are you?', 'chat');
    $XMPP->disconnect();
} catch (XMPPHP\Exception $e) {
    die($e->getMessage());
}