- array_unshift: documentation ( source)
- var_export: documentation ( source)
- array_shift: documentation ( source)
- explode: documentation ( source)
- preg_split: documentation ( source)
<?php
$string = ':foo!bar@cookie.net strawberry cheesecake :hello world: this is a message!';
$result = preg_split('/[^:]*:[^:]*\K /', $string, 2);
array_unshift($result, ...explode(' ', array_shift($result)));
var_export($result);