- var_dump: documentation ( source)
- preg_match_all: documentation ( source)
<?php
$t = 'Hi @[4232:mark__MΛRK ATTLEY] how are you ?
Hi @[4232:ryan__RYΛN вυηту] how are you ?
Hi @[4232:david__DΛVID शाहिद ] how are you ?
';
$pattern = "/@\[.*\]/mi";
preg_match_all($pattern, $t, $out, PREG_PATTERN_ORDER);
var_dump($out);