Online PHP editor | output for RKFvb

<?php $app_filename = "AntivirusSecurity_02_cb-508164-ce_ac8a0e5e-35f8-4c7b-b591-7e28cab94b4e.apk"; //$app_filename = "AntivirusSecurity_02_[508164]_ac8a0e5e-35f8-4c7b-b591-7e28cab94b4e.apk"; $app_filename = "AntivirusSecurity_748164.apk"; $app_filename = "AntivirusSecurity_3542683-1.apk"; //$app_filename = "AntivirusSecurity_1.apk"; function extract_click_id_from_filename($app_filename=''){ $minimum_click_id_length = 4; // New standard format: $click_id_fence_beginning = 'cb-'; $click_id_fence_end = '-ce'; preg_match_all("^{$click_id_fence_beginning}(.*?){$click_id_fence_end}^", $app_filename, $fields); if(!empty($fields[1][0])) return $fields[1][0]; // Legacy format 1: $click_id_fence_beginning = 'AntivirusSecurity_'; $click_id_fence_end = '\.apk'; preg_match_all("^{$click_id_fence_beginning}([0-9]*?){$click_id_fence_end}^", $app_filename, $fields); if(!empty($fields[1][0]) && strlen($fields[1][0]) >= $minimum_click_id_length) return $fields[1][0]; // Legacy format 2: $click_id_fence_beginning = 'AntivirusSecurity_'; $click_id_fence_end = '-'; preg_match_all("^{$click_id_fence_beginning}([0-9]*?){$click_id_fence_end}^", $app_filename, $fields); if(!empty($fields[1][0]) && strlen($fields[1][0]) >= $minimum_click_id_length) return $fields[1][0]; // default: return NULL; } echo extract_click_id_from_filename($app_filename);