What does this PHP do? Is it an encoder/decoder?

[soft2day]

I don't know php at all; this is more of a question of curiosity.Following the php function below in the text file are a few thousand characters of text, such as\[code\]xnEFstUhSNWGSx5zTq4X/AUw/rtism+klrBETWg0xE1uwb49rnRxrgrgY5EEp3Y0uvTcvLqhUFOP4n7LDLQpQ9UACTyuUjGBKmUScQCYLCP08u06t0K3nWTNiM7Q6bQMk/iZBE+UK1ywbVC1Lzr9OOEK\[/code\]Does this php function encode the random-looking text into php? Can the encryption scheme be figured out from this?EDIT: The client says he has full ownership and rights to the code, developed by someone else. How would it be decoded? Does it require a password?\[code\]<?php //003acif (!extension_loaded('ionCube Loader')) { $__oc = strtolower(substr(php_uname(), 0, 3)); $__ln = 'ioncube_loader_' . $__oc . '_' . substr(phpversion(), 0, 3) . (($__oc == 'win') ? '.dll' : '.so'); @dl($__ln); if (function_exists('_il_exec')) { return _il_exec(); } $__ln = '/ioncube/' . $__ln; $__oid = $__id = realpath(ini_get('extension_dir')); $__here = dirname(__FILE__); if (strlen($__id) > 1 && $__id[1] == ':') { $__id = str_replace('\\', '/', substr($__id, 2)); $__here = str_replace('\\', '/', substr($__here, 2)); } $__rd = str_repeat('/..', substr_count($__id, '/')) . $__here . '/'; $__i = strlen($__rd); while ($__i--) { if ($__rd[$__i] == '/') { $__lp = substr($__rd, 0, $__i) . $__ln; if (file_exists($__oid . $__lp)) { $__ln = $__lp; break; } } } @dl($__ln);} else { die('The file ' . __FILE__ . " is corrupted.\n");}if (function_exists('_il_exec')) { return _il_exec();}echo ('Site error: the file <b>' . __FILE__ . '</b> requires the ionCube PHP Loader ' . basename($__ln) . ' to be installed by the site administrator.');exit(199);?>\[/code\]