Description:
------------
(sorry for my poor english.....)
It seems unpack can not deal with an odd number of hex string args. Under a xterm, it will cause "xterm" displayed on term. 

Reproduce code:
---------------
<?php
$a=pack("H3i","181",5);
$b=unpack("H3/ias",$a);
var_dump($b);
?>

Expected result:
----------------
array(2){
[1]=>
string(3)"181"
["as"]=>
int(5)
}

Actual result:
--------------
array(2){
[1]=>
string(2)"18"
["as"]=>
int(1296)
}