Mi ha outputtato questo:

Array
(
[0] => zip
[1] => xmlrpc
[2] => xml
[3] => wddx
[4] => tokenizer
[5] => swf
[6] => standard
[7] => sockets
[8] => snmp
[9] => session
[10] => posix
[11] => pdf
[12] => overload
[13] => mysql
[14] => mhash
[15] => mcrypt
[16] => mbstring
[17] => imap
[18] => iconv
[19] => gettext
[20] => gd
[21] => ftp
[22] => exif
[23] => domxml
[24] => curl
[25] => ctype
[26] => calendar
[27] => bcmath
[28] => zlib
[29] => pcre
[30] => openssl
[31] => apache
[32] => Zend Optimizer
)