Type specifiers
---------------
- l - long
- d - double
- s - string (with possible null bytes) and its length
- b - boolean, stored in zend_bool
- r - resource (stored in zval)
a - array
+ b - boolean, stored in zend_bool
+ d - double
+ f - function or array containing php method call info (returned as
+ zend_fcall_info* and zend_fcall_info_cache*)
+ h - array (returned as HashTable*)
+ l - long
o - object (of any type)
O - object (of specific type, specified by class entry)
+ r - resource (stored in zval)
+ s - string (with possible null bytes) and its length
z - the actual zval
The following characters also have a meaning in the specifier string: