To call user functions from an internal function, you should use
the call_user_function() function.
call_user_function() returns SUCCESS on success,
and FAILURE in case the function cannot be found. You should check
that return value! If it returns SUCCESS, you are responsible for
destroying the retval pval yourself (or return it as the return value
of your function). If it returns FAILURE, the value of retval is
undefined, and you mustn't touch it.
All internal functions that call user functions
must be reentrant. Among other things, this
means they must not use globals or static variables.
call_user_function() takes six arguments:
This is the hash table in which the function is to be looked up.
This is a pointer to an object on which the function is invoked.
This should be NULL if a global function is called. If it's not
NULL (i.e. it points to an object), the function_table argument is
ignored, and instead taken from the object's hash. The object *may*
be modified by the function that is invoked on it (that function
will have access to it via $this). If for some reason you don't
want that to happen, send a copy of the object instead.
The name of the function to call. Must be a pval of type
IS_STRING with function_name.str.val and function_name.str.len
set to the appropriate values. The function_name is modified by
call_user_function() - it's converted to lowercase. If you need to
preserve the case, send a copy of the function name instead.
A pointer to a pval structure, into which the return value of
the invoked function is saved. The structure must be previously
allocated - call_user_function() does NOT allocate
it by itself.
The number of parameters being passed to the function.
An array of pointers to values that will be passed as arguments to the
function, the first argument being in offset 0, the second in offset
1, etc. The array is an array of pointers to pval's; The pointers
are sent as-is to the function, which means if the function modifies
its arguments, the original values are changed (passing by reference).
If you don't want that behavior, pass a copy instead.