Programming PHP

A More Complex Example
Here’s an example that forces the function to fetch only the first three parameters: an
array, a Boolean, and an object. We are using 'O' and also supplying an object type,
which we can check in case we want to accept only a certain class of object.
zval *arr;
zend_bool b;
zval *obj;
zend_class_entry obj_ce;
if (zend_parse_parameters(3 TSRMLS_CC, "abO", &arr, &b, &obj,
obj_ce) == FAILURE) {
return;
}
Forcing them to fetch only three parameters is useful for functions that can take a
variable amount of parameters. You can then check the total number of arguments
passed to see if there are any further arguments to process.
An Example with Variable Argument List
The following code illustrates how to process a variable argument list. It uses zend_
parse_parameters( ) to fetch the first argument and reads further arguments into a
zval *** array, then puts all the passed parameters into a PHP array and returns
them:
PHP_FUNCTION(foo) {
long arg;
zval ***args;
int i, argc = ZEND_NUM_ARGS( );
if (zend_parse_parameters(1 TSRMLS_CC, "l", &arg) == FAILURE) return;
array_init(return_value);
add_index_long(return_value, 0, arg);
if(argc>1) {
args = (zval ***)emalloc(argc * sizeof(zval **));
if(zend_get_parameters_array_ex(argc, args) == FAILURE) {
efree(args);
return;
}
for(i = 1; i < argc; i++) {
zval_add_ref(args[i]);
add_index_zval(return_value,i, *args[i]);
}
efree(args);
}
}
The zval_add_ref( ) call increments the reference count of the zval container. It is
explained in detail in the “References” section.
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Parameter Handling | 337