PHP extension development - Confusion caused by two zend_api during PHP extension development

My extension code is like this

<code>ZEND_BEGIN_ARG_INFO_EX(helloZvalArg, 0, 0, 1)
    ZEND_ARG_INFO (0, name)
    ZEND_ARG_INFO (0, age)
    ZEND_ARG_INFO (0, zval_args)
ZEND_END_ARG_INFO()



PHP_FUNCTION(debug_zval)
{
    zend_string *name, *age;
    zval zval_args;
    if(zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "SSz", &name, &age, &zval_args) == FAILURE){
        php_error_docref(NULL TSRMLS_CC, E_WARNING, "参数接受错误");
        RETURN_FALSE;
    }

    php_printf("zval_args的type类型:%d\n", Z_TYPE(zval_args));
    ZVAL_STR(&zval_args, name);
    php_printf("将name复制后的zval_args的type类型:%d\n",Z_TYPE (zval_args));
    php_printf("named:%s\n",name->val);
    php_printf("age:%s\n",age->val);
    zval_ptr_dtor(&zval_args);
}</code>

PHP code

<code><?php
$br = (php_sapi_name() == "cli")? "":"<br>";

if(!extension_loaded('helloZval')) {
    dl('helloZval.' . PHP_SHLIB_SUFFIX);
}
debug_zval("sss",2,4);

?>
</code>

Output

<code>zval_args的type类型:0    (IS_UNDF)
将name复制后的zval_args的type类型:6(IS_STRING)                                                                                  
named:sss
age:2</code>

I have two doubts

• When I use zval as a container for receiving parameters (let’s call it that), why do I not receive the parameters successfully, but IS_UNDEF

• If zval cannot be used as a parameter container, then zend_string has other types that are defined at the same time (such as zend_array, zend_object....) What is the difference between zend_string and zval (both zend_string and zval can be GCed and zend_string is more lightweight) , or what is the difference between the usage of zval and zend_string?

Reply content:

My extension code is like this

<code>ZEND_BEGIN_ARG_INFO_EX(helloZvalArg, 0, 0, 1)
    ZEND_ARG_INFO (0, name)
    ZEND_ARG_INFO (0, age)
    ZEND_ARG_INFO (0, zval_args)
ZEND_END_ARG_INFO()



PHP_FUNCTION(debug_zval)
{
    zend_string *name, *age;
    zval zval_args;
    if(zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "SSz", &name, &age, &zval_args) == FAILURE){
        php_error_docref(NULL TSRMLS_CC, E_WARNING, "参数接受错误");
        RETURN_FALSE;
    }

    php_printf("zval_args的type类型:%d\n", Z_TYPE(zval_args));
    ZVAL_STR(&zval_args, name);
    php_printf("将name复制后的zval_args的type类型:%d\n",Z_TYPE (zval_args));
    php_printf("named:%s\n",name->val);
    php_printf("age:%s\n",age->val);
    zval_ptr_dtor(&zval_args);
}</code>

PHP code

<code><?php
$br = (php_sapi_name() == "cli")? "":"<br>";

if(!extension_loaded('helloZval')) {
    dl('helloZval.' . PHP_SHLIB_SUFFIX);
}
debug_zval("sss",2,4);

?>
</code>

Output

<code>zval_args的type类型:0    (IS_UNDF)
将name复制后的zval_args的type类型:6(IS_STRING)                                                                                  
named:sss
age:2</code>

I have two doubts

• When I use zval as a container for receiving parameters (let’s call it that), why do I not receive the parameters successfully, but IS_UNDEF

• If zval cannot be used as a parameter container, then zend_string has other types that are defined at the same time (such as zend_array, zend_object....) What is the difference between zend_string and zval (both zend_string and zval can be GCed and zend_string is more lightweight) , or what is the difference between the usage of zval and zend_string?