[通译][php扩展和嵌入式]第7章-接受参数

PHP_FUNCTION(sample_getlong)
{
    long foo;
    if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC,
                         "l", &foo) == FAILURE) {
        RETURN_NULL();
    }
    php_printf("The integer value of the parameter you "
             "passed is: %ld\n", foo);
    RETURN_TRUE;
}

function sample_hello_world($name) {
    echo "Hello $name!\n";
}
/* 在C中, 你将使用zend_parse_parameters()函数接受一个字符串 */
PHP_FUNCTION(sample_hello_world)
{
    char *name;
    int name_len;


    if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s",
                        &name, &name_len) == FAILURE) {
        RETURN_NULL();
    }
    php_printf("Hello ");
    PHPWRITE(name, name_len);
    php_printf("!\n");
}

function sample_hello_world($name, $greeting) {
    echo "Hello $greeting $name!\n";
}
sample_hello_world('John Smith', 'Mr.');
Or:
PHP_FUNCTION(sample_hello_world)
{
    char *name;
    int name_len;
    char *greeting;
    int greeting_len;


    if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "ss",
      &name, &name_len, &greeting, &greeting_len) == FAILURE) {
        RETURN_NULL();
    }
    php_printf("Hello ");
    PHPWRITE(greeting, greeting_len);
    php_printf(" ");
    PHPWRITE(name, name_len);
    php_printf("!\n");
}

function sample_hello_world($name, $greeting='Mr./Ms.') {
    echo "Hello $greeting $name!\n";
}

sample_hello_world('Ginger Rogers','Ms.');
sample_hello_world('Fred Astaire');

PHP_FUNCTION(sample_hello_world)
{
    char *name;
    int name_len;
    char *greeting = "Mr./Mrs.";
    int greeting_len = sizeof("Mr./Mrs.") - 1;

    /* 如果调用时没有传递第二个参数, 则greeting和greeting_len保持不变. */
    if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s|s",
      &name, &name_len, &greeting, &greeting_len) == FAILURE) {
        RETURN_NULL();
    }
    php_printf("Hello ");
    PHPWRITE(greeting, greeting_len);
    php_printf(" ");
    PHPWRITE(name, name_len);
    php_printf("!\n");
}

PHP_FUNCTION(sample_arg_fullnull)
{
    zval *val;
    if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "z",
                                    &val) == FAILURE) {
        RETURN_NULL();
    }
    if (Z_TYPE_P(val) == IS_NULL) {
        val = php_sample_make_defaultval(TSRMLS_C);
    }
...
PHP_FUNCTION(sample_arg_nullok)
{
    zval *val;
    if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "z!",
                                    &val) == FAILURE) {
        RETURN_NULL();
    }
    if (!val) {
        val = php_sample_make_defaultval(TSRMLS_C);
    }
...

PHP_FUNCTION(sample_onearg)
{
    zval *firstarg;
    if (zend_get_parameters(ZEND_NUM_ARGS(), 1, &firstarg)
                                        == FAILURE) {
        php_error_docref(NULL TSRMLS_CC, E_WARNING,
            "Expected at least 1 parameter.");
        RETURN_NULL();
    }
    /* Do something with firstarg... */
}

PHP_FUNCTION(sample_onearg)
{
    zval **firstarg;
    if (zend_get_parameters_ex(1, &firstarg) == FAILURE) {
        WRONG_PARAM_COUNT;
    }
    /* Do something with firstarg... */
}

PHP_FUNCTION(var_dump)
{
    int i, argc = ZEND_NUM_ARGS();
    zval ***args;


    args = (zval ***)safe_emalloc(argc, sizeof(zval **), 0);
    if (ZEND_NUM_ARGS() == 0 ||
        zend_get_parameters_array_ex(argc, args) == FAILURE) {
        efree(args);
        WRONG_PARAM_COUNT;
    }
    for (i=0; i<argc i php_var_dump tsrmls_cc efree>
<p style="margin-top:0px; margin-bottom:0px; text-indent:25.2px; font-family:Helvetica">
<span style="letter-spacing:0.0px">这里, var_dump()预分配了一个传给函数的参数个数大小的zval **指针向量. 接着使用zend_get_parameters_array_ex()一次性将参数摊入到该向量中. 你可能会猜到, 存在这个函数的另外一个版本: zend_get_parameters_array(), 它们仅有一点不同: 自动隔离, 返回zval *而不是zval **, 在第一个参数上要求传递ZEND_NUM_ARGS().</span></p>
<p style="margin-top:0px; margin-bottom:0px; font-size:24px; font-family:Helvetica">
<span style="letter-spacing:0.0px"><strong>参数信息和类型暗示</strong></span></p>
<p style="margin-top:0px; margin-bottom:0px; text-indent:25.2px; font-family:Helvetica">
<span style="letter-spacing:0.0px">在上一章已经简短的向你介绍了使用Zend引擎2的 参数信息结构进行类型暗示的概念. 我们应该记得, 这个特性是针对ZE2(Zend引擎2)的, 对于php4的ZE1(Zend引擎1)不可用.</span></p>
<p style="margin-top:0px; margin-bottom:0px; text-indent:25.2px; font-family:Helvetica">
<span style="letter-spacing:0.0px">我们重新从ZE2的参数信息结构开始. 每个参数信息都使用ZEND_BEGIN_ARG_INFO()或ZEND_BEGIN_ARG_INFO_EX()宏开始, 接着是0个或多个ZEND_ARG_*INFO()行, 最后以ZEND_END_ARG_INFO()调用结束.</span></p>
<p style="margin-top:0px; margin-bottom:0px; text-indent:25.2px; font-family:Helvetica">
<span style="letter-spacing:0.0px">这些宏的定义和基本使用可以在刚刚结束的第6章"返回值"的编译期引用传值一节中找到.</span></p>
<p style="margin-top:0px; margin-bottom:0px; text-indent:25.2px; font-family:Helvetica">
<span style="letter-spacing:0.0px">假设你想要重新实现count()函数, 你可能需要创建下面这样一个函数:</span></p>
<pre name="code" class="cpp">PHP_FUNCTION(sample_count_array)
{
    zval *arr;
    if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "a",
                                    &arr) == FAILURE) {
        RETURN_NULL();
    }
    RETURN_LONG(zend_hash_num_elements(Z_ARRVAL_P(arr)));
}

static
    ZEND_BEGIN_ARG_INFO(php_sample_array_arginfo, 0)
        ZEND_ARG_ARRAY_INFO(0, "arr", 0)
    ZEND_END_ARG_INFO()

PHP_FE(sample_count_array, php_sample_array_arginfo)

static
    ZEND_BEGIN_ARG_INFO(php_sample_class_arginfo, 0)
        ZEND_ARG_OBJECT_INFO(1, "obj", "stdClass", 0)
    ZEND_END_ARG_INFO()