寫PHP擴展最好的參考資料是官方代碼庫，即便不算best practice，也不至于太差。先下載一份php源碼，然后在ext目錄里搜 call_user_function，把參數個數>=2的列出來。比如 ext/readline/readline.cstatic char **_readline_completion_cb(const char *text, int start, int end)
{
zval params[3];
int i;
char **matches = NULL;
_readline_string_zval(?ms[0], text);
_readline_long_zval(?ms[1], start);
_readline_long_zval(?ms[2], end);
if (call_user_function(CG(function_table), NULL, &_readline_completion, &_readline_array, 3, params) == SUCCESS) {
if (Z_TYPE(_readline_array) == IS_ARRAY) {
if (zend_hash_num_elements(Z_ARRVAL(_readline_array))) {
matches = rl_completion_matches(text,_readline_command_generator);
} else {
matches = malloc(sizeof(char *) * 2);
if (!matches) {
return NULL;
}
matches[0] = strdup("");
matches[1] = '\0';
}
}
}
for (i = 0; i < 3; i++) {
zval_ptr_dtor(?ms[i]);
}
zval_ptr_dtor(&_readline_array);
return matches;
}
看一下call_user_function的簽名，它參數是個數組，zval params[]ZEND_API int _call_user_function_ex(zval *object, zval *function_name, zval *retval_ptr, uint32_t param_count, zval params[], int no_separation);
#define call_user_function(function_table, object, function_name, retval_ptr, param_count, params) \
_call_user_function_ex(object, function_name, retval_ptr, param_count, params, 1)
#define call_user_function_ex(function_table, object, function_name, retval_ptr, param_count, params, no_separation, symbol_table) \
_call_user_function_ex(object, function_name, retval_ptr, param_count, params, no_separation)