C语言 结构体 指针的用法 程序解释

typedef struct
{
uint8 cmd_head;
uint8 cmd_type;
uint8 ctrl_msg;
uint16 screen_id;
uint16 control_id;
uint8 param[256];//可变长度参数，最多256个字节
}CTRL_MSG,*PCTRL_MSG;
相当于
struct __CTRL_MSG {
uint8 cmd_head;
uint8 cmd_type;
uint8 ctrl_msg;
uint16 screen_id;
uint16 control_id;
uint8 param[256];//可变长度参数，最多256个字节
};
typedef struct __CTRL_MSG CTRL_MSG;
typedef struct __CTRL_MSG *PCTRL_MSG;