Linux的c程序和动态链接库的初始化函数类似golang里面的init函数
dlopen 支持_init函数的
https://man7.org/linux/man-pages/man3/dlopen.3.html
不过现在建议使用gcc的constructor attribute,像下面这样定义，xxxx_init 会在初始化阶段dlopen返回之前被调用，和main入口之前被调用吧
destructor 函数
void __attribute__((constructor)) xxxx_init(void);
void __attribute__((destructor)) xxxx_exit(void);
void xxxx_init(void)
{
}
void xxxx_exit(void)
{
}
gcc的文档说明
constructor
destructor
constructor (priority)
destructor (priority)
The constructor attribute causes the function to be called automatically before execution enters main (). Similarly, the destructor attribute causes the function to be called automatically after main () has completed or exit () has been called. Functions with these attributes are useful for initializing data that will be used implicitly during the execution of the program.
You may provide an optional integer priority to control the order in which constructor and destructor functions are run. A constructor with a smaller priority number runs before a constructor with a larger priority number; the opposite relationship holds for destructors. So, if you have a constructor that allocates a resource and a destructor that deallocates the same resource, both functions typically have the same priority. The priorities for constructor and destructor functions are the same as those specified for namespace-scope C++ objects (see C++ Attributes).