extern int ustcomm_create_unix_sock(const char *pathname);
extern int ustcomm_connect_unix_sock(const char *pathname);
extern int ustcomm_accept_unix_sock(int sock);
extern int ustcomm_create_unix_sock(const char *pathname);
extern int ustcomm_connect_unix_sock(const char *pathname);
extern int ustcomm_accept_unix_sock(int sock);