void do_usb_del(Monitor *mon, const char *devname);
void usb_info(Monitor *mon);
-const char *get_opt_name(char *buf, int buf_size, const char *p, char delim);
-const char *get_opt_value(char *buf, int buf_size, const char *p);
int get_param_value(char *buf, int buf_size,
const char *tag, const char *str);
int check_params(const char * const *params, const char *str);