argtoi
static int argtoi(const char *, int, int, int);
d_arg = argtoi(optarg, 0, 0xff, 'd');
m_arg = argtoi(optarg, 0, 0xf, 'm');
s_arg = argtoi(optarg, 1, 6, 's');
t_arg = argtoi(optarg, 1, 0xffff, 't');