. It cannot have two consecutive dots `..` anywhere;
. It cannot have ASCII control character (i.e. bytes whose
values are lower than \040, or \177 `DEL`), space, tilde `~`,
. It cannot have two consecutive dots `..` anywhere;
. It cannot have ASCII control character (i.e. bytes whose
values are lower than \040, or \177 `DEL`), space, tilde `~`,