val is_dir: string -> bool (** @return true if file is a directory *)
val is_regular: string -> bool (** @return true if file is a regular file *)
val mkdir: string -> unit (** create dir and parents. @raise Failure *)
+val tilde_expand: string -> string (** bash-like (head) tilde expansion *)
(** find all _files_ matching test under a filesystem root *)
val find: ?test:(string -> bool) -> string -> string list
val finally: (unit -> unit) -> ('a -> 'b) -> 'a -> 'b
+(** {2 Char processing} *)
+
+val is_alpha: char -> bool
+val is_digit: char -> bool
+val is_alphanum: char -> bool (** is_alpha || is_digit *)
+
(** {2 String processing} *)
val split: ?sep:char -> string -> string list (** @param sep defaults to ' ' *)