val hostname : unit -> string
(* Get hostname of this machine *)
+
+ val readList : string -> string list
+ val writeList : string * string list -> unit
+ (* Reading and writing lists of strings stored on separate lines in files *)
+
+ val lineInFile : string -> string -> bool
+ (* Is there a line in the file (first arg) that matches that given? *)
+
+ val inGroup : {user : string, group : string} -> bool
+ (* Check membership in a UNIX group. *)
+
end