A simple logging module (OCaml)

simplelog.ml

module Logs = struct

  let hash = Hashtbl.create 256

  let log name msg =
    let ch = Hashtbl.find hash name in
    Printf.fprintf ch "%s\n%!" msg

  let close name =
    let ch = Hashtbl.find hash name in
    close_out ch

  let channel	target =
    match	target with
    | "stdout" -> stdout
    | "stderr" ->	stderr
    | filename -> open_out_gen [Open_creat; Open_text; Open_append] 0o640 filename

  let create name target =
    let ch = channel target in
    Hashtbl.add hash name ch;
    at_exit (fun _ -> close name)

end

let main () =
  Logs.create "verbose_log" "verbose.log";
  Logs.log "verbose_log" "Logging to verbose log...";

  Logs.create "other_verbose_log"	"verbose.log";
  Logs.log "other_verbose_log" "Logging	to other verbose log...";

  Logs.create "main_log" "stdout";
  Logs.log "main_log" "Logging to stdout...";
  Printf.printf	"Done\n%!"

let () = Unix.handle_unix_error main ()