hop-2012/server/thirdparty/lwt-2.3.2/examples/unix/logging.ml

63 lines
2.3 KiB
OCaml

(* Lightweight thread library for Objective Caml
* http://www.ocsigen.org/lwt
* Program Logging
* Copyright (C) 2011 Jérémie Dimino
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, with linking exceptions;
* either version 2.1 of the License, or (at your option) any later
* version. See COPYING file for details.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*)
(* This example illustrate the use of the Lwt_log module from
lwt.unix. *)
(* The logging section for this module: *)
let section = Lwt_log.Section.make "test"
lwt () =
(* Enable all logging levels superior from [Info] to [Fatal]: *)
Lwt_log.Section.set_level section Lwt_log.Info;
(* A message with the default logger: *)
lwt () = Lwt_log.log ~section ~level:Lwt_log.Info "this message will appear only on stderr" in
(* Same as begore, but using [Lwt_log.info]: *)
lwt () = Lwt_log.info ~section "this one too" in
(* A message to a custom logger, logging simultaneously to [stderr]
and to the system logger daemon: *)
let logger =
Lwt_log.broadcast
[Lwt_log.channel ~close_mode:`Keep ~channel:Lwt_io.stderr ();
Lwt_log.syslog ~facility:`User ()]
in
lwt () = Lwt_log.info ~section ~logger "this message will appear on stderr and in '/var/log/user.log'" in
(* Logging of exceptions: *)
Printexc.record_backtrace true;
let f () : unit = raise Exit in
let g () = f () in
let h () = g () in
lwt () =
try
h ();
Lwt.return ()
with exn ->
Lwt_log.error ~section ~exn "h failed with"
in
let logger = Lwt_log.channel ~template:"$(name): $(section): $(loc-file): $(loc-line): $(loc-column): $(message)" ~close_mode:`Keep ~channel:Lwt_io.stderr () in
Lwt_log.info ~section ~logger "this message will appear with a location"