Module Lwt_log

module Lwt_log: sig .. end

Logging facility

This module provides functions to deal with logging. It extends Lwt_log_core with Unix features. It adds:

logging to the syslog daemon
logging to a channel (stderr, stdout, ...)
logging to a file

include Lwt_log_core

val render : buffer:Buffer.t ->
       template:template -> section:section -> level:level -> message:string -> unit

Same as Lwt_log_core.render, except that the template may also contain the following variables:

date, which will be replaced with the current local date and time,
milliseconds, which will be replaced by the fractional part of the current Unix time, to millisecond accuracy.

For example:

"$(date) $(name)[$(pid)]: $(message)"
"$(date).$(milliseconds) $(name)[$(pid)]: $(message)"
"$(date): $(loc-file): $(loc-line): $(loc-column): $(message)"

type syslog_facility = [ `Auth
       | `Authpriv
       | `Console
       | `Cron
       | `Daemon
       | `FTP
       | `Kernel
       | `LPR
       | `Local0
       | `Local1
       | `Local2
       | `Local3
       | `Local4
       | `Local5
       | `Local6
       | `Local7
       | `Mail
       | `NTP
       | `News
       | `Security
       | `Syslog
       | `UUCP
       | `User ]

Syslog facility. Look at the SYSLOG(3) man page for a description of syslog facilities

val syslog : ?template:template ->
       ?paths:string list -> facility:syslog_facility -> unit -> logger

syslog ?template ?paths ~facility () creates an logger which send message to the system logger.

template : defaults to "$(date) $(name)[$(pid)]: $(section): $(message)"

paths : is a list of path to try for the syslogd socket. It default to ["/dev/log"; "/var/run/log"].

val file : ?template:template ->
       ?mode:[ `Append | `Truncate ] ->
       ?perm:Unix.file_perm -> file_name:string -> unit -> logger Lwt.t

desf_file ?template ?mode ?perm ~file_name () creates an logger which will write messages to file_name.

if mode = `Truncate then the file is truncated and previous contents will be lost.

if mode = `Append, new messages will be appended at the end of the file

template : defaults to "$(date): $(section): $(message)"

mode : defaults to `Append

val channel : ?template:template ->
       close_mode:[ `Close | `Keep ] ->
       channel:Lwt_io.output_channel -> unit -> logger

channel ?template ~close_mode ~channel () creates a logger from a channel.

If close_mode = `Close then channel is closed when the logger is closed, otherwise it is left open.

template : defaults to "$(name): $(section): $(message)"