logging_handlers – Additional Logging Handlers

Introduction

Python’s builtin logging module offers the concept of handlers each of which takes the logged message and passes to an output channel. There are handlers provided for screen, files, NT Event Logs and so on. This module offers two handlers to output to a named Windows mailslot. It makes use of the ipc.Mailslot class and can write to a one-time mailslot or to a mailslot which is running permanently.

The sort of situation where this might be useful is where you have a number of system routines running on and off. If they all log to the same mailslot, say on an administrator’s desktop, then he can see the progress of all in one place. Better still, if they log to all the mailslots of the same name in the domain, then everyone can have a logging screen running on their desktop which they can start up and close down at will to see the current progress.

Classes

class MailslotHandler(mailslot_name : string)

Set up a handler going to the named mailslot. Note that the usual possibilities obtain for mailslot names: an unqualified name must exist on the local machine; a computer or domain-qualified name will broadcast to that machine or that domain without checking existence; a * will just broadcast, full-stop.

The close function sends a None to the receiving mailslot, intended to act as a prompt to shut down. (Although that’s obviously in the hands of the receiver).

class PermanentMailslotHandler(mailslot_name : string)

Subclass the MailslotHandler and override the close function so that it doesn’t send the shutdown token to the receiving mailslot(s).