localsyslogappender.cs

精通SQL Server2005项目开发

#region Copyright & License
/*
 * Copyright 2004-2006 The Apache Software Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#endregion

// .NET Compact Framework 1.0 has no support for Marshal.StringToHGlobalAnsi
// SSCLI 1.0 has no support for Marshal.StringToHGlobalAnsi
#if !NETCF && !SSCLI

using System;
using System.Runtime.InteropServices;

using log4net.Core;
using log4net.Appender;
using log4net.Util;
using log4net.Layout;

namespace log4net.Appender 
{
	/// <summary>
	/// Logs events to a local syslog service.
	/// </summary>
	/// <remarks>
	/// <note>
	/// This appender uses the POSIX libc library functions <c>openlog</c>, <c>syslog</c>, and <c>closelog</c>.
	/// If these functions are not available on the local system then this appender will not work!
	/// </note>
	/// <para>
	/// The functions <c>openlog</c>, <c>syslog</c>, and <c>closelog</c> are specified in SUSv2 and 
	/// POSIX 1003.1-2001 standards. These are used to log messages to the local syslog service.
	/// </para>
	/// <para>
	/// This appender talks to a local syslog service. If you need to log to a remote syslog
	/// daemon and you cannot configure your local syslog service to do this you may be
	/// able to use the <see cref="RemoteSyslogAppender"/> to log via UDP.
	/// </para>
	/// <para>
	/// Syslog messages must have a facility and and a severity. The severity
	/// is derived from the Level of the logging event.
	/// The facility must be chosen from the set of defined syslog 
	/// <see cref="SyslogFacility"/> values. The facilities list is predefined
	/// and cannot be extended.
	/// </para>
	/// <para>
	/// An identifier is specified with each log message. This can be specified
	/// by setting the <see cref="Identity"/> property. The identity (also know 
	/// as the tag) must not contain white space. The default value for the
	/// identity is the application name (from <see cref="SystemInfo.ApplicationFriendlyName"/>).
	/// </para>
	/// </remarks>
	/// <author>Rob Lyon</author>
	/// <author>Nicko Cadell</author>
	public class LocalSyslogAppender : AppenderSkeleton 
	{
		#region Enumerations

		/// <summary>
		/// syslog severities
		/// </summary>
		/// <remarks>
		/// <para>
		/// The log4net Level maps to a syslog severity using the
		/// <see cref="LocalSyslogAppender.AddMapping"/> method and the <see cref="LevelSeverity"/>
		/// class. The severity is set on <see cref="LevelSeverity.Severity"/>.
		/// </para>
		/// </remarks>
		public enum SyslogSeverity
		{
			/// <summary>
			/// system is unusable
			/// </summary>
			Emergency = 0,

			/// <summary>
			/// action must be taken immediately
			/// </summary>
			Alert = 1,

			/// <summary>
			/// critical conditions
			/// </summary>
			Critical = 2,

			/// <summary>
			/// error conditions
			/// </summary>
			Error = 3,

			/// <summary>
			/// warning conditions
			/// </summary>
			Warning = 4,

			/// <summary>
			/// normal but significant condition
			/// </summary>
			Notice = 5,

			/// <summary>
			/// informational
			/// </summary>
			Informational = 6,

			/// <summary>
			/// debug-level messages
			/// </summary>
			Debug = 7
		};

		/// <summary>
		/// syslog facilities
		/// </summary>
		/// <remarks>
		/// <para>
		/// The syslog facility defines which subsystem the logging comes from.
		/// This is set on the <see cref="Facility"/> property.
		/// </para>
		/// </remarks>
		public enum SyslogFacility
		{
			/// <summary>
			/// kernel messages
			/// </summary>
			Kernel = 0,

			/// <summary>
			/// random user-level messages
			/// </summary>
			User = 1,

			/// <summary>
			/// mail system
			/// </summary>
			Mail = 2,

			/// <summary>
			/// system daemons
			/// </summary>
			Daemons = 3,

			/// <summary>
			/// security/authorization messages
			/// </summary>
			Authorization = 4,

			/// <summary>
			/// messages generated internally by syslogd
			/// </summary>
			Syslog = 5,

			/// <summary>
			/// line printer subsystem
			/// </summary>
			Printer = 6,

			/// <summary>
			/// network news subsystem
			/// </summary>
			News = 7,

			/// <summary>
			/// UUCP subsystem
			/// </summary>
			Uucp = 8,

			/// <summary>
			/// clock (cron/at) daemon
			/// </summary>
			Clock = 9,

			/// <summary>
			/// security/authorization  messages (private)
			/// </summary>
			Authorization2 = 10,

			/// <summary>
			/// ftp daemon
			/// </summary>
			Ftp = 11,

			/// <summary>
			/// NTP subsystem
			/// </summary>
			Ntp = 12,

			/// <summary>
			/// log audit
			/// </summary>
			Audit = 13,

			/// <summary>
			/// log alert
			/// </summary>
			Alert = 14,

			/// <summary>
			/// clock daemon
			/// </summary>
			Clock2 = 15,

			/// <summary>
			/// reserved for local use
			/// </summary>
			Local0 = 16,

			/// <summary>
			/// reserved for local use
			/// </summary>
			Local1 = 17,

			/// <summary>
			/// reserved for local use
			/// </summary>
			Local2 = 18,

			/// <summary>
			/// reserved for local use
			/// </summary>
			Local3 = 19,

			/// <summary>
			/// reserved for local use
			/// </summary>
			Local4 = 20,

			/// <summary>
			/// reserved for local use
			/// </summary>
			Local5 = 21,

			/// <summary>
			/// reserved for local use
			/// </summary>
			Local6 = 22,

			/// <summary>
			/// reserved for local use
			/// </summary>
			Local7 = 23
		}

		#endregion // Enumerations

		#region Public Instance Constructors

		/// <summary>
		/// Initializes a new instance of the <see cref="LocalSyslogAppender" /> class.
		/// </summary>
		/// <remarks>
		/// This instance of the <see cref="LocalSyslogAppender" /> class is set up to write 
		/// to a local syslog service.
		/// </remarks>
		public LocalSyslogAppender() 
		{
		}

		#endregion // Public Instance Constructors

		#region Public Instance Properties
		
		/// <summary>
		/// Message identity
		/// </summary>
		/// <remarks>
		/// <para>
		/// An identifier is specified with each log message. This can be specified
		/// by setting the <see cref="Identity"/> property. The identity (also know 
		/// as the tag) must not contain white space. The default value for the
		/// identity is the application name (from <see cref="SystemInfo.ApplicationFriendlyName"/>).
		/// </para>
		/// </remarks>
		public string Identity
		{
			get { return m_identity; }
			set { m_identity = value; }
		}

		/// <summary>
		/// Syslog facility
		/// </summary>
		/// <remarks>
		/// Set to one of the <see cref="SyslogFacility"/> values. The list of
		/// facilities is predefined and cannot be extended. The default value
		/// is <see cref="SyslogFacility.User"/>.
		/// </remarks>