Logger.cs

using UnityEngine;
using System.IO;

public class Logger : MonoBehaviour
{
	StreamWriter _writer;

	public void Prepare()
	{
		#if UNITY_EDITOR
		if (_writer == null) {
			_writer = new StreamWriter ( File.Create(@"mylog.txt") );
		}
		#endif
	}

	void OnEnable ()
	{
		Application.RegisterLogCallback (HandleLog);
	}

	void OnDisable ()
	{
		Application.RegisterLogCallback (null);
	}

	void OnApplicationQuit ()
	{
		if (_writer == null) {
			return;
		}

		_writer.Close ();
	}

	void HandleLog (string logString, string stackTrace, LogType type)
	{
		if (_writer == null) {
			return;
		}

		_writer.WriteLine (logString);
		_writer.WriteLine (stackTrace);
		_writer.WriteLine ();
		_writer.Flush ();
	}


	//
	// singleton pattern
	//
	private static Logger _instance;
	private static GameObject _container;

	public static Logger Instance {
		get {
			_instance = GameObject.FindObjectOfType (typeof(Logger)) as Logger;
			if (_instance == null) {
				_container = new GameObject ("LogMaster");
				_instance = _container.AddComponent (typeof(Logger)) as Logger;
			}

			return _instance;
		}
	}

}