KeywordReplace.cs

// Put this file in Assets/Editor/
using UnityEngine;
using UnityEditor;

public class KeywordReplace : UnityEditor.AssetModificationProcessor
{
	public static void OnWillCreateAsset(string path)
	{
		path = path.Replace(".meta", "");
		int index = path.LastIndexOf(".");
		string file;
		try
		{
			file = path.Substring(index);
		}
		catch(System.ArgumentOutOfRangeException)
		{
			return;
		}
		if (!file.Contains(".cs")) return;
		index = Application.dataPath.LastIndexOf("Assets");
		path = Application.dataPath.Substring(0, index) + path;
		file = System.IO.File.ReadAllText(path);
		string[] splitPath = path.Split('/');
		string folder = splitPath[splitPath.Length - 2];

		file = file.Replace("#NAMESPACE#", folder);
		file = file.Replace("#CREATIONDATE#", System.DateTime.Now + "");
		file = file.Replace("#PROJECTNAME#", PlayerSettings.productName);
		file = file.Replace("#DEVELOPERS#", PlayerSettings.companyName);

		System.IO.File.WriteAllText(path, file);
		AssetDatabase.Refresh();
	}
}