A Keyword processor for Unity script templates. Allows one to replace pre-defined symbols in a script template with procedurally determined values.

ScriptKeywordProcessor.cs

// Original gist by JoaoBorks, but the gist is no longer available
using UnityEngine;
using UnityEditor;

internal sealed class ScriptKeywordProcessor : UnityEditor.AssetModificationProcessor
{
    private const string ASSETS_FOLDER = "Assets";
    private const string SCRIPTS_FOLDER = "Scripts/";

    public static void OnWillCreateAsset(string path)
    {
        path = path.Replace(".meta", "");
        int index = path.LastIndexOf(".");
        if (index < 0)
        {
            return;
        }

        string file = path.Substring(index);
        if (file != ".cs" && file != ".js")
        {
            return;
        }

        index = Application.dataPath.LastIndexOf(ASSETS_FOLDER);
        path = Application.dataPath.Substring(0, index) + path;
        if (!System.IO.File.Exists(path))
        {
            return;
        }

        string fileContent = System.IO.File.ReadAllText(path);
        string author = System.Security.Principal.WindowsIdentity.GetCurrent().Name;
        author = author.Contains("\\") ? author.Split('\\')[1] : author;

        // At this part you could actually get the name from Windows user directly or give it whatever you want
        fileContent = fileContent.Replace("#AUTHOR#", System.Security.Principal.WindowsIdentity.GetCurrent().Name.Split('\\')[1]);
        fileContent = fileContent.Replace("#CREATIONDATE#", System.DateTime.Now.ToString("dd/MM/yy"));
        fileContent = fileContent.Replace("#NAMESPACE#", GetNamespace(path));

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

    private static string GetNamespace(string path)
    {
        path = path.Replace(".meta", "");

        string rootNamespace = GetRootNamespace();
        int index = path.LastIndexOf(".");
        if (index < 0)
        {
            return rootNamespace;
        }
        
        string lastPart = path.Substring(path.IndexOf(ASSETS_FOLDER));
        string _namespace = lastPart.Substring(0, lastPart.LastIndexOf('/'));

        _namespace = _namespace.Replace(ASSETS_FOLDER, "");
        _namespace = _namespace.Replace(SCRIPTS_FOLDER, "");
        _namespace = _namespace.Replace('/', '.');

        if (!string.IsNullOrEmpty(_namespace))
        {
            _namespace = string.Join("", rootNamespace, _namespace);
        }

        return _namespace;
    }

    private static string GetRootNamespace()
    {
        if (string.IsNullOrEmpty(EditorSettings.projectGenerationRootNamespace))
        {
            Debug.LogWarning("No Root Namespace defined in Editor settings, using Project name");

            return Application.productName;
        }

        return EditorSettings.projectGenerationRootNamespace;
    }
}