#unity3d post-process class (c#) that copies a directory including content and subdirectories from source to target location as unity build post-process. place this script inside Editor folder somewhere within Assets directory

PostProcessorFileCopy.cs

/// <summary>
/// PostProcessorFileCopy class contains functions to copy source folder and subfolders/files (recursive)
/// to build directory as post process after build. Place this class inside Editor folder.
/// </summary>
public class PostProcessorFileCopy {
	
	[PostProcessBuild]
	public static void OnPostprocessBuild(BuildTarget target, string pathToBuildfile) {
	
		// Path to source directory.
		string sourceDir = Application.dataPath + "/../"+ _SOURCE_DIRECTORY_2_COPY;
		
		// Path to target directory.
		DirectoryInfo buildPath = Directory.GetParent(pathToBuildfile);
		string targetDir = buildPath + "/"+ _TARGET_DIRECTORY;
		
		// Check if directory exists at given location.
		if (Directory.Exists(sourceDir)) {
			
			if (!Directory.Exists(targetDir)) 
			{
				// Create the folder since it doesn't exist yet
				Directory.CreateDirectory(targetDir);
			}
			// Copy source folder to target location
			// including subdirectories
			DirectoryCopy(sourceDir, targetDir, true);
		}
	}
	
	/// <summary>
	/// Function copies files and subdirectories from source to target.
	/// Subdirectories and their content will be copied (recursive) by 
	/// setting the copySubDirs of the DirectoryCopy method to true.
	/// </summary>
	/// <param name="sourceDirName">Path to source directory.</param>
	/// <param name="destDirName">Path to target directory.</param>
	/// <param name="copySubDirs">Set true to recursively copy subdir.</param>
	private static void DirectoryCopy(string sourceDirName, string destDirName, bool copySubDirs)
	{
		// Get the subdirectories for the specified directory.
		DirectoryInfo dir = new DirectoryInfo(sourceDirName);
		
		if (!dir.Exists)
		{
			throw new DirectoryNotFoundException(
				"Source directory does not exist or could not be found: "
				+ sourceDirName);
		}
		
		DirectoryInfo[] dirs = dir.GetDirectories();
		// If the destination directory doesn't exist, create it.
		if (!Directory.Exists(destDirName))
		{
			Directory.CreateDirectory(destDirName);
		}
		
		// Get the files in the directory and copy them to the new location.
		FileInfo[] files = dir.GetFiles();
		foreach (FileInfo file in files)
		{
			string temppath = Path.Combine(destDirName, file.Name);
			file.CopyTo(temppath, false);
		}
		
		// If copying subdirectories, copy them and their contents to new location.
		if (copySubDirs)
		{
			foreach (DirectoryInfo subdir in dirs)
			{
				string temppath = Path.Combine(destDirName, subdir.Name);
				DirectoryCopy(subdir.FullName, temppath, copySubDirs);
			}
		}
	}
}