powershell compress single file via NTFS (pinvoke)

	Add-Type @"
	using System;
	using System.IO;
	using System.Runtime.InteropServices;
	public class NTFSFileCompression
	{
	#pragma warning disable
	[DllImport("kernel32.dll")]
	public static extern bool DeviceIoControl(
	IntPtr hDevice, uint dwIoControlCode, ref short lpInBuffer, uint nInBufferSize,
	IntPtr lpOutBuffer, uint nOutBufferSize, ref uint lpBytesReturned,
	IntPtr lpOverlapped);
	private const uint FSCTL_SET_COMPRESSION = 0x0009C040;
	private const short COMPRESSION_FORMAT_NONE = 0;
	private const short COMPRESSION_FORMAT_DEFAULT = 1;
	private static bool SetCompression(IntPtr handle, short compression)
	{
	uint lpBytesReturned = 0;
	return DeviceIoControl(
	handle, FSCTL_SET_COMPRESSION, ref compression, 2, IntPtr.Zero,
	0, ref lpBytesReturned, IntPtr.Zero);
	}
	public static bool SetFileCompressed(string path)
	{
	using (FileStream fs = OpenFileStream(path))
	{
	return SetCompression(fs.Handle, COMPRESSION_FORMAT_DEFAULT);
	}
	}
	public static bool SetFileUncompressed(string path)
	{
	using (FileStream fs = OpenFileStream(path))
	{
	return SetCompression(fs.Handle, COMPRESSION_FORMAT_NONE);
	}
	}
	private static FileStream OpenFileStream(string path)
	{
	return File.Open(path, FileMode.Open, FileAccess.ReadWrite, FileShare.None);
	}
	}
	"@
	[NTFSFileCompression]::SetFileCompressed([string]"aFile.txt")

view raw NTFSFileCompression.ps1 hosted with ❤ by GitHub

C# Source: http://www.blackwasp.co.uk/FileCompression.aspx