How to copy one file to many locations at once

Instead of using the utility method, File.Copyyou can open the source file as FileStream, and then open as much as possible FileStreamsso that you need as many destination files as you need, read from the source and write a stream to each destination.

UPDATE Modified to write files using Parallel.ForEach to increase throughput.

public static class FileUtil
{
    public static void CopyMultiple(string sourceFilePath, params string[] destinationPaths)
    {
        if (string.IsNullOrEmpty(sourceFilePath)) throw new ArgumentException("A source file must be specified.", "sourceFilePath");

        if (destinationPaths == null || destinationPaths.Length == 0) throw new ArgumentException("At least one destination file must be specified.", "destinationPaths");

        Parallel.ForEach(destinationPaths, new ParallelOptions(),
                         destinationPath =>
                             {
                                 using (var source = new FileStream(sourceFilePath, FileMode.Open, FileAccess.Read, FileShare.Read))
                                 using (var destination = new FileStream(destinationPath, FileMode.Create))
                                 {
                                     var buffer = new byte[1024];
                                     int read;

                                     while ((read = source.Read(buffer, 0, buffer.Length)) > 0)
                                     {
                                         destination.Write(buffer, 0, read);
                                     }
                                 }

                             });
    }
}

Using:

FileUtil.CopyMultiple(@"C:\sourceFile1.txt", @"C:\destination1\sourcefile1.txt", @"C:\destination2\sourcefile1.txt");