Compute the intersection of two hashsets

HashsetIntersect.cs

// The format of our checksum file is: b6f60e956ea5dc8b7056b35689b67efa *info.png
// We'll use the " *" as a mid-point and line start/end anchors (^ and $) to isolate them
Regex fileRegex = new Regex(@"^(?<hash>[\w\W]*?)\s\*(?<name>[\w\W]*?)$");

// Load hashes from the first file
var hashset1 = from line in File.ReadAllLines(@"C:\example\checksums.md5") // Each hash is separated by a newline, so ReadAllLines will do the trick here
	 let match = fileRegex.Match(line) // Perform the Regex
	 select new // Create an anonymously typed object containing the hash and filename.
	 {
		Hash = match.Groups["hash"].Value,
		FileName = match.Groups["name"].Value,
	 };

// Load hashes from the second file
var hashset2 = from line in File.ReadAllLines(@"C:\example\checksums2.md5")
			   let match = fileRegex.Match(line)
			   select new
			   {
				   Hash = match.Groups["hash"].Value,
				   FileName = match.Groups["name"].Value,
			   };

// Now we have two lists of objects with Hash and FileName properties.
// Through the magic of LINQ, use the Intersect method to find where the two datasets agree.
hashset1.Intersect(hashset2).Dump();
// The Dump() command is a LINQPad thing (see www.linqpad.net) but you could just as easily Console.Writeline in VS