Compare binary files in C#

Question

I want to compare two binary files. One of them is already stored on the server with a pre-calculated CRC32 in the database from when I stored it originally.

I know that if the CRC is different, then the files are definitely different. However, if the CRC is the same, I don't know that the files are. So, I'm looking for a nice efficient way of comparing the two streams: one from the posted file and one from the file system.

I'm not an expert on streams, but I'm well aware that I could easily shoot myself in the foot here as far as memory usage is concerned.

Answer 1

static bool FileEquals(string fileName1, string fileName2) {     // Check the file size and CRC equality here.. if they are equal...         using (var file1 = new FileStream(fileName1, FileMode.Open))         using (var file2 = new FileStream(fileName2, FileMode.Open))             return FileStreamEquals(file1, file2); }  static bool FileStreamEquals(Stream stream1, Stream stream2) {     const int bufferSize = 2048;     byte[] buffer1 = new byte[bufferSize]; //buffer size     byte[] buffer2 = new byte[bufferSize];     while (true) {         int count1 = stream1.Read(buffer1, 0, bufferSize);         int count2 = stream2.Read(buffer2, 0, bufferSize);          if (count1 != count2)             return false;          if (count1 == 0)             return true;          // You might replace the following with an efficient "memcmp"         if (!buffer1.Take(count1).SequenceEqual(buffer2.Take(count2)))             return false;     } }