C# Signature:

[DllImport("msvcrt.dll", CallingConvention=CallingConvention.Cdecl)]
static extern int memcmp(byte[] b1, byte[] b2, UIntPtr count);

Alternative Managed API:

Enumerable.SequenceEqual see: http://msdn.microsoft.com/en-us/library/system.linq.enumerable.sequenceequal.aspx

Notes:

Tips & Tricks:

When calling memcmp via pinvoke there is no need to use unsafe code or pinning because the framework will automatically pin the arrays for you.

Sample Code:

Example:

//Extension Method example
public static class ByteArrayExtensions
{
   [DllImport("msvcrt.dll", CallingConvention=CallingConvention.Cdecl)]
   private static extern int memcmp(byte[] b1, byte[] b2, UIntPtr count);

   public static bool SequenceEqual(this byte[] b1, byte[] b2)
   {
      if (b1 == b2) return true; //reference equality check

      if (b1 == null || b2 == null || b1.Length != b2.Length) return false;

      return memcmp(b1, b2, new UIntPtr((uint)b1.Length)) == 0;
   }
}

Edits:

Added (x86 and x64) signature and example.
Removed SetLastError attribute from bottom 2 signatures as memset does not use this API.
Removed confusing signatures

Please edit this page!

Do you have...

• helpful tips or sample code to share for using this API in managed code?
• corrections to the existing content?
• variations of the signature you want to share?
• additional languages you want to include?

Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).