using System;
using System.Text.RegularExpressions;

public class Test
{
	public static void Main()
	{
		var rx = new Regex("([^=\\s]+)='([^']*)'");
		var str = "key1='value1' key2='value 2' key3='value3' key4='value4' key5='5555' key6='xxx666'";
		foreach (Match m in rx.Matches(str)) {
			Console.WriteLine("{0} {1}", m.Groups[1], m.Groups[2]);
		}
	}
}