using System;

using System.Text.RegularExpressions;

​

namespace X

{

    public class Program

    {

        public static void Main(string[] args)

        {

            var number = @"[-]?(?:[\.[0-9]+]|[0-9]+(?:\.[0-9]*)?)";

            var point = $"(?:{number},{number})";

            var end = $"(?<endPoint>{point})";

            var start = $"(?<startPoint>{point})";

            var main = $"(?<mainPoint>{point})";

            var triple = $"(?<cubicTriple>{point} {point} {point})";

            var exp = new Regex($"^(?:s,{start} {end}|e,{end} {start}) {main}( {triple})*");

            var spline = "e,149.82,80.634 95.314,168.45 104.04,157.76 113.71,146.27 123,136 130.59,127.61 135.81,128.05 141,118 145.31,109.66 147.62,99.683 148.84,90.651";

​

            var m = exp.Match(spline);

            foreach (var ct in m.Groups["cubicTriple"].Captures)

            {

                Console.WriteLine(ct);

            }

            Console.WriteLine(m.Success);

        }

    }

}