using System;

using System.IO;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var fileName = "sw100yr07da.asc";

        var gridInfo = GetGridInfoFromFileName(fileName); //pass in file name

        Console.WriteLine(gridInfo.Abbreviation);

    }

    public static GridInfo GetGridInfoFromFileName(string fileName) 

    {   

        var fn = Path.GetFileNameWithoutExtension(fileName); //remove extention

        var gi = new GridInfo();

        gi.Abbreviation = new String(fn.TakeWhile(char.IsLetter).ToArray());

        return gi;

    }

    public class GridInfo {

        public string Abbreviation {get; set;}

        public DurationEnum Duration {get; set;}

        public FrequencyEnum Frequency {get; set;}

        public TypeEnum Type {get; set;}

        public SeriesEnum Series {get; set;}

    }   

    // Can add descriptions to enum [Description("05m")]

    public enum DurationEnum { m5, m10, m15, m30, m60, h2, h3, h6, h12, h24, d2, d3, d4, d7, d10, d20, d30, d45, d60 };

    public enum FrequencyEnum { y1, y2, y5, y10, y25, y50, y100, y200, y500, y1000 };

    public enum TypeEnum { PrecipFreqEst, LwrConfLimits, UpprConfLimits };

    public enum SeriesEnum { PartialDuration, AnnualMax };

}