using System;

using System.IO;

using System.Linq;

​

var CountChars = (string fname) => Console.WriteLine(File.ReadAllBytes(fname).Length);

​

var CountLines = (string fname) => Console.WriteLine(File.ReadLines(fname).Count());

​

var CountWhitespaces = (string fname) => Console.WriteLine(File.ReadAllText(fname).AsParallel().Count(x => x == ' '));

​

var DefaultInfo = (string _) => Console.WriteLine("you should give one of the options ['-c', '-l', '-w']");

​

var RunOp = (string op, string fname) =>

    (op switch

    {

        "-c" => CountChars,

        "-l" => CountLines,

        "-w" => CountWhitespaces,

        _ => DefaultInfo

    })(fname);

​

if (args.Length == 0)

    Console.WriteLine("you should give additional parameters to the program");

else if (args.Length == 1)

    CountChars(args[0]);

else if (args.Length == 2)

    RunOp(args[0], args[1]);

else

    Console.WriteLine("you gave more than needed");