Compress and decompress files using the Deflate algorithm

deflate.cs

/*
 * Title: Deflate Tool
 * Purpose: Compress and decompress files using the Deflate algorithm
 * Author: Osanda Malith Jayathissa (@OsandaMalith)
 * Website: https://OsandaMalith.com
 */
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.IO.Compression;

namespace compress2
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("[~] Deflate Tool - @OsandaMalith\n");

            if (args.Length != 3)
            {
                Console.WriteLine("Usage: {0} input.dat output.dat -c or -d", System.AppDomain.CurrentDomain.FriendlyName);
                System.Environment.Exit(-1);
            }

            DeflateStream deflate = null;
            FileStream sink = null;
            FileStream source = new FileStream(Environment.GetCommandLineArgs()[1], FileMode.Open);

            if (Environment.GetCommandLineArgs()[3].Substring(1, 1).Equals("d"))
            {
                deflate = new DeflateStream(source, CompressionMode.Decompress);
                sink = new FileStream(Environment.GetCommandLineArgs()[2], FileMode.Create);

                byte[] buffer = new byte[source.Length];
                buffer = new byte[source.Length];

                deflate.Read(buffer, 0, buffer.Length);
                sink.Write(buffer, 0, buffer.Length);
                sink.Close();
            }
            else if (Environment.GetCommandLineArgs()[3].Substring(1, 1).Equals("c"))
            {
                deflate = new DeflateStream(source, CompressionMode.Compress);
                sink = new FileStream(Environment.GetCommandLineArgs()[2], FileMode.Create);
                byte[] buffer = new byte[source.Length];
                source.Read(buffer, 0, buffer.Length);
                deflate.Write(buffer, 0, buffer.Length);
                sink.Write(buffer, 0, buffer.Length);
                sink.Close();
            }
            else
            {
                Console.WriteLine("Enter an option -c compress or -d decompress");
                System.Environment.Exit(-1);
            }

            source.Close();
       
        }
    }
}