FtlDat.cs

using System;
using System.IO;
using System.Text;

namespace FtlDat
{
    class Program
    {
        static void Main(string[] args)
        {
            string dir = @"E:\Steam\steamapps\common\FTL Faster Than Light\resources\";
            foreach (string path in Directory.GetFiles(dir, "*.dat"))
            {
                using (BinaryReader br = new BinaryReader(new FileStream(path, FileMode.Open, FileAccess.Read)))
                {
                    int num_files = br.ReadInt32();
                    byte[] table = br.ReadBytes(num_files * 4);

                    for (int i = 0; i < num_files; i++)
                    {
                        int offset = BitConverter.ToInt32(table, i * 4);

                        if (offset == 0)
                        {
                            continue;
                        }

                        br.BaseStream.Position = offset;
                        int file_len = br.ReadInt32();
                        int name_len = br.ReadInt32();
                        string name = Encoding.ASCII.GetString(br.ReadBytes(name_len));
                        byte[] file = br.ReadBytes(file_len);

                        string outputPath = Path.Combine(dir, name);

                        FileInfo fi = new FileInfo(outputPath);
                        if (fi.Directory.Exists == false)
                        {
                            fi.Directory.Create();
                        }

                        using (BinaryWriter bw = new BinaryWriter(new FileStream(outputPath, FileMode.Create, FileAccess.Write)))
                        {
                            bw.Write(file);
                        }
                    }
                }
            }
        }
    }
}