User:JayJeckel/Servers.dat File Format

The servers.dat file uses a simple binary format and is composed of two sections: the header and the server data.

Type Formats

The types used in the servers.dat file are below, all are stored little-endian.

Types	Bytes	Notes
Int32	4	Signed -2,147,483,648 .. 2,147,483,647
String	*	Pascal string. First byte contains the length of the string.

Header

The header stores a single value, the integer representation of the Terraria version that wrote the servers.dat file.

Type	Description
Int32	Terraria Release Version Integer

Server List Data

The server list is composed of ten (10) entries, each entry being comprised of three (3) values.

Type	Description
String	Server Name
String	Server IP
Int32	Server Port

Example Code

C#

First, define a struct to hold the server entries.

public struct ServerData
{
    public ServerData(string name, string ip, int port)
    {
        this.Name = name;
        this.IP = ip;
        this.Port = port;
    }

    public readonly string Name;
    public readonly string IP;
    public readonly int Port;
}

Second, define a static method to load a servers.dat file.

public static void LoadServersFile(string path, ref Int32 release, ref ServerData[] servers)
{
    if (File.Exists(path))
    {
        using (FileStream stream = new FileStream(path, FileMode.Open))
        {
            using (BinaryReader reader = new BinaryReader(stream))
            {
                release = reader.ReadInt32();
                for (int index = 0; index < servers.Length; index++)
                {
                    servers[index] = new ServerData(reader.ReadString(), reader.ReadString(), reader.ReadInt32());
                }
            }
        }
    }
}

Third, define a static method to save a servers.dat file.

public static void SaveServersFile(string path, Int32 release, ServerData[] servers)
{
    using (FileStream stream = new FileStream(path, FileMode.Create))
    {
        using (BinaryWriter writer = new BinaryWriter(stream))
        {
            writer.Write(release);
            for (int index = 0; index < servers.Length; index++)
            {
                writer.Write(servers[index].Name);
                writer.Write(servers[index].IP);
                writer.Write(servers[index].Port);
            }
        }
    }
}

Lastly, examples of how to use the methods.

string path = /* path to the servers.dat file */;
int release = 0;
ServerData[] servers = new ServerData[10];
LoadServersFile(path, ref release, ref servers);
SaveServersFile(path, release, servers);