source: binary-improvements/WebInterface/Web/API/GetPlayersOnline.cs@ 224

using AllocsFixes.JSON;
using System;
using System.Collections.Generic;
using System.Net;

namespace AllocsFixes.NetConnections.Servers.Web.API
{
        public class GetPlayersOnline : WebAPI
        {
                public override void HandleRequest (HttpListenerRequest req, HttpListenerResponse resp, HttpListenerBasicIdentity user)
                {
                        JSONArray players = new JSONArray();

                        World w = CommonMappingFunctions.GetGameManager ().World;
                        foreach (KeyValuePair<int, EntityPlayer> current in w.Players.dict) {
                                ClientInfo ci = CommonMappingFunctions.GetClientInfoFromEntityID (current.Key);
                                string ip = string.Empty;
                                if (ci != null) {
                                        ip = ci.networkPlayer.ipAddress;
                                }

                                JSONObject pos = new JSONObject();
                                pos.Add("x", new JSONNumber((int)current.Value.GetPosition().x));
                                pos.Add("y", new JSONNumber((int)current.Value.GetPosition().y));
                                pos.Add("z", new JSONNumber((int)current.Value.GetPosition().z));

                                JSONObject p = new JSONObject();
                                p.Add("steamid", new JSONString(CommonMappingFunctions.GetSteamID (ci)));
                                p.Add("ip", new JSONString(ip));
                                p.Add("name", new JSONString(current.Value.EntityName));
                                p.Add("online", new JSONBoolean(true));
                                p.Add("position", pos);

                                players.Add(p);
                        }

                        WriteJSON(resp, players);
                }
        }
}