source: binary-improvements/AllocsCommands/Commands/SayToPlayer.cs@ 416

using System;
using System.Collections.Generic;

namespace AllocsFixes.CustomCommands {
        public class SayToPlayer : ConsoleCmdAbstract {
                public override string GetDescription () {
                        return "send a message to a single player";
                }

                public override string GetHelp () {
                        return "Usage:\n" +
                               "   pm <player name / steam id / entity id> <message>\n" +
                               "Send a PM to the player given by the player name or entity id (as given by e.g. \"lpi\").";
                }

                public override string[] GetCommands () {
                        return new[] {"sayplayer", "pm"};
                }

                private void RunInternal (ClientInfo _sender, List<string> _params) {
                        if (_params.Count < 2) {
                                SdtdConsole.Instance.Output ("Usage: sayplayer <playername|entityid> <message>");
                                return;
                        }

                        string message = _params [1];

                        ClientInfo receiver = ConsoleHelper.ParseParamIdOrName (_params [0]);
                        if (receiver != null) {
                                Chat.SendMessage (receiver, _sender, message);
                        } else {
                                SdtdConsole.Instance.Output ("Playername or entity ID not found.");
                        }
                }

                public override void Execute (List<string> _params, CommandSenderInfo _senderInfo) {
                        if (_senderInfo.RemoteClientInfo != null) {
                                RunInternal (_senderInfo.RemoteClientInfo, _params);
                        } else {
                                RunInternal (null, _params);
                        }
                }
        }
}