Code:

// Server side :

//  - start a server

//  - wait for a client

function StartServer(Port:word):integer;

function WaitClient(Server:integer):integer;

function WaitClientEx(Server:integer; var ip:string):integer;

// Client side :

//  - call a server

function CallServer(Server:string;Port:word):integer;

// Both side :

//  - Assign CRT Sockets

//  - Disconnect server

procedure AssignCrtSock(Socket:integer;

                       Var Input,Output:TextFile);

procedure Disconnect(Socket:integer);

// BroadCasting (UDP)

function StartBroadCast(Port:word):integer;

function SendBroadCast(Server:integer;

                      Port:word; s:string):integer;

function SendBroadCastTo(Server:integer;

                        Port:word;

                        ip,s:string):integer;

function ReadBroadCast(Server:integer; Port:word):string;

function ReadBroadCastEx(Server:integer;

                        Port:word;

                        var ip:string):string;

// BlockRead

function SockAvail(Socket:integer):integer;

function DataAvail(Var F:TextFile):integer;

Function BlockReadsock(Var F:TextFile;

                      var s:string):boolean;

Function send(socket:integer;

             data:pointer;

             datalen,

             flags:integer):integer; stdcall; far;

Function recv(socket:integer;

             data:pchar;

             datalen,

             flags:integer):integer; stdcall; far;