안녕하세요. 텔넷은 그냥 raw TCP/IP 접속입니다. 물론 여러가지 옵션이 있어서

그를 처리해줘야 하지만.. 그냥 TClientSocket을 써주면 무난히 만들 수 있죠

아래 프로그램은 제가 예전에 같은 질문을 받았을때 예제로 만들었던 간단한

텔넷 프로그램입니다. 참고하세요...



TMainForm = class(TForm)

Screen: TMemo;

btConnect: TButton;

btDisconnect: TButton;

edHost: TEdit;

ClientSocket: TClientSocket;

Label1: TLabel;



위대로 컴포넌트 만드시고 이름 설정하는거 잊지 마시고요..



unit Telnet_main;



interface



uses

Winsock,

Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,

StdCtrls, ScktComp;



const

IAC = #255;

DONT = #254;

DOO = #253;

WONT = #252;

WILL = #251;

SB = #250;

SE = #240;

TELOPT_ECHO = #1;

TELOPT_TTYPE = #24;

Num = '0123456789';

Alphabet = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';



type

TMainForm = class(TForm)

Screen: TMemo;

btConnect: TButton;

btDisconnect: TButton;

edHost: TEdit;

ClientSocket: TClientSocket;

Label1: TLabel;

procedure btConnectClick(Sender: TObject);

procedure FormCreate(Sender: TObject);

procedure btDisconnectClick(Sender: TObject);

procedure ClientSocketConnect(Sender: TObject;

Socket: TCustomWinSocket);

procedure ClientSocketError(Sender: TObject; Socket: TCustomWinSocket;

ErrorEvent: TErrorEvent; var ErrorCode: Integer);

procedure ClientSocketRead(Sender: TObject; Socket: TCustomWinSocket);

procedure ScreenKeyPress(Sender: TObject; var Key: Char);

procedure ClientSocketDisconnect(Sender: TObject;

Socket: TCustomWinSocket);

private

public

end;



var

MainForm: TMainForm;



implementation



{$R *.DFM}



procedure TMainForm.FormCreate(Sender: TObject);

begin

btDisconnect.Enabled := false;

end;



procedure TMainForm.btConnectClick(Sender: TObject);

var

i, port: integer;

host: string;

begin

host := edHost.Text;

i := Pos(':', host);

if i > 0 then begin // 포트번호가 지정돼있으면

port := StrToInt(copy(host, i + 1, maxint));

host := copy(host, 1, i - 1);

end else port := 23; // Telnet 프로토콜의 port번호

ClientSocket.Host := host;

ClientSocket.Port := port;

ClientSocket.Open;

btConnect.Enabled := false;

edHost.Enabled := false;

edHost.Color := clBtnFace;

end;



procedure TMainForm.ClientSocketConnect(Sender: TObject;

Socket: TCustomWinSocket);

begin

btDisconnect.Enabled := true;

Screen.SetFocus;

end;



procedure TMainForm.btDisconnectClick(Sender: TObject);

begin

ClientSocket.Close;

edHost.SetFocus;

end;



procedure TMainForm.ClientSocketDisconnect(Sender: TObject;

Socket: TCustomWinSocket);

begin

btDisconnect.Enabled := false;

btConnect.Enabled := true;

edHost.Enabled := true;

edHost.Color := clWindow;

if Sender <> nil then ShowMessage('접속이 끊겼네용..');

end;



procedure TMainForm.ClientSocketError(Sender: TObject;

Socket: TCustomWinSocket; ErrorEvent: TErrorEvent;

var ErrorCode: Integer);

begin

case ErrorCode of

WSAENETDOWN: ShowMessage('오류: 네트웍 작동불능');

WSAECONNREFUSED: ShowMessage('오류: 연결이 거부됨');

WSAENETUNREACH: ShowMessage('오류: 닿지않는 호스트');

WSAETIMEDOUT: ShowMessage('오류: 연결시간 초과');

else ShowMessage(Format('연결 오류(코드 %d)', [ErrorCode]));

end;

ClientSocketDisconnect(nil, ClientSocket.Socket);

ErrorCode := 0;

end;



procedure TMainForm.ClientSocketRead(Sender: TObject;

Socket: TCustomWinSocket);

var

s, t, reply: string;

i, j, l: integer;

begin

l := Socket.ReceiveLength;

SetLength(s, l); // 버퍼 공간 확보

Socket.ReceiveBuf(s[1], l);

reply := '';

i := 1;

s := s + #0#0#0#0#0#0#0#0; // i가 l보다 넘을때를 대비해서...

while i <= l do begin

if s[i] = IAC then begin // 텔넷 명령이 오면...

j := i;

inc(i);

if s[i] = SB then begin

inc(i);

if s[i] = TELOPT_TTYPE then // 터미날 타입 요구가 들어오면

// 우리는 vt100을 쓴다네...

reply := reply + IAC + SB + TELOPT_TTYPE + #0 + 'vt100' + IAC + SE;

repeat inc(i); until ((s[i - 1] = IAC) and (s[i] = SE)) or (i > l);

end else if s[i] = DOO then begin

// 우리는 ECHO와 TTYPE에 대해서만 취급하고 수행할꺼라네...

inc(i);

if (s[i] = TELOPT_ECHO) or (s[i] = TELOPT_TTYPE) then

reply := reply + IAC + WILL + s[i]

else reply := reply + IAC + WONT + s[i];

end else if s[i] = DONT then begin

// 하지말라면 안하고

inc(i);

reply := reply + IAC + WONT + s[i]

end else if s[i] = WILL then begin

// 한다면 시키고

inc(i);

reply := reply + IAC + DOO + s[i]

end else if s[i] = WONT then begin

// 하지않는다면 시키지 말지어다..

inc(i);

reply := reply + IAC + DONT + s[i]

end;

// 텔넷 명령은 출력에 포함시키지 않도록 빼야겠죠?

s := copy(s, 1, j - 1) + copy(s, i + 1, maxint);

l := l - (i - j + 1);

i := j;

end else if s[i] = #27 then begin // 안시닷!

j := i;

inc(i);

if s[i] = '[' then begin

repeat inc(i) until Pos(s[i], Alphabet) > 0;

if (s[i] = 'J') then Screen.Lines.Clear; // 화면지