Delphi DLL Requires Chilkat v11.0.0+

Transfer a File using Sockets (TLS or non-TLS)

See more Socket/SSL/TLS Examples

Demonstrates how to two programs, one a socket writer and the other a socket reader, can transfer a file. The connection can be TLS or a regular non-encrypted TCP connection. Delphi DLL

var
success: Boolean;
bdToSend: HCkBinData;
sndSock: HCkSocket;
bUseTls: Boolean;
port: Integer;
maxWaitMs: Integer;
numBytes: Integer;
bBigEndian: Boolean;
listenSock: HCkSocket;
rcvSock: HCkSocket;
numBytesComing: Integer;
bdReceived: HCkBinData;
maxWaitMs: Integer;

begin
success := False;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

//  On the sending side, we'll load the file into a BinData object and send.
//  On the receiving side, we'll read from the socket connection into a BinData, and save to a file.
//  This example assumes the file is not crazy-large, and that the entire contents
//  can fit into memory.  
//  (If the file is too large for memory, there are other ways to send. It just involves streaming or 
//  sending the file chunk-by-chunk..)

//  This section of code is for the sender.
bdToSend := CkBinData_Create();
success := CkBinData_LoadFile(bdToSend,'somePath/someFile.dat');
//  Assume success for the example...

sndSock := CkSocket_Create();
bUseTls := True;
port := 5555;
maxWaitMs := 5000;
success := CkSocket_Connect(sndSock,'some_domain_or_ip.com',port,bUseTls,maxWaitMs);
//  Assume success for the example...

//  Tell the receiver how many bytes are coming.
numBytes := CkBinData_getNumBytes(bdToSend);
bBigEndian := True;
success := CkSocket_SendInt32(sndSock,numBytes,bBigEndian);

//  Send the file data (sends the entire contents of bdToSend).
success := CkSocket_SendBd(sndSock,bdToSend,0,0);

//  Get an acknowledgement.
success := CkSocket_ReceiveInt32(sndSock,bBigEndian);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSocket__lastErrorText(sndSock));
    Exit;
  end;

//  Did the receiver get the correct number of bytes?
if (CkSocket_getReceivedInt(sndSock) <> numBytes) then
  begin
    Memo1.Lines.Add('The receiver did not acknowledge with the correct number of bytes.');
    Exit;
  end;

Memo1.Lines.Add('File sent!');

//  ------------------------------------------------------------------------------------
//  The code below is for the receiving side (running on some other computer..)

listenSock := CkSocket_Create();

success := CkSocket_BindAndListen(listenSock,5555,25);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSocket__lastErrorText(listenSock));
    Exit;
  end;

//  Get the next incoming connection
//  Wait a maximum of 20 seconds (20000 millisec)
rcvSock := CkSocket_Create();
success := CkSocket_AcceptNext(listenSock,20000,rcvSock);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSocket__lastErrorText(listenSock));
    Exit;
  end;

//  The sender will first send the big-endian integer for the number of bytes
//  that are forthcoming..
success := CkSocket_ReceiveInt32(rcvSock,bBigEndian);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkSocket__lastErrorText(rcvSock));
    Exit;
  end;

numBytesComing := CkSocket_getReceivedInt(rcvSock);

//  Receive that many bytes..
bdReceived := CkBinData_Create();
success := CkSocket_ReceiveBdN(rcvSock,numBytesComing,bdReceived);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkSocket__lastErrorText(rcvSock));
    Exit;
  end;

//  Acknowledge the sender by sending back the number of bytes we received.
success := CkSocket_SendInt32(rcvSock,CkBinData_getNumBytes(bdReceived),bBigEndian);

//  Close the connection.
maxWaitMs := 20;
CkSocket_Close(rcvSock,maxWaitMs);

//  Save the received data to a file.
success := CkBinData_WriteFile(bdReceived,'somePath/someFile.dat');
//  Assume success for the example...

Memo1.Lines.Add('File received!');

CkBinData_Dispose(bdToSend);
CkSocket_Dispose(sndSock);
CkSocket_Dispose(listenSock);
CkSocket_Dispose(rcvSock);
CkBinData_Dispose(bdReceived);