Visual FoxPro

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. Visual FoxPro

LOCAL lnSuccess
LOCAL loBdToSend
LOCAL loSndSock
LOCAL lnBUseTls
LOCAL lnPort
LOCAL lnMaxWaitMs
LOCAL lnNumBytes
LOCAL lnBBigEndian
LOCAL loListenSock
LOCAL loRcvSock
LOCAL lnNumBytesComing
LOCAL loBdReceived
LOCAL lnMaxWaitMs

lnSuccess = 0

* 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.
loBdToSend = CreateObject('Chilkat.BinData')
lnSuccess = loBdToSend.LoadFile("somePath/someFile.dat")
* Assume success for the example...

loSndSock = CreateObject('Chilkat.Socket')
lnBUseTls = 1
lnPort = 5555
lnMaxWaitMs = 5000
lnSuccess = loSndSock.Connect("some_domain_or_ip.com",lnPort,lnBUseTls,lnMaxWaitMs)
* Assume success for the example...

* Tell the receiver how many bytes are coming.
lnNumBytes = loBdToSend.NumBytes
lnBBigEndian = 1
lnSuccess = loSndSock.SendInt32(lnNumBytes,lnBBigEndian)

* Send the file data (sends the entire contents of bdToSend).
lnSuccess = loSndSock.SendBd(loBdToSend,0,0)

* Get an acknowledgement.
lnSuccess = loSndSock.ReceiveInt32(lnBBigEndian)
IF (lnSuccess = 0) THEN
    ? loSndSock.LastErrorText
    RELEASE loBdToSend
    RELEASE loSndSock
    CANCEL
ENDIF

* Did the receiver get the correct number of bytes?
IF (loSndSock.ReceivedInt <> lnNumBytes) THEN
    ? "The receiver did not acknowledge with the correct number of bytes."
    RELEASE loBdToSend
    RELEASE loSndSock
    CANCEL
ENDIF

? "File sent!"

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

loListenSock = CreateObject('Chilkat.Socket')

lnSuccess = loListenSock.BindAndListen(5555,25)
IF (lnSuccess = 0) THEN
    ? loListenSock.LastErrorText
    RELEASE loBdToSend
    RELEASE loSndSock
    RELEASE loListenSock
    CANCEL
ENDIF

* Get the next incoming connection
* Wait a maximum of 20 seconds (20000 millisec)
loRcvSock = CreateObject('Chilkat.Socket')
lnSuccess = loListenSock.AcceptNext(20000,loRcvSock)
IF (lnSuccess = 0) THEN
    ? loListenSock.LastErrorText
    RELEASE loBdToSend
    RELEASE loSndSock
    RELEASE loListenSock
    RELEASE loRcvSock
    CANCEL
ENDIF

* The sender will first send the big-endian integer for the number of bytes
* that are forthcoming..
lnSuccess = loRcvSock.ReceiveInt32(lnBBigEndian)
IF (lnSuccess <> 1) THEN
    ? loRcvSock.LastErrorText
    RELEASE loBdToSend
    RELEASE loSndSock
    RELEASE loListenSock
    RELEASE loRcvSock
    CANCEL
ENDIF

lnNumBytesComing = loRcvSock.ReceivedInt

* Receive that many bytes..
loBdReceived = CreateObject('Chilkat.BinData')
lnSuccess = loRcvSock.ReceiveBdN(lnNumBytesComing,loBdReceived)
IF (lnSuccess <> 1) THEN
    ? loRcvSock.LastErrorText
    RELEASE loBdToSend
    RELEASE loSndSock
    RELEASE loListenSock
    RELEASE loRcvSock
    RELEASE loBdReceived
    CANCEL
ENDIF

* Acknowledge the sender by sending back the number of bytes we received.
lnSuccess = loRcvSock.SendInt32(loBdReceived.NumBytes,lnBBigEndian)

* Close the connection.
lnMaxWaitMs = 20
loRcvSock.Close(lnMaxWaitMs)

* Save the received data to a file.
lnSuccess = loBdReceived.WriteFile("somePath/someFile.dat")
* Assume success for the example...

? "File received!"

RELEASE loBdToSend
RELEASE loSndSock
RELEASE loListenSock
RELEASE loRcvSock
RELEASE loBdReceived