(Chilkat2-Python) Transfer a File using Sockets (TLS or non-TLS)

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.

Chilkat2 Python Downloads install with pip pip3 install chilkat2 or download... Python Module for Windows, Linux, Alpine Linux, MacOS, Solaris

import sys
import chilkat2

# 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 = chilkat2.BinData()
success = bdToSend.LoadFile("somePath/someFile.dat")
# Assume success for the example...

sndSock = chilkat2.Socket()
bUseTls = True
port = 5555
maxWaitMs = 5000
success = sndSock.Connect("some_domain_or_ip.com",port,bUseTls,maxWaitMs)
# Assume success for the example...

# Tell the receiver how many bytes are coming.
numBytes = bdToSend.NumBytes
bBigEndian = True
success = sndSock.SendInt32(numBytes,bBigEndian)

# Send the file data (sends the entire contents of bdToSend).
success = sndSock.SendBd(bdToSend,0,0)

# Get an acknowledgement.
success = sndSock.ReceiveInt32(bBigEndian)
if (success != True):
    print(sndSock.LastErrorText)
    sys.exit()

# Did the receiver get the correct number of bytes?
if (sndSock.ReceivedInt != numBytes):
    print("The receiver did not acknowledge with the correct number of bytes.")
    sys.exit()

print("File sent!")

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

listenSock = chilkat2.Socket()

success = listenSock.BindAndListen(5555,25)
if (success != True):
    print(listenSock.LastErrorText)
    sys.exit()

# Get the next incoming connection
# Wait a maximum of 20 seconds (20000 millisec)

# rcvSock is a CkSocket
rcvSock = listenSock.AcceptNextConnection(20000)
if (listenSock.LastMethodSuccess == False):
    print(listenSock.LastErrorText)
    sys.exit()

# The sender will first send the big-endian integer for the number of bytes
# that are forthcoming..
success = rcvSock.ReceiveInt32(bBigEndian)
if (success != True):
    print(rcvSock.LastErrorText)

    sys.exit()

numBytesComing = rcvSock.ReceivedInt

# Receive that many bytes..
bdReceived = chilkat2.BinData()
success = rcvSock.ReceiveBdN(numBytesComing,bdReceived)
if (success != True):
    print(rcvSock.LastErrorText)

    sys.exit()

# Acknowledge the sender by sending back the number of bytes we received.
success = rcvSock.SendInt32(bdReceived.NumBytes,bBigEndian)

# Close the connection.
maxWaitMs = 20
rcvSock.Close(maxWaitMs)

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

print("File received!")