Xbase++

Socket Send/Receive 16-bit Integers

Demonstrates sending and receiving 16-bit integers over a socket connection using either big-endian or little-endian byte ordering. Xbase++

LOCAL nSuccess
LOCAL oSock
LOCAL nUseTls
LOCAL nPort
LOCAL nMaxWaitMs
LOCAL nValue
LOCAL nBigEndian
LOCAL cHexStr

nSuccess := 0

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

oSock := CreateObject("Chilkat.Socket")

//  --------------------------------------------------------------------
//  This example uses the public TCP echo service at https://tcpbin.com/
//  --------------------------------------------------------------------

nUseTls := 0
nPort := 4242
nMaxWaitMs := 5000
nSuccess := oSock:Connect("tcpbin.com", nPort, nUseTls, nMaxWaitMs)
IF (nSuccess == 0)
    ? oSock:LastErrorText
    oSock:destroy()
    RETURN
ENDIF

//  Wait a max of 2 seconds for a response..
oSock:MaxReadIdleMs := 2000

//  Send a 16-bit integer using big-endian byte ordering (also called network byte order)
//  12022 decimal = 2EF6 hex
nValue := 12022
nBigEndian := 1
oSock:SendInt16(nValue, nBigEndian)
//  Send it again, because we'll read it two different ways..
oSock:SendInt16(nValue, nBigEndian)

//  The tcpbin.com echo server only echoes after receiving an LF (linefeed char)
oSock:SendByte(10)

//  Let's see hex values of the 2 bytes sent in network byte order (big-endian)
//  (The echo server sends back exactly the bytes received.)
cHexStr := oSock:ReceiveNBytesENC(2, "hex")

//  In the big-ending byte order, the byte order is most significant byte to least significant,
//  therefore we should see the bytes in the order 0x2E 0xF6.
? "Expecting big-endian 2EF6"
? cHexStr

//  Let's read directly to an integer..
nSuccess := oSock:ReceiveInt16(nBigEndian, 1)
? "Expecting 12022"
? "Received: " + Str(oSock:ReceivedInt)

//  Consume the LF that gets echoed back..
oSock:ReceiveByte(1)

//  --------------------------------------------------------------------
//  Let's do the same thing, but with little-endian byte ordering.

? "----"

//  12022 decimal = 2EF6 hex, but little-endian byte ordering will send the bytes in the order 0xF6 0x2E
nValue := 12022
nBigEndian := 0
oSock:SendInt16(nValue, nBigEndian)
oSock:SendInt16(nValue, nBigEndian)
oSock:SendByte(10)

cHexStr := oSock:ReceiveNBytesENC(2, "hex")

? "Expecting little-endian F62E"
? cHexStr

nSuccess := oSock:ReceiveInt16(nBigEndian, 1)
? "Expecting 12022"
? "Received: " + Str(oSock:ReceivedInt)

//  Consume the LF that gets echoed back..
oSock:ReceiveByte(1)

oSock:Close(1000)

//  Output:

//  Expecting big-endian 2EF6
//  2EF6
//  Expecting 12022
//  Received: 12022
//  ----
//  Expecting little-endian F62E
//  F62E
//  Expecting 12022
//  Received: 12022

oSock:destroy()