Visual Basic 6.0

Socket Receive String Until Specific Byte Value is Received

Demonstrates the Chilkat Socket ReceiveStringUntilByte method. Visual Basic 6.0

Dim success As Long
success = 0

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

Dim sock As New ChilkatSocket

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

Dim useTls As Long
useTls = 0
Dim port As Long
port = 4242
Dim maxWaitMs As Long
maxWaitMs = 5000
success = sock.Connect("tcpbin.com",port,useTls,maxWaitMs)
If (success = 0) Then
    Debug.Print sock.LastErrorText
    Exit Sub
End If

' Wait a max of 2 seconds for a response..
sock.MaxReadIdleMs = 2000

' Send some strings, each terminated by a 0 byte.
success = sock.SendString("This is the 1st string")
success = sock.SendByte(0)
success = sock.SendString("This is string number 2")
success = sock.SendByte(0)

' The tcpbin.com echo server only echoes after receiving an LF (linefeed char)
success = sock.SendByte(10)

' Now let's receive what is echoed back....
' Receive each string and the NULL byte.
' The call to ReceiveStringUntilByte will receive incoming data until the lookForByte is encountered.
' The lookForByte is receive and discarded (it is not returned in the string)
Dim lookForByte As Long
lookForByte = 0
Dim s1 As String
s1 = sock.ReceiveStringUntilByte(lookForByte)
If (sock.LastMethodSuccess = 0) Then
    Debug.Print sock.LastErrorText
    Exit Sub
End If

Debug.Print s1

Dim s2 As String
s2 = sock.ReceiveStringUntilByte(lookForByte)
If (sock.LastMethodSuccess = 0) Then
    Debug.Print sock.LastErrorText
    Exit Sub
End If

Debug.Print s2

' The echo server will also echo back the final LF
success = sock.ReceiveByte(1)
maxWaitMs = 100
success = sock.Close(100)

' Output:
' This is the 1st string
' This is string number 2