SQL Server

Socket Receive String Until Specific Byte Value is Received

Demonstrates the Chilkat Socket ReceiveStringUntilByte method. SQL Server

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @success int
    SELECT @success = 0

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

    DECLARE @sock int
    EXEC @hr = sp_OACreate 'Chilkat.Socket', @sock OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

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

    DECLARE @useTls int
    SELECT @useTls = 0
    DECLARE @port int
    SELECT @port = 4242
    DECLARE @maxWaitMs int
    SELECT @maxWaitMs = 5000
    EXEC sp_OAMethod @sock, 'Connect', @success OUT, 'tcpbin.com', @port, @useTls, @maxWaitMs
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @sock, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sock
        RETURN
      END

    -- Wait a max of 2 seconds for a response..
    EXEC sp_OASetProperty @sock, 'MaxReadIdleMs', 2000

    -- Send some strings, each terminated by a 0 byte.
    EXEC sp_OAMethod @sock, 'SendString', @success OUT, 'This is the 1st string'
    EXEC sp_OAMethod @sock, 'SendByte', @success OUT, 0
    EXEC sp_OAMethod @sock, 'SendString', @success OUT, 'This is string number 2'
    EXEC sp_OAMethod @sock, 'SendByte', @success OUT, 0

    -- The tcpbin.com echo server only echoes after receiving an LF (linefeed char)
    EXEC sp_OAMethod @sock, 'SendByte', @success OUT, 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)
    DECLARE @lookForByte int
    SELECT @lookForByte = 0
    DECLARE @s1 nvarchar(4000)
    EXEC sp_OAMethod @sock, 'ReceiveStringUntilByte', @s1 OUT, @lookForByte
    EXEC sp_OAGetProperty @sock, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 = 0
      BEGIN
        EXEC sp_OAGetProperty @sock, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sock
        RETURN
      END

    PRINT @s1

    DECLARE @s2 nvarchar(4000)
    EXEC sp_OAMethod @sock, 'ReceiveStringUntilByte', @s2 OUT, @lookForByte
    EXEC sp_OAGetProperty @sock, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 = 0
      BEGIN
        EXEC sp_OAGetProperty @sock, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sock
        RETURN
      END

    PRINT @s2

    -- The echo server will also echo back the final LF
    EXEC sp_OAMethod @sock, 'ReceiveByte', @success OUT, 1
    SELECT @maxWaitMs = 100
    EXEC sp_OAMethod @sock, 'Close', @success OUT, 100

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

    EXEC @hr = sp_OADestroy @sock


END
GO