Streaming SFTP Download

Demonstrates how to download a file chunk by chunk from an SSH server.

Download Chilkat SSH / SFTP ActiveX

CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @sTmp0 nvarchar(4000)
    --  Important: It is helpful to send the contents of the
    --  sftp.LastErrorText property when requesting support.

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

    --  Any string automatically begins a fully-functional 30-day trial.
    DECLARE @success int

    EXEC sp_OAMethod @sftp, 'UnlockComponent', @success OUT, 'Anything for 30-day trial'
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @sftp, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    --  Set some timeouts, in milliseconds:
    EXEC sp_OASetProperty @sftp, 'ConnectTimeoutMs', 5000
    EXEC sp_OASetProperty @sftp, 'IdleTimeoutMs', 15000

    --  Connect to the SSH server.
    --  The standard SSH port = 22
    --  The hostname may be a hostname or IP address.
    DECLARE @port int

    DECLARE @hostname nvarchar(4000)

    SELECT @hostname = 'www.my-ssh-server.com'
    SELECT @port = 22
    EXEC sp_OAMethod @sftp, 'Connect', @success OUT, @hostname, @port
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @sftp, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    --  Authenticate with the SSH server.  Chilkat SFTP supports
    --  both password-based authenication as well as public-key
    --  authentication.  This example uses password authenication.
    EXEC sp_OAMethod @sftp, 'AuthenticatePw', @success OUT, 'myLogin', 'myPassword'
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @sftp, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    --  After authenticating, the SFTP subsystem must be initialized:
    EXEC sp_OAMethod @sftp, 'InitializeSftp', @success OUT
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @sftp, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    --  Open a file on the server:
    DECLARE @handle nvarchar(4000)

    EXEC sp_OAMethod @sftp, 'OpenFile', @handle OUT, 'hamlet.xml', 'readOnly', 'openExisting'
    IF @handle Is NULL 
      BEGIN
        EXEC sp_OAGetProperty @sftp, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    DECLARE @bEof int

    SELECT @bEof = 0
    DECLARE @chunkSize int

    SELECT @chunkSize = 10000

    WHILE @bEof = 0
      BEGIN

        EXEC sp_OAMethod @sftp, 'ReadFileBytes', @pData OUT, @handle, @chunkSize
        EXEC sp_OAMethod @sftp, 'LastReadFailed', @sTmp0 OUT, @handle        IF @sTmp0 = 1
          BEGIN
            EXEC sp_OAGetProperty @sftp, 'LastErrorText', @sTmp0 OUT
            PRINT @sTmp0
            BREAK
          END
        ELSE
          BEGIN

            --  Do whatever  you wish with the data received...
            --  It is possible that if the EOF is reached, 0 bytes will be returned.

          END

        EXEC sp_OAMethod @sftp, 'Eof', @bEof OUT, @handle
      END

    --  Close the file.
    EXEC sp_OAMethod @sftp, 'CloseHandle', @success OUT, @handle
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @sftp, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    PRINT 'Success.'
END
GO