Read Bytes from a Remote SFTP File (BinData)

See more SFTP Examples

Demonstrates the Chilkat SFtp.ReadFileBd method, which reads up to a number of bytes from the current position of an open handle and appends them to a BinData. The arguments are the handle, the maximum number of bytes, and the BinData. This example reads in chunks until end-of-file.

-- 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
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @success int
    SELECT @success = 0

    --  Demonstrates the SFtp.ReadFileBd method, which reads up to a number of bytes from the current
    --  position of an open handle and appends them to a BinData.  The 1st argument is the handle, the
    --  2nd is the maximum number of bytes, and the 3rd is the BinData.

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

    --  Connect, authenticate, and initialize the SFTP subsystem.
    DECLARE @port int
    SELECT @port = 22
    EXEC sp_OAMethod @sftp, 'Connect', @success OUT, 'sftp.example.com', @port
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @sftp, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sftp
        RETURN
      END

    --  Normally you would not hard-code the password in source.  You should instead obtain it
    --  from an interactive prompt, environment variable, or a secrets vault.
    DECLARE @password nvarchar(4000)
    SELECT @password = 'mySshPassword'

    EXEC sp_OAMethod @sftp, 'AuthenticatePw', @success OUT, 'mySshLogin', @password
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @sftp, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sftp
        RETURN
      END

    EXEC sp_OAMethod @sftp, 'InitializeSftp', @success OUT
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @sftp, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sftp
        RETURN
      END

    DECLARE @handle nvarchar(4000)
    EXEC sp_OAMethod @sftp, 'OpenFile', @handle OUT, 'subdir/image.png', 'readOnly', 'openExisting'
    EXEC sp_OAGetProperty @sftp, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 = 0
      BEGIN
        EXEC sp_OAGetProperty @sftp, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sftp
        RETURN
      END

    --  Read the file in chunks until end-of-file, accumulating the bytes in a BinData.
    DECLARE @bd int
    EXEC @hr = sp_OACreate 'Chilkat.BinData', @bd OUT

    DECLARE @chunkSize int
    SELECT @chunkSize = 8192
    DECLARE @reading int
    SELECT @reading = 1
    WHILE @reading
      BEGIN
        EXEC sp_OAMethod @sftp, 'ReadFileBd', @success OUT, @handle, @chunkSize, @bd
        EXEC sp_OAMethod @sftp, 'LastReadFailed', @iTmp0 OUT, @handle
        IF @iTmp0
          BEGIN
            EXEC sp_OAGetProperty @sftp, 'LastErrorText', @sTmp0 OUT
            PRINT @sTmp0
            EXEC @hr = sp_OADestroy @sftp
            EXEC @hr = sp_OADestroy @bd
            RETURN
          END

        EXEC sp_OAMethod @sftp, 'Eof', @iTmp0 OUT, @handle
        SELECT @reading = Not @iTmp0
      END

    EXEC sp_OAMethod @sftp, 'CloseHandle', @success OUT, @handle
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @sftp, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sftp
        EXEC @hr = sp_OADestroy @bd
        RETURN
      END

    EXEC sp_OAGetProperty @bd, 'NumBytes', @iTmp0 OUT

    PRINT 'Read ' + @iTmp0 + ' bytes.'

    EXEC sp_OAMethod @sftp, 'Disconnect', NULL

    EXEC @hr = sp_OADestroy @sftp
    EXEC @hr = sp_OADestroy @bd


END
GO