Multiple SendReqExec on Same Connection

Shows how to execute a series of commands on an SSH server and retrieve each command's output (using SendReqExec). Each call to SendReqExec requires its own logical session channel. This is not a separate TCP/IP connection -- it's simply a new session channel on the existing connection. The sequence of Chilkat SSH calls would look like this:

Connect
AuthenticatePw (or AuthenticatePk)

OpenSessionChannel
SendReqExec
<retrieve command output...>
SendChannelClose
ChannelReceiveToClose (to make sure all remaining output is received)

OpenSessionChannel
SendReqExec
<retrieve command output...>
SendChannelClose
ChannelReceiveToClose (to make sure all remaining output is received)

...

OpenSessionChannel
SendReqExec
<retrieve command output...>
SendChannelClose
ChannelReceiveToClose (to make sure all remaining output is received)

Disconnect

Download Chilkat 32-bit SSH / SFTP ActiveX (.msi)

Download All 32-bit Chilkat ActiveX Components (.zip)

Download All 64-bit Chilkat ActiveX Components (.zip)

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

    DECLARE @ssh int
    EXEC @hr = sp_OACreate 'Chilkat.Ssh', @ssh 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 @ssh, 'UnlockComponent', @success OUT, 'Anything for 30-day trial'
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    --  Connect to an SSH server:
    DECLARE @hostname nvarchar(4000)

    DECLARE @port int

    --  Hostname may be an IP address or hostname:
    SELECT @hostname = '192.168.1.108'
    SELECT @port = 22

    EXEC sp_OAMethod @ssh, 'Connect', @success OUT, @hostname, @port
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    --  Wait a max of 5 seconds when reading responses..
    EXEC sp_OASetProperty @ssh, 'IdleTimeoutMs', 5000

    --  Authenticate using login/password:
    EXEC sp_OAMethod @ssh, 'AuthenticatePw', @success OUT, 'myLogin', 'myPassword'
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    --  Open a session channel.  (It is possible to have multiple
    --  session channels open simultaneously.)
    DECLARE @channelNum int

    EXEC sp_OAMethod @ssh, 'OpenSessionChannel', @channelNum OUT
    IF @channelNum < 0
      BEGIN
        EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    --  Request a directory listing on the remote server:
    --  If your server is Linux/UNIX, change the string from "dir" to "ls"
    --  Note: Some SSH servers require a CRLF instead of a bare-LF
    DECLARE @cmd nvarchar(4000)

ERROR-CONCAT    SELECT @cmd = 'ls -al' + @lf
    EXEC sp_OAMethod @ssh, 'SendReqExec', @success OUT, @channelNum, @cmd
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    --  Read whatever output may already be available on the
    --  SSH connection.  ChannelReadAndPoll returns the number of bytes
    --  that are available in the channel's internal buffer that
    --  are ready to be "picked up" by calling GetReceivedText
    --  or GetReceivedData.
    --  A return value of -1 indicates failure.
    --  A return value of -2 indicates a failure via timeout.

    --  The ChannelReadAndPoll method waits
    --  for data to arrive on the connection usingi the IdleTimeoutMs
    --  property setting.  Once the first data arrives, it continues
    --  reading but instead uses the pollTimeoutMs passed in the 2nd argument:
    --  A return value of -2 indicates a timeout where no data is received.
    DECLARE @n int

    DECLARE @pollTimeoutMs int

    SELECT @pollTimeoutMs = 2000
    EXEC sp_OAMethod @ssh, 'ChannelReadAndPoll', @n OUT, @channelNum, @pollTimeoutMs
    IF @n < 0
      BEGIN
        EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    --  Close the channel:
    EXEC sp_OAMethod @ssh, 'ChannelSendClose', @success OUT, @channelNum
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    --  Perhaps we did not receive all of the commands output.
    --  To make sure,  call ChannelReceiveToClose to accumulate any remaining
    --  output until the server's corresponding "channel close" is received.
    EXEC sp_OAMethod @ssh, 'ChannelReceiveToClose', @success OUT, @channelNum
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    --  Let's pickup the accumulated output of the command:
    DECLARE @cmdOutput nvarchar(4000)

    EXEC sp_OAMethod @ssh, 'GetReceivedText', @cmdOutput OUT, @channelNum, 'ansi'
    IF @cmdOutput Is NULL 
      BEGIN
        EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    --  Display the remote shell's command output:

    PRINT @cmdOutput

    PRINT '----'

    --  -----------------------------------------------------------------
    --  Now for the 2nd SendReqExe (on the same connection,
    --  but on a separate logical channel).
    --  -----------------------------------------------------------------

    EXEC sp_OAMethod @ssh, 'OpenSessionChannel', @channelNum OUT
    IF @channelNum < 0
      BEGIN
        EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

ERROR-CONCAT    SELECT @cmd = 'nslookup chilkatsoft.com' + @lf
    EXEC sp_OAMethod @ssh, 'SendReqExec', @success OUT, @channelNum, @cmd
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    SELECT @pollTimeoutMs = 2000
    EXEC sp_OAMethod @ssh, 'ChannelReadAndPoll', @n OUT, @channelNum, @pollTimeoutMs
    IF @n < 0
      BEGIN
        EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    EXEC sp_OAMethod @ssh, 'ChannelSendClose', @success OUT, @channelNum
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    EXEC sp_OAMethod @ssh, 'ChannelReceiveToClose', @success OUT, @channelNum
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    EXEC sp_OAMethod @ssh, 'GetReceivedText', @cmdOutput OUT, @channelNum, 'ansi'
    IF @cmdOutput Is NULL 
      BEGIN
        EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END


    PRINT @cmdOutput

    --  Disconnect
    EXEC sp_OAMethod @ssh, 'Disconnect', NULL
END
GO