DataFlex

Get Received SSH Text into a StringBuilder

Demonstrates the Chilkat Ssh.GetReceivedSb method, which decodes a channel's receive buffer and appends the text to a StringBuilder. The arguments are the channel number, the charset, and the StringBuilder. The receive buffer is cleared afterward.

Background: Because this appends rather than replaces, it is the natural choice for accumulating output across repeated reads — call it in a loop and the StringBuilder grows into the complete transcript. It also avoids creating a new string on every retrieval, which matters when a command produces a large amount of text.

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DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoSsh
    Integer iSshPort
    String sPassword
    Integer iChannelNum
    Variant vSb
    Handle hoSb
    String sOutput
    String sTemp1
    Integer iTemp1

    Move False To iSuccess

    //  Demonstrates the Ssh.GetReceivedSb method, which decodes the channel's receive buffer and
    //  appends the text to a StringBuilder.  The 1st argument is the channel number, the 2nd is the
    //  charset, and the 3rd is the StringBuilder.  The receive buffer is cleared afterward.

    Get Create (RefClass(cComChilkatSsh)) To hoSsh
    If (Not(IsComObjectCreated(hoSsh))) Begin
        Send CreateComObject of hoSsh
    End

    Move 22 To iSshPort
    Get ComConnect Of hoSsh "ssh.example.com" iSshPort To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSsh To sTemp1
        Showln sTemp1
        Procedure_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.
    Move "mySshPassword" To sPassword

    Get ComAuthenticatePw Of hoSsh "mySshLogin" sPassword To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSsh To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComOpenSessionChannel Of hoSsh To iChannelNum
    If (iChannelNum < 0) Begin
        Get ComLastErrorText Of hoSsh To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComSendReqExec Of hoSsh iChannelNum "ls -l /tmp" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSsh To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  IMPORTANT: Set a read timeout.  ReadTimeoutMs defaults to 0, which means no limit -- without
    //  it, this call waits forever if the server never sends channel close.
    Set ComReadTimeoutMs Of hoSsh To 15000

    Get ComChannelReceiveToClose Of hoSsh iChannelNum To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSsh To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Append the received text to a StringBuilder.  Existing content is preserved.
    Get Create (RefClass(cComChilkatStringBuilder)) To hoSb
    If (Not(IsComObjectCreated(hoSb))) Begin
        Send CreateComObject of hoSb
    End
    Get pvComObject of hoSb to vSb
    Get ComGetReceivedSb Of hoSsh iChannelNum "utf-8" vSb To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSsh To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComLength Of hoSb To iTemp1
    Showln "Characters received: " iTemp1
    Get ComGetAsString Of hoSb To sOutput
    Showln sOutput

    Send ComDisconnect To hoSsh


End_Procedure