DataFlex

SSH Quick/Simple Shell Session

Demonstrates the simplified way to run multiple commands in a shell session using QuickShell, which combines OpenSessionChannel, SendReqPty, and SendReqShell into one call. The commands are built in a StringBuilder, sent together, and the output is read up to a marker echoed by the final command.

Background: Note that QuickShell does allocate a PTY, so the remote shell runs interactively: it prints a prompt and echoes back every command sent to it, and both the echo and the real output appear in what is received. That is what motivates the quoting trick on the final marker — writing echo THIS 'IS' THE END means the echoed command line contains the quotes while the command's actual output does not, so matching the unquoted text reliably matches the real output instead of the echo. For clean, prompt-free output, request a shell without a PTY instead.

Chilkat DataFlex Downloads

Download Chilkat for DataFlex

DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoSsh
    Integer iPort
    String sPassword
    Integer iChannelNum
    Handle hoSbCommands
    String sCommands
    Boolean iCaseSensitive
    String sSessionOutput
    String sTemp1
    Boolean bTemp1

    Move False To iSuccess

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

    //  Demonstrates the simplified way to run multiple commands in a shell session using QuickShell.
    //  
    //  Note: QuickShell internally does OpenSessionChannel, SendReqPty, and SendReqShell, so it DOES
    //  allocate a pseudo-terminal.  The remote shell therefore runs interactively: it prints a
    //  command prompt and echoes back the commands that are sent to it.  Both the echoed input and
    //  the real output appear in what is received.

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

    Move 22 To iPort
    Get ComConnect Of hoSsh "ssh.example.com" iPort 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

    //  Start the shell session.  A negative return value indicates failure.
    Get ComQuickShell Of hoSsh To iChannelNum
    If (iChannelNum < 0) Begin
        Get ComLastErrorText Of hoSsh To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Build the commands, one per line.  Line endings matter: Unix/Linux servers typically expect
    //  a bare LF, while Windows servers may require CRLF.
    Get Create (RefClass(cComChilkatStringBuilder)) To hoSbCommands
    If (Not(IsComObjectCreated(hoSbCommands))) Begin
        Send CreateComObject of hoSbCommands
    End
    Get ComAppend Of hoSbCommands "echo hello world" + (character(10)) To iSuccess
    Get ComAppend Of hoSbCommands "date" + (character(10)) To iSuccess
    Get ComAppend Of hoSbCommands "df" + (character(10)) To iSuccess

    //  The final command echoes a marker used to detect the end of the output.  The single quotes
    //  around 'IS' are a trick: the terminal echo of the typed command includes the quotes, while
    //  the command's actual output does not.  Matching the unquoted form therefore matches the real
    //  output rather than the echo.
    Get ComAppend Of hoSbCommands "echo THIS 'IS' THE END OF THE SCRIPT" + (character(10)) To iSuccess

    Get ComGetAsString Of hoSbCommands To sCommands
    Get ComChannelSendString Of hoSsh iChannelNum sCommands "utf-8" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSsh To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  IMPORTANT: Set a read timeout before receiving until a match.  ReadTimeoutMs defaults to 0,
    //  which means no limit -- without it, this call waits forever if the received data never
    //  contains a match.
    Set ComReadTimeoutMs Of hoSsh To 15000

    Move True To iCaseSensitive
    Get ComChannelReceiveUntilMatch Of hoSsh iChannelNum "THIS IS THE END OF THE SCRIPT" "utf-8" iCaseSensitive To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSsh To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Indicate that no more commands will be sent, then close the channel.  Close only after the
    //  desired output has been received.
    Get ComChannelSendEof Of hoSsh iChannelNum To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSsh To sTemp1
        Showln sTemp1
        Procedure_Return
    End

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

    //  Collect any remaining output.
    Get ComChannelReceiveToClose Of hoSsh iChannelNum To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSsh To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComGetReceivedText Of hoSsh iChannelNum "utf-8" To sSessionOutput
    Get ComLastMethodSuccess Of hoSsh To bTemp1
    If (bTemp1 = False) Begin
        Get ComLastErrorText Of hoSsh To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "--- output ----"
    Showln sSessionOutput

    Send ComDisconnect To hoSsh


End_Procedure