PureBasic

Send an SSH IGNORE Message over SFTP

Demonstrates the Chilkat SFtp.SendIgnore method, which sends an SSH IGNORE message. It takes no arguments. The server sends no reply, but a successful send helps confirm the connection is still writable. No SFTP file handle is required.

Background: The SSH IGNORE message is discarded by the peer by design; its value is as a lightweight keep-alive or liveness probe. During a long-idle SFTP session — for instance while waiting between scheduled transfers — a periodic SendIgnore both keeps the connection from being dropped for inactivity and proves the link is still usable, without touching any file.

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PureBasic

IncludeFile "CkSFtp.pb"

Procedure ChilkatExample()

    success.i = 0

    ;  Demonstrates the SFtp.SendIgnore method, which sends an SSH IGNORE message.  It takes no
    ;  arguments.  The server sends no reply, but a successful send helps confirm the connection is
    ;  still writable.  No SFTP file handle is required.

    sftp.i = CkSFtp::ckCreate()
    If sftp.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ;  Step 1: Connect the SSH transport.  Port 22 is the usual port.
    port.i = 22
    success = CkSFtp::ckConnect(sftp,"sftp.example.com",port)
    If success = 0
        Debug CkSFtp::ckLastErrorText(sftp)
        CkSFtp::ckDispose(sftp)
        ProcedureReturn
    EndIf

    ;  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.
    password.s = "mySshPassword"

    success = CkSFtp::ckAuthenticatePw(sftp,"mySshLogin",password)
    If success = 0
        Debug CkSFtp::ckLastErrorText(sftp)
        CkSFtp::ckDispose(sftp)
        ProcedureReturn
    EndIf

    ;  Step 3: Open the SFTP subsystem.  This must be done after authentication and before any
    ;  file or directory operations.
    success = CkSFtp::ckInitializeSftp(sftp)
    If success = 0
        Debug CkSFtp::ckLastErrorText(sftp)
        CkSFtp::ckDispose(sftp)
        ProcedureReturn
    EndIf

    ;  Send an IGNORE message to verify the connection is still writable.
    success = CkSFtp::ckSendIgnore(sftp)
    If success = 0
        Debug CkSFtp::ckLastErrorText(sftp)
        CkSFtp::ckDispose(sftp)
        ProcedureReturn
    EndIf

    Debug "IGNORE message sent."

    CkSFtp::ckDisconnect(sftp)


    CkSFtp::ckDispose(sftp)


    ProcedureReturn
EndProcedure