SSH Remote Shell

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Demonstrates starting a shell on a remote SSH server, running a command, and retrieving the output. The example sends the command, signals EOF so the server knows no more input is coming, and then receives the remaining output until the channel closes.

IncludeFile "CkSsh.pb"

Procedure ChilkatExample()

    success.i = 0

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

    ;  Demonstrates starting a shell on a remote SSH server, running a command, and retrieving the
    ;  output.  No PTY is requested, which is the recommended approach for automation.

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

    hostname.s = "ssh.example.com"
    port.i = 22
    success = CkSsh::ckConnect(ssh,hostname,port)
    If success = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        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 = CkSsh::ckAuthenticatePw(ssh,"mySshLogin",password)
    If success = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    channelNum.i = CkSsh::ckOpenSessionChannel(ssh)
    If channelNum < 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    ;  Start a shell WITHOUT requesting a PTY.  Without a PTY the shell sees it is connected to a
    ;  raw data pipe and enters non-interactive mode: it suppresses the command prompt, does not
    ;  echo typed commands back, and skips interactive login scripts.  The output is therefore
    ;  clean and easily parseable -- but because no prompt is ever sent, code must not wait for
    ;  one.  Instead, have each command print a predictable marker, or wait for EOF / channel close.
    success = CkSsh::ckSendReqShell(ssh,channelNum)
    If success = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    ;  Send the command.  The trailing newline is required -- the shell acts on a line at a time.
    success = CkSsh::ckChannelSendString(ssh,channelNum,"ls -l /tmp" + Chr(10),"utf-8")
    If success = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    ;  Send EOF to tell the server no more input is coming.  The channel stays open and output can
    ;  still be received.
    success = CkSsh::ckChannelSendEof(ssh,channelNum)
    If success = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    ;  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.
    CkSsh::setCkReadTimeoutMs(ssh, 15000)

    ;  Receive the remaining output until the server closes the channel.
    success = CkSsh::ckChannelReceiveToClose(ssh,channelNum)
    If success = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    cmdOutput.s = CkSsh::ckGetReceivedText(ssh,channelNum,"utf-8")
    If CkSsh::ckLastMethodSuccess(ssh) = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    Debug cmdOutput

    CkSsh::ckDisconnect(ssh)


    CkSsh::ckDispose(ssh)


    ProcedureReturn
EndProcedure