SSH to a Cisco Switch - Processing "More" Responses

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Demonstrates connecting to a Cisco switch, entering privileged mode with the ena command, and running a command whose response is paged. Each page ends with --More-- and requires a SPACE character to request the next page.

Note: QuickShell allocates a PTY, which is what a network device console expects. The device presents an interactive prompt, and each command's output is read up to the next prompt.

    success := false

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

    //  Demonstrates connecting to a Cisco switch, entering privileged mode, and running a command
    //  whose response is paged -- each page ends with "--More--" and requires a SPACE character to
    //  request the next page.

    ssh := chilkat.NewSsh()

    port := 22
    success = ssh.Connect("172.16.16.100",port)
    if success == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    //  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 := "mySshPassword"

    success = ssh.AuthenticatePw("mySshLogin",password)
    if success == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    channelNum := ssh.QuickShell()
    if channelNum < 0 {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    //  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.
    ssh.SetReadTimeoutMs(15000)

    caseSensitive := true

    //  In unprivileged mode the switch prompt ends with ">".
    success = ssh.ChannelReceiveUntilMatch(channelNum,">","utf-8",caseSensitive)
    if success == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    received := ssh.GetReceivedText(channelNum,"utf-8")
    if ssh.LastMethodSuccess() == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    fmt.Println(*received)

    //  Send "ena" to enter privileged mode.  Cisco devices expect a bare CR to terminate a command.
    success = ssh.ChannelSendString(channelNum,"ena\r","utf-8")
    if success == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    success = ssh.ChannelReceiveUntilMatch(channelNum,"Password:","utf-8",caseSensitive)
    if success == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    received = ssh.GetReceivedText(channelNum,"utf-8")
    if ssh.LastMethodSuccess() == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    fmt.Println(*received)

    //  The enable password is separate from the login password, and likewise should come from a
    //  secure source rather than being hard-coded.
    enablePassword := "myEnablePassword"
    success = ssh.ChannelSendString(channelNum,enablePassword,"utf-8")
    if success == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    success = ssh.ChannelSendString(channelNum,"\r","utf-8")
    if success == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    //  In privileged mode the prompt ends with "#" instead of ">".
    success = ssh.ChannelReceiveUntilMatch(channelNum,"#","utf-8",caseSensitive)
    if success == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    received = ssh.GetReceivedText(channelNum,"utf-8")
    if ssh.LastMethodSuccess() == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    fmt.Println(*received)

    //  Run a command whose output is delivered a page at a time.
    success = ssh.ChannelSendString(channelNum,"show running-config\r","utf-8")
    if success == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    //  Each read ends either at the device prompt (output complete) or at "--More--" (another page
    //  is waiting).  Match the full prompt rather than a bare "#", because "#" also appears inside
    //  configuration text and would match too early.
    saMatch := chilkat.NewStringArray()
    saMatch.Append("MySwitchName#")
    saMatch.Append("--More--")

    sbReceived := chilkat.NewStringBuilder()
    moreComing := true

    for moreComing {
        success = ssh.ChannelReceiveUntilMatchN(channelNum,saMatch,"utf-8",caseSensitive)
        if success == false {
            fmt.Println(ssh.LastErrorText())
            ssh.DisposeSsh()
            saMatch.DisposeStringArray()
            sbReceived.DisposeStringBuilder()
            return
        }

        sbReceived.Clear()
        pageText := ssh.GetReceivedText(channelNum,"utf-8")
        if ssh.LastMethodSuccess() == false {
            fmt.Println(ssh.LastErrorText())
            ssh.DisposeSsh()
            saMatch.DisposeStringArray()
            sbReceived.DisposeStringBuilder()
            return
        }

        sbReceived.Append(*pageText)
        fmt.Println(*pageText)

        //  If this page ended with "--More--", send a SPACE to request the next page.
        moreComing = sbReceived.Contains("--More--",caseSensitive)
        if moreComing {
            success = ssh.ChannelSendString(channelNum," ","utf-8")
            if success == false {
                fmt.Println(ssh.LastErrorText())
                ssh.DisposeSsh()
                saMatch.DisposeStringArray()
                sbReceived.DisposeStringBuilder()
                return
            }

        }

    }

    ssh.Disconnect()

    ssh.DisposeSsh()
    saMatch.DisposeStringArray()
    sbReceived.DisposeStringBuilder()