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.

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    boolean 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.

    CkSsh ssh = new CkSsh();

    int port = 22;
    success = ssh.Connect("172.16.16.100",port);
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        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.
    String password = "mySshPassword";

    success = ssh.AuthenticatePw("mySshLogin",password);
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    int channelNum = ssh.QuickShell();
    if (channelNum < 0) {
        System.out.println(ssh.lastErrorText());
        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.put_ReadTimeoutMs(15000);

    boolean caseSensitive = true;

    //  In unprivileged mode the switch prompt ends with ">".
    success = ssh.ChannelReceiveUntilMatch(channelNum,">","utf-8",caseSensitive);
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    String received = ssh.getReceivedText(channelNum,"utf-8");
    if (ssh.get_LastMethodSuccess() == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    System.out.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) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    success = ssh.ChannelReceiveUntilMatch(channelNum,"Password:","utf-8",caseSensitive);
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    received = ssh.getReceivedText(channelNum,"utf-8");
    if (ssh.get_LastMethodSuccess() == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    System.out.println(received);

    //  The enable password is separate from the login password, and likewise should come from a
    //  secure source rather than being hard-coded.
    String enablePassword = "myEnablePassword";
    success = ssh.ChannelSendString(channelNum,enablePassword,"utf-8");
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    success = ssh.ChannelSendString(channelNum,"\r","utf-8");
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    //  In privileged mode the prompt ends with "#" instead of ">".
    success = ssh.ChannelReceiveUntilMatch(channelNum,"#","utf-8",caseSensitive);
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    received = ssh.getReceivedText(channelNum,"utf-8");
    if (ssh.get_LastMethodSuccess() == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    System.out.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) {
        System.out.println(ssh.lastErrorText());
        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.
    CkStringArray saMatch = new CkStringArray();
    saMatch.Append("MySwitchName#");
    saMatch.Append("--More--");

    CkStringBuilder sbReceived = new CkStringBuilder();
    boolean moreComing = true;

    while (moreComing) {
        success = ssh.ChannelReceiveUntilMatchN(channelNum,saMatch,"utf-8",caseSensitive);
        if (success == false) {
            System.out.println(ssh.lastErrorText());
            return;
            }

        sbReceived.Clear();
        String pageText = ssh.getReceivedText(channelNum,"utf-8");
        if (ssh.get_LastMethodSuccess() == false) {
            System.out.println(ssh.lastErrorText());
            return;
            }

        sbReceived.Append(pageText);
        System.out.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) {
                System.out.println(ssh.lastErrorText());
                return;
                }

            }

        }

    ssh.Disconnect();
  }
}