Dart

Send an SSH IGNORE Message

Demonstrates the Chilkat Ssh.SendIgnore method, which sends an SSH IGNORE message. It takes no arguments. The server does not reply, but a successful send helps confirm the connection is still writable. No channel is required.

Background: The SSH IGNORE message is discarded by the peer by design; its usefulness is as a lightweight keep-alive or liveness probe. Because it exercises the actual write path, a successful SendIgnore is stronger evidence than CheckConnection that the link is still usable, without side effects on any channel.

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Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // Demonstrates the Ssh.SendIgnore method, which sends an SSH IGNORE message.  It takes no
  // arguments.  The server does not reply, but a successful send helps confirm the connection is
  // still writable.  No channel is required.

  final ssh = CkSsh();

  // Connect to the SSH server.  Port 22 is the usual SSH port.
  final sshPort = 22;
  try {
    ssh.connect('ssh.example.com', sshPort);
  } on ChilkatException catch (e) {
    print(e.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.
  final password = 'mySshPassword';

  try {
    ssh.authenticatePw('mySshLogin', password);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Send an IGNORE message to verify the connection is still writable.
  try {
    ssh.sendIgnore();
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('IGNORE message sent.');

  ssh.disconnect();
}