libupsclient provides a low-level interface to directly dialog with upsd. It is a wrapper around the NUT network protocol.

For more information, refer to the upsclient(3), manual page and the various upscli_*(3) functions documentation referenced in the same file.

Clients like upsc are provided as examples of how to retrieve data using the upsclient functions. Other programs not included in this package may also use this library, such as wmnut.

libnutclient provides a high-level interface representing devices, variables and commands with an object-oriented API in C++ and C.

For more information, refer to the libnutclient(3) manual page.

  #include <iostream>
  #include <unistd.h>
  #include <stdlib.h>

  #include <nutclient.h>

  using namespace nut;
  using namespace std;

  /* argv[1] is the mandatory NUT device name (@localhost),
   *    used to list variables from
   * argv[2] is an optional command. When provided, it will be
   *    executed and possibly with status tracking enabled
   */
  int main(int argc, char **argv)
  {
    Client *client;
    try
    {
      // Connection
      client = new TcpClient("localhost", 3493);

      if (argc >= 2)
      {
        // Reading data from device
        Device mydev = client->getDevice(argv[1]);
        cout << "Description: " << mydev.getDescription() << endl;
        Variable var = mydev.getVariable("device.model");
        cout << "Model: " <<  var.getValue()[0] << endl;

        if (argc >= 3)
        {
          // Authenticate to NUT server
          const char *user = getenv("NUT_USER");
          const char *password = getenv("NUT_PASSWD");
          client->authenticate(user ? user : "", password ? password : "");

          // Enable command tracking, if available
          if (client->hasFeature(Client::TRACKING))
          {
            cout << "Server can do command tracking" << std::endl;
            client->setFeature(Client::TRACKING, true);
          }
          else
          {
            std::cout << "Server can't do command tracking" << std::endl;
          }

          // Perform an asynchronous command
          TrackingID id = mydev.executeCommand(argv[2]);
          TrackingResult result;
          do
          {
            sleep(1);
            result = client->getTrackingResult(id);
          }
          while (result == PENDING);

          // Display result of command
          const char *output = "<UNRECOGNIZED>";
          switch (result)
          {
            case SUCCESS: output = "SUCCESS"; break;
            case FAILURE: output = "FAILURE"; break;
            case UNKNOWN: output = "UNKNOWN"; break;
          }
          cout << "Command sent, result=" << output << endl;
        }
      }
    }
    catch (NutException &ex)
    {
      cerr << "Unexpected problem : " << ex.str() << endl;
    }
    delete client;
    return 0;
  }