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;
}