log_dbm.js

var fs            = require("fs"),
    exec          = require("child_process").exec,
    macAddresses  = {
      "00:25:00:48:26:b3": {
        name:   "Christopher",
        times:  0,
        log:    0
      },
      "74:e5:0b:a6:6f:94": {
        name:   "Wolfgang",
        times:  0,
        log:    0
      },
      "00:26:bb:09:62:7d": {
        name:   "Ali",
        times:  0,
        log:    0
      },
      "74:e5:0b:ca:96:28": {
        name:   "Daniel",
        times:  0,
        log:    0
      }
    };

function log() {
  exec("iw wlan0 station dump", function(err, output) {
    for (var macAddress in macAddresses) {
      var match = output.match(new RegExp(macAddress + "[\\s\\S]+?signal:.+?-(\\d+)", "i"));
      if (match) {
        macAddresses[macAddress].log    += Number(match[1]);
        macAddresses[macAddress].times  += 1;
      }
    }
    
    renderResults();
  });
}

function renderResults() {
  output = "";
  
  for (var macAddress in macAddresses) {
    if (macAddresses[macAddress].times) {
      var average = macAddresses[macAddress].log / macAddresses[macAddress].times;
      output += macAddresses[macAddress].name + ": -" + average + " dBm (" + macAddresses[macAddress].times + " logs)\n";
    }
  }
  
  fs.writeFile('dbm.log', output, function (err) {});
}

log();

setInterval(log, 1000 * 60 * 5);