title: Write gpxlogger data to the same file
body: <p>I have some very basic gpxlogger code that writes all the data to file quite well. (below)</p>
  
  <pre><code>gpxlogger -d  -f /home/pi/Desktop/EPQ/temp_gps/gpslog
  </code></pre>
  
  <p>However I would like this code to always write to the same file without overwriting it. So if possible when it started logging it would go to the bottom of the file and start logging the data there, below what has already been logged.</p>
  
  <p>Thanks,
  Dan.</p>
  
  <p>Javascript to read xml file</p>
  
  <pre><code>  &lt;script src="http://maps.google.com/maps?file=api&amp;amp;v=2&amp;amp;key=ABQIAAAA7_kD1t_m22HBF9feCaDPZxQwcATY4FXmxYwkk9LNWGtAQdNKTBS1kBsTEqrRPg2kWxuNdmf2JVCIkQ" type="text/javascript"&gt;&lt;/script&gt;
      &lt;script src="http://gmaps-utility-library.googlecode.com/svn/trunk/markermanager/release/src/markermanager.js"&gt;   &lt;/script&gt;&lt;script&gt;
       var map;
  
       function initialize () {  
        if (GBrowserIsCompatible()) {
           map = new GMap2(document.getElementById("map_canvas"));
           map.setCenter(new GLatLng(53.423027, -1.523462), 10);  
       map.addControl(new GLargeMapControl());
           map.addControl(new GMapTypeControl());
           map.addMapType(G_PHYSICAL_MAP);
       map.setMapType(G_PHYSICAL_MAP);
  
       addMarkersFromXML();
  
        }
  
        }
  
        function addMarkersFromXML(){
         var batch = [];
         mgr = new MarkerManager(map); 
  
         var request = GXmlHttp.create();
         request.open('GET', 'gpslog.xml', true);
         request.onreadystatechange = function() {
         if (request.readyState == 4 &amp;&amp; request.status == 200) {
          var xmlDoc = request.responseXML;
          var xmlrows = xmlDoc.documentElement.getElementsByTagName("trkpt");
  
          for (var i = 0; i &lt; xmlrows.length; i++) {
              var xmlrow = xmlrows[i];
  
              var xmlcellLatitude = parseFloat(xmlrows[i].getAttribute("lat"));
            var xmlcellLongitude = parseFloat(xmlrows[i].getAttribute("lon"));
            var point = new GLatLng(xmlcellLatitude,xmlcellLongitude);
  
            //get the time of the pin plot
              var xmlcellplottime = xmlrow.getElementsByTagName("time")[0];
              var celltextplottime = xmlcellplottime.firstChild.data;
  
            //get the elevation of the pin plot
              var xmlcellplotelevation = xmlrow.getElementsByTagName("ele")[0];
              var celltextplotelevation = xmlcellplotelevation.firstChild.data;
  
            //get the number of satellites at the time of the pin plot
              var xmlcellplotsat = xmlrow.getElementsByTagName("sat")[0];
              var celltextplotsat = xmlcellplotsat.firstChild.data;
  
  
              var htmlString = "Time: " + celltextplottime + "&lt;br&gt;" + "Elevation: " + celltextplotelevation + "&lt;br&gt;" + "Satellites: " + celltextplotsat;
              //var htmlString = 'yes'
  
              var marker = createMarker(point,htmlString);
              batch.push(marker);
  
          }
  
          mgr.addMarkers(batch,10);
          mgr.refresh();
  
        }
          }
      request.send(null);
  
        }
  
       function createMarker(point,html) {
             var marker = new GMarker(point);
             GEvent.addListener(marker, "click", function() {
               marker.openInfoWindowHtml(html);
             });
             return marker;
       }
  
      &lt;/script&gt;
    &lt;/head&gt;
    &lt;body onload="initialize()" onunload="GUnload()"&gt;
      &lt;div id="map_canvas" style="width: 1350px; height: 800px"&gt;&lt;/div&gt;
      &lt;div id="message"&gt;&lt;/div&gt;
    &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>