Convert postcode to longitude and latitude

August 14, 2008 at 12:55 am · Filed under Linux, Uncategorized

Usage:

./postcodetolonglat.sh 'SK99 9LZ'

Creates a little temp file called ‘postcode’. The file is put in /tmp and is of course unique for each execution of the program.  These files can be cleared out quite easily as part of maintenance of the /tmp folder. (i.e. a weekly cron that executes

find /tmp -mtime +1 -user apache -exec rm {} \;

where the file will be at least a day old and is owned by apache which (in my case) is the apache user for the apache web server.

Script:

#!/bin/bash
. `/usr/bin/wget "http://maps.google.com/maps/geo?q=$1" -O "/tmp/$1"`
LAT=`cat "/tmp/$1" | awk -F "[" '{print $4}' | awk -F "," '{print $2}'`
LON=`cat "/tmp/$1" | awk -F "[" '{print $4}' | awk -F "," '{print $1}'`
echo "<script language=JavaScript>"
echo "   var Lon=$LON;"
echo "   var Lat=$LAT;"
echo "   var orig='$1';"
echo "</script>"

Then in, say, google maps:

From your browser, call (for example for the Warminster postcode of the R.E.M.E - BA12 0BS)

http://server.com/map4.php?pc=BA12%200BS

The code for map4.php is below.

<html xmlns="http://www.w3.org/1999/xhtml" xmlns:v="urn:schemas-microsoft-com:vml">
  <head>
    <?php
$Postcode= $_GET['pc'];
echo passthru("./postcodetolonglat.sh '$Postcode'");
?>
    <meta http-equiv="content-type" content="text/html; charset=utf-8"/>
    <script src="http://maps.google.com/maps?file=api&amp;v=2&amp;key=ABQIAAAA2OgjrxQMCCnZOIKNKqdqqxQQ2LfZc7AlgWy0LicD3n_XCYU-EBSRAF96CM-HbX18JJscTSEShXpbfg"
            type="text/javascript"></script>
    <script type="text/javascript">
    function initialize() {
      if (GBrowserIsCompatible()) {
        var map = new GMap2(document.getElementById("map_canvas"));
        var gll = new GLatLng(Lat,Lon);
        map.setCenter(gll,17);
        map.addControl(new GSmallMapControl());
        map.addControl(new GMapTypeControl());
        GEvent.addListener(map,"click", function(overlay,latlng) {
          if (latlng) {
            var myHtml = "The GLatLng value is: " + map.fromLatLngToDivPixel(latlng) + " at zoom level " + map.getZoom();
            //map.openInfoWindow(latlng, myHtml);
                alert(gll.toUrlValue(10));
          }
        });

      }
    }
    </script>
  </head>

  <body onload="initialize()" onunload="GUnload()">
    <div id="map_canvas" style="width: 100%; height: 100%"></div>
    <div id="message"></div>
  </body>
</html>

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