php - Converting City&Country to Coordinate points -

is there fast php code convert city + country latitude , longitude coordinates. have list of locations , need convert them coordinates. tried doing in javascript, encountered problems trying results php store in json file. there efficient php code this?

thanks.

in app, i'm using following function geo-code locations using google service. function takes 1 parameter - location geo-code (e.g. "boston, usa" or "sw1 1aa, united kingdom") , returns associative array lat/lon. if error occurs or location cannot determined, returns false.

note in many cases city + country not able determine location uniquely. example, there 100 cities named springfield in usa alone. also, when passing country geo-coding service, make sure put full country name , not 2-letter code. found hard way: passing 'ca' "canada" , getting strange results. apparently, google assumed 'ca' means "california".

function getgeolocationgoogle($location) {     $url = "http://maps.googleapis.com/maps/api/geocode/xml?address=". urlencode($location) . "&sensor=false";     $useragent = "mozilla/5.0 (x11; u; linux i686; en-us; rv:1.9.2) gecko/20100115 firefox/3.6 firephp/0.4";      //setup curl object , execute     $curl = curl_init($url);     curl_setopt($curl, curlopt_useragent, $useragent);     curl_setopt($curl, curlopt_failonerror, true);     curl_setopt($curl, curlopt_returntransfer, 1);     $result = curl_exec($curl);      $req = $location;      //process response google servers     if (($error = curl_errno($curl)) > 0)     {         return false;     }       $geo_location = array();     //try convert xml response object     try     {         $xmldoc = new domdocument();         $xmldoc->loadxml($result);         $root = $xmldoc->documentelement;          //get errors         $status = $root->getelementsbytagname("status")->item(0)->nodevalue;         if($status != "ok")         {             $error_msg = "could not determine geographical location of $location - response code $status";         }         $location = $root->getelementsbytagname("geometry")->item(0)->getelementsbytagname("location")->item(0);         if(!$location)         {             return false;         }          $xmllatitude = $location->getelementsbytagname("lat")->item(0);         $valuelatitude = $xmllatitude->nodevalue;         $geo_location['latitude'] = $valuelatitude;           //get longitude         $xmllongitude = $location->getelementsbytagname("lng")->item(0);         $valuelongitude = $xmllongitude->nodevalue;         $geo_location['longitude'] = $valuelongitude;          //return location - measure         $geo_location['location'] = $req;     }     catch (exception $e)     {         return false;     }             return $geo_location; }