Scoprie ip con php via curl json

$URL="http://api.ipinfodb.com/v3/ip-city/?key=tuakey&ip=$ip&format=json";
#####per la citta ip-city##############
#echo"$URL
";

    $URL = rawurldecode($URL);
    $URL = stripslashes($URL);

    // make sure curl is installed
    if (function_exists('curl_init')) {
       // initialize a new curl resource
       $ch = curl_init();

       // set the url to fetch
       curl_setopt($ch, CURLOPT_URL, $URL);

       // don't give me the headers just the content
       curl_setopt($ch, CURLOPT_HEADER, 0);

       // return the value instead of printing the response to browser
       curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

       // use a user agent to mimic a browser
       curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.5) Gecko/20041107 Firefox/1.0');

       $content = curl_exec($ch);
    
        #echo $content;

       // remember to always close the session and free all resources
       curl_close($ch);
    } else {
       // curl library is not installed so we better use something else
    }
#####################################################################
$json=$content;
$obj = json_decode($json);
$regionName=$obj->{'regionName'}; // 12345
$cityName=$obj->{'cityName'}; // 12345
echo"#$regionName#";