Class: Net_GeoIP  - X-Ref

GeoIP class provides an API for performing geo-location lookups based on IP
address.

To use this class you must have a [binary version] GeoIP database. There is
a free GeoIP country database which can be obtained from Maxmind:
{@link http://www.maxmind.com/app/geoip_country}


<b>SIMPLE USE</b>


Create an instance:

<code>
$geoip = Net_GeoIP::getInstance('/path/to/geoipdb.dat', Net_GeoIP::SHARED_MEMORY);
</code>

Depending on which database you are using (free, or one of paid versions)
you must use appropriate lookup method:

<code>
// for free country db:
$country_name = $geoip->lookupCountryName($_SERVER['REMOTE_ADDR']);
$country_code = $geoip->lookupCountryCode($_SERVER['REMOTE_ADDR']);

// for [non-free] region db:
list($ctry_code, $region) = $geoip->lookupRegion($_SERVER['REMOTE_ADDR']);

// for [non-free] city db:
$location = $geoip->lookupLocation($_SERVER['REMOTE_ADDR']);
print "city: " . $location->city . ", " . $location->region;
print "lat: " . $location->latitude . ", long: " . $location->longitude;

// for organization or ISP db:
$org_or_isp_name = $geoip->lookupOrg($_SERVER['REMOTE_ADDR']);
</code>


<b>MULTIPLE INSTANCES</b>


You can have several instances of this class, one for each database file
you are using.  You should use the static getInstance() singleton method
to save on overhead of setting up database segments.  Note that only one
instance is stored per filename, and any flags will be ignored if an
instance already exists for the specifiedfilename.

<b>Special note on using SHARED_MEMORY flag</b>

If you are using SHARED_MEMORY (shmop) you can only use SHARED_MEMORY for
one (1) instance  (i.e. for one database). Any subsequent attempts to
instantiate using SHARED_MEMORY will read the same shared memory block
already initialized, and therefore will cause problems since the expected
database format won't match the database in the shared memory block.

Note that there is no easy way to flag "nice errors" to prevent attempts
to create new instances using SHARED_MEMORY flag and it is also not posible
(in a safe way) to allow new instances to overwrite the shared memory block.

In short, is you are using multiple databses, use the SHARED_MEMORY flag
with care.


<b>LOOKUPS ON HOSTNAMES</b>


Note that this PHP API does NOT support lookups on hostnames.  This is so
that the public API can be kept simple and so that the lookup functions
don't need to try name lookups if IP lookup fails (which would be the only
way to keep the API simple and support name-based lookups).

If you do not know the IP address, you can convert an name to IP very
simply using PHP native functions or other libraries:

<code>
$geoip->lookupCountryName(gethostbyname('www.sunset.se'));
</code>

Or, if you don't know whether an address is a name or ip address, use
application-level logic:

<code>
if (ip2long($ip_or_name) === false) {
$ip = gethostbyname($ip_or_name);
} else {
$ip = $ip_or_name;
}
$ctry = $geoip->lookupCountryName($ip);
</code>