GeoIP Legacy C Library
This library is for the GeoIP Legacy format (dat). To read the MaxMind DB format (mmdb) used by GeoIP2, please see libmaxminddb.
The GeoIP Legacy C library enables the user to find geographical and network information of an IP address. To use this library, you may user our commercial GeoIP Legacy databases. For more details, see:
IP Geolocation Usage
IP geolocation is inherently imprecise. Locations are often near the center of the population. Any location provided by a GeoIP database should not be used to identify a particular address or household.
On Ubuntu Using PPA
MaxMind provides a PPA for recent version of Ubuntu. To add the PPA to your APT sources, run:
$ sudo add-apt-repository ppa:maxmind/ppa
Then install the packages by running:
$ sudo apt update $ sudo apt install libgeoip1 libgeoip-dev geoip-bin
From Source on Unix/Linux
To install, run:
./configure make make check make install
If you are using a GitHub checkout, please run the
bootstrap script first
to set up the build environment.
The GeoIP Legacy C library relies on GNU make, not on BSD make
From Source with Visual Studio (nmake)
To make a static GeoIP.lib, edit the top level Makefile.vc to reflect where the GeoIP.dat database file should be placed, as well as the locations of the lib, include, and bin directories for installation.
To build and install, issue the following commands from a developer console:
nmake /f Makefile.vc nmake /f Makefile.vc test nmake /f Makefile.vc install
From Source with MinGW
./configure make cp data/GeoIP.dat test/ make check
Note that GeoIP.dat file should be placed in the same place as GeoIP-enabled executable modules.
Memory Caching and Other Options
There are five options available:
GEOIP_STANDARD- Read database from file system. This uses the least memory.
GEOIP_MEMORY_CACHE- Load database into memory. Provides faster performance but uses more memory.
GEOIP_CHECK_CACHE- Check for updated database. If database has been updated, reload file handle and/or memory cache.
GEOIP_INDEX_CACHE- Cache only the the most frequently accessed index portion of the database, resulting in faster lookups than
GEOIP_STANDARD, but less memory usage than
GEOIP_MEMORY_CACHE. This is useful for larger databases such as GeoIP Legacy Organization and GeoIP Legacy City. Note: for GeoIP Legacy Country, Region and Netspeed databases,
GEOIP_INDEX_CACHEis equivalent to
GEOIP_MMAP_CACHE- Load database into mmap shared memory. MMAP is not available for 32bit Windows.
GEOIP_SILENCE- Disables diagnostic messages to stderr in the library; error conditions are detectable via the return values.
These options can be combined using bit operators. For example you can
GEOIP_CHECK_CACHE by calling:
GeoIP_open("/path/to/GeoIP.dat", GEOIP_MEMORY_CACHE | GEOIP_CHECK_CACHE);
By default, the city name is returned in the ISO-8859-1 charset. To obtain the city name in UTF-8 instead, run:
To get the netmask of the netblock of the last lookup, use
See the following files for examples of how to use the API:
test/ test-geoip.c test-geoip-region.c test-geoip-city.c test-geoip-isp.c test-geoip-org.c test-geoip-netspeed.c
These example programs use our GeoIP Legacy databases.
In case of trouble building from source with libtool or autotools, update the generated configuration files by running:
aclocal && autoconf && automake --add-missing
Lookups are thread safe, but libGeoIP does not guard the functions. Do not drop or change the GeoIP database if other threads might be using the database.
The recommended pattern is:
- open database with GEOIP_MEMORY_CACHE
- use the database
- close database
Thread Safety on Windows
The Windows build is not thread-safe in STANDARD mode because the
Other Build Issues
If you run into trouble building your application with GeoIP Legacy support,
-fms-extensions to your
CFLAGS. If you use Solaris and the
default C compiler, use
-features=extensions instead. These options enable
unnamed union support to fix problems like:
improper member use: dma_code or
'GeoIPRecord' has no member named 'dma_code'.
Note that it is recommended that you use GNU make. Also, if you are using OpenBSD, this library requires OpenBSD 3.1 or greater.
If you get a "cannot load shared object file: No such file or directory"
error, add the directory
libGeoIP.so was installed to the
file and run
On Solaris, if you get a
ld: fatal: relocations remain against allocatable but non-writable sections, try running:
make clean ./configure --disable-shared make
If you get a
ar : command not found error, make sure that
ar is in your
path. On Solaris,
ar is typically found in
If you get a
passing argument 3 of 'gethostbyname_r' from incompatible pointer type error on AIX, untar a fresh copy of this library and delete the
following two lines from
#define HAVE_GETHOSTBYNAME_R 1 #define GETHOSTBYNAME_R_RETURNS_INT 1
then save the configure script and build it as usual:
./configure make sudo make install
Please report all issues with this code using the GitHub issue tracker.
If you are having an issue with a MaxMind database that is not specific to this API, please contact MaxMind support.
To contribute, please submit a pull request on GitHub.