psl 0.0.1 ========= This extension contains a single PostgreSQL function, registered_domain(), that uses the [Public Suffix List](https://publicsuffix.org) to return the registered domain within which a hostname exists. Installation ------------ To build it, do this: make make install make installcheck If you encounter an error such as: "Makefile", line 8: Need an operator You need to use GNU make, which may well be installed on your system as `gmake`: gmake gmake install gmake installcheck If you encounter an error such as: make: pg_config: Command not found Be sure that you have `pg_config` installed and in your path. If you used a package management system such as RPM to install PostgreSQL, be sure that the `-devel` package is also installed. If necessary tell the build process where to find it: env PG_CONFIG=/path/to/pg_config make && make installcheck && make install If you encounter an error such as: ERROR: must be owner of database regression You need to run the test suite using a super user, such as the default "postgres" super user: make installcheck PGUSER=postgres Once psl is installed you can add it to a database by running, as a superuser: CREATE EXTENSION psl; Psl uses a compiled-in copy of the public suffix list, with no way to dynamically update it after it has been built. A snapshot is included in the distributed soure, but you can update that to the latest version by running `make fetch`. Usage ----- `registered_domain()` will return the enclosing domain for any hostname, folded to lower case. For a registered domain it will return the domain itself. For a top level domain or a hostname without periods it will return null. As a special case, if passed an apparently correct hostname with a top level domain it doesn't recognize it will return the final two components of the hostname. steve=# select registered_domain('foo.bar.blighty.com'); registered_domain ------------------- blighty.com (1 row) steve=# select registered_domain('blighty.co.uk'); registered_domain ------------------- blighty.co.uk (1 row) steve=# select registered_domain('www.blighty.co.uk'); registered_domain ------------------- blighty.co.uk (1 row) steve=# select registered_domain('co.uk'); registered_domain ------------------- (1 row) steve=# select registered_domain('co.uk.ie'); registered_domain ------------------- uk.ie (1 row) Copyright and License --------------------- Copyright 2018 Steve Atkins This module is free software; you can redistribute it and/or modify it under the [PostgreSQL License](http://www.opensource.org/licenses/postgresql). The core functionality is from [regdom-libs](https://github.com/usrflo/registered-domain-libs/), code released under the [Apache license](http://www.apache.org/licenses/LICENSE-2.0). Test vectors were taken from [libpsl](https://github.com/rockdaboot/libpsl), under [MIT license](https://github.com/rockdaboot/libpsl/blob/master/LICENSE).