psl 0.0.1

This Release
psl 0.0.1
Date
Status
Stable
Abstract
Canonicalize domain names using the public suffix list
Description
This extension provides a function that given a hostname will return the registered domain that contains that host
Released By
wttw
License
The PostgreSQL License
Resources
Special Files
Tags

Extensions

psl 0.0.1
Canonicalize domain names using the public suffix list

README

psl 0.0.1

This extension contains a single PostgreSQL function, registered_domain(), that uses the Public Suffix List 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.

The core functionality is from regdom-libs, code released under the Apache license.

Test vectors were taken from libpsl, under MIT license.