pg_tidyurl is a PostgreSQL extension function that optimizes strings for use in urls. It replaces western UTF-8 characters with their ASCII equivalents and removes or encodes special characters.

PostgreSQL development headers need to be installed. E.g. for Debian systems with Postgres 9.0, install postgresql-server-dev-9.0.

$ make
# cp pg_tidyurl.so /usr/lib/postgresql/9.0/lib/
$ psql dbname

dbname=# \i tidyurl.sql

SELECT tidyurl('äüö') AS tidy;


 tidy
------
 auo