UVs by world position

Please can anybody tell me how to use the x and z worldspace coordinates as my UV coordinates in a surface shader?

[edit] Never mind I found the information I needed in the docs!

For the sake of people who come here to find out, can you post a link?

At the end of this page in the documentation, Aras explains that you can add float3 worldPos to the input structure, and Unity will fill it out for you.