Specify robots.txt using IIS for different sub-domains

Question

I have a site at say www.example.com and also have two staging platforms at beta.example.com and preview.example.com and I need a way to set different robots.txt for each using IIS or something similar

The reason for this is that I want to disallow spiders on all but the www domain as they are spidering duplicated content

Anyone know if this is possible?

Answer 1

Is there a reason you can't just have 3 different robots.txt files, one for each host?

If you need to handle this automatically, I would suggest a HTTPHandler that handles requests for robots.txt. If the Request.Url.Host is www.example.com, return robots.allow.txt, if not, return robots.deny.txt.

If you are interested in this idea and need some example code to get you started, let me know.