finding header files

[Joe]

I'm trying to install a package that needs a header file I don't have 
loaded.

checking for readline... not found
configure: error: Development headers for readline were not found.

How do I figure out what package, etc. it's in so I can install it?

I need to know how to find stuff like this for the next time it happens too.

Joe

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Vision without Action is merely a dream. Action without Vision is passing the time. Vision with Action can change the world