check build options

[Romeo Theriault]

How can I check what options where built into a specific rpm? For  
instance I would like to know if vsftpd was build with xinetd  
support. But even more than that I would like to know how to do this  
for all rpm's. I looked through the rpm man page but was unable to  
find anything that stood out, suggesting it could do this.

Thanks for any help.

Romeo Theriault