"h2xs builds a Perl extension from C header files"

That's what 'man h2xs' says - you should read it for yourself, but in the meantime, try this command:

h2xs -A -X FooBar
[download]

And look inside the newly created directory (FooBar) for a pleasant surprise. ;)

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)