> Using getaddrinfo() on IPv4-only legacy systems will not do harm - it will

if it is supported.

> do exactly the same as gethostbyname() (namely, return all available IPv4
> addresses for the target system), but will not put you into the IPv4-only
> corner forever.
> 
> Imagine your system having IPv6 one day - do you want to recompile all
> installed software to be able to use it?

with pkgsrc that should be relatively easy :-)

No, seriously, I was refering to systems that do not support IPv6, so
there's little "danger" of this happening overnight.
pkgsrc provides a variable, USE_INET6. My question is, if it is set to no,
should rfc2553 support be compiled in nonetheless (assuming the libraries
would support it; some systems' libs do not)?
My understanding is that the whole purpose of USE_INET6 is to indicate
whether you want to compile in IPv6 support or not (regardless whether your
setup then actually makes use of it or not).

-- 
Georg Schwarz    http://home.pages.de/~schwarz/
 georg.schwarz@freenet.de  +49 178 8545053