[gentoo-user] Is there a "zypper ps" (from openSUSE) equivalent for Gentoo?

[Nikos Chantziaras]

On openSUSE, there's a very helpful command after performing updates 
that tells me which running programs are using files that were just 
overwritten by updated copies.  The command is "zypper ps".  It helps to 
avoid rebooting the machine (as I have to do in Gentoo), since I know 
exactly what needs to be restarted (like X, sshd, etc.)

Is there something like that in Gentoo?