Net::Ident is a module that looks up the username on the remote side of a
TCP/IP connection through the ident (auth/tap) protocol described in
RFC1413 (which supersedes RFC931). Note that this requires the remote
site to run a daemon (often called identd) to provide the requested
information, so it is not always available for all TCP/IP connections.

WWW: https://metacpan.org/release/Net-Ident