Paul Evans


getnameinfo - command-line tool to getnameinfo(3) resolver


getnameinfo [options...] address port


This tool provides a convenient command-line wrapper around the getnameinfo(3) resolver function. It will perform a single reverse lookup to convert an address and port number into its host and service names. This is mainly useful when debugging names resolution problems, because it allows inspection of the getnameinfo(3) behaviour itself, outside of any real program that is trying to use it.


--address, -A ADDR

Numerical form of address to look up. If not supplied, will use the first positional argument.

--port, -P PORT

Port number to look up. If not supplied, will use the second positional argument.


Sets the NI_DGRAM flag; looks up a SOCK_DGRAM (udp) port allocation rather than SOCK_STREAM (tcp).


Display a help summary and exit


Paul Evans <>