You want to find your (fully qualified) hostname.
use Sys::Hostname; $hostname = hostname();
use POSIX qw(uname); ($kernel, $hostname, $release, $version, $hardware) = uname(); $hostname = (uname); # or just one
Then turn it into an IP address and convert to its canonical name:
use Socket; # for AF_INET $address = gethostbyname($hostname) or die "Couldn't resolve $hostname : $!"; $hostname = gethostbyaddr($address, AF_INET) or die "Couldn't re-resolve $hostname : $!";
Sys::Hostname tries to be portable by using knowledge about your system to decide how best to find the hostname. It tries many different ways of getting the hostname, but several involve running other programs. This can lead to tainted data (see Recipe 19.1).
POSIX::uname, on the other hand, only works on POSIX systems and isn't guaranteed to provide anything useful in the
nodename field that we are examining. That said, the value is useful on many machines and doesn't suffer from the tainted data problem that Sys::Hostname does.
Once you have the name, though, you must consider that it might be missing a domain name. For instance, Sys::Hostname may return you
guanaco instead of
guanaco.camelids.org. To fix this, convert the name back into an IP address with
gethostbyname and then back into a name again with
gethostbyaddr. By involving the domain name system, you are guaranteed of getting a full name.