#!/usr/bin/perl
use strict;

my %adapter_names = ();
for (split /\n/, `netstat -i`)  {
  next if /lo|sit|link|Name/;
  /(\S+)/;  # Takes first block of non-spaces, assigns to $1
  my $interface = $1;
  my $adapter = $interface;
  $adapter =~ s/^en/ent/;  # Add other substitutions here
  $adapter_names{$adapter} = $interface if !defined $adapter_names{$adapter};
}
print "$_ : $adapter_names{$_}\n" for sort keys %adapter_names;