use Time::HiRes qw( gettimeofday tv_interval );
use Net::Ping;

my $p = Net::Ping->new("icmp");
my $t0 = [gettimeofday];
$p->ping('127.0.0.1',5);
my $elapsed=tv_interval ( $t0, [gettimeofday]);
print "latency=$elapsed\n";