#!/usr/bin/perl

use strict;
use warnings;

use AnyEvent;
$|++;

my $done = AnyEvent->condvar;

# set up event handler
my $w = AnyEvent->signal(signal => "HUP", cb => sub { print "Got SIGHU
+P, reloading...\n"; });

# wait for event
$done->recv;

exit 0;
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Works fine. Don't forget that stdout is buffered (which $|++ fixes.