examples/unsubscribe.milter: use IO::Socket, again

Sendmail::PMilter requires an IO::Socket object, not a GLOB.

Fixes: e901a56b3b30b22f (treewide: favor open(..., '+<&=', $fd), 2021-05-21)

diff --git a/examples/unsubscribe.milter b/examples/unsubscribe.milter
index 608524cbaca40337a8ca45a1f0b7d0ba38cfd774..04a3976142da5dc29b805052b7ae105fb30767ea 100644 (file)
--- a/examples/unsubscribe.milter
+++ b/examples/unsubscribe.milter
@@ -127,7 +127,7 @@ my $fds = $ENV{LISTEN_FDS};
 if ($fds && (($ENV{LISTEN_PID} || 0) == $$)) {
        die "$0 can only listen on one FD\n" if $fds != 1;
        my $start_fd = 3;
-       open(my $s, '<&=', $start_fd) or
+       my $s = IO::Socket->new_from_fd($start_fd, 'r') or
                die "inherited bad FD from LISTEN_FDS: $!\n";
        $milter->set_socket($s);
 } else {