I have this snippet where it works if I use a constant in "use constant REMOTE_HOST":

  my $udp_server = shift @ARGV;

  my $trans_serv;
  my $remote_host;
  my $remote_port;
  my $destination;

  if ( $udp_server )
  {
    use Socket;
    use constant SIMPLE_UDP_PORT => 4001;

    use constant REMOTE_HOST => 'myservername'; 
  # use constant REMOTE_HOST => $udp_server;

    $trans_serv  = getprotobyname('udp');
    $remote_host = gethostbyname(REMOTE_HOST);
    $remote_port = SIMPLE_UDP_PORT;
    $destination = sockaddr_in($remote_port, $remote_host);

    socket (UDP_SOCK, PF_INET, SOCK_DGRAM, $trans_serv);
  }
[download]

but if instead I try to use a variable (set to a passed-in argument) for REMOTE_HOST:

  use constant REMOTE_HOST => $udp_server;
[download]

I get the following runtime error:

  Bad arg length for Socket::pack_sockaddr_in, length is 0, should be 
+4 at
  /opt/perl/lib/5.3.7/i686-linux-thread-multi/Socket.pm line 373
[download]

There's not a rule that "use constant NAME => value" can't use a variable for the value is there?

I'm only wanting to pull in Socket if the user wants to send data to one of several servers and would hate to have to do:

  my $udp_server = shift @ARGV;

  if    ( $udp_server eq 'server1' ) { use constant REMOTE_HOST => 'se
+rver1'; }
  elsif ( $udp_server eq 'server2' ) { use constant REMOTE_HOST => 'se
+rver2'; }
  elsif ( $udp_server eq 'server3' ) { use constant REMOTE_HOST => 'se
+rver3'; }
  elsif ( $udp_server eq 'server4' ) { use constant REMOTE_HOST => 'se
+rver4'; }
                                else { $udp_server = '';              
+        }

  if ( $udp_server )
  {
    use Socket;
    use constant SIMPLE_UDP_PORT => 4001;
      :
      :
[download]

The above works, but I'd have to change the program every time the server list changes.

I'm running ActivePerl 5.8.7 on Linux.

Do you see anything wrong that I'm doing?

Thanks.

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