Reading through this post today, I found a comment by Gibble near the end of the page. It offered up some code to check for whether a remote port is listening or not. I took the code and modified it a little as:

#!/usr/bin/perl -w

use strict;
use IO::Socket;

my $remoteip = "10.6.21.10";
my $port = "69";
my $proto = "udp";
 my $disconn = 0;
 my $checkport = IO::Socket::INET->new(
              PeerAddr => "$remoteip",
              PeerPort => "$port",
              Proto => "$proto",
              Timeout => '0') or $disconn = 1;

 if ($disconn) {
   print "  Port $port is down.\n";
 } else {
  print "  Port $port is up.\n";
 }
 close $checkport;

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The code doesnt appear to work. I think the <code>or $disconn</code statement is never set since the io::socket call is started. I'm not sure if it fails if the remote port is not listening.

I like the simplicity behind the idea of this code. Can it be made to work, or is this altogether wrong?

humbly -c

In reply to Check for tftp daemon listening on remote server by c

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