net ping question

perlknight has asked for the wisdom of the Perl Monks concerning the following question:

All, below is a code snipet from the doc of net ping. AFAIK, this is suppose to test if www port is open (listening).

$p = Net::Ping->new("tcp", 2);
           # Try connecting to the www port instead of the echo port
           $p->{port_num} = getservbyname("http", "tcp");
           #while ($stop_time > time())
           #{
               print "$host not reachable ", scalar(localtime()), "\n"
                   unless $p->ping($host);
               sleep(300);
           #}
           undef($p);
[download]

I tried using this, but it seems to fail. I changed "www" to ssh and telnet. I ran it on a host that should have failed. Anyone knows what this did not fail?

Comment on net ping question Download Code

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Re: net ping question by gellyfish (Monsignor) on Apr 15, 2005 at 09:48 UTC
You probably don't want to use Net::Ping to this as this will use the TCP echo service and all you are doing is changing the port to which it tries to connect to this service. I would suggest if you just want to check whether you have a particular port open on a particular machine you do something like: `use IO::Socket; + my $sock = IO::Socket::INET->new(PeerAddr => 'localhost', PeerPort => 'http(80)', Proto => 'tcp'); + + print $sock ? "alive" : "not alive";` [download] /J\	[reply] [d/l]
Re^2: net ping question by perlknight (Pilgrim) on Apr 15, 2005 at 15:01 UTC
Thanks. Will try it out and see if it works.	[reply]
Re: net ping question by moot (Chaplain) on Apr 15, 2005 at 04:43 UTC
You mention changing 'www' to ssh and telnet, but the only place www is mentioned in your code is a comment. Also your last few sentences aren't clear. Are you saying that pinging ssh/ telnet should fail on the host you specify? Are you sure that the server has something listening on the http port?	[reply]


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