Hm. Now I am confused (and/or stupid; your choice). I was thinking that perhaps Net::Ping would support which port to perform a "tcp ping" against (after all, there is a hash element called "port_num") in the initialization of the class: 
elsif ($self->{"proto"} eq "tcp")           
{
  $self->{"proto_num"} = (getprotobyname('tcp'))[2] ||
  croak("Can't get tcp protocol by name");
  $self->{"port_num"} = (getservbyname('echo', 'tcp'))[2] ||
  croak("Can't get tcp echo port by name");
  $self->{"fh"} = FileHandle->new();
}

[download]
So I figured I'd create the class and modify $self->{"port_num"} by myself. Well, I've run into a problem: the following code doesn't work: 
#!/usr/bin/perl 
 
use Net::Ping; 
 
$host="localhost"; 
 
$p = Net::Ping->new(); 
print "$host is alive.\n" if $p->ping($host); 
$p->close();

[download]
It produces the error message of 
Bad arg length for Socket::unpack_sockaddr_in, length is 0, should be 
+16 at /usr/lib/perl5/5.00503/i386-linux/Socket.pm line 295.

[download]
Now, I realize that I'm probably missing something here, but I can't figure out what it is; after all, this example is the first listed in the pod for Net::Ping.

Any ideas?

In reply to Re: Ping and check for server running on port 27015 by mr.nick
in thread Ping and check for server running on port 27015 by Gibble

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.