Use nmap. It might not be pure-Perl, but it'll work. Usually, I don't like relying on external programs from my Perl code, but I don't know of any module that comes close to the functionality of nmap.

----
I wanted to explore how Perl's closures can be manipulated, and ended up creating an object system by accident.
-- Schemer

Note: All code is untested, unless otherwise stated

Without totally re-engineering nmap in Perl I can't think of a better way of doing it than:

#!/usr/bin/perl -w

use strict;

my @hosts = qw(localhost);

HOST:
foreach my $host (@hosts )
{
   open(NMAP, "nmap -O $host |") || next;

   while(<NMAP>)
   {
      chomp;
      if(/Remote operating system guess: (.*)/)
      {
         print "$host $1\n";
         next HOST;
      }
   }
}
[download]

/J\

Just for reference, that discussion is here.

I can think of two basic ways, with a large number of variations on each of them. The first is to use somthing like nmap to analize the remote box and guess the OS. The second is to ask it. There's many variations on that, from looking at the telnet banner, through telneting in, to SSHing with the command-to-run being uname -a. I'd recommend either ssh/uname -a (or not -a, depending on exactly what you want, of course), or using nmap. Which depends on if you have ssh access to the box, and if your project spec and sense of elegance will let you run nmap. (I'd be very surprised if nmap is standard on prety much anything, with the possible exception of forensic kits, because it's often considered a "hackers tool" (and by "hacker", such people mean "cracker").)

I wonder if nmap would be any faster, and if its installed as standard on things like AIX and HP-UX on which my script is running.. (I somehow doubt it though)

Any other ideas, perchance?

C.

Unfortunately, the problem with using telnet to connect is that A) you are transmitting a password in clear text across the network and B) you are relying on the telnet service to be running on the remote host. This typically would work fine for all flavours of *nix but not necessarally for WinNT-based systems, IIRC, telnet services need to be turned on explicitly on an NT/2000 server (but I'm not an NT admin so I'm not 100% sure of that). Using nmap() is probably a better solution.

Just my $.02 :-)

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"Ex libris un peut de tout"

A) doesn't matter at all, since its a user/pass just for ftp with a specific directory, and an internal network. As to B), we are requiring it to be for this very reason.

Tho whether I require that, or nmap to be installed, is probably just the same..

Yes I know it doesn't on Win, I said that :) (Which is the other problem, since we now to support ftp servers on Win too.. so I'll need another solution sometime soon anyway..)

C.

you are relying on the telnet service to be running on the remote host. This typically would work fine for all flavours of *nix

Not while I'm in charge of the *nix machines! (But normaly nmap wont detect the os-type on these either, thanks grsecurity, Update: though this is likely to change, as far as I know nmap, it will be able soon).

regards,
tomte

---

Hlade's Law:

If you have a difficult task, give it to a lazy person --
they will find an easier way to do it.