Simple WebServer Scanner

[Asmo]

Category:

Networking Code

Description:

This script prints out the webserver version the scanned host is running (with a simple HEAD request)

#!/usr/bin/perl

use Socket;
use Strict;
use warnings;

my $remote = $ARGV[0];
my $port=80;

if ($ARGV[0] eq "") {
affichage();
}

sub affichage
{
        print "\n\nUsage : $0 <remote host>\n";
exit();
}



$submit = "HEAD / HTTP/1.0\r\n\r\n";
if($port =~ /\D/) { $port = getservbyname($port, 'tcp') }
die "no port specified" unless $port;
my $iaddr = inet_aton($remote) || die "$remote";
my $paddr = sockaddr_in($port, $iaddr) || die "Caca !!";
my $proto = getprotobyname('tcp') || die "protocol !!";

socket(SOCK, PF_INET, SOCK_STREAM, $proto) || die "cannot open socket 
+: $!";
connect(SOCK, $paddr) || die "cannot connect to $remote: $!";
send(SOCK,$submit,0);
while(<SOCK>)
{
if($_ =~ /Server: (.*)/) {
        print $_;
}

}
close(SOCK);

[ybiC]

It's sad to see young Asmo's reasonable effort at coding being downvoted.   Of course the Other Ways To Do It in this thread are beneficial, and doubtless better, but the downvotes aren't a terribly monkish way to encourage new Perlers to learn and grow.
    a bit less cheerful,
    Don
    striving toward Perl Adept
    (it's pronounced "why-bick")

[helmex]

I agree completely. Have mercy o great monks!!! %^+^%

[merlyn]

Your perl4-style code ignores the advances made in Perl in the past 8 years. Socket code without "use IO::Socket", and HTTP code without touching the LWP library. Feh!

use LWP;
use HTTP::Request::Common;
my $response = LWP::UserAgent->new->
  simple_request(HEAD "http://perltraining.stonehenge.com");
unless ($response->is_error) {
  print "server: ", $response->server, "\n";
} else {
  print "error: ", $response->status_line, "\n";
}

-- Randal L. Schwartz, Perl hacker

[davorg]

You're right about LWP of course and your version is much nicer, but the original script does "use Socket".

--
<http://www.dave.org.uk>

"The first rule of Perl club is you don't talk about Perl club."

[merlyn]

Ahh. Brainlapse. I was thinking IO::Socket, which gives a nice interface, and is part of the core Perl.

-- Randal L. Schwartz, Perl hacker

[stefp]

I am not advocating writing perl4 code but not all programmers have the right of installing new modules on a given site. I don't know for this particular monk though.

-- stefp

[merlyn]

I already covered this in "No excuses about not using CGI.pm".

And hosting solutions are a dime-a-dozen these days. Not having basic tools like IO::Socket (which is part of the core distribution) or LWP available to you means you are burning a lot of time needlessly. Move to a different server.

-- Randal L. Schwartz, Perl hacker

[jeffa]

Hmmmm . . . let's get the with times, eh? ;)

use strict;
use warnings;
use LWP;

my $url = shift || 'localhost';
$url    = "http://$url";

my $agent    = LWP::UserAgent->new();
my $request  = HTTP::Request->new(HEAD => $url);
my $response = $agent->request($request);

print $response->{_headers}->{server}, "\n";

jeffa

[echo]

Writing perl code is always nice, but in this case it seems overkill:

% perl -MCPAN -e 'install LWP'
% HEAD http://www.example.com/ | grep ^Server

[Asmo]

perl -MCPAN -e 'install LWP'
Can't locate object method "install" via package "LWP" at -e line 1.

[Anonymous Monk]

To work around this problem use: perl -MCPAN -e shell then at the prompt enter: install LWP Linuxboy