Category: Net
Author/Contact Info ackme
Description: Uses Activeperl to check logs on a unix box from an NT machine. It tails the log, grabs the last line, and posts it into a logfile I create on the NT box. The log on the Unix box is in the form eod.log.mmddyy. Also logs a warning if the last line of the log is not the expected one. 
use Net::Telnet ();
$username = "ackme";
$password = "XXXXXXXXX";
$t = new Net::Telnet (Timeout => 60);
$t->open("some.otherbox.com");
$t->login($username, $password);
@d = $t->cmd("date +%m%d%y");
chop(@d);
@lines = $t->cmd("tail -1 /home/ackme/eod.log.$d[0]");
$->logout;
open (LOG, ">>I:/perl/testlog") || "cannot create testlog! $!";
print LOG "the date: $d[0]\n";
chop @lines[0];
$correct = "eod complete exit status = 0";
if (${lines}[0] ne $correct)  {
print LOG "WARNING LOG NOT CORRECT!!";
} else {
print LOG "the last line of the EOD log is: \"$lines[0]\"\n";
}
close (LOG) || "can't close testlog: $!"
Replies are listed 'Best First'.
Re: remote logchecker
by crenz (Priest) on Aug 02, 2002 at 08:14 UTC

    This way, your password is transferred in plain text over the net!

    You could use a CGI script to give you the last line of the file; there is no need to use telnet.

        use strict;
    use warnings;

    my $correct = "eod complete exit status = 0";

    use LWP::UserAgent;
    my $ua = new LWP::UserAgent;
    my $req = new HTTP::Request
        GET => "http://server.net/obscure-url/loglastline.cgi";
    $res = $ua->request($req);
    if ($res->is_success) {
        warn "Log not correct: " . $res->content . "\n"
            unless ($res->content =~ /$correct/;
    } else {
        die "Ooops. something went wrong:\n" . 
            $res->as_string() . "\n";
    }

    [download]

    Update: Sorry -- maybe I shouldn't just assume that the Unix server has a webserver installed. I do recommend using ssh, though. You could even set up a user that upon login is presented with the last line of the shell script (set the login shell to a shell script that does that), then logs out. Set up a key pair for this user on the NT box and the Unix box, then call ssh using perl and catch the output. This should be much more secure.

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Re: remote logchecker
by Tomte (Priest) on Aug 02, 2002 at 08:25 UTC
    Due to my recent readings (including Intrusion Detection An Analyst's Handbook) and general paranoia I can't help but comment:

    Do not use Telnet! Even inside a firewalled network it compromises security a lot. You may want to check Net-SSH-W32Perl and its requirements to see if you can get the same functionality out of it.

    Otherwise a cool idea :-)
    regards,
    tomte
[reply]
Re: remote logchecker
by ackme (Scribe) on Aug 02, 2002 at 08:54 UTC
    Thanks. If only I could! The unix box a) has no web service, and b) has no ssh service! And *I*, being a lowly "support engineer," at a remote location, have no juice with the admin. I was told that the "eod" script didn't run one day and no one noticed until too late, so I better be sure I check it. I wrote this and set up an "at" process on NT so that, even if I forgot, I would have a record of it running (or not). In fact, the perl on the unix box is 5.005, with almost no modules and the OS is Solaris 4.something (7?). ~Scary~
[reply]
      Then perhaps you ought to just create a cron job to scan the log and email an appropriate excerpt to you periodically. This way you don't need to expose your password over the net.
[reply]
        I was wanting to be cleverly Perlish, but that is a much safer way to do it. Thx, Bro!
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