Re: [misterhouse-users] Getting IP address and posting to web-site

[Kevin O. <ke...@ol...>]

I got this from the net somewhere long ago (maybe freshmeat), it just emails my
work email and cell phone when the stored address is different from the found
address.  I run it from cron every five minutes.  I'd imagine this problem has
been solved in bunches of different ways.

Kevin

#!/usr/bin/perl -w

$oldIPFilename = "/root/dhinfo/oldIP"; # dir to store state info
$email = "your\@email.com"; # address to notify changes
$email = $email . " phonenumber\@mobile.att.net";
#$subject = "IP Change";
$link = "eth0"; # name of link to watch

sub GetIP {
    my $currentIP;

    open(IFCONFIG,"/sbin/ifconfig $link|");

    while (<IFCONFIG>)  {
        if (/inet addr:/)  {
            my @data = split;
            $currentIP = $data[1];
            $currentIP =~ s/addr://;
        }
    }

    close(IFCONFIG);

    return($currentIP);
}

sub GetOldIP
{
    open(OLDIP,$oldIPFilename);
    my $oldIP = <OLDIP>;
    close(OLDIP);

    return($oldIP);
}

sub MailChanges
{
    $currentIP = shift;

    my $msg = "From: root\@mh.machine.com\n";
    $msg = sprintf("%sSubject: IP change\n\n", $msg);
    $msg = sprintf("%sIP change for mh.machine.com.  New IP is \n\t%s",
                      $msg,
                      $currentIP);

    print $msg;
    my $command = sprintf("echo \"%s\" | /usr/sbin/sendmail -f
dhcp\@mh.machine.com %s",
                          $msg, $email);

    system($command);
}

sub WriteNewIP
{
    my $currentIP = shift;

    open(FILE,">" . $oldIPFilename);
    print FILE $currentIP;
    close(FILE);
}


################

my $currentIP = GetIP();
my $oldIP = GetOldIP();

if ($currentIP ne $oldIP)  {
    MailChanges($currentIP);
    WriteNewIP($currentIP);
}