#!/usr/bin/perl

    # Ri404 v1.0. Copyright 1998 Jon Hedley. All Rights Reserved.
    # http://www.cgi.tj
    # Do not distribute without express written permission of Jon Hedley.
    # Usage is free as long as you link to me: see http://www.cgi.tj/links/
    # for the exact details.

    ###################################################
    #             INSTALLATION NOTES                  #
    #                                                 #
    #  1) Set first line to path of the Perl 5        #
    #     Interpreter.                                #
    #  2) Set $logpath to the world writable text     #
    #     file to log to. Comment it out to disable   #
    #     logging.                                    #
    #  3) Set $mailprog to the path of your sendmail  #
    #     compatible mailer.                          #
    #  4) Set $email to the email address to send     #
    #     to. Comment out to disable email feature.   #
    #  5) If you wish to disable ENV Report in email, #
    #     comment out $send_env.                      #
    #  6) After the "END" token insert RAW HTML       #
    #     to be printed out to browser on 404 error.  #
    ###################################################

$logpath    = '/home/yutopian/404/log.txt';
$mailprog   = '/usr/sbin/sendmail';
# $email      = 'info@yutopian.com';
$send_env   = 'yes';

# First, Send Email if enabled:

if ($email and $mailprog)
    {
    open(MAIL,"|$mailprog -t") or error("Could not open mailer: $!");
    print MAIL "To: $email\n";
    print MAIL "From: $email (Ri 404)\n";
    print MAIL "Subject: Ri 404 Report\n";
    print MAIL "X-Priority: 1 (Highest)\n\n";
    print MAIL "Flags tripped for attempted access to $ENV{'REDIRECT_URL'}\n";
    print MAIL "by $ENV{'REMOTE_HOST'}.\n\n";
    if ($ENV{'HTTP_REFERER'})
        {
        @terms = split(/\//,$ENV{'HTTP_REFERER'});
        print MAIL "Visitor linked in from $ENV{'HTTP_REFERER'}. ";
        print MAIL "You may wish to contact the administrator of $terms[0]//$terms[2].\n\n";
        }
    else
        {print MAIL "No referring URL was logged in association with this visit.\n\n";}
    
    if ($send_env)
        {
        print MAIL "Details follow:\n\n";
        foreach $key (sort keys %ENV)
            {print MAIL "$key: $ENV{$key}\n";}
        }
    close(MAIL) or error("Could not send mail: $? $!");
    }
    
# Secondly, log error if enabled:

if ($logpath)
    {
    unless (-e $logpath) {error("$logpath does not exist.")}
    unless (-W $logpath) {error("$logpath is not world writable.")}
    
    ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday) = localtime(time);
    $mon++;
    if (length($mday) == 1)  {$mday = 0 . $mday}
    if (length($mon)  == 1)  {$mon = 0 . $mon}
    if (length($hour) == 1)  {$hour = 0 . $hour}
    if (length($min)  == 1)  {$min = 0 . $min}
    $year = $year + 1900;
    $dt = "$year$mon$mday.$hour$min";
    
    $line = "$dt\t $ENV{'REDIRECT_URL'}\t $ENV{'HTTP_REFERER'}\t $ENV{'REMOTE_HOST'}\n";
    
    open(FILE, ">>$logpath") or error("Could not open $logpath for append: $!");
    flock(FILE,2) or error("Could not lock file $logpath: $!");
    print FILE $line;
    close(FILE);
    }
    
# Finally, output HTML to browser (Content after "END" token below)

print "Content-Type: text/html\n\n";
while (<DATA>) {print}

sub error
    {
    my $error = $_[0];
    print "Content-Type: text/html\n\n";
    print "<h2>Error</h2><b>$error</b>\n\n";
    exit(0);
    }
    
__END__

<META HTTP-EQUIV="Refresh" CONTENT="0;url=http://www.yutopian.com">