#!/usr/local/bin/perl

 #===============================
 # A Simple Guestbook Script
 # Copyright 1999, Emmie P. Lewis
 # Created 07/09/99
 #===============================
 # This script shows how to write
 # a guestbook script.
 #===============================

 print "Content-type:text/html\n\n";

 # Initialize File Pathnames

 # Relative path of Guestbook.html
 $guestbook_file = "../guestbook.html";

 # URL to guestbook.html
 $guestbook_url = "http://localhost/guestbook.html";

 # Initialize list of months
 @month = ("January", "February", "March", "April", "May", "June", "July", 
             "August", "September", "October", "November", "December");


 # Read in the CGI Data, no matter which method was used
 #    (If you're unsure what this code does, see 'Reading CGI Data'
 #    http://perl.about.com/library/weekly/aa052499.htm)

 if($ENV{'REQUEST_METHOD'} eq "GET"){
 $my_data = $ENV{'QUERY_STRING'};
 }
 else {
 $data_length = $ENV{'CONTENT_LENGTH'};
 $bytes_read = read(STDIN, $my_data, $data_length);
 }

 # Let's load it into something we can use
 @name_value_array = split(/&/, $my_data);

 # Here's where we do the actual work. We're going to cycle 
 # through @name_value_array to decode the name=value pairs
 foreach $name_value_pair (@name_value_array) {
     # Split the name=value pair in your HTML form data
     ($name, $value) = split(/=/, $name_value_pair);

     # Now, replace '+' with ' '
     $name =~ tr/+/ /;
     $value =~ tr/+/ /;

     # Next, we'll translate any hex values back into characters
     $name =~ s/%(..)/pack("C",hex($1))/eg;
     $value =~ s/%(..)/pack("C",hex($1))/eg;

     # Finally, we'll load the variables into an associative array 
     # so we can use it when we need it.
     $FormData{$name} = $value;
 }

 # Get the date and time information
 ($Seconds, $Minutes, $Hours, $DayInMonth, $Month, $ShortYear,
 $DayOfWeek, 
 $DayOfYear, $IsDST) = localtime(time);

 # Fix the year to keep it Y2K compliant, as described in 'Perl and Y2K'
 # http://perl.about.com/library/weekly/aa070299.htm
 $Year = $ShortYear + 1900;

 $EntryDate = "$month[$Month] $DayInMonth, $Year";

 # OK, now open the current guestbook file and read it in
 open(GUESTBOOK, "$guestbook_file") || die "Can't open
 GUESTBOOK: $guestbook_file\n";
 @guestbook =<GUESTBOOK>;
 close(GUESTBOOK);

 # Open it again so that we can add the current guest to the file
 open(GUESTBOOK, ">$guestbook_file") || die "Can't open
 GUESTBOOK: $guestbook_file\n";
 foreach $line (@guestbook) {
     # Check to see if we're at the beginning of the guest book
     if($line =~ /<!--My Latest Guest:-->/i) {
         # We are, so add our latest guest
         # Start by adding the guestbook header to the file, so we can find it
 next time
         print GUESTBOOK "<!--My Latest Guest:-->\n";

         # The guestbook is an HTML file, so we'll have to add the tags too
         print GUESTBOOK "<DL>\n";

         if($FormData{'email'}) {
             # if there's an email address, let's add it as a link
             print GUESTBOOK "<DD><I><B><A
 HREF=\"mailto:$FormData{'email'}\">
             $FormData{'name'}</A></B> - $FormData{'city'},
 $FormData{'location'}</I>\n";
         }
         else {
             # otherwise, just add their name
             print GUESTBOOK "<I><B>From:</B>
 $FormData{'name'}</I><BR>\n";
         }

         if($FormData{'web_url'}) {
             # If they included their web url, add the link
             print GUESTBOOK "<DD>Homepage : <A
 HREF=\"$FormData{'web_url'}\">$FormData{'web_title'}</A>\n";
         }
         # add the comments
         print GUESTBOOK "<ul><p>\n";
         print GUESTBOOK "$FormData{'comments'}\n";
         print GUESTBOOK "</ul>\n";

         # add the date 
         print GUESTBOOK "<p><I><font size=2>\n";
         print GUESTBOOK "signed on $EntryDate\n";
         print GUESTBOOK "</I></font>\n";

         # finish up
         print GUESTBOOK "</DL>\n";
         print GUESTBOOK "<HR>\n";
     }
     else {
         # just print the existing line to the updated file
         print GUESTBOOK "$line";
     }
 }
 close(GUESTBOOK);

 # Tell our new guest they've been added, and let them see their entry
 print <<"EOF"
 <H1>Thanks\!</H1>
 Your entry has been added to the <A
 HREF="$guestbook_url">guestbook</A>.
 You may need to click reload to view your guestbook entry.<P>
 EOF