#!perl
# Fig. 10.11: fig10_11.pl
# Logs visitors to web site.

use strict;
use warnings;
use CGI qw( :standard );
use Fcntl qw( :flock );

my @vars = 
   qw( REMOTE_ADDR REMOTE_PORT REQUEST_URI QUERY_STRING );
my @stuff = @ENV{ @vars };
my $info = join( " | ", @stuff );

open( FILE, "+>>log.txt" )
   or die( "Could not open log.txt: $!" );
flock( FILE, LOCK_EX )
   or die( "Could not get exclusive lock: $!" );
print( FILE "$info\n\n" );
flock( FILE, LOCK_UN ) or die( "Could not unlock file: $!" );

close( FILE );

if ( $stuff[3] ne "" ) {
   print( header( -Refresh=> '5; URL=http://www.deitel.com' ) );
   print( start_html( "log.txt" ) );
   print( h1( "Welcome to Deitel & Associates, $stuff[3]!\n" ) );
   print( p( i( "You will now be redirected to our home page." ) ) );
}
else {
   print( header() );
   print( start_html( "log.txt" ) );
   print( h1( "Please add a \"?\" and your name to the URL.\n" ) );
}

print( end_html() ); 

###########################################################################
#  (C) Copyright 2001 by Deitel & Associates, Inc. and Prentice Hall.     #
#  All Rights Reserved.                                                   #
#                                                                         #
#  DISCLAIMER: The authors and publisher of this book have used their     #
#  best efforts in preparing the book. These efforts include the          #
#  development, research, and testing of the theories and programs        #
#  to determine their effectiveness. The authors and publisher make       #
#  no warranty of any kind, expressed or implied, with regard to these    #
#  programs or to the documentation contained in these books. The authors #
#  and publisher shall not be liable in any event for incidental or       #
#  consequential damages in connection with, or arising out of, the       #
#  furnishing, performance, or use of these programs.                     #
###########################################################################