#!/usr/local/bin/perl use CGI qw(:standard); @ANIMALS=sort qw/lion tiger bear pig porcupine ferret zebra gnu ostrich emu moa goat weasel yak chicken sheep hyena dodo lounge-lizard squirrel rat mouse hedgehog racoon baboon kangaroo hippopotamus giraffe/; # Recover the previous animals from the magic cookie. # The cookie has been formatted as an associative array # mapping animal name to the number of animals. %zoo = cookie('animals'); # Recover the new animal(s) from the parameter 'new_animal' @new = param('new_animals'); # If the action is 'add', then add new animals to the zoo. Otherwise # delete them. foreach (@new) { if (param('action') eq 'Add') { $zoo{$_}++; } elsif (param('action') eq 'Delete') { $zoo{$_}-- if $zoo{$_}; delete $zoo{$_} unless $zoo{$_}; } } # Add new animals to old, and put them in a cookie $the_cookie = cookie(-name=>'animals', -value=>\%zoo, -expires=>'+1h'); # Print the header, incorporating the cookie and the expiration date... print header(-cookie=>$the_cookie); # Now we're ready to create our HTML page. print start_html('Animal crackers'); print <Animal Crackers Choose the animals you want to add to the zoo, and click "add". Come back to this page any time within the next hour and the list of animals in the zoo will be resurrected. You can even quit Netscape completely!

Try adding the same animal several times to the list. Does this remind you vaguely of a shopping cart?

This script only works with Netscape browsers

Add/Delete	Current Contents EOF ; print "
",start_form; print scrolling_list(-name=>'new_animals', -values=>[@ANIMALS], -multiple=>1, -override=>1, -size=>10)," "; print submit(-name=>'action',-value=>'Delete'), submit(-name=>'action',-value=>'Add'); print end_form; print "	"; if (%zoo) { # make a table print " \n"; foreach (sort keys %zoo) { print " $zoo{$_} $_\n"; } print " \n"; } else { print "The zoo is empty.\n"; } print "

"; print <

Lincoln D. Stein

More Examples EOF ; print end_html;