1#!/usr/local/bin/perl 2 3use CGI qw(:standard); 4 5@ANIMALS=sort qw/lion tiger bear pig porcupine ferret zebra gnu ostrich 6 emu moa goat weasel yak chicken sheep hyena dodo lounge-lizard 7 squirrel rat mouse hedgehog racoon baboon kangaroo hippopotamus 8 giraffe/; 9 10# Recover the previous animals from the magic cookie. 11# The cookie has been formatted as an associative array 12# mapping animal name to the number of animals. 13%zoo = cookie('animals'); 14 15# Recover the new animal(s) from the parameter 'new_animal' 16@new = param('new_animals'); 17 18# If the action is 'add', then add new animals to the zoo. Otherwise 19# delete them. 20foreach (@new) { 21 if (param('action') eq 'Add') { 22 $zoo{$_}++; 23 } elsif (param('action') eq 'Delete') { 24 $zoo{$_}-- if $zoo{$_}; 25 delete $zoo{$_} unless $zoo{$_}; 26 } 27} 28 29# Add new animals to old, and put them in a cookie 30$the_cookie = cookie(-name=>'animals', 31 -value=>\%zoo, 32 -expires=>'+1h'); 33 34# Print the header, incorporating the cookie and the expiration date... 35print header(-cookie=>$the_cookie); 36 37# Now we're ready to create our HTML page. 38print start_html('Animal crackers'); 39 40print <<EOF; 41<h1>Animal Crackers</h1> 42Choose the animals you want to add to the zoo, and click "add". 43Come back to this page any time within the next hour and the list of 44animals in the zoo will be resurrected. You can even quit Netscape 45completely! 46<p> 47Try adding the same animal several times to the list. Does this 48remind you vaguely of a shopping cart? 49<p> 50<em>This script only works with Netscape browsers</em> 51<p> 52<center> 53<table border> 54<tr><th>Add/Delete<th>Current Contents 55EOF 56 ; 57 58print "<tr><td>",start_form; 59print scrolling_list(-name=>'new_animals', 60 -values=>[@ANIMALS], 61 -multiple=>1, 62 -override=>1, 63 -size=>10),"<br>"; 64print submit(-name=>'action',-value=>'Delete'), 65 submit(-name=>'action',-value=>'Add'); 66print end_form; 67 68print "<td>"; 69if (%zoo) { # make a table 70 print "<ul>\n"; 71 foreach (sort keys %zoo) { 72 print "<li>$zoo{$_} $_\n"; 73 } 74 print "</ul>\n"; 75} else { 76 print "<strong>The zoo is empty.</strong>\n"; 77} 78print "</table></center>"; 79 80print <<EOF; 81<hr> 82<ADDRESS>Lincoln D. Stein</ADDRESS><BR> 83<A HREF="./">More Examples</A> 84EOF 85 ; 86print end_html; 87 88 89