#!/usr/bin/perl
print qq{Content-type: text/html\n\nCGI Processor};
%images = (
"One" => "http://www.cs.indiana.edu/dept/img/lh01.gif",
"Seven" => "http://www.cs.indiana.edu/dept/img/lh07.gif",
"Eight" => "http://www.cs.indiana.edu/dept/img/lh08.gif",
"Nine" => "http://www.cs.indiana.edu/dept/img/lh09.gif"
);
%next = (
"One" => "Seven",
"Seven" => "Eight",
"Eight" => "Nine",
"Nine" => "One"
);
%prev = (
"One" => "Nine",
"Seven" => "One",
"Eight" => "Seven",
"Nine" => "Eight"
);
&readParse; # [1] read, parse and ...
$pic = $in{pic}; # [1] name (the state)
# [1] is called "retrieve state"
if ($pic eq "") { # if state is empty
$pic = "One"; # initialize it
} else { # otherwise (state is not empty, this is an existing user)
# print "
($pic)
";
$action = $in{action}; # see what they want
if ($action eq "next") { # if they want the next picture
$pic = $next{$pic}; # set the state to next picture
} else { # otherwise
if ($action eq "previous") { # if they want the previous picture
$pic = $prev{$pic}; # we give them that
} else { } # otherwise we don't do anything
}
}
# so now we report, store the state and get ready for more input
print qq{
};
print qq{};
sub readParse {
$user = $ENV{"QUERY_STRING"};
@pairs = split(/&/, $user);
foreach $pair (@pairs) {
($name, $value) = split(/=/, $pair, 2);
$value =~ s/%(..)/chr(hex($1))/ge;
$in{$name} = $value;
}
}