package TripodCGI;



################

# TripodCGI.pm #                          

#############################################################################

# TripodCGI is a module to help you deal with CGI input, which is the kind  #

# of input your script can get from forms (as well as from specially-coded  #

# links).  When you have a form submit its information to your script,      #

# you can use TripodCGI to grab some or all of the inputs that the form     #

# provided, so that you can use them for your own nefarious ends ;)         #

#                                                                           #

# Of the functions below, the only two that you are likely to need to pay   #

# attention to are param() and redirect().  param() is the function which   #

# lets you grab CGI input.  If you specify the name of a particular input   #

# that you want to grab, param() will grab the value associated with the    #

# input of that name.  So if I have a form with a text input box named      #

# 'address', and somebody types in '160 Water St.' and hits the submit      #

# button, I can assign '160 Water St.' to the variable $form_address within #

# my form with this statement:                                              #

#                                                                           #

#   $form_address = $CGI->param('address');                                 #

#                                                                           #

# If you just want to know all of the names of the inputs returned by       #

# the form, don't specify an input, and the names of all the inputs will be # 

# returned as an array - like this:                                         #

#                                                                           #

# @all_inputs = $CGI->param();                                              #

#                                                                           #

# The other function you might want to use is redirect().  redirect() lets  #

# you specify the URL of a page or script that you want to move your        #

# visitor to.  You could use it like this:                                  #

#                                                                           #

# $CGI->redirect('http://www.tripod.com');  <- redirects to the Tripod      #

#                                              front page                   #

#############################################################################



sub new {

    my $class = shift;

    my $self = {};

    bless $self, $class;

    %data = ();

    $self->_initialize();

    return $self;

}





sub param {

    my($self,$key) = @_;

    return keys %data unless $key;



    return undef unless defined($data{$key});



    my @values = split("\0", $data{$key});

    return wantarray ? @values : $values[0];

}





sub redirect {

    my($self,$url) = @_;

    return "Status: 302 Found\nLocation: $url\n" . 

	   "URI: $url\nContent-type: text/html\n\n";

}





sub _initialize {

    my $query_string = '';



    if ($ENV{REQUEST_METHOD} eq 'POST') {

	read(STDIN, $query_string, $ENV{CONTENT_LENGTH});

    } else {

	$query_string = $ENV{QUERY_STRING};

    }



    my($key,$val);



    for (split(/&/, $query_string)) {

	s/\+/ /g;

	($key,$val) = split(/=/, $_, 2);



	$key =~ s/%(..)/pack("c",hex($1))/ge;

	$val =~ s/%(..)/pack("c",hex($1))/ge;



	$val =~ s/\r\n/\n/g;

	$val =~ s/\r/\n/g;



	if (defined($data{$key})) {

	    $data{$key} .= "\0";

	    $data{$key} .= $val;

	} else {

	    $data{$key} = $val;

	}

    }

}





1;