package users;
use base qw(Exporter);
use strict;
our @EXPORT = qw($dbh validate dienice dbdie);
our @EXPORT_OK = qw();

use DBI;
use CGI qw(:standard);

our $dbh = DBI->connect( "dbi:mysql:usertable", "usertable", "jutedi2") or 
    &dienice("Can't connect to db: $DBI::errstr");

sub validate {
   # look for the cookie. if it exists and is valid, return the
   # username associated with that cookie.
    my $username = "";
    if (cookie('cid')) {
       my $sth = $dbh->prepare("select * from user_cookies where cookie_id=?") or &dbdie;
       $sth->execute(cookie('cid')) or &dbdie;
       my $rec;
       unless ($rec = $sth->fetchrow_hashref) {
       # there's a cookie set in the browser but we don't have a record
       # for it in the db.
       if ($rec->{ip_addr} ne $ENV{REMOTE_ADDR}) {
       # their IP address has changed since the last time they 
       # were here.
       $username = $rec->{username};
    } else {
    # no cookie is set. go to the login page.
    return $username;

sub dienice {
    my($msg) = @_;
    print header;
    print start_html("Error");
    print "<h2>Error</h2>\n";
    print $msg;

sub goto_login {
    # by passing the attempted URL on to login.cgi, you can
    # redirect to that URL once they successfully log in
    my $url = $ENV{REQUEST_URI};
    print redirect("$url");

sub dbdie {
    my($package, $filename, $line) = caller;
    my($errmsg) = "Database error: $DBI::errstr<br>\n called from $package $filename line $line";