use File::Basename        qw( dirname );
use File::Spec::Functions qw( rel2abs );

my $script_path = rel2abs($0);
my $script_dir  = dirname($script_path);
my $script_url  = $ENV{SCRIPT_NAME};
my $doc_root    = $ENV{DOCUMENT_ROOT};

my $redirect_to = URI->new_abs('bar.cgi', $script_url); # /dir/bar.cgi