my %files = (
'/var/www/index.html' => 1,
'/var/www/home/index.html' => 1;
);
my $request = $query->param('fulltxtpath');
if (exists($files{$request})) {
open (FILE, "> " . $request) or dienice("couldn't open $request: $!");
# open and print file
} else {
# error
}