#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

use Path::Tiny;

my $path = 'Path::Tiny'->cwd;
$path = path("$path/..")->realpath
    until -e "$path/.marker" || '/' eq $path;
say -e "$path/.marker" ? 'F' : 'Not f', 'ound';