libfile-flat-perl binary package in Ubuntu Xenial amd64

 File::Flat implements a flat filesystem. A flat filesystem is a filesystem
 in which directories do not exist. It provides an abstraction over any normal
 filesystem which makes it appear as if directories do not exist.
 .
 In effect, it will automatically create directories as needed. This is create
 for things like install scripts and such, as you never need to worry about the
 existance of directories, just write to a file, no matter where it is.

Source package