Я хотел бы, чтобы все файлы, созданные в определенном каталоге, принадлежали определенному пользователю в Linux, который возможен?

Assuming you only want to the be able to share files seamlessly between a group of users, on Linux you can set the 'set group id' bit on the directory:

chmod 2777 /shared

or

chmod g+s /shared

To make the files actually be owned by your user you would have to do some scripting. For example, running this find command suggested on wikipedia via a cron entry every minute.