If you have recently upgraded your Ubuntu to Ubuntu 14.04 and found that when you open the Nautilus File Manager, all the hidden files are visible rather than hidden, here is the fix.
Open a terminal and type:
Alternatively, you can do it with a GUI.
1. Install dconf
2. Run dconf-editor
3. On the left panel, navigate to “org -> gnome -> nautilus -> preferences”. On the right panel, search for an entry “show-hidden-files.” Uncheck the box beside it.
4. That’s it.
Next time you open your Nautilus File Manager, all the hidden files will stay hidden. You can then press “Ctrl + h” to show the hidden files.