I'd like to know if there's any alternative for previewing these kind of filetypes without having to open LibreOffice.
I don't mean the little thumbnail that appears on Nautilus. I mean a basic, simple viewer, just as Image Viewer is to GIMP Image Editor.
Gloobus Preview should do the job for you. Just search for it in the Ubuntu Software Centre, you can get all the information about it from their Launchpad page
I agree with Victor9098, except you will also need to install
unoconv package. This package is necessary for converting office documents so that
gloobus-preview can preview the files without office suite.
This requirement has been discussed under this launchpad bug thread.
Right now I am using
gnome-sushi. You can install it like this:
sudo apt-get install gnome-sushi
Then after the installation you are able to get a quick view on the preview of a file. You can access this animation by single-clicking on the file and then pressing the space-bar. Got it from here if you want an expert to talk about this.
I hope this helps. :D
Found another tool that allows you to also quickly review
.docx files. It's called
gloobus-sushi. To install this feature you have to remove
sudo apt-get remove gnome-sushi sudo apt autoremove
After you have removed this program you can install
gloobus-sushi like this:
sudo add-apt-repository ppa:nilarimogard/webupd8 sudo apt-get update sudo apt-get install gloobus-preview
For some types of documents you have to install
sudo apt-get install unoconv gnumeric
Now you have to install Gloobus Preview helper tool which integrates the application with either Nautilus or Nemo:
sudo apt-get install gloobus-sushi nautilus -q
sudo apt-get install nemo-gloobus-sushi nemo -q
After the installation you are able to preview every file. To use this awesome feature you have to single-click on the file and then press the space-bar.