Ubuntu Open File do Terminal
xdg-open file-name
# xdg-open myPicture.png
HRZP
xdg-open file-name
# xdg-open myPicture.png
#for short files
cat filename.txt
#for longer files
less filename.txt
#to edit files inside terminal open using vim or nano
#using vim
vim filename.txt
#using nano
nano filename.txt
nautilus .
#or
nautilus /home/john/Downloads