[HOW TO] set default program in Ubuntu?

In this article I will show you how to set default program in Ubuntu?

1. Go as below:
$sudo vi /usr/share/applications/default.list

2. Then you change as you want.
Example you must be changed the OpenOffice is default:

Original file:

[Default Applications]
application/csv=wps-office-wps.desktop
application/excel=wps-office-wps.desktop
application/ogg=rhythmbox.desktop
application/oxps=evince.desktop
application/pdf=evince.desktop
application/postscript=evince.desktop
application/tab-separated-values=libreoffice-calc.desktop
application/vnd.lotus-1-2-3=libreoffice-calc.desktop
application/vnd.ms-xpsdocument=evince.desktop
application/vnd.rn-realmedia=totem.desktop
application/vnd.sun.xml.base=libreoffice-base.desktop
application/vnd.sun.xml.calc=libreoffice-calc.desktop
application/vnd.sun.xml.calc.template=libreoffice-calc.desktop
application/vnd.sun.xml.draw=libreoffice-draw.desktop
application/vnd.sun.xml.draw.template=libreoffice-draw.desktop
application/vnd.sun.xml.math=libreoffice-math.desktop
application/vnd.sun.xml.writer=libreoffice-writer.desktop
application/vnd.sun.xml.writer.template=libreoffice-writer.desktop
application/vnd.sun.xml.writer.global=libreoffice-writer.desktop
application/vnd.oasis.opendocument.database=libreoffice-base.desktop
application/vnd.oasis.opendocument.formula=libreoffice-math.desktop
application/vnd.oasis.opendocument.graphics=libreoffice-draw.desktop
application/vnd.oasis.opendocument.graphics-template=libreoffice-draw.desktop

Now you change follow:
[Default Applications]
application/csv=libreoffice-calc.desktop
application/excel=libreoffice-calc.desktop
application/ogg=rhythmbox.desktop
application/oxps=evince.desktop
application/pdf=evince.desktop
application/postscript=evince.desktop
application/tab-separated-values=libreoffice-calc.desktop
application/vnd.lotus-1-2-3=libreoffice-calc.desktop
application/vnd.ms-xpsdocument=evince.desktop
application/vnd.rn-realmedia=totem.desktop
application/vnd.sun.xml.base=libreoffice-base.desktop
application/vnd.sun.xml.calc=libreoffice-calc.desktop
application/vnd.sun.xml.calc.template=libreoffice-calc.desktop
application/vnd.sun.xml.draw=libreoffice-draw.desktop
application/vnd.sun.xml.draw.template=libreoffice-draw.desktop
application/vnd.sun.xml.math=libreoffice-math.desktop
application/vnd.sun.xml.writer=libreoffice-writer.desktop
application/vnd.sun.xml.writer.template=libreoffice-writer.desktop
application/vnd.sun.xml.writer.global=libreoffice-writer.desktop
application/vnd.oasis.opendocument.database=libreoffice-base.desktop
application/vnd.oasis.opendocument.formula=libreoffice-math.desktop
application/vnd.oasis.opendocument.graphics=libreoffice-draw.desktop
application/vnd.oasis.opendocument.graphics-template=libreoffice-draw.desktop