Change default system font using terminal only in 14.04

The following question answers how to Adjust fonts using tweak tool but the luddite in me would like to know how to do this without installing unity-tweak-tool.

How can I adjust the default system font from a terminal.

gsettings offers a simple commandline interface to GSettings. It lets you get, set or monitor an individual key for changes.

• You can set fonts by following commands in terminal :

  gsettings set org.gnome.desktop.interface document-font-name 'Sans 10'
  gsettings set org.gnome.desktop.interface font-name 'Ubuntu 10'
  gsettings set org.gnome.desktop.interface monospace-font-name 'Ubuntu Mono 11'
  gsettings set org.gnome.nautilus.desktop font 'Ubuntu 10'
  

• To Know current settings type following commands in terminal :

  gsettings get org.gnome.desktop.interface document-font-name
  gsettings get org.gnome.desktop.interface font-name 
  gsettings get org.gnome.desktop.interface monospace-font-name
  gsettings get org.gnome.nautilus.desktop font
  

Additional:

• To find all similar keys on schema type following command:

  gsettings list-recursively org.gnome.desktop.interface
  

• To reset all valuses of keys run following command in terminal:

  gsettings reset-recursively org.gnome.desktop.interface
  

Recent updates have been changing the font scaling factors on my system, reset them with this command...

gsettings set org.gnome.desktop.interface text-scaling-factor '1.0'

You can use dconf to change the default system font:

dconf write /org/gnome/desktop/interface/font-name "'NanumGothic Italic 11'"

To restore the original value:

dconf write /org/gnome/desktop/interface/font-name "'Ubuntu 11'"

Note: to check the current value, use the following command:

dconf read /org/gnome/desktop/interface/font-name