Change default system font using terminal only in 14.04

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