Install fonts in Linux without the root privilege

1. For normal fonts:
mkdir ~/.fonts
cp <new_font> ~/.fonts
mkfontdir ~/.fonts
xset fp+ ~/.fonts
xset fp rehash

The new font should now be available. Check if the new font has been added by running xlsfonts.
xlsfonts

Try out the new font:
xterm -fn "new_font"
 
2. For TrueType fonts, the installation process is a little different.
mkdir ~/.fonts
cp <new_font.ttf> ~/.fonts
cd ~/.fonts
mkfontscale
mkfontdir
fc-cache -fv ~/.fonts

The new font should now be available. Check if the font has been added by running:
fc-list

Try out the new font:
xterm -fa "xft:new_font"