Change default persian font in Ubuntu

vazirmatn-ubuntu.md

1. Install the font

sudo apt install fonts-vazirmatn

or download it and place it in ~/.local/share/fonts/ or /usr/share/fonts/truetype/.

2. Create this file

mkdir -p ~/.config/fontconfig
nano ~/.config/fontconfig/fonts.conf

3. Paste this in it

<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
  <!-- Prefer Vazirmatn for sans-serif -->
  <match>
    <test name="family" compare="eq">
      <string>sans-serif</string>
    </test>
    <edit name="family" mode="prepend" binding="strong">
      <string>Vazirmatn</string>
    </edit>
  </match>

  <!-- Force Persian (fa) language to use Vazirmatn -->
  <match>
    <test name="lang" compare="contains">
      <string>fa</string>
    </test>
    <edit name="family" mode="prepend" binding="strong">
      <string>Vazirmatn</string>
    </edit>
  </match>
</fontconfig>

4. Reload

fc-cache -f -v