One-click-fonts-install GUI utility for installing fonts like gnome-font-viewer are available in Debian. But installing fonts without using any GUI tool is much for straightforward and fun. You just need to copy the fonts in a specific directory in which Debian would search for fonts to use. That’s all.
Debian searches for fonts in some specified directories. The directories are specified in /etc/fonts/fonts.conf file. You can open this file in your system to see which directories holds the fonts. Usually, /usr/share/fonts, /usr/X11R6/lib/X11/fonts, /usr/local/share/fonts, etc. directories hold fonts which are available system wide. Better yet, use ~/.fonts directory that would make the fonts available only for your account or userid. Understandably this .fonts directory resides in your home directory, the path being ~/.fonts, or /home/your_userid/.fonts. Therefore, copy the fonts you would use in this directory to make them available for your user account or userid.
Say, a directory named font_collections holds your desired fonts. Open terminal from this directory and execute the following command to copy all the fonts from this directory to .fonts directory in your home folder:
cp * ~/.fonts
The * (asterisk) character used here acts as an wild card; meaning it denotes every file in the specified directory. Assuming your font_collections directory holds only fonts, the above command would copy all of them in ~/.fonts.
If your font_collections directory holds fonts and other files, then you can mention every fonts file by their extension and copy only them with the following command:
cp *.ttf ~/.fonts
Assuming your fonts are in ttf (True Type Font) format.
You can also copy the fonts without being in the directory that holds the font. Just use the following command format:
cp /path/to/the/directory/that/holds/fonts/* ~/.fonts
That would do the job of copying fonts. Now, you have to re-generate fonts cache file to make your system aware of the updated ~/.fonts directory. Open terminal and execute the following command:
This would make the fonts available for you. Open any text/word processing application, and see the fonts appear in that application, and use them, of course!