In Linux OS, Here are ways to install.ttf,.otf,.ttc,.pfa fonts, among which,.pfa fonts need to affiliated with.afm fonts :

A.Desk System

a.Double click the file and click "Install" button.

b.Input "/" key and input "fonts:/" to build a new sub-catalog such as Chinese and drag font file to it.(such as/usr/share/fonts/chinese/)

B.Command Line

Step 1.Build a new sub-catalog under the catalog of/usr/share/fonts and as in:

# mkdir/usr/share/fonts/chinese

Step 2: Copy font file to the sub-catalog such as/root/desktop as in:

# cd/root/desktop

# cp font.ttf /usr/share/fonts/chinese/

Step3: Build index information of Fonts and update font cache, as in:

# cd/usr/share/fonts/chinese

# mkfontscale

# mkfontdir

# fc-cache

There, the font is installed.

Tip: It is slightly different in different Linux operational systems and you should adjust it.