Provided by: freetype2-demos_2.9.1-3_amd64
ftlint - simple font tester
ftlint ppem fontname[.ttf|.ttc] ...
ftlint opens the given font(s), loads and renders all glyphs at the given ppem value, and reports failing glyphs if there are less than ten fails, or the number of fails only if there are more fails. This program does not have any options. It is part of the FreeType demos package.