Linux Firefox default sans-serif font

Question

Which font is the default sans-serif font in Linux? When I go in Windows in Firefox to Options > Font > Advanced I can see that the default sans-serif font is Arial, but in Linux it only shows sans-serif as a font by itself.

Any idea how can I check which sans-serif font is this?

Solution 1

If fonts are handled by fontconfig then they are defined in /etc/fonts. It seems the command fc-match does the mapping from 'serif', 'sans-serif', etc. to the actual fonts:

$ fc-match sans-serif
Vera.ttf: "Bitstream Vera Sans" "Roman"
$ fc-match monospace
VeraMono.ttf: "Bitstream Vera Sans Mono" "Roman"

Solution 2

The sans-serif font will be an open-source alternative to the proprietary fonts you may be accustomed to.

As a generalisation, Linux distributions have support for TrueType fonts like Lucida, Helvetica and Arial, but you have to download them separately - they don't come pre-installed.

for example, see this link

Solution 3

Most modern GNU/Linux distributions, like OpenSuSE and Fedora for example, use fontconfig for fonts management and configuration. The configuration is stored in /etc/fonts/ and it's sub-directories. There will be a mapping file there, but the name of the file varies from distribution to distribution and from version to version. For example in OpenSuSE 12.3 you can find default mappings in /etc/fonts/conf.d/58-suse-post-user.conf