In order to install font Fandol, I've put font files into ~/.TeXmacs/fonts/truetype. But when I want to refresh TeXmacs font cache with shell command "texmacs --delete-font-cache", the shell shows "Unknown command 'texmacs'". I install TeXmacs by .dmg file. So how could I refresh font cache of TeXmacs? Thanks.
You should know exactly where you install texmacs in, then run:
$ path/to/the/binary --delete-font-cache