# fc-cache --help
usage: fc-cache [-frsvVh] [--force|--really-force] [--system-only] [--verbose] [--version] [--help] [dirs]
Build font information caches in [dirs]
(all directories in font configuration by default).

  -f, --force          scan directories with apparently valid caches
  -r, --really-force   erase all existing caches, then rescan
  -s, --system-only    scan system-wide directories only
  -v, --verbose        display status information while busy
  -V, --version        display font config version and exit
  -h, --help           display this help and exit

fc-list