fc-validate --version (return code: 0)
fontconfig version 2.11.94
fc-validate --help (return code: 0)
usage: fc-validate [-Vhv] [-i index] [-l LANG] [--index index] [--lang LANG] [--verbose] [--version] [--help] font-file...
Validate font files and print result
-i, --index INDEX display the INDEX face of each font file only
-l, --lang=LANG set LANG instead of current locale
-v, --verbose show more detailed information
-V, --version display font config version and exit
-h, --help display this help and exit