fc-cache(1) -- Linux man page
NAMEfc-cache, fonts.cache - create an index of FreeType font files in a directory
SYNOPSISfc-cache [directory-name ... ]
DESCRIPTIONIf directory arguments are not given, fc-cache uses each directory in the current font configuration. Each directory is scanned for font files readable by FreeType. A cache is created which contains properties of each font and the associated filename. This cache is used to speed application startup when using the fontconfig library.
- Maps file names to font properties. Read by the fontconfig library at application startup to locate appropriate fonts.