How to use the command 'fc-cache' (with examples)
The fc-cache command is used to scan font directories and generate font cache files. This command helps improve the performance of font rendering by caching font files for faster access. The font cache files are used by applications to quickly locate and use installed fonts.
Use case 1: Generate font cache files
Code:
fc-cache
Motivation: Running fc-cache without any arguments generates font cache files for all font directories. This is useful when new fonts are installed or when changes are made to existing font files.
Explanation: The fc-cache command without any arguments scans all directories listed in the font configuration to build the font cache files. It checks for new font files and updates the cache with the latest information.
Example output:
/usr/share/fonts: caching, new cache contents: 0 fonts, 3 dirs
/usr/share/fonts/X11: caching, new cache contents: 0 fonts, 5 dirs
/usr/share/fonts/X11/Type1: caching, new cache contents: 23 fonts, 0 dirs
...
/usr/local/share/fonts: skipping, no such directory
...
/usr/share/fonts/truetype/dejavu: caching, new cache contents: 21 fonts, 0 dirs
...
Use case 2: Force a rebuild of all font cache files
Code:
fc-cache -f
Motivation: In some cases, the font cache files may still be considered up-to-date even when changes have been made to the font directories. By using the -f option, you can force a rebuild of all font cache files, ensuring that the cache reflects the latest changes made to the font directories.
Explanation: The -f option tells fc-cache to ignore the check if the font cache is up-to-date and forces a rebuild of all font cache files. This can be useful when changes have been made to the font directories, but the cache is not being updated automatically.
Example output:
/usr/share/fonts: cleaning cache directory
/usr/share/fonts/X11: cleaning cache directory
/usr/share/fonts/X11/Type1: cleaning cache directory
...
/usr/share/fonts/truetype/dejavu: cleaning cache directory
...
/usr/share/fonts: caching, new cache contents: 0 fonts, 3 dirs
/usr/share/fonts/X11: caching, new cache contents: 0 fonts, 5 dirs
...
/usr/share/fonts/truetype/dejavu: caching, new cache contents: 21 fonts, 0 dirs
...
Use case 3: Erase font cache files and generate new ones
Code:
fc-cache -r
Motivation: The -r option erases the existing font cache files and generates new ones from scratch. This can be helpful when there are inconsistencies or corruption in the font cache files, or when you want to completely rebuild the font cache.
Explanation: The -r option performs a complete re-caching of the font directories. It first erases the existing font cache files and then generates new cache files by scanning the font directories. This is useful when you want to start with a clean font cache or when there are issues with the existing cache.
Example output:
/usr/share/fonts: cleaning cache directory
/usr/share/fonts/X11: cleaning cache directory
/usr/share/fonts/X11/Type1: cleaning cache directory
...
/usr/share/fonts: caching, new cache contents: 0 fonts, 3 dirs
/usr/share/fonts/X11: caching, new cache contents: 0 fonts, 5 dirs
...
/usr/share/fonts/truetype/dejavu: caching, new cache contents: 21 fonts, 0 dirs
...
Conclusion:
The fc-cache command is a useful tool for managing font cache files. Whether you need to generate new cache files, force a rebuild of existing ones, or start with a clean cache, the fc-cache command provides the necessary functionality. By regularly running fc-cache, you can ensure that your system has an up-to-date font cache, resulting in improved font rendering performance for applications.
