How to add the option to flush system caches resp. flush all caches in TYPO3 6, 7, 8, 9
How to get absolute and relative paths of an extension in TYPO3 6, 7, 8.
How to activate the option to add the page uid next to the page title inside the page tree.
How to get constants from whole TYPO3 Installation into your extbase extension. Method for TYPO3 6.2.x -> 7.x.x
How to use the TYPO3 clear cache command