This is a fork from opentmpfiles, a standalone utility written to process systemd-style tmpfiles.d files so that they can be handled on systems with or without systemd installed.
Hardened changes prevent removal or change of ownership when directories are owned by root.
Race conditions reported in CVE-2017-18925 are prevented by first deleting the directory recursively and then creating a new one with mkdir. If the destination is created before mkdir, the command will fail.
Under the principle of "better fail than corrupt", this script will exit on any error.
For more information on the files this utility can process, see the tmpfiles.d man page.