[CentOS] systemd private tmp dirs

Is there a generic way that processes written to share files with (say) apache in /tmp can figure out that they are running on an OS with systemd and in that case, where the daemon in question thinks /tmp is?

For example, twiki has a backup/restore add-in where the backup part is normally done from cron with a command line script but the resulting archives that go in /tmp are supposed to be seen in the web interface where you can choose and restore from them. How should that have been written so the file lands where systemd has remapped /tmp for httpd if it happens to be running on a host with systemd?