Filesystem permissions / Access Control List (ACL)

https://www.redhat.com/sysadmin/linux-access-control-lists

chmod

chmod +r file.php # -rw-r--r--

https://www.howtogeek.com/437958/how-to-use-the-chmod-command-on-linux/

chown

chown +R apache file.php

setfacl