Selinux - centos - missing /etc/selinux/config

sestatus will tell you if SELinux is enabled, as well as a few other characteristics.

To change the SELinux to disable you can use the below command:

setenforce 0

While this does not replace the config file it will put SELinux into permissive mode until the next reboot, meaning that SELinux is running and logging but not actually controlling permissions.

You can as well try the command:

/usr/bin/system-config-securitylevel-tui

To totally disable it.