nologin(5) - Linux man page
Name
nologin - prevent unprivileged users from logging into the system
Description
If the file /etc/nologin exists and is readable, login(1) will allow access only to
root. Other users will be shown the contents of this file and their logins will be refused.
Files
/etc/nologin
See Also
login(1), shutdown(8)
Referenced By
pam_nologin(8)