GDM is the GNOME Display Manager which handles graphical login for GNOME based systems. The disable-user-list option controls if a list of users is displayed on the login screen Displaying the user list eliminates half of the Userid/Password equation that an unauthorized person would need to log on.
Solution
- IF - GDM is installed: Run the following script to enable the disable-user-list option: Note: the l_gdm_profile variable in the script can be changed if a different profile name is desired in accordance with local site policy. #!/usr/bin/env bash { l_gdmprofile="gdm" if [ ! -f "/etc/dconf/profile/$l_gdmprofile" ]; then echo "Creating profile \"$l_gdmprofile\"" echo -e "user-db:user\nsystem-db:$l_gdmprofile\nfile-db:/usr/share/$l_gdmprofile/greeter-dconf-defaults" > /etc/dconf/profile/$l_gdmprofile fi if [ ! -d "/etc/dconf/db/$l_gdmprofile.d/" ]; then echo "Creating dconf database directory \"/etc/dconf/db/$l_gdmprofile.d/\"" mkdir /etc/dconf/db/$l_gdmprofile.d/ fi if ! grep -Piq '^\h*disable-user-list\h*=\h*true\b' /etc/dconf/db/$l_gdmprofile.d/*; then echo "creating gdm keyfile for machine-wide settings" if ! grep -Piq -- '^\h*\[org\/gnome\/login-screen\]' /etc/dconf/db/$l_gdmprofile.d/*; then echo -e "\n[org/gnome/login-screen]\n# Do not show the user list\ndisable-user-list=true" >> /etc/dconf/db/$l_gdmprofile.d/00-login-screen else sed -ri '/^\s*\[org\/gnome\/login-screen\]/ a\# Do not show the user list\ndisable-user-list=true' $(grep -Pil -- '^\h*\[org\/gnome\/login-screen\]' /etc/dconf/db/$l_gdmprofile.d/*) fi fi dconf update } Note: When the user profile is created or changed, the user will need to log out and log in again before the changes will be applied.