Exibindo um prompt de usuário na tela de início de sessão do GNOME

Para exibir um prompt de usuário na tela de login do GNOME, abra um terminal e siga os próximos passos:

Create a file for the GNOME Display Manager (GDM) configuration.

$ sudo mkdir /etc/dconf/db/gdm.d

$ sudo vim /etc/dconf/db/gdm.d/01-hide-users

In a text editor of your choice, vim in this example, insert the following content to the /etc/dconf/db/gdm.d/01-hide-users file:
```
[org/gnome/login-screen]
banner-message-enable=true
banner-message-text='ENTER ANY MESSAGE YOU WANT HERE. FOR A NEW LINE USE \n.'
disable-restart-buttons=true
disable-user-list=true
```
To not display the banner message, do not include the first and second line. To enable the Restart button, do not include the fourth line.

Save the file and return to the terminal.
Create another file for GDM configuration.
```
$ sudo vim /etc/dconf/profile/gdm
```
Insert the following content in the /etc/dconf/profile/gdm file:
```
user-db:user
system-db:gdm
```
Save the file.
Enter the following command:
```
$ sudo dconf update
```
Check if the command was executed correctly:
```
$ ls /etc/dconf/db
```
The output should contain the following:
```
gdm gdm.d ... [output truncated]
```
Restart GDM for the changes to take effect.
```
$ sudo systemctl restart gdm
```

Exibindo um prompt de usuário ao invés de uma lista de usuários na tela de login do GNOME