how to have the root in the login screen

In the past I remember that there was the possibility to include the root icon in the graphic login screen, I cannot find it now, how can I have the root icon in the login screen??

I assume you mean the graphical login screen showed by the display manager?

First, it is then of course interesting which display manager. As root

update-alternatives --display default-displaymanager

And then you might want to explain what you mean with “the root icon”.

yes, that one

pla@pla4-TW:~> sudo update-alternatives --display default-displaymanager
[sudo] password for root: 
default-displaymanager - auto mode
  link best version is /usr/lib/X11/displaymanagers/sddm
  link currently points to /usr/lib/X11/displaymanagers/sddm
  link default-displaymanager is /usr/lib/X11/displaymanagers/default-displaymanager
/usr/lib/X11/displaymanagers/console - priority 5
/usr/lib/X11/displaymanagers/gdm - priority 25
/usr/lib/X11/displaymanagers/lightdm - priority 15
/usr/lib/X11/displaymanagers/sddm - priority 25
/usr/lib/X11/displaymanagers/xdm - priority 10
pla@pla4-TW:~> 

when the graphical login screen showed by the display manager appear it shows the three users icon where click on to login and insert password, I would like to have also the root icon to login as root

Well, I can imgaine that there is no “icon” for user root as it is not a very clever thing to log in in the GUI as root.

But are there no text fields where you can simply type the username and password (again, please do not read this as any encouraging to log in as root)?

I am personaly not using sddm, thus I have to guess a bit what you see.

root icon or root user?

root icon for root user

there is an icon called “different user” but if I click on it everything freeze and I cannot access to no other user

On 5/11/19 10:36 AM, Sauerland wrote:
>
> root icon or root user?
>

To quote the OP:

“when the graphical login screen showed by the display manager appear it
shows the three users icon where click on to login and insert password,
I would like to have also the root icon to login as root”

He wants to be able to select the root user at the login screen and the
selection is not available.

I agree that the choice should not be readily available but should be
the users choice no matter how hard you make it so that the users cannot
“shoot themselves in the foot”.


Ken
unix since 1986
S.u.S.E.-openSUSE since 1998

Well, that is not what I understood from the OP, but as we have found out that this is sddm, one should of course look at sddm documentation.
Or wait for sddm users who tried the same. I am not an sddm user and will certainly not try the same for obvious reasons.

I see that

man sddm

is rather short, but it links to more documentation. HTH.

User Icon (Avatar)

SDDM reads the user icon (a.k.a. “avatar”) as a PNG image from either ~/.face.icon for each user, or the common location for all users specified by FacesDir in an SDDM configuration file. The configuration setting can be placed in either /etc/sddm.conf directly, or, better, a file under /etc/sddm.conf.d/ such as /etc/sddm.conf.d/avatar.conf.

To use the FacesDir location option, place a PNG image for each user named as username.face.icon into location specified in for FacesDir in the configuration file. The default location for FacesDir is /usr/share/sddm/faces/. You can change the default FacesDir location to match your requirements. Here is an example:

/etc/sddm.conf.d/avatar.conf

[Theme]
FacesDir=/var/lib/AccountsService/icons/

The other option is to put a PNG image named .face.icon at the root of your home directory. In this case, no changes to any SDDM configuration file is required. However, you need to make sure that sddm user can read the PNG image file(s) for the user icon(s).
Note: In many KDE versions, the user icon image file is ~/.face and ~/.face.icon is a symlink to that file. If the user icon images are symlinks, you need to set proper file permissions to the target files.

To set proper permissions run:

$ setfacl -m u:sddm:x ~/
$ setfacl -m u:sddm:r ~/.face.icon

You can check permissions with:

$ getfacl ~/
$ getfacl ~/.face.icon

See SDDM README: No User Icon.

https://wiki.archlinux.org/index.php/SDDM

yes but:
“SDDM only displays users with a UID in the range of 1000 to 65000 by default, if the UIDs of the desired users are below this value then you will have to modify this range. For example, for a UID of 501, say:”
how to know the UID number of root?

Thats why I asked for icon and user.

Change:

MinimumUid=1000

to

MinimumUid=1

in /etc/sddm.conf

But:
You should not login to KDE or Gnome as root.

You can use Apllications as root such as dolphin or krusader and when you want to change a file, you can open it by rightclicking in the root-filemanager and open by kate/kwrite.

That is very, very basic. It is 0 (zero).

That is very, very basic. It is 0 (zero).

My fault, so change it to

MinimumUid=0

That wouldn’t also include at, bin, daemon, dnsmasq, ftp, games…wwwrun in the users list???

Unless any specific SDDM fuctionality or eye candy is required, I recommend trying out the comparably efficient, unthemed kdm with a minimal dependencies and minimal config (/usr/share/kde4/config/kdm/kdmrc) and explicit list of allowed users:

[General]
GreeterUID=kdm

[X-*-Greeter]
LogoArea=None
GreetString=
AntiAliasing=false
UserList=***true***
Users=**root;***standarduser1;standarduser2;…]]*
SortUsers=false
ForgingSeed=*[redacted]*
Preloader=
UseTheme=false

[X-:*-Core]
AllowShutdown=All

[X-:*-Greeter]
PreselectUser=Previous
FocusPasswd=true
LoginMode=DefaultLocal
AllowClose=true

It shaved about half a second from my system startup (which, according to systemd-analyze, is around 1.3 to 1.5 seconds from GRUB to KDE by now).
KDM can sort your user list (change SortUsers=false to true above), it can auto-login your standard user to your standard window manager/desktop environment, and it can log in root into, say, IceWM, which I do from time to time whenever I have a bit more work to do as root, doing backups or many updates, managing VMs, working with graphical YaST for stretches of time etc.

Give it a whirl. Cheers!

Of course it would.

The simplest solution to the question which worked in the past (may not work today and may not work with specific DMs),
This would apply to all User accounts, including root…

Logon at least once by selecting “Other…” and then enter the new Username and Password.
After that, the login screen should display all User accounts which had successfully logged in before.

TSU

My twopence worth:

The user “root” is, from a system point of view, necessary but, that user is “The root of all evil”.
Yes, on small non-commercial systems, logging into a GUI as the user “root” is sometimes needed but, at the end of the day, it’s a “quick and dirty” solution …

A better solution is, IMHO, to create at least one “Administrator” user – for the case of openSUSE, ‘/etc/login.defs’ gives the clues as to suitable UID and GID values:


#
# Min/max values for automatic uid selection in useradd(8)
#
# SYS_UID_MIN to SYS_UID_MAX inclusive is the range for
# UIDs for dynamically allocated administrative and system accounts.
# UID_MIN to UID_MAX inclusive is the range of UIDs of dynamically
# allocated user accounts.
#
UID_MIN                  1000
UID_MAX                 60000
# System accounts
SYS_UID_MIN               100
SYS_UID_MAX               499
# Extra per user uids
SUB_UID_MIN                100000
SUB_UID_MAX             600100000
SUB_UID_COUNT               65536

#
# Min/max values for automatic gid selection in groupadd(8)
#
# SYS_GID_MIN to SYS_GID_MAX inclusive is the range for
# GIDs for dynamically allocated administrative and system groups.
# GID_MIN to GID_MAX inclusive is the range of GIDs of dynamically
# allocated groups.
#
GID_MIN                  1000
GID_MAX                 60000
# System accounts
SYS_GID_MIN               100
SYS_GID_MAX               499
# Extra per user group ids
SUB_GID_MIN                100000
SUB_GID_MAX             600100000
SUB_GID_COUNT               65536

AFAICS, there’s nothing in the openSUSE documentation on this but, from my point of view, an administrator user with a UID within the “System account” range and a GID of “root” should be able to perform everything “root” does and, “sddm” can be setup to display this user on the login screen …