steamos-session-select for Fedora 42 using GDM (GNOME).

[isaranghi]

Hello,

I am on Fedora 42, and would like to implement steamless swtiching between gnome and gamescope sessions.... Any chance you can provide a steamos-session-select script for Fedora 42 using GNOME and GDM along with those sudoers rule to switching without asking for password?

Thanks.

[unlbslk]

First of all, this script is only for Arch Linux based distros.

But if you did set up a Gamescope session it may work on Fedora too.

steamos-session-select is currently configured to only work with SDDM.
But you can easily switch from GDM to SDDM:

sudo dnf install sddm
sudo systemctl disable gdm
sudo systemctl enable sddm

Then, create a config file at /etc/sddm.conf and copy this into it with sudo nano /etc/sddm.conf:

[Autologin]
Relogin=true
Session=gnome
User=put your username here

[General]
HaltCommand=/usr/bin/systemctl poweroff
RebootCommand=/usr/bin/systemctl reboot

[Theme]
Current=

[Users]
MaximumUid=60513
MinimumUid=1000

After that, find the name of the gamescope session with this command:

ls /usr/share/wayland-sessions

Next, edit the script with sudo nano /usr/bin/steamos-session-select:
(change the NEW_SESSION="gamescope-session-steam" variable if the name of the wayland session is different)

#!/usr/bin/bash

CONFIG_FILE="/etc/sddm.conf"

# If no arguments are provided, list valid arguments
if [ $# -eq 0 ]; then
    echo "Valid arguments: plasma, gamescope"
    exit 0
fi

# If the argument is "plasma"
# IMPORTANT: If you want to use a desktop environment other than KDE Plasma, do not change the IF command. 
# Steam always runs this file as "steamos-session-select plasma" to switch to the desktop. 
# Instead, change the code below that edits the config file.

if [ "$1" == "plasma" ] || [ "$1" == "desktop" ]; then
    
    echo "Switching session to Desktop."
    if [ ! -f "$CONFIG_FILE" ]; then
        echo "SDDM config file could not be found at $CONFIG_FILE."
        exit 1
    fi
    NEW_SESSION='$selected_de' # For other desktops, change here.
    sudo sed -i "s/^Session=.*/Session=gnome/" "$CONFIG_FILE"
    steam -shutdown

# If the argument is "gamescope"
elif [ "$1" == "gamescope" ]; then
    
    echo "Switching session to Gamescope."
    if [ ! -f "$CONFIG_FILE" ]; then
        echo "SDDM config file could not be found at $CONFIG_FILE."
        exit 1
    fi
   
# Change gamescope session name NEW_SESSION="gamescope-session-steam"  
    sudo sed -i "s/^Session=.*/Session=gnome/" "$CONFIG_FILE"
    dbus-send --session --type=method_call --print-reply --dest=org.kde.Shutdown /Shutdown org.kde.Shutdown.logout || gnome-session-quit --logout --no-prompt || cinnamon-session-quit --logout --no-prompt || loginctl terminate-session $XDG_SESSION_ID
else
    echo "Valid arguments are: plasma, gamescope."
    exit 1
fi

For sudoers rule run this command:

sudoers_file="/etc/sudoers.d/sddm_config_edit"
echo "ALL ALL=(ALL) NOPASSWD: /usr/bin/sed -i s/^Session=*/Session=*/ /etc/sddm.conf" | sudo tee "$sudoers_file" > /dev/null