Bash script to easily toggle in Nvidia Optimus based laptops between integrated and discrete graphics cards, compatible out of the box with Archlinux+LightDM systems

optiswitch

#!/bin/bash

# Nvidia official linux drivers and the bbswitch module are asumed to be installed, when using the integrated 
# intel video card bbswitch will be used to turn the Nvidia card off for energy saving purposes. Reboot is needed to
# switch between  modes.
# NOTE:
# /etc/lightdm.conf must contain this text, uncommented:
#
# [Seat:*]
# ... etc ...
# display-setup-script=/etc/lightdm/display-setup


[ "$UID" -eq 0 ] || exec sudo "$0" "$@"

ME=$(echo $(basename $0))
MODPROBE_CONF_FILE="/etc/modprobe.d/video.conf"
XORG_CONFIG_FILE="/usr/share/X11/xorg.conf.d/10-nvidia.conf"
LIGHTDM_CONF_FILE="/etc/lightdm/display-setup"

IFS='' read -r -d '' MODPROBE_NVIDIA <<"EOD"
blacklist bbswitch
EOD

IFS='' read -r -d '' MODPROBE_INTEL <<"EOD"
install nvidia /bin/true
install nvidia_drm /bin/true
install nvidia_modeset /bin/true

options bbswitch load_state=0 unload_state=1
EOD

IFS='' read -r -d '' LIGHTDM_NVIDIA_INFO <<"EOD"
#!/bin/bash
xrandr --setprovideroutputsource modesetting NVIDIA-0
xrandr --auto
xrandr --dpi 96
EOD

IFS='' read -r -d '' XORG_CONF_NVIDIA <<"EOD"
Section "OutputClass"
    Identifier "nvidia"
    MatchDriver "nvidia-drm"
    Driver "nvidia"
    Option "AllowEmptyInitialConfiguration"
    Option "PrimaryGPU" "yes"
    ModulePath "/usr/lib/nvidia/xorg"
    ModulePath "/usr/lib/xorg/modules"
EndSection
EOD

set -eu

echo

if [ $# -lt 1 ]; then
    if [ ! -x "$(which glxinfo)" ]; then
        echo "Missing required tool glxinfo for autodetection, please install it or specify a setup (NVIDIA|INTEL)"
        exit
    fi
    if [ -z "$(glxinfo|grep 'OpenGL vendor string: NVIDIA')" ]; then
        echo "Autodetected INTEL OpenGL vendor in use"
        WILLENABLE="NVIDIA"
    else
        echo "Autodetected NVIDIA OpenGL vendor in use"
        WILLENABLE="INTEL"
    fi
elif [ "$1" = "intel" ]; then
    WILLENABLE="INTEL"
elif [ "$1" = "nvidia" ]; then
    WILLENABLE="NVIDIA"
else
    echo -e "Invalid parameter, use:\n$ME (optional: nvidia|intel)"
    exit
fi

echo "Will switch to $WILLENABLE video setup, a reboot is needed after that"
read -p "Please press Enter to continue, C-c to abort"

DONE=0

echo -n "Processing"

if [ "$WILLENABLE" = "NVIDIA" ]; then
  echo -n "."
  echo "${MODPROBE_NVIDIA}" > $MODPROBE_CONF_FILE
  echo -n "."
  echo "${XORG_CONF_NVIDIA}" > $XORG_CONFIG_FILE
  echo -n "."
  echo "${LIGHTDM_NVIDIA_INFO}" > $LIGHTDM_CONF_FILE
  chmod a+x $LIGHTDM_CONF_FILE
  DONE=1
elif [ "$WILLENABLE" = "INTEL" ]; then
  echo -n "."
  echo "${MODPROBE_INTEL}" > $MODPROBE_CONF_FILE
  echo -n "."
  test -f $XORG_CONFIG_FILE && rm $XORG_CONFIG_FILE
  echo -n "."
  test -f $LIGHTDM_CONF_FILE && echo "" > $LIGHTDM_CONF_FILE
  DONE=1
fi

if [ "$DONE" = "1" ]; then
  echo -e "\nDone"
  if [ -z "$(lsmod | egrep "(^nvidia|^bbswitch)")" ]; then
      echo "Warning: Neither the nvidia or the bbswitch kernel modules are loaded, recommending a full system halt"
  fi
  read -p "Do you want to reboot now?(y/N) " yn
  if [ "$yn" = "y" ]; then
    reboot
  fi
else
  echo "Something went wrong"
fi

exit