autogpuswitch.sh

#!/usr/bin/bash

# # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
# You would have to create an xorg.conf file for your Nvidia setup		#
# before using this script! It can be done by running:				#
#										#
#	nvidia-xconfig -o /etc/X11/xorg.conf.nvidia				#
#										#
# Make sure your system has eGPU connected and a monitor plugged into the GPU.	#
# The reason I've never automated this is that you have to have it all plugged	#
# in and ready to go. Also some may prefer writing xorg.conf.nvidia by hand.	#
# # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #

echo "Checking the bus for any Nvidia cards.."
if lspci | grep NVIDIA
then
	echo "Nvidia GPU detected!"
	echo "Switching to Nvidia..."
	if pacman -Qe | grep mesa-libgl
	then
		yes | pacman -S nvidia-libgl lib32-nvidia-libgl
	fi
	ln -sf /etc/X11/xorg.conf.nvidia /etc/X11/xorg.conf
else	
	echo "No Nvidia GPU detected"
	echo "Switching to Mesa.."
	if pacman -Qe | grep nvidia-libgl
	then
		yes | pacman -S mesa-libgl lib32-mesa-libgl
	fi
	rm /etc/X11/xorg.conf
fi

echo "Switched"
#sudo systemctl restart lightdm

Since I've been using a lot of things changed, in particular now we have a libglvnd that allows us to have more than 1 libgl on our systems at once. So the dirty hack with uninstalling/installing the libgl is no longer needed, and I don't know what else is broken here.

Thanks.