This script easily downloads public files from Google Drive onto your disk using a file identifier.

gdrive-download-tool.sh

#!/bin/bash
###########
# Download public files from Google Drive using file identifier

if [ $# -lt 1 ]; then
	echo "No argument defined. Usage: $0 fileID [destination]" >&2
	echo "Try '$0 --help' for more information."
	exit 1
elif [ $# -gt 2 ]; then
	echo "Too many arguments. Usage: $0 fileID [destination]" >&2
	echo "Try '$0 --help' for more information."
	exit 1
elif [ "$1" = '--help' ]; then
	echo -e "$(tput setaf 3)GDrive Download-Tool v1.0$(tput sgr0)"
	echo -e "This script easily downloads $(tput smul)public files$(tput rmul) from Google Drive onto your disk."
	echo -e "Downloaded files will be stored to the directory where this script is placed in if no second argument is given."
	echo -e "\nOnly the file identifier is needed of the file you want to download and to be appended to the script name on your command line."
	echo -e "Therefore the usage is as the following: $(tput bold)$0 $(tput setaf 3)fileID$(tput sgr0) [destination]"
	exit 0
elif [[ "$1" =~ [^0-9A-Za-z]+ ]]; then
	echo "Invalid characters found in fileID"
	exit 1
fi

# Continue if no errors occurred
if [ -z "$2" ]; then
	directory="$(dirname $0)"
else
	directory="$2"
fi

directory="${directory%/}"

if [ ! -d "$directory" ]; then
	echo "'$directory' is not a valid directory"
	exit 1
fi

filename="$(wget --quiet -O - https://docs.google.com/file/d/$1/edit?usp=sharing | sed -n -e 's!.*<title>\(.*\) - Google Drive</title>.*!\1!p')"

if [ -n "$filename" ]; then
	file="$directory/$filename"
	if [ ! -f "$file" ]; then
		wget https://googledrive.com/host/$1 -O "$file"
	else
		echo "File '$file' already exists on disk. Aborting..."
		exit 1
	fi
else
	echo "Given fileID '$1' does not point to a valid file. Aborting..."
	exit 1
fi

exit 0

Created this script quite a while ago to download a backup I stored on Google Drive.