bash script for gnome3 classic startup applications in debian 7.1

The reason for this script: The Debian 7.1 nouveau driver runs opengl perfectly with Intel or Nvidia cards but does not work with ATI cards. So I cannot turn on compiz opengl automatically in startup applications by default. I must first find out if the user has an Intel, Nvidia card or an ATI card in their pc or laptop before turning on compiz which also turns on opengl Please note: ATI cards only work with compiz and opengl if the ATI fglrx driver is installed on the pc or laptop. This cli tells me what VGA controller is in pc or laptop: lspci | grep -i --color vga The output is this: 02:00.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI Cedar PRO [Radeon HD 5450/6350] The script first needs to search that output and if it finds ATI or Radeon then the script needs to check if the user has also installed the ATI fglrx driver. This cli tells me if the user has installed ATI fglrx driver: lsmod | grep -i fglrx The output is this: fglrx 5170830 181 button 12937 1 fglrx So if the script finds that the ATI fglrx driver is installed then the script should run compiz --replace to turn on compiz and opengl Very Important: If the script finds an ATI or Radeon card but does not find the ATI fglrx driver installed then it should stop running. It should not run compiz --replace If the script does not find an ATI card then it should always run compiz --replace to turn on compiz and opengl So we always want compiz --replace to run if the user has either an Intel or Nvidia driver in their pc or laptop. This ati card & fglrx driver lookup startup script will need to be put by me into the startup applications where I will turn it on. Obviously we do not want the user to have to enter a sudo password for the script to run. The script must be transparent to the user. I will do all of the testing for you. So you do not need to set up Debian 7 running Gnome 3 classic.