whisperer(){
    echo "Add nomodeset to your kernel line in /boot/grub/grub.cfg , ie.:"
    echo "ernel /boot/vmlinuz-linux root=/dev/sda1 ro nomodeset"
    echo "----------------------------------------------------------------"
    echo "If experiencing problems with white/gray/black_artifacts you can"
    echo "[as root] kill Xserver and use this command:"
    echo "# aticonfig --set-pcs-str=DDX,ForceXAA,TRUE"
    echo "----------------------------------------------------------------"
    echo "Now you can swítch between xorg-libgl for intel/radeon or fglrx"
    echo "[as root] use this command:"
    echo "# pxp_switch_catalyst <amd|intel|query>"
    echo "----------------------------------------------------------------"
}

check_libdri_so(){
    if [ ! -e usr/lib/xorg/modules/extensions/libdri.so ]; then
        ln -sf usr/lib/xorg/modules/extensions/libdri.xorg usr/lib/xorg/modules/extensions/libdri.so
    fi
}

#pXp = powerXpress, set catalyst libs in default
pXp_set_to_amd(){      
    usr/lib64/fglrx/switchlibGL amd
    usr/lib64/fglrx/switchlibglx amd
}

post_install(){
    check_libdri_so
    pXp_set_to_amd
    whisperer
}

post_upgrade(){
    check_libdri_so
    pXp_set_to_amd
    whisperer
}

post_remove(){
    # If the symlink is dead, remove it
    check_libdri_so
    #remove /usr/lib/catalystpxp/libGL.so* symlinks and dir
    rm usr/lib/catalystpxp/libGL.so* &>/dev/null
    rmdir -p "usr/lib/catalystpxp/" --ignore-fail-on-non-empty &>/dev/null
    #remove usr/lib/xorg/modules/updates/extensions/libglx.so symlink and dir
    rm usr/lib/xorg/modules/updates/extensions/libglx.so &>/dev/null
    rmdir -p "usr/lib/xorg/modules/updates/extensions" --ignore-fail-on-non-empty &>/dev/null
    rmdir -p "usr/lib/xorg/modules/updates" --ignore-fail-on-non-empty &>/dev/null
}