Mate-desktop on Centos 7

#!/bin/bash
#
### This script will install Mate desktop from EPEL repository
#   on a CentOS 7 system.
#   Optionaly, the "Gnome3 shell", "Gnome Classic desktop"
#   and gdm will be removed. In this case, the lightdm display
#   manager will be set as the default window manager.
#
#
#   Copyright 2014 by Yoram Gnat <yoram.gnat@gmail.com>
#   Published under GPL v2 License
#
#   Note: Since this script may change the display session
#   ====  and display manager it should run at runlevel 3 (multiuser)
#         and not runlevel 5 (graphical user)
#
#================================================================
### Be sure we are at runlevel 3
runlevel | grep 3 > /dev/null
if [ "$?" != "0" ]; then
   echo "This script should run at level 3 (multiuser level)."
   echo "As root, type the command 'init 3' in a shell"
   echo "then, login as root and run this script again"
   exit 1
fi
#================================================================
InstallX="false"
RemoveG3="false"
LightdmIsDefault="false"
InstallCompiz="false"
echo
echo "Mate Desktop will be installed on your system."
echo
### if X server is not installed we have the minimal installation and the
#   questions are irrelevant.
rpm -q xorg-x11-server-Xorg > /dev/null
if [ "$?" != "0" ]; then
   InstallX="true"
   LightdmIsDefault="true"
### else let's find what we should do
else
   echo "Do you want to remove GNOME3 and Gnome Classic desktops "
   echo -n "after installing Mate ? (y/n)"
   read A
   if [ "$A" = "y" ]; then
      RemoveG3="true"
      LightdmIsDefault="true"
   else
      echo -n "Do you want to make lightdm the default window manager ? (y/n)"
      read A
      if [ "$A" = "y" ]; then
         LightdmIsDefault="true"
      fi
   fi
fi
#============================ Here we start =============================
#
### Update the system
echo
echo "Updating System"
echo
yum -y update
#==============================================================================
#
### Enable extra repos (epel, nux-dextop and elrepo)for CentOS 7
# EPEL
if [ ! -f /etc/yum.repos.d/epel.repo ]; then
   rpm -Uvh https://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-8.noarch.rpm
fi
# nux-dextop
if [ ! -f /etc/yum.repos.d/nux-dextop.repo ]; then
   rpm -Uvh http://li.nux.ro/download/nux/dextop/el7/x86_64/nux-dextop-release-0-5.el7.nux.noarch.rpm
fi
# ELREPO
if [ ! -f /etc/yum.repos.d/elrepo.repo ]; then
   rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
   rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-2.el7.elrepo.noarch.rpm
fi
#==========================================================================
# If we start with minimal system, we should install X
# Since we do not want proprietary drivers at this stage, let's disable elrepo
# Such drivers, eg. nvidia, can be installed later.
if [ $InstallX = "true" ]; then
   yum -y --disablerepo=elrepo groupinstall "X Window System"
fi
#==========================================================================
#
### Mate Desktop
#
yum -y groupinstall "MATE Desktop"
### Be sure we start at what was once called run level 5 (graphical user).
systemctl set-default graphical.target
### Be sure caja is autostarting so that desktop icons will be visible
#
cat > /etc/xdg/autostart/caja-manage-desktop.desktop << EOF
[Desktop Entry]
Name=caja-manage-desktop.desktop
GenericName=File Manager
Exec=caja --no-default-window
Icon=system-file-manager
Terminal=false
Type=Application
StartupNotify=true
NoDisplay=true
OnlyShowIn=MATE;
X-MATE-Bugzilla-Bugzilla=MATE
X-MATE-Bugzilla-Product=caja
X-MATE-Bugzilla-Component=general
X-MATE-Bugzilla-Version=1.8.0
X-MATE-Autostart-Phase=Desktop
X-MATE-Autostart-Notify=true
X-MATE-AutoRestart=true
X-MATE-Provides=filemanager
X-Desktop-File-Install-Version=0.21
Name[en_US]=caja-manage-desktop.desktop
EOF
#==========================================================================
#
if [ "$RemoveG3" = "true" ]; then
   ### Remove gdm, Gnome3 shell and Gnome Classic
   yum -y remove \
      gdm \
      gnome-backgrounds gnome-boxes gnome-calculator \
      gnome-classic-session gnome-color-manager \
      gnome-contacts gnome-dictionary gnome-documents \
      gnome-font-viewer gnome-getting-started-docs \
      gnome-initial-setup gnome-packagekit gnome-shell \
      gnome-shell-extension* gnome-system-log gnome-terminal \
      gnome-tweak-tool gnome-video-effects gnome-weather \
      gnome-session nautilus*
      # just to be sure, remove definitions of old sessions if still there
      rm -f /usr/share/xsessions/*gnome*.desktop
      rm -f /usr/share/xsessions/*custom*.desktop
fi
#===============================================================================
#
if [ "$LightdmIsDefault" = "true" ]; then
      ### make lightdm the default display manager
      ln -sf /usr/lib/systemd/system/lightdm.service /etc/systemd/system/display-manager.service
fi
#===================================================================================
#  Be sure some stuff we need is installed.
#  We need gcc and kernel-devel if we are a VirtualBox guest and want the
#  VirtualBox additions installed.
#  We need wget later in this script and if docky is installed, xdotool may be helpful.
#  Since the xdotool from EPEL won't install we will install the one from nux-dextop.
#  Luckily epel is not needed for the other stuff.
   yum -y --disablerepo=epel install  gcc kernel-devel kernel-headers wget xdotool yumex && yum -y remove brasero rhythmbox totem evince* \
      eog empathy filezilla transmission* xchat  ekiga \
      evolution* baobab abrt* gnome-system-monitor orca gedit \
      gnote file-roller gnome-screenshot gnome-clocks && yum -y update
#==========================================================================
#
echo
echo "Reboot the system now."
echo
echo "Have fun."
echo
exit 0