#!/usr/bin/env python
import os
import commands
default_ubuntu_gnome_releases=["8.04", "9.10", "10.04", "10.10"]
distribution_id=commands.getoutput("lsb_release -i -s")
release=commands.getoutput("lsb_release -r -s")
try:
     desktop_environment=os.environ["DESKTOP_SESSION"]
except KeyError:
    #If I get root privilege with sudo su command, this environment is not defined.
    print "desktop environment is impossible to determining."
    exit()
if (distribution_id not in "Ubuntu"):
#For example Debian squeeze default using GNOME environment if the user using GNOME session.
    print "Current desktop environment is %s." %(desktop_environment)
#Handling oldest releases generated wrong output, because between 8.04 and 10.10 the desktop session name is gnome.
#For example in 10.04 not have Unity.
if (desktop_environment=="gnome") and ((distribution_id=="Ubuntu") and (release in default_ubuntu_gnome_releases)):
    print "Current desktop environment is %s." %(desktop_environment)
elif (desktop_environment=="gnome") and ((distribution_id=="Ubuntu") and (release not in default_ubuntu_gnome_releases)):
    print "Current desktop environment is unity."
elif ((desktop_environment=="gnome-classic") or (desktop_environment=="gnome-2d")) and (distribution_id=="Ubuntu"):
    print "Your desktop environment is classic GNOME"