How to determine which window manager is running

Question

Is there any way (such as a command or environmental variable) to determine what window manager is the one actively running in the current session?

Answer 1

On Linux systems I tested environment variables XDG_CURRENT_DESKTOP and GDMSESSION and got the following results.

You can use this line to get the output:

printf 'Desktop: %s\nSession: %s\n' "$XDG_CURRENT_DESKTOP" "$GDMSESSION"

---

Ubuntu 16.04

---

Unity (7)

• XDG_CURRENT_DESKTOP=Unity
• GDMSESSION=ubuntu

---

Ubuntu 14.04

---

Unity running with Mir

• XDG_CURRENT_DESKTOP=Unity
• GDMSESSION=ubuntu

Note MIR_SERVER_NAME is also set

• MIR_SERVER_NAME=session-$NUMBER

Unity running without Mir

• XDG_CURRENT_DESKTOP=Unity
• GDMSESSION=ubuntu

XFCE

• XDG_CURRENT_DESKTOP=XFCE
• GDMSESSION=xfce

---

Ubuntu 12.04

---

KDE

• XDG_CURRENT_DESKTOP=
• GDMSESSION=kde-plasma

Unity 3d

• XDG_CURRENT_DESKTOP=Unity
• GDMSESSION=ubuntu

Unity 2d

• XDG_CURRENT_DESKTOP=Unity
• GDMSESSION=ubuntu-2d

Gnome

• XDG_CURRENT_DESKTOP=GNOME
• GDMSESSION=gnome-shell

Gnome Classic

• XDG_CURRENT_DESKTOP=GNOME
• GDMSESSION=gnome-classic

Gnome Classic (no effects)

• XDG_CURRENT_DESKTOP=GNOME
• GDMSESSION=gnome-fallback

---

Other Ubuntu based distributions

---

Mint 13 (Cinnamon)

• XDG_CURRENT_DESKTOP=GNOME
• GDMSESSION=cinnamon

Mint 16 (KDE edition)

• XDG_CURRENT_DESKTOP=KDE
• GDMSESSION=default

Mint 17 (Cinnamon)

• XDG_CURRENT_DESKTOP=X-Cinnamon
• GDMSESSION=default

Lubuntu 12.04

• XDG_CURRENT_DESKTOP=LXDE
• GDMSESSION=Lubuntu

Wasta 14.04

• XDG_CURRENT_DESKTOP=X-Cinnamon
• GDMSESSION=cinnamon

Wasta 14.04 using Gnome desktop.

• XDG_CURRENT_DESKTOP=GNOME
• GDMSESSION=gnome

Answer 2

None of the above actually worked for me, I just wanted to know whether I had Gnome running as my current desktop session.

This is what worked, open a terminal

lsb_release -a

(to check which flavor or version I had installed on my UBUNTU​ machine)

ls /usr/bin/*session

(launches which desktop session/desktop environment currently in use)

gnome-shell --version 

(to find out which version of gnome is installed)

Answer 3

If you have wmctrl installed, the first line of output from command

    wmctrl -m

will show you the name of the window manager. If you don't have wmctrl installed, use the following command to install it:

    sudo apt-get install wmctrl

Note, man wmctrl (that is, the man page for wmctrl) says in part:

-m Display information about the window manager ...

On my Ubuntu 11.10 / Linux 3.0.0-14-generic #23-Ubuntu x86_64 / metacity 2.34.1 system, the first line of output from wmctrl -m was: Name: Metacity
while echo $DESKTOP_SESSION showed ubuntu-2d and echo $XDG_CURRENT_DESKTOP showed Unity.

On a fresh Ubuntu 15.10 install of Ubuntu desktop software on an old laptop, the first line of output from wmctrl -m was: Name: Compiz
while the DESKTOP_SESSION and XDG_CURRENT_DESKTOP values were ubuntu and Unity

Answer 4

This is sort of possible with dbus and the Accounts Service (both by default in Ubuntu).

$ qdbus --system org.freedesktop.Accounts \                                                                
> /org/freedesktop/Accounts/User1000 \                                                                                     
> org.freedesktop.Accounts.User.XSession                                                                                   
ubuntu

Worth noting that I've tested this with logging in through lightdm (that is the graphical login screen) , it did detect a classic desktop like blackbox , and obviously detects Unity. I suspect this is a value of what user selects on the login screen as session, that's why it's a bit easier to use that checking for processes

Answer 5

xprop -id $(xprop -root -notype | awk '$1=="_NET_SUPPORTING_WM_CHECK:"{print $5}') -notype -f _NET_WM_NAME 8t 

Answer 6

I found pstree to be a big help. I believe you have to install it with sudo apt-get install pstree. This is what I got.

 ├─lightdm─┬─Xorg───2*[{Xorg}]
 │         ├─lightdm─┬─gnome-session─┬─bluetooth-apple───2*[{bluetooth-apple}]
 │         │         │               ├─compiz─┬─sh───gtk-window-deco───2*[{gtk-window-deco}]
 │         │         │               │        └─5*[{compiz}]
 │         │         │               ├─deja-dup-monito───2*[{deja-dup-monito}]
 │         │         │               ├─gnome-fallback-───2*[{gnome-fallback-}]
 │         │         │               ├─gnome-screensav───2*[{gnome-screensav}]
 │         │         │               ├─gnome-settings-───2*[{gnome-settings-}]
 │         │         │               ├─nautilus───2*[{nautilus}]
 │         │         │               ├─nm-applet───2*[{nm-applet}]
 │         │         │               ├─polkit-gnome-au───2*[{polkit-gnome-au}]
 │         │         │               ├─ssh-agent
 │         │         │               ├─telepathy-indic───2*[{telepathy-indic}]
 │         │         │               ├─update-notifier───2*[{update-notifier}]
 │         │         │               ├─vino-server───2*[{vino-server}]
 │         │         │               ├─zeitgeist-datah───{zeitgeist-datah}
 │         │         │               └─3*[{gnome-session}]
 │         │         └─{lightdm}
 │         └─2*[{lightdm}]

Answer 7

The following script resulted as the best answer to a similar question I posted over at unix.se. It also works great with Unity and LXDE.

if [ "$XDG_CURRENT_DESKTOP" = '' ]
then
  desktop=$(echo "$XDG_DATA_DIRS" | sed 's/.*\(xfce\|kde\|gnome\).*/\1/')
else
  desktop=$XDG_CURRENT_DESKTOP
fi

desktop=${desktop,,}  # convert to lower case
echo "$desktop"

Answer 8

In the terminal type env to see all environment variables. Some of them are:

XDG_CURRENT_DESKTOP - Tells you what Windows Manager you are using

GDMSESSION - Tells you what option you selected from the lightdm greeter to login.

To use them, go to the terminal and type:

echo $XDG_CURRENT_DESKTOP

(Will output for example 'unity' if you are using Unity)

or

echo $GDMSESSION  

(Will output for example 'ubuntu' if you selected ubuntu in the login or 'ubuntu-2d' if you selected that one in the login.)

You have others if you look closer at the output of env like DESKTOP_SESSION and COMPIZ_CONFIG_PROFILE

Since what you are looking for is the name of what Window Manager is in usem the only way I see how to get this is by looking in the process list. To do this there is a command called pgrep ( Wikipedia ). I did the following to get the name since the parameter -l adds the process ID:

pgrep -l compiz |cut -d " " -f2 since the process is running by the same user there is no need to prefix the sudo part. You can then use this to create a script that does an action based on the Window Manager.

To look for other types, just change the word compiz to another like mutter, kwin, etc..

Answer 9

I've been testing also with KDE and my conclusion is:

a) Graphical way, with HardInfo: the answer is normally in "Operating System" > "Desktop Environment", but if not you can look to "Environment variables". HardInfo is ready with all the tested distros, except the one with KDE, but it can be easily and quickly installed (only 2 packages in Linux Mint 13).

b) Command line, with this command: ps -A | egrep -i "gnome|kde|mate|cinnamon|lx|xfce|jwm". The item that appears in more lines should be the answer (if there is a draw the item with "session" should be the solution).

Answer 10

I can only think of checking for known window managers in the running processes. There used to be a key in gconf that was set to the preferred window manager, but its deprecated since Gnome 2.12.

So, if this is for a programming purpose, I suggest you to research for all the linux window managers; some popular are:

• gnome-shell*
• compiz
• metacity
• mutter
• sawfish

You would have to run a check for each with the command pgrep -l $WINDOW_MANAGER, where $WINDOW_MANAGER is the name of the window manager you want to check for. The pgrep command checks for running processes.

I am not 100% sure if Gnome Shell is considered a window manager; the rest of the window managers I got from a list in the /usr/bin/gnome-wm script. This script in fact should be usable (since its present on a clean install) but in my case it tries to run compiz which is not my default window manager (not in my Gnome session).

EDIT:

Well @Anarci 's comment seems to be more accurate. In my case it did show gnome-shell.