How to get the internal names of GUI programs?

Question

I want to find out what is the internal name of a graphical program.

I know that ps aux or top can be used, but is there a way to find out without console, using the mouse?

Maybe an app I can start and then click on a window to see it's application name?

Answer 1

I didn't find a tool without console, but there are some console tools: xwininfo and xprop

You can start a console and type

xprop|grep WM_CLASS

click on the desired window and you get for example

WM_CLASS(STRING) = "Navigator", "Firefox"

some programs already have the program name in that output, for example:

WM_CLASS(STRING) = "muon", "Muon"  
or   
WM_CLASS(STRING) = "xfce4-taskmanager", "Xfce4-taskmanager"

If not, then use xwininfo to search for that name:

xwininfo -root -children|grep Firefox

you get a list of all processes, and some of them contain the program name "firefox"

 0x1424f98 "Firefox": ("firefox" "Firefox")  1x1+-100+-100  +-100+-100

Answer 2

Open the System Monitor application (which is gnome-system-monitor).

or Task Manager (which is xfce4-taskmanager on Xubuntu)