Best way to check if Nautilus File Manager is running?

Question

I've been working hours on this problem. When nautilus file manager is NOT running nautilus is running because it controls icons on the desktop.

$ ps -aux | grep nautilus | grep -v grep
rick      5613  0.2  1.7 2355392 140012 pts/19 Sl+  19:04   0:08 nautilus

So use this command without nautilus file manager open and you see:

$ ps -L -p 5613 -o pid,nice,lwp,comm
  PID  NI   LWP COMMAND
 5613   0  5613 nautilus
 5613   0  5614 gmain
 5613   0  5615 gdbus
 5613   0  5617 dconf worker

Now open up nautilus file manager and redo ps command:

$ nautilus

$ ps -L -p 5613 -o pid,nice,lwp,comm
  PID  NI   LWP COMMAND
 5613   0  5613 nautilus
 5613   0  5614 gmain
 5613   0  5615 gdbus
 5613   0  5617 dconf worker
 5613   0  4788 pool

Close the nautilus files window and rerun the command (after waiting a second or two) and the pool disappears.

Is this the correct way of seeing if nautilus file manager is running?

I've incorporated above technique into an answer in Ask Ubuntu I'd like to improve if possible:

• How can I automatically relaunch nautilus if I quit the program?

Answer 1

The best way to check whether there are any Nautilus windows open is to check for them on the session D-Bus:

gdbus introspect --session --dest org.gnome.Nautilus \
      --object-path /org/gnome/Nautilus --recurse | awk '/^ *node /{print $2}'

This will show window entries under /org/gnome/Nautilus/window if there are any open windows; so

gdbus introspect --session --dest org.gnome.Nautilus \
      --object-path /org/gnome/Nautilus --recurse |
grep -q '^ *node /org/gnome/Nautilus/window/'

will succeed if there are any open windows, fail otherwise.