Ubuntu – shortcut to force close an application

To do this only for your user, you need to run this command in a terminal:

echo 'STEAM_FRAME_FORCE_CLOSE DEFAULT=1' >> ~/.pam_environment

Then logout and log back in.

Alternatively, you could add it for all users with this command:

echo 'STEAM_FRAME_FORCE_CLOSE=1' | sudo tee -a /etc/environment

Then logout and log back in.

References:

• https://wiki.archlinux.org/index.php/Steam#The_close_button_only_minimizes_the_window
• https://help.ubuntu.com/community/EnvironmentVariables#Persistent_environment_variables

The answer by user72216 didn't work always. For example if I opened several Okular (a KDE PDF viewer) windows, the code won't close all windows, as different window ids are assigned to the windows. The following code extracts all window ids and closes them gracefully:

#!/usr/bin/env python3
import subprocess

def get(cmd):
    return subprocess.check_output(cmd).decode("utf-8").strip()

pid = get(["xdotool", "getactivewindow", "getwindowpid"])

# Identify the name of the application
username = get(["users"])
jobs = get(["ps","-u",username])
jobname = ""
for w in jobs.splitlines():
    jobinfo = w.split()
    if pid == jobinfo[0]:
        jobname = jobinfo[-1]
        break

# Get all pids that match the jobname
pidlist = []
for w in jobs.splitlines():
    jobinfo = w.split()
    if jobinfo[-1] == jobname:
        pidlist = pidlist + [jobinfo[0]]

# Close all windows with having the pids
wlist = get(["wmctrl", "-lp"])
for pid in pidlist:
    for w in wlist.splitlines():
        if pid in w and not "Desktop" in w:
            print(w.split()[0])
            subprocess.call(["wmctrl", "-ic", w.split()[0]])