How can I determine if a process has a window, and subsequently show, hide or close it?

Question

Is it possible, either through a shell script or terminal command, assuming you have the PID, determine if it has a main window (form), and then get info about it (title) and show/hide/close it?

Answer 1

Script to look up possible window(s) of given pid, then show, minimize or close it

Since you mention the command line, the script below runs in a terminal window. You run it with the pid as an argument, e.g.:

python3 /path/to/script.py 1234

Subsequently, a window (list) appears, of which you can choose a (list-) number and type an option to perform on it:

Current Windows for pid 2189:
------------------------------------------------------------
[1] Niet-opgeslagen document 1 - gedit
[2] testbackup.py (~/Bureaublad) - gedit

------------------------------------------------------------
Type window number + option:
-k  [kill (gracfully)]
-m  [minimize]
-s  [show]
Press <Enter> to cancel
------------------------------------------------------------
1 -k

If there are no windows:

There are no windows for pid 1234

The script

#!/usr/bin/env python3
import subprocess
import sys

pid = sys.argv[1]

message = """
------------------------------------------------------------
Type window number + option:
-k  [kill (gracfully)]
-m  [minimize]
-s  s[how]
<Enter> to cancel
------------------------------------------------------------
"""
# just a helper function
get = lambda cmd: subprocess.check_output(cmd).decode("utf-8").strip()
# get the window list
wlist = [l.split()[0] for l in get(["wmctrl", "-lp"]).splitlines() if pid in l]
# create a indexed list of window name, id
wdata = [[i+1, get(["xdotool", "getwindowname", w_id]), w_id] \
         for i, w_id in enumerate(wlist)]

# if the list is not empty (windows exist)
if wdata:
    # print the window list
    print("\nCurrent Windows for pid "+pid+":\n"+"-"*60)
    for item in wdata:
        print("["+str(item[0])+"]", item[1])
    # ask for user input (see "message" at the top)
    action = input(message)
    action = action.split()
    # run the chosen action
    try:
        subj = [item[2] for item in wdata if item[0] == int(action[0])][0]
        options = ["-k", "-m", "-s"]; option = options.index(action[1])
        command = [
            ["wmctrl", "-ic", subj],
            ["xdotool", "windowminimize", subj],
            ["wmctrl", "-ia", subj],
            ][option]
        subprocess.Popen(command)    
    except (IndexError, ValueError):
        pass
else:
    print("There are no windows for pid", pid)

How to use

1. The script uses both xdotool and wmctrl:

   sudo apt-get install wmctrl xdotool
   

2. Copy the script into an empty file, save it as get_wlist.py

3. Run it with the command:

   python3 /path/to/get_wlist.py <pid>
   

Explanation on the procedure

---

About xdotool and wmctrl:

To manipulate, move or close windows, there are two important tools on Linux: xdotool and wmctrl. Of these two, xdotool is probably the most robust one, which I prefer in general. Although the options of both tools overlap, they do complete each other however, and to create a window list we simply need wmctrl.

In most cases therefore, I end up using a mixture of both tools.

---

What the script does:

• The script gets the currently opened window list, using the command:

  wmctrl -lp
  

  Which gives us information on both the window id and the pid it belongs to, with an output, looking like:

  0x05a03ecc  0 2189   jacob-System-Product-Name Niet-opgeslagen document 1 - gedit
  

• The script then filters out the windows, belonging to the corresponding pid, looks up the window name with the xdotool command:

  xdotool getwindowname <window_id>
  

  and displays the found windows by name. Under the hood, these windows are numbered.

• subsequently, if the user types a number + an option, the corresponding action is performed on the chosen window:

  wmctrl -ic <window_id>
  

  to close the window gracefully, or

  xdotool windowminimize <window_id>
  

  to minimize the chosen window, or

  wmctrl -ia <window_id>
  

  to raise the window.