I need to wait until the user is done editing a text file in the default graphical application (Debian and derivates).
If I use xdg-open with subprocess.call (which usually waits) it will continue after opening the file in the editor. I assume because xdg-open itself starts the editor asynchronously.
I finally got a more or less working code by retrieving the launcher for the text/plain mime-type and use that with Gio.DesktopAppInfo.new to get the command for the editor. Provided that the editor is not already open in which case the process ends while the editor is still open.
I have added solutions checking the process.pid and polling for the process. Both end in an indefinite loop.
It seems such a overly complicated way to wait for the process to finish. So, is there a more robust way to do this?
#! /usr/bin/env python3
import subprocess
from gi.repository import Gio
import os
from time import sleep
import sys
def open_launcher(my_file):
print('launcher open')
app = subprocess.check_output(['xdg-mime', 'query', 'default', 'text/plain']).decode('utf-8').strip()
print(app)
launcher = Gio.DesktopAppInfo.new(app).get_commandline().split()[0]
print(launcher)
subprocess.call([launcher, my_file])
print('launcher close')
def open_xdg(my_file):
print('xdg open')
subprocess.call(['xdg-open', my_file])
print('xdg close')
def check_pid(pid):
""" Check For the existence of a unix pid. """
try:
os.kill(int(pid), 0)
except OSError:
return False
else:
return True
def open_pid(my_file):
pid = subprocess.Popen(['xdg-open', my_file]).pid
while check_pid(pid):
print(pid)
sleep(1)
def open_poll(my_file):
proc = subprocess.Popen(['xdg-open', my_file])
while not proc.poll():
print(proc.poll())
sleep(1)
def open_ps(my_file):
subprocess.call(['xdg-open', my_file])
pid = subprocess.check_output("ps -o pid,cmd -e | grep %s | head -n 1 | awk '{print $1}'" % my_file, shell=True).decode('utf-8')
while check_pid(pid):
print(pid)
sleep(1)
def open_popen(my_file):
print('popen open')
process = subprocess.Popen(['xdg-open', my_file])
process.wait()
print(process.returncode)
print('popen close')
# This will end the open_xdg function while the editor is open.
# However, if the editor is already open, open_launcher will finish while the editor is still open.
#open_launcher('test.txt')
# This solution opens the file but the process terminates before the editor is closed.
#open_xdg('test.txt')
# This will loop indefinately printing the pid even after closing the editor.
# If you check for the pid in another terminal you see the pid with: [xdg-open] <defunct>.
#open_pid('test.txt')
# This will print None once after which 0 is printed indefinately: the subprocess ends immediately.
#open_poll('test.txt')
# This seems to work, even when the editor is already open.
# However, I had to use head -n 1 to prevent returning multiple pids.
#open_ps('test.txt')
# Like open_xdg, this opens the file but the process terminates before the editor is closed.
open_popen('test.txt')
