This is my program, and it works very well.
import subprocess
result = subprocess.check_output("wmctrl -l",shell=True,stderr=subprocess.STDOUT)
result = result.decode('UTF-8')
print(result)
Output:
0x03800003 -1 name-PC Desktop
0x03e00037 0 name-PC How to fix wmctrl Cannot open display when Python open subprocess - Stack
Overflow - Firefox
0x05000006 0 name-PC name@name-PC: ~
0x05a00001 0 name-PC pr.py — ~/Program — Atom
0x05001c85 0 name-PC Terminal
But if I want to run this program at startup as root in Linux Mint I have problems. I want to run this py file at startup as root but I don't know how to do it. The main question is how to do it.
This is my attempt to solve the problem. It does not work.
I added a file pr.service
to folder /etc/systemd/system/
:
[Unit]
After=network.target
[Service]
ExecStart=/usr/local/bin/pr.sh
[Install]
WantedBy=default.target
I created a file pr.sh in folder /usr/local/bin/
:
#!/bin/bash
/usr/bin/python3 '/home/name/Program/pr.py'
I used these commands:
sudo chmod 744 /usr/local/bin/pr.sh
sudo chmod 664 /etc/systemd/system/pr.service
sudo systemctl daemon-reload
sudo systemctl enable pr.service
If I run my program with command
systemctl start pr.service
I can see this error with command
sudo journalctl -u pr.service
I have an error command subprocess.CalledProcess Error: Command 'wmctrl -l' returned non-zero exit status 1.
I can change my py file, for example I can run
result = subprocess.check_output("/usr/bin/wmctrl -l",shell=True,stderr=subprocess.STDOUT)
I can change my py file to see error:
import subprocess
try:
result = subprocess.check_output("/usr/bin/wmctrl -l -p",shell=True,stderr=subprocess.STDOUT)
result = result.decode('UTF-8')
except subprocess.CalledProcessError as e:
raise RuntimeError("command '{}' return with error (code {}): {}".format(e.cmd, e.returncode, e.output))
print(result)
RuntimeError: command '/usr/bin/wmctrl -l -p' return with error (code 1): b'Cannot open display.
I have read about this attempt to find solution: https://linuxconfig.org/how-to-automatically-execute-shell-script-at-startup-boot-on-systemd-linux
This is an article how to autorun script in Linux as root. I did these things.
My main goal is to autostart my program as root:
import subprocess
try:
result = subprocess.check_output("/usr/bin/wmctrl -l -p",shell=True,stderr=subprocess.STDOUT)
result = result.decode('UTF-8')
except subprocess.CalledProcessError as e:
raise RuntimeError("command '{}' return with error (code {}): {}".format(e.cmd, e.returncode, e.output))
print(result)
You don't need to find mistake in my solution. It will be interesting to find any solution.
I have find solution myself. The key is to use two commands:
os.system("xhost local:root &>/dev/null")
allow root opening X windows. And
subprocess.check_output([command], shell=True, stderr=subprocess.STDOUT).decode('UTF-8')
command = "env DISPLAY=:0 XAUTHORITY=/home/ourname/.Xauthority "+"wmctrl -l -p -lp"
allow root to read our settings.
So we can rewrite our program.
import subprocess
import gc
import time
prf = ["env", "DISPLAY=:0", "XAUTHORITY=/home/ourname/.Xauthority"]
while True:
r1 = subprocess.run(['xhost', 'local:root'],stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL )
r2 = subprocess.run([prf[0], prf[1], prf[2],"wmctrl", "-l", "-p", "-lp"], encoding='utf-8', stdout=subprocess.PIPE)
if r1.returncode == 0 and r1.returncode == 0:
print("Now we will not have problem with display error")
break
time.sleep(3)
while True:
r1 = subprocess.run([prf[0], prf[1], prf[2],"wmctrl", "-l", "-p", "-lp"], encoding='utf-8', stdout=subprocess.PIPE)
for line in r1.stdout.split('\n'):
print(line)
time.sleep(3)
gc.collect()