Easiest way to check if M100-M199 working? M100 doing nothing on LinuxCNC 2.9.2

Welcome. So I tried to use M100 P0 to show a window on the screen I found a good script on the forum and pasted it to M100 with the option "allow to run as a program" try to open it with Python 3.1 and everything was fine but when I open linuxcnc with axis and do M100 P0 in MDI program just flash and doing nothing like nothing happened. Linux see the file because MDI M101 giving some error when M100 only quick flash. Any ideas on where to look for the problem and the easiest way to check if M1xx can execute from Linux MDI? 

Okay i tried: 

#!/bin/bash
open /home/cnc/linuxcnc/nc_files/test.png
exit 0

And its working from MID but still my script wont.  
 

Okay, I figured it out. Simply python 3.1 by executing M100 was running fine but python3 from the terminal was not so I have to debug it a bit and now it's working just fine