Thanks for the explanation, I didn't have a clear idea where that icon was to be shown really, I was just thinking to make visible somewhere that the script is running ^_^
I will try this first, maybe it does the job in the easy way
@mindlord: tried the commands, and it is not exactly what I need, my script is endless until manually stopped, so that indicator is not exactly for this purpose
@slaeshjag: if it will works like the bluetooth icon that appear on the bar after the activation (and maybe also disappear after deactivation), can be very useful to me, but then the 2 programs will be dependent, right ?