thank you, I can't remember how I once installed Arduino IDE on my Pi or if I altered a prior installation, I once followed some instructions I found in the web (which I do not remember exactly).
Anyway, there is no hidden folder visible.
Is there meanwhile a working apt-get install version?
or just these commands I found here in this forum?
wget http://downloads.arduino.cc/arduino-1.8.8-linuxarm.tar.xz
tar -x -f arduino-1.8.8-linuxarm.tar.xz
will that install automatically also the hidden folder?
if yes, can it be simply deleted, or do I have to change entries in preferences as well?
After that I assume that I'll just have to copy my old portable folde into the new 1.8.8 folder like for Windows, correct?