Using udev rules

[Anti-Ultimate]

The Dolphin Emulator AppImage needs a udev rule to access the GC - Adapter.
I was also creating a Steam AppImage, and Steam needs udev rules to access the Steam Controller, HTC Vive, and several other devices.

[probonopd]

Hi @Anti-Ultimate how is this related to AppImage? Remember, AppImage is just a self-mounting filesystem that executes whatever payload you put in there.

[Anti-Ultimate]

Because some Applications require udev access for specific devices, e.g. Dolphin needs udev access for GC - Adapter and controllers in general (in their case it works far better than SDL2). It installed a udev rule, and now the application/the user can access said device.

If a package is installed onto the system, the corresponding udev rules gets put in /usr/lib/udev/rules.d, which gets loaded during install.

However, AppImages are generally executed without root access, so udev rules cannot be loaded. AppRun could be extended so it searches for udev rules in the AppImage and asks the user (via Zenity or whatever), if he wants to enable them.

[probonopd]

In this case it is up to the payload application (or a custom AppRun script) to acquire administrative rights, and copy the needed files to /usr/lib/udev/rules.d. AppImage is really just a self-mounting container format, all the logic lives inside the AppImage - it is what you put inside.

[probonopd]

The Etcher AppImage, for example, also acquires administrative rights to write to /dev/sdX.

[probonopd]

I've spelled out a possible approach here.