This can be done in one of two ways:
-
The executable name can be specified as the first command line argument. If there is an executable with that name inside the AppImage, it will be run instead of the default one. So, just specify
darktable-cltestas the first argument when running AppImage -
You can create a symlink to the AppImage file and run it via the symlink. If inside the AppImage there is an executable with a name that matches the symlink name, it will be launched instead of the default one. That is, you can simply run the AppImage via a symlink named
darktable-cltest.