I authored an R package that will be licensed under GPL2 due to some dependencies that I use also being GPL2. I was wondering if I would be allowed to make a commercial closed source JAVA GUI interface though to use this R package in a user-friendly way, or would that also have to have a GPL2 license? It would just be a GUI that would drive some of the functions from that package via the command line (for users that don't like command-line stuff), e.g. allowing one to select files to be analyzed and select a few analysis options and maybe view the analysis output...
shell_exec("your_gpl_code --option value --data=1,3,4,6")
and then capturing out put and doing something with it that the GPL would even come into play... – ivanivan Jan 15 '19 at 2:23