I wasn't expecting the output of 'ls' to be covered, however by making my program dependant on calling the 'ls' program, it could be that we now have a combined

I wasn't expecting the output of 'ls' to be covered, however by making my program dependant on calling the 'ls' program, it could be that we now have a combined work of the two. Arguably, this is no different than calling a hypothetical "lib-ls" function, but if "lib-ls" is GPL (not LGPL), then that is usually considered a combined work. My point, however, wasn't these specific scenarios, I was using them as examples as examples in response to the parent's comment inferring that you know exactly what it means. "Consult a lawyer" kind of just reinforces the point. Of course, I do agree that most community licenses such as the GPL are infinitely more readable than most proprietary software licenses.