That's trickier than it sounds. find for instance has the -exec command, which allows arbitrary code to be executed. build tools and linters are also a security nightmare, because they can also be modified to execute arbitrary code. And this is all assuming you can implement the whitelist properly. A naive check like

    cmd.split(" ") in ["cd", "ls", ...]

is easy target for command injections. just to think of a few:

    ls . && evil.sh

    ls $(evil.sh)