For example, the following bash will give a permissions fail:

sudo-prompt.exec("echo 'some text' > /Library/some-file.txt")

It's easily fixed by doing:

sudo-prompt.exec("bash -c \"echo 'some text' > /Library/some-file.txt\"")

Perhaps sudo-prompt should do this (bash -c) at the module level instead? String escaping may need a little bit of thought but should be ok.