On Dec 17, 2020, at 9:21 AM, M Douglas McIlroy <m.douglas.mcilroy@dartmouth.edu> wrote:

shell, including the story of do...done, has often been told. It
shows up most vividly in the condition part of if and while
statements.

I was never so happy as when SVR2 came out and found that someone had “translated” the shell source code back into C.