>Have you ever exported anything in a shell script So, shells use a single thread that can safely modify the environment - then start new child processes by th

>Have you ever exported anything in a shell script So, shells use a single thread that can safely modify the environment - then start new child processes by the same thread. The child processes get a =copy= of the said environment. That's a textbook example how to use env. Starting multiple threads on your own, then modifying env should be considered a textbook example how not to do things - env is not intended for interprocess communication.