1) java shell starts 2) read getenv into a java hashmap 3) evaluate shell input - any sets update the hashmap, any gets read from the hashmap 4) when you get to

1) java shell starts 2) read getenv into a java hashmap 3) evaluate shell input - any sets update the hashmap, any gets read from the hashmap 4) when you get to a point where you need to exec a process you use the hashmap to pass envvars into process builder - which is going to call execvpe for you. So yeah you definitely could (there'd be other reasons why java wouldn't be a good choice). TBH reading that folks were calling setenv before an exec to propagate env vars to a child made me sad. I would guess that other use cases were leveraging environ as a poor man's global variable - which is also unfortunate.