IIRC, Microsoft C (quite some years ago - had worked on a product using it) had different variants of functions to spawn or execute a process from another one -

IIRC, Microsoft C (quite some years ago - had worked on a product using it) had different variants of functions to spawn or execute a process from another one - like the exec family - execlp, execvp, execvpe, execlpe, etc., which varied in things like fixed vs. variable number of args, checking environment vs. not, etc. I also remember reading about it in a Waite Publications book, The Microsoft C Bible, by Nabajyoti Barkakati. Not sure if the issues mentioned in the OP could be solved if those functions were present - need to check. Edit: and the DOS / Windows exec family of functions was likely derived from Unix's exec().