[Info-vax] CTRL/D Versus CTRL/Z

[lawrencedo99 at gmail.com]

Even though they started out very different, somehow along the way, *nix systems managed to pick up most of the DEC conventions for control characters (CTRL/C to interrupt a process, CTRL/Q and CTRL/S for flow control, CTRL/U to discard the input line), except one: the end-of-file indicator is CTRL/D, not CTRL/Z as it is on DEC systems.

Instead, CTRL/Z means “suspend the foreground process group”. This is part of the job-control facility for managing multiple concurrent processes. I also see a mention in the bash docs of a “delayed-suspend” character, which defaults to (wait for it) CTRL/Y. However, this might be a Hurd or BSD feature; it doesn’t seem to be available on Linux.

Did VMS ever pick up the idea of foreground/background process groups?

No, there was never an equivalent to CTRL/T. I get around that by running multiple terminal sessions, so I can keep an eye on one process using a separate session.