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A comment on The Earliest Unix Code: An Anniversary Source Code Release. Parent comment

Re:The Earliest Unix Code: An Anniversary Source Code Release by quicklime on Thursday October 17, 2019 @06:24PM (#21286896)
I don't know PDP7 assembly either, but I don't see how it could stand for "previous directory" (and be equivalent to today's `cd -`). Any command to change directory needs to be done in-process by the shell, so it would need to be implemented as a builtin, not a standalone executable.

So "print directory" or (print something about the) "parent directory" seem more likely to me.

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Re:The Earliest Unix Code: An Anniversary Source Code Release by kragen on Friday October 18, 2019 @12:30AM (#21288702)
In the earliest versions of Unix, the shell didn't fork to run programs. It would exec the program, and then the program would exec the shell instead of exiting. Makes sense, right? That's what you'd do if you didn't have an operating system at all, and it's how, for example, CP/M worked. So you could write "cd" as a non-built-in command.

But it sounds like the other commenters have figured out that it's "pack directory".

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