Mac OS X is only partially related to its predecessors - large parts of OS X were imported from Apple’s acquisition of NeXTSTEP, which had a different kernel and design from Mac OS 9. This is significant enough that applications made for one don’t run natively* in the other.

Recently, I got a 2001 iMac which was dual booting OS 9 and OS X.

There was a little problem - I didn’t know the admin password on the OS X install.

I thought that maybe I could reset it from inside OS 9 - in an OS with less concept of user permissions, maybe I would be able to pop open some kind of terminal with admin rights and run a password reset command.

But not only is there no password reset command, there is actually no shell at all.

What???

I had this feeling that I should have known better, but this honestly surprised me a lot - it didn’t occur to me that anyone would build an OS without a shell. Even Windows has a shell!

Here’s one weird related fact - there is no standard output stream on OS 9 either. This is even stranger to me - do you need to write GUI code just to make a standalone hello world program?

Funnily enough, this would have seemed totally reasonable to me when I was a kid - I thought CLIs were a thing of the past and not essential any more. Now that I’ve been programming for a long time, I’ve come to expect stdout (or something analogous) to exist in every environment.

In spite of (or perhaps because of) taking stdout for granted, I only have a hazy understanding of what stdout is/where it “lives”. Nevertheless, it is disorienting for it to simply not be there.

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