I had completely forgotten about A/UX, what a blast from the past. Has A/UX gotten any recent open-source attention?
You would invoke Commando from the shell for a command and it would bring up a dialog to help you construct the command line, which would be written back to the shell.
There's a screen shot of it for ls here [1], and mount here [2].
[1] http://toastytech.com/guis/aux3.html
[2] https://retrocomputingforum.com/t/running-a-ux-apples-at-t-u...
(Also, OS/400 commands all follow a very strict naming convention, such as the example WrkActJob in the link. The consistency of the words used and the abbreviations for those words were intended to make learning easier.)
You see a bit of this today in PowerShell's command auto-completion for built-in commands, PowerShell script files, and cmdlets (user-defined commands written as PowerShell script functions or .NET CLI methods). The graphical PowerShell Integrated Scripting Environment (ISE) even pops up windows that let you interactively fill out forms to enter command options, just like Commando: https://blog.netwrix.com/2018/02/21/windows-powershell-scrip...
Regrettably, PowerShell ISE is deprecated, and the recommended replacement of Visual Studio Code with the PowerShell extension isn't an exact one.
I suspect that, like other pre-SysVR4/Solaris-y unixes, compiling anything newer than GCC 2.95-ish will be pretty much impossible. But, depending on your interest/curiosity, it looks like there's some fun stuff to play with.