On 19.02.2022 23:39, John Cowan wrote:

On Sat, Feb 19, 2022 at 1:45 PM Rob Pike <robpike@gmail.com> wrote:

I undid all the macros for the v8 shell, with Steve's blessing, before doing the key work on that shell. But no one outside cared about any of the research Unixes after v7,

Lots of us would have loved to care about them and were sad that we couldn't until they were open sourced much later.

8th ed sh (about '84) brought quite a few changes and fixes. Just naming a few:
- environment variable HISTORY, pointing to a writable file, providing a history mechanism by means of "=(1)"
- type is replaced by whatis, which produces output that can be re-evaluated by the shell
- functions can be exported, in the same ways like variables

keyword history: I always imagined that the Bourne shell would have been in much wider use even nowadays, if only it had provided line editing and a history at some point. Why not? Even Kenneth Almquist released his SVR4-like reimplementation intentionally without history. All that might have been implemented more elegant directly in the terminal I/O instead of in every program? (that is, not in a MS-DOS-like way, where every program even needs its own pager).

I still wonder if it would be possible to properly provide line editing and history in the terminal I/O in general.

Sven