Re: [RFC PATCH 3/3] FAQ: sync newuser-install

["Daniel Shahaf" <d.s@xxxxxxxxxxxxxxxxxx>]

Bart Schaefer wrote on Thu, 25 Aug 2022 23:08 +00:00:
> On Thu, Aug 25, 2022 at 3:44 PM Felipe Contreras
> <felipe.contreras@xxxxxxxxx> wrote:
>>
>> This is *less* complicated:
>
> Every addition of an option to change the way something works is
> making the shell as a whole more complicated and the interactions
> among the settings more difficult to explain and understand.
>
> Unless there's an important behavior that it's simply not possible to
> accomplish with the existing configuration controls,

Does "enable saving of history without specifying the history file's name" qualify?

> adding magical interdependencies and switches to enable same is not
> IMO a good plan.

What I had in mind was a new option, HIST_RECORD, and have it implicitly
setopt'd by assignment to $HISTFILE and implicitly unsetopt'd by «unset
HISTFILE«»; and then the default (zsh -f) could be to have HISTFILE set to some
value but HIST_RECORD off.

This design:

- would not change the default behaviour.

- would be compatible with existing dotfiles, since assigning to
  HISTFILE would set HIST_RECORD implicitly.

- would provide the ability to enable history without particularly
  caring about the filename it's saved in, which would put us on par
  with most other programs.  Most programs don't require the user
  to name files the user doesn't interact with directly.  (cc(1) goes even
  further with its default output filenames, such as foo.o and a.out.)

- /would/ be an action at a distance.  However, in this case,
  considering a user who unsets $HISTFILE in a universe in which
  HIST_RECORD exists,  I don't immediately see what alternative
  behaviour that user might expect.  As to a user who sets $HISTFILE and
  expects HIST_RECORD to remain off, that's backwards compatibility.

If that's nevertheless undersirable, then we could go the deprecation
route: leave $HISTFILE as is; add an entirely new way to specify the
history file's name and whether writing to it is enabled (perhaps a
couple of zstyles); in 5.10 recommend that people transition to the new
way; starting 5.11 issue a warning if the old way is used, saying it's
deprecated and will be removed no sooner than ${date or version number}.

Any other alternatives?

[The option's proposed name was chosen for consistency with other
options and for avoidance of ambiguity with $SAVEHIST.]

Cheers,

Daniel