why is 2 the smallest HISTSIZE?

why is 2 the smallest HISTSIZE?

[Derek Peschel]

The manual refers to a hierarchy of history files: the saved history file,
then the internal history list, then the "last command" buffer which is
always available even if the history list is disabled.

Setting HISTSIZE to zero would disable the history list -- are there
any other ways of disabling it? -- but the code prevents HISTSIZE from
actually becoming zero.  I guess that prevention is what creates the
illusion of a "last comamnd" buffer (Is there a separate buffer,
not maintained by the history mechanism?).

But the code uses 2, not 1, as a minimum value for HISTSIZE.  So you
actually get the command you're typing and the two you typed eariler.

Did the implementation (of the "last command" buffer) change, but the
2 not get changed to 1?  Or do I not understand the code?

Thanks,

-- Derek

Re: why is 2 the smallest HISTSIZE?

[Bart Schaefer]

On Feb 12,  4:59am, Derek Peschel wrote:
}
} Did the implementation (of the "last command" buffer) change, but the
} 2 not get changed to 1?

I think that's what happened, but only Wayne Davison can say for certain.

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net   

Re: why is 2 the smallest HISTSIZE?

[Wayne Davison]

On Tue, 12 Feb 2002, Derek Peschel wrote:
> Setting HISTSIZE to zero would disable the history list -- are there
> any other ways of disabling it?

One (drastic) way to disable it is to "unsetopt zle".  Of course, it
disables all the fancy command-line editing as well.

> but the code prevents HISTSIZE from actually becoming zero.  I guess
> that prevention is what creates the illusion of a "last comamnd"
> buffer (Is there a separate buffer, not maintained by the history
> mechanism?).

Right (there's no separate buffer).

> Did the implementation (of the "last command" buffer) change, but the
> 2 not get changed to 1?

Yeah, looks like I overlooked this "2" value.  I'll fix this.

..wayne..