Re: multiline ZLE w/ bash-like single line .zsh_history...?

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

On Dec 6, 11:02am, zsh@xxxxxxxx wrote:
}
} I like the multiline capability of ZLE, but when history lines are
} appended to the .zsh_history file, I would like for multiline commands
} to be morphed into a single line (similar to what bash does).

In a sufficiently new zsh, there is a zshaddhistory hook function
(like precmd, chpwd, etc.).  You can manipulate the history any way
you like; e.g., the following saves each line of the multiline as a
single line in the history:

    zshaddhistory() { print -sr "${(z)1%%$'\n'}"; return 1 }

(And I finally get another chance to point out to PWS why it's a good
thing that (z) converts newlines into semicolons ... but it also
reveals a bug in the handling of here-documents ... moving that over
to zsh-workers.)  [Bash appears to ignore here-documents entirely?]

As was discussed in a lengthy thread earlier this year, the full multi-
line command "lingers" in the interactive history for one cycle even
if zshaddhistory returns nonzero.

} Is there a way to get zsh to be bash-like when it writes to the
} history file...?  I'm willing to lose the multiline niceness for old
} commands in new shells.

There is not a way to get the interactive history and the history file
to behave differently from one another, except by using more than one
history file (the "fc -p" example for zshaddhistory in the manual).
You could, for example, do

    zshaddhistory() {
      fc -p ${HISTFILE}_bash_format $HISTSIZE $SAVEHIST
      print -sr "${(z)1%%$'\n'}"
      return 0
    }

which would still save in zsh native format in $HISTFILE, but keep a
bash-format copy in a parallel file.