bug#46351: 28.0.50; Add convenient way to bypass Eshell's own pipelining

[Michael Albinus]

Sean Whitton <spwhitton@spwhitton.name> writes:

Hi Sean,

> I think that it would be good to have a way to easily toggle Eshell's
> own pipelining support on and off for particular commands.  I have come
> up with the attached patches.  When the new functions I've defined are
> enabled, you can type
>
>     !! foo | bar 'arg' >baz >>#<buffer *scratch*>
>
> and it will be executed by Eshell as if you had typed
>
>     bash -c 'foo | bar '"'"'arg'"'"' >baz' >>#<buffer *scratch*>
>
> The idea is that you can easily toggle Eshell's pipelining on and off as
> appropriate to your needs just by adding and removing the "!!" prefix.

Nice idea.

> I think that the patches I've prepared are a clean implementation of
> this feature that would be good to include in Emacs.

Applying your patch, I get the compiler warning

--8<---------------cut here---------------start------------->8---
  ELC      eshell/esh-mode.elc

In end of data:
eshell/esh-mode.el:1114:1: Warning: the function ‘(setf buffer-substring)’ is
    not known to be defined.
--8<---------------cut here---------------end--------------->8---

And using it in eshell, there is

--8<---------------cut here---------------start------------->8---
~/src/emacs $ !! cat ~/.emacs | grep albinus
!!: command not found
--8<---------------cut here---------------end--------------->8---

I wanted to see, whether this works also for remote directories. Have
you tested this?

> Sean Whitton

Best regards, Michael.