Re: amd@gnu.org: eshell and external commands

[Chong Yidong <cyd@stupidchicken.com>]

John Wiegley <johnw@newartisans.com> writes:

> Chong Yidong <cyd@stupidchicken.com> writes:
>
>> The following patch fixes this.  However, maybe it is too drastic
>> because it imposes the use of eshell-eval-command on *every* build-in
>> command.
>
> This is how Eshell used to behave.  It's is a bit drastic, because
> eshell-eval-command is much, much slower than plain eval.

I thought so at first, but after trying out, I don't notice any
observable slowdown for using eshell-eval-command for the eshell/*
lisp commands.

> I'm prefer to find a fix which preservers the faster behavior for all cases
> except those which break.

Another simple possibility is to make the code that falls back on
external commands perform eshell/wait on the external process, but
this has obvious drawbacks too.

I don't know how to hack the code to implement the deferment behavior
for "fallback to external programs" commands.  Do you have an idea how
to do it?