[For emacs-devel: 

In gnu.emacs.help there is a discussion about some little eshell,
eshell/ls bug.  Processes in a pipeline get a TTY for IO (via
`start-process').  Quite some programs behave different whether they
have a TTY or not. 

The other thing is that eshell/ls does not output one file per line
when in a pipeline (as the usual GNU ls does).]

On Wed, 13 Aug 2008 13:21:00 +0200 Thierry Volpiatto wrote:

> As Lennart said you call ls with -1 arg or you can always call ls with
> this arg setting it like that:
>
> ,----
> | (setq eshell-ls-initial-args '(-1)) 
> `----
>
> now when you call for example "ls | wc -l" , you will have the
> good number of lines.
>
> It would be cool to have a function to call in some hook to call ls -1
> only if there is a "|" after ls, this function do that but i need a hook
> to call it:
>
> ,----
> | (defun eshell-set-ls ()
> |   (let ((com-line
> |          (eshell-parse-arguments (re-search-backward "ls") (line-end-position))))
> |     (if (equal (nth 1 com-line) '(eshell-operator "|"))
> |         (setq eshell-ls-initial-args '(-1))
> |         (setq eshell-ls-initial-args nil))))
> `----

Try the attached patch.  It

 * Starts subprocesses in a (eshell) pipeline using a pipe and not a TTY
   (this should also give some performance boost).

 * Appends "-1" to eshell/ls if ls is called in a pipeline.

At the time it's feature freeze for Emacs so it will probably take some
time to make it in there.  Cc: anyways, maybe some old timer can approve
the two lines.


David