Re: request for review: Doing direct file I/O in Emacs Lisp

[David Kastrup <dak@gnu.org>]

John Wiegley <johnw@gnu.org> writes:

> The following patch implements a file-handle interface for Emacs Lisp,
> which allows files to be directly opened and read/written to without
> an intervening buffer.  Eshell can now use this, for example, to
> greatly speed up output redirection (by several orders of magnitude).
> 
> It is a simple interface that reads in strings, given a length, and
> writes strings by examining their length:
> 
>   (let ((handle (file-handle-open "/tmp/some-file" "w")))
>     (file-handle-write handle "Test data\n")
>     (file-handle-close handle)
> 
>     (setq handle (file-handle-open "/tmp/some-file" "r"))
>     (message (file-handle-read handle 128))
>     (file-handle-close handle))
> 
> Please post comments here, or mail them to johnw@gnu.org.

I had posted a proposal to change start-process instead some time ago
that would have allowed for efficient I/O redirection under eshell.
Have you seen that proposal?  That would be, IMO, a much more Emacsy
solution.  The above looks like being quite ugly low level.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum