How to Write grep in Emacs Lisp (tutorial)

[Xah Lee]

On Feb 8, 9:32 am, Icarus Sparry <i.sparry... at gmail.com> wrote:
> On Tue, 08 Feb 2011 13:51:54 +0100, Petter Gustad wrote:
> > Xah Lee <xah... at gmail.com> writes:
>
> >> problem with find xargs is that they spawn grep for each file, which
> >> becomes too slow to be usable.
>
> > find . -maxdepth 2 -name '*.html -print0 | xargs -0 grep whatever
>
> > will call grep with a list of filenames given by find, only a single
> > grep process will run.
>
> > //Petter
>
> This is getting off-topic for the listed newsgroups and into
> comp.unix.shell (although the question was originally posed in a MS
> windows context).
>
> The 'modern' way to do this is
> find . -maxdepth 2 -name '*.html' -exec grep whatever {} +
>
> The key thing which makes this 'modern' is the '+' at the end of the
> command, rather than '\;'. This causes find to execute the grep once per
> group of files, rather than once per file.

Nice. When was the + introduced?

 Xah