bug#18209: Add ability to truncate long grep matches

[Stefan Monnier <monnier@iro.umontreal.ca>]

>>>>> "Reuben" == Reuben Thomas <rrt@sc3d.org> writes:

> In some files (e.g. in text files using newline as a paragraph delimiter)
> one can get matches in very long lines that can occupy several screenfuls.
> These are not always straightforward to avoid. There's no way to tell (GNU)
> grep to truncate its output; perhaps Emacs could help here, by being able
> to specify a maximum length of match to show? For bonus points, show part
> of the line that matches, with ellipses, rather than just truncating the
> line; but even without that it would be useful, provided that the
> truncation is clearly marked: the annoyance and slowness of navigating
> *grep* buffers full of enormous matches which are almost always not what
> one is looking for would be great!

FWIW, I have the following in my ~/.emacs:

   (defun sm-compilation-mode-hook ()
     (setq truncate-lines t))
   (add-hook 'compilation-mode-hook #'sm-compilation-mode-hook)


-- Stefan