Re: linebreak after 78characters

[rgb]

> >> I just wondered where I can set permanently the option, that emacs breaks 
> >> eac
> >> line after 78characters. I can`t find it on the menu.
> >
> > If you want auto-fill-mode to be on when in a particular mode you
> > need to add this to the mode's hook.
> >
> > (add-hook 'foo-mode-hook  'auto-fill-mode)
> >
> > If you want it on for every buffer regardless of mode you could try
> > putting it on the after-change-major-mode-hook but that won't cover
> > fundamental mode.
> >
> > Personally I use (global-set-key [f12] 'auto-fill-mode) so I can
> > toggle it on and off with a single key no matter what mode I'm in.
>
> I donot know how it is done, but in auctex (latex) mode the following
> lines at the end of a file set the column width to 90 columns.
>
> %%% Local Variables
> %%% mode: latex
> %%% fill-column: 90
> %%% End:

That would be permanent only for the file you've put that in.

It seems different people have different views on what the OP is
asking.
1) turning auto-fill-mode on
2) setting the column at which wrapping occurs

To set the fill-column globally (for all files that don't have
Local Variables (described above) or a mode-hook etc. use
M-x customize-option <ret> fill-column <ret>