20.1.8 Scrolling During Incremental Search
Vertical scrolling during incremental search can be enabled by
setting the customizable variable isearch-allow-scroll
to a
non-nil
value.
You can then use the vertical scroll-bar or certain keyboard
commands such as <PRIOR> (scroll-down
),
<NEXT> (scroll-up
) and C-l (recenter
)
within the search, thus letting you see more of the text near the
current match. You must run these commands via their key sequences to
stay in the search—typing M-x command-name will always
terminate a search.
You can give prefix arguments to these commands in the usual way.
The current match cannot be scrolled out of the window—this is
intentional.
Several other commands, such as C-x 2
(split-window-vertically
) and C-x ^
(enlarge-window
) which don't scroll the window, are
nevertheless made available under this rubric, since they are likewise
handy during a search.
You can make other commands usable within an incremental search by
giving the command a non-nil
isearch-scroll
property.
For example, to make C-h l usable within an incremental search
in all future Emacs sessions, use C-h c to find what command it
runs. (You type C-h c C-h l; it says view-lossage
.) Then
you can put the following line in your .emacs file (see Init File):
(put 'view-lossage 'isearch-scroll t)
This works for commands that don't permanently change point, the
buffer contents, the match data, the current buffer, or the selected
window and frame. The command must not delete the current window and
must not itself attempt an incremental search.