Begin incremental search (isearch-forward).
Begin reverse incremental search (isearch-backward).
C-s (isearch-forward) starts a forward incremental
search. It reads characters from the keyboard, and moves point just
past the end of the next occurrence of those characters in the buffer.
For instance, if you type C-s and then F, that puts the cursor after the first ‘F’ that occurs in the buffer after the starting point. If you then type O, the cursor moves to just after the first ‘FO’; the ‘F’ in that ‘FO’ might not be the first ‘F’ previously found. After another O, the cursor moves to just after the first ‘FOO’.
At each step, Emacs highlights the current match—the buffer
text that matches the search string—using the isearch face
(see Text Faces). See Tailoring Search to Your Needs, for various options
that customize this highlighting. The current search string is also
displayed in the echo area.
If you make a mistake typing the search string, type DEL
(isearch-delete-char). Each DEL cancels the last input
item entered during the search. Emacs records a new input item
whenever you type a command that changes the search string, the
position of point, the success or failure of the search, the direction
of the search, the position of the other end of the current search
result, or the “wrappedness” of the search. See Errors in Incremental Search, for more about dealing with unsuccessful search.
When you are satisfied with the place you have reached, type
RET (isearch-exit). This stops searching, leaving the
cursor where the search brought it. Also, any command not specially
meaningful in searches stops the searching and is then executed.
Thus, typing C-a exits the search and then moves to the
beginning of the line; typing one of the arrow keys exits the search
and performs the respective movement command; etc. RET is
necessary only if the next command you want to type is a printing
character, DEL, RET, or another character that is special
within searches (C-q, C-w, C-r, C-s,
C-y, M-y, M-r, M-c, M-e, and some others
described below). You can fine-tune the commands that exit the
search; see Not Exiting Incremental Search.
As a special exception, entering RET when the search string is empty launches nonincremental search (see Nonincremental Search). (This can be customized; see Tailoring Search to Your Needs.)
To abandon the search and return to the place where you started,
type ESC ESC ESC (isearch-cancel) or
C-g C-g (isearch-abort).
When you exit the incremental search, it adds the original value of point to the mark ring, without activating the mark; you can thus use C-u C-SPC or C-x C-x to return to where you were before beginning the search. See The Mark Ring. (Emacs only does this if the mark was not already active; if the mark was active when you started the search, both C-u C-SPC and C-x C-x will go to the mark.)
To search backwards, use C-r (isearch-backward) instead
of C-s to start the search. A backward search finds matches
that end before the starting point, just as a forward search finds
matches that begin after it.