A symbol search is much like an ordinary search, except that
the boundaries of the search must match the boundaries of a symbol.
The meaning of symbol in this context depends on the major mode,
and usually refers to a source code token, such as a Lisp symbol in
Emacs Lisp mode. For instance, if you perform an incremental symbol
search for the Lisp symbol
forward-word, it would not match
isearch-forward-word. This feature is thus mainly useful for
searching source code.
If incremental search is active, toggle symbol search mode
isearch-toggle-symbol); otherwise, begin an incremental
forward symbol search (
Start a symbol incremental search forward with the symbol found near point added to the search string initially.
Search forward for symbol, nonincrementally.
Search backward for symbol, nonincrementally.
To begin a forward incremental symbol search, type M-s _ (or
M-s . if the symbol to search is near point). If incremental
search is not already active, M-s _ runs the command
isearch-forward-symbol and M-s . runs the command
isearch-forward-symbol-at-point. With a numeric prefix
argument of n, M-s . will search for the nthe next
occurrence of the symbol at point; negative values of n search
backwards. If incremental search is already active, M-s _
switches to a symbol search, preserving the direction of the search
and the current search string; you can disable symbol search by typing
M-s _ again. In incremental symbol search, while you are typing
the search string, only the beginning of the search string is required
to match the beginning of a symbol, and ‘Pending’ appears in the
search prompt until you use a search repeating key like C-s.
To begin a nonincremental symbol search, type M-s _ RET for a forward search, or M-s _ C-r RET or a backward search. In nonincremental symbol searches, the beginning and end of the search string are required to match the beginning and end of a symbol, respectively.
The symbol search commands don’t perform character folding, and toggling lax whitespace matching (see lax space matching) has no effect on them.