Take the 2-minute tour ×  Every once in a while I want to
replace all instances of values like:     i.e. do a regular
expression replace of all things inside angle brackets with its
lowercase equivalent.  Anyone got a nice snippet of Lisp that
does this? It's safe to assume that we're dealing with just
ASCII values. Bonus points for anything that is generic enough
to take a full regular expression, and doesn't just handle the
angle brackets example. Even more bonus points to an answer
which just uses M-x query-replace-regexp.    share|improve this
question  1 Answer 1  up vote 50 down vote accepted  Try M-x
query-replace-regexp with "<\([^>]+\)>" as the search string and
"<\,(downcase \1)>" as the replacement.  This should work for
Emacs 22 and later, see this Steve Yegge blog post for more
details on how Lisp expressions can be used in the replacement
string.  For earlier versions of Emacs you could try something
like this:  (defun tags-to-lower-case ()     (goto-char (point-
min))     (while (re-search-forwa