Looking for a replace-in-string function in elisp

s.el string manipulation library has s-replace function:

(s-replace "." "bar" "foo.buzz") ;; => "foobarbuzz"

I recommend installing s.el from Emacs package manager, if you work with strings in your Elisp.

Try this:

(defun replace-in-string (what with in)
  (replace-regexp-in-string (regexp-quote what) with in nil 'literal))