Make CSI u mode work in emacs

.emacs

(unless (display-graphic-p)
  (add-hook 'after-make-frame-functions
  '(lambda 
     ;; Take advantage of iterm2's CSI u support (https://gitlab.com/gnachman/iterm2/-/issues/8382).
     (xterm--init-modify-other-keys)

     ;; Courtesy https://emacs.stackexchange.com/a/13957, modified per
     ;; https://gitlab.com/gnachman/iterm2/-/issues/8382#note_365264207
     (defun character-apply-modifiers (c &rest modifiers)
       "Apply modifiers to the character C.
MODIFIERS must be a list of symbols amongst (meta control shift).
Return an event vector."
       (if (memq 'control modifiers) (setq c (if (and (<= ?a c) (<= c ?z))
                                                 (logand c ?\x1f)
                                               (logior (lsh 1 26) c))))
       (if (memq 'meta modifiers) (setq c (logior (lsh 1 27) c)))
       (if (memq 'shift modifiers) (setq c (logior (lsh 1 25) c)))
       (vector c))
     (when (and (boundp 'xterm-extra-capabilities) (boundp 'xterm-function-map))
       (let ((c 32))
         (while (<= c 126)
           (mapc (lambda (x)
                   (define-key xterm-function-map (format (car x) c)
                     (apply 'character-apply-modifiers c (cdr x))))
                 '(;; with ?.VT100.formatOtherKeys: 0
                   ("\e\[27;3;%d~" meta)
                   ("\e\[27;5;%d~" control)
                   ("\e\[27;6;%d~" control shift)
                   ("\e\[27;7;%d~" control meta)
                   ("\e\[27;8;%d~" control meta shift)
                   ;; with ?.VT100.formatOtherKeys: 1
                   ("\e\[%d;3u" meta)
                   ("\e\[%d;5u" control)
                   ("\e\[%d;6u" control shift)
                   ("\e\[%d;7u" control meta)
                   ("\e\[%d;8u" control meta shift)))
           (setq c (1+ c)))))
     )))