Emacs How to redefine Shift-R for expected use

I've checked my elisp files to make su开发者_如何学Cre that I do not have any bindings that contain Shift+R (and I have not found any). I expect SHIFT+R to print an uppercase character, but instead I get R R undefined inside of the Emacs command line. This is only in C/C++ major modes.

Any suggestions?

Update: Describing the key shows that it is undefined. How would I define it for the normal, expected use (capitalizing the letter R)?

I assume by the 'expected use' you mean to insert the 'R' character. For this, you'd need to bind the key to 'self-insert-command':

M-x global-set-key R self-insert-command

Or, in your .emacs or .emacs.d/init.el file:

(global-set-key "R" 'self-insert-command)

Of course, this should be the default....

I'm getting a little deja-vu here and if memory serves the behavior I encountered some years ago was that (on Windows) certain accessibility settings unset or changed the keycode for the right shift key. Sorry I cannot be more specific but maybe this will stimulate someone else to come up with the real answer. A test you can make: does the behavior work with both shift keys or just one? If the answer is just one shows the bad behavior, is that bad behavior shown with all keys?

Try C-h k (describe-key), then press Shift-R. describe-key will then tell you what is bound to that key. At least that will give you a hint as to whether or not there is an active binding. If there's a binding, perhaps it will give you a hint of something else to search for in your startup files.

You sound like you're having the same problem I had. Typing Re... in any html buffer would try to execute an R- command, when every single R-* command was undefined. Turned out that I had a typo in my .emacs file. I had a global-key-map set to (kbd "REF") instead of (kbd "RET"), and fixing it made the problem immediately vanish. So I'd recommend checking for anything similar in your .emacs file.