How to make everything in a textfield be capital letters / uppercase?

Question

I want to make everything I write in a textfield to be capital letters. As I write, not after losing focus.

How do I do this using jQuery?

Answer 1

To build on @Gazler's answer, an enhanced solution that better handles modifier keys ( assuming that you have a placeholder of mixed case and cannot set text-transform: uppercase; ):

$('.search-input input[type=text]').keyup(function() {
    var v = $(this).val();
    var u = v.toUpperCase();
    if( v != u ) $(this).val( u );
})