capturing cmd-s and ctrl-s in browser

The homebrew backend for my personal blog is an ugly, aged, idiosyncratic mix of Perl and PHP

(to paraphrase yoda, "When 6580 days old you reach, look as good, you will not, hmm?") but I have total control and the editor I use has some features I like - 

• convenience forms for "quick hits" vs longer pieces (the former auto translates linebreaks into <br> tags) along with a simple tab interface with back button support
• scaling images taking care of iPhone rotation issues - but keeping the fullsize images around as well (wish I had done that years earlier, the blog really is my best archive of cool stuff) 
• Relatedly, it's not really well integrated into the editor, but my new CSS-only thumbnail gallery system is still pretty keen.
• a simple but slick way of saving me from typing up <a href> tags - I prefer to be in raw HTML mode rather than markdown, but still, the idea of "linkify this" using the highlighted text as the URL if it starts with "http" or as the clickable text if not works super well and doesn't require any other UI bits.

and now:

• support for cmd-s to save

The code for that is a bit temperamental to setup: some similar variants don't do the job but this worked for me:

jQuery(document).ready(function(){

    setupCmdSIntercept('#maintext_titleplus','#submit_titleplus');

    setupCmdSIntercept('#maintext_normal','#submit_normal');

    setupCmdSIntercept('#maintext_raw','#submit_raw');

});

function setupCmdSIntercept(sel,clicksel) {

    jQuery(sel).keydown(function(event) {

            // If Control or Command key is pressed and the S key is pressed

            // run save function. 83 is the key code for S.

            if((event.ctrlKey || event.metaKey) && event.which == 83) {

                // Save Function

                jQuery(clicksel).click();

                event.preventDefault();

                return false;

            };

        }

    );

}

Code modified from Pascal Bajorat's sample...

(oh the embarrassment - not only is it jQuery, but I can't even use the $ short cut because of the way it's embedded in even older Perl)

Of course the more general "edit any file on any of my subsites" edit system I refreshed last spring is going great (and probably why I longed to put the cmd-S support in the blog system as well.) The UI is idiosyncratic, but it's removed like 85% of my need to use an FTP program or ssh to do work (file upload, file deletion, and making directories are where it goes above and beyond the normal bounds of a browser based text editor)

FOLLOWUP (2019.02.01):
Here is a version that works without jQuery. Tested on modern chrome, safari, firefox, edge, and even old ie.

document.onkeydown=function(e){
    if(e.key === "s" && (e.metaKey || e.ctrlKey)) {
        document.getElementById("myForm").submit();
        return false;   
    }
}

Obviously you might want a more specific element than "document" (which I guess might need stopping propagation) but you get the idea.