Is there a way to create a shortcut to copy the file size in bytes?

This will put the byte size of each selected file into the clipboard, one file per line:

function OnClick(clickData) {
    var cmd = clickData.func.command;
    var tab = clickData.func.sourcetab;
    cmd.deselect = false;

    var tmp = '';
    for (var e = new Enumerator(tab.selected_files); !e.atEnd(); e.moveNext()) {
        var item = e.item();
        var sizeStr = item.size;
        if (tmp != '')
        	tmp += '\r\n';
        tmp += sizeStr;
    }
    if (tmp != '')
    	DOpus.SetClip(tmp);
}
Button as XML <?xml version="1.0"?> Copy Byte Sizes #script @script JScript function OnClick(clickData) { var cmd = clickData.func.command; var tab = clickData.func.sourcetab; cmd.deselect = false; var tmp = ''; for (var e = new Enumerator(tab.selected_files); !e.atEnd(); e.moveNext()) { var item = e.item(); var sizeStr = item.size; if (tmp != '') tmp += '\r\n'; tmp += sizeStr; } if (tmp != '') DOpus.SetClip(tmp); }