start . me .
Directory path . web .

HTML Document File : new-tab.html

<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<title>new-tab option</title>
</head>
<body>

<div>
<label><input type="checkbox" oninput="set_new_tab(this.checked)">new tab</label>
</div>

<a href="https://microsoft.com">microsoft.com</a>

<a href="https://google.com" target="_blank">google.com</a>

<a href="https://ibm.com" target="_self">ibm.com</a>

<script>
function set_new_tab(new_tab){
    //alert(new_tab)
    for(var link of document.querySelectorAll('a:not([target]), a[data-target_set]')){
        link.target=new_tab?'_blank':''
        link.dataset.target_set=true
    }
        
}
</script>

<script src="/web/show-source.js"></script>

</body>
</html>