This was used on the PRG ( Green Crop Information (Dyson Farming)) website to alter links shown in an iFrame for content protection.
<script>
jQuery( document ).ready(function() {
jQuery('.entry-content a').each(function() {
var original = jQuery(this).text();
var link = jQuery(this).text(original).attr("href");
if (link.indexOf(".pdf") >= 0){
var newLink = jQuery(this).text(original).attr("href");
newLink = newLink.replace("/uploads/","/uploads/_pda/");
newLink = newLink.replace("/_pda/_pda/","/_pda/");
jQuery(this).text(original).attr("href",newLink);
}
});
});
</script>