Question: Let's say I have a WordPress installation, with a page named "About". If I go to `http://example.com/about`, I know from WordPress' template hierarchy page that I'm looking at the theme file `page.php`. 

I'm wondering if there's a way to display that fact (for theme debugging) on the page somewhere? Like what function (or code) would I call to display the current PHP page that is being used to render the page I'm looking at. 

I could do something with `$_SERVER['PHP_SELF']`, but I'm looking for a way where I don't have to edit every PHP file. Like something that spits out the list of files it's using as the pages are called.

Answer: 
It can be printed in the Html source code like this: 

```
add_action( 'wp_head', 'so_9405896_show_template', 999 );

function so_9405896_show_template() {
    global $template;
    echo '
    <!--

    TEMPLATE = ' . basename($template) .'

    -->
    ';
}

```

Or for easier visualization, directly in the content with this:

```
add_filter( 'the_content', 'so_9405896_the_content_filter', 20, 1 );

function so_9405896_the_content_filter( $content ) 
{
    if( is_admin() || !current_user_can( 'administrator' ) ) 
        return $content;

    global $template;
    $the_templ =  '<strong style="background-color: #CCC;padding:10px">TEMPLATE = ' 
                  . basename( $template ) . '</strong><br />';  

    $content = sprintf( $the_templ . '%s', $content );

    return $content;
}

```

Which results in:

> 
> ![output template name to content](https://i.stack.imgur.com/yXbUP.png)
> 
> 
>
As far as I've seen there's no built in option to enable such logging, only for errors.

I'm not sure what editor you use, but most common text editors allow you to do a find replace across an entire folder.

I'd suggest doing a temporary replace on includes and require's to add an echo of the PHP\_SELF. Just make sure to add a comment or something before the echo so that you can easily replace them with nothing when you're done.