Bloginfo hook – can it be more precise?

You can access that, using the additional variable in the Filter Functions.

The Filter bloginfo_url uses the $show parameter (the parameter you use when calling bloginfo) and passes it to apply_filters.

So hooking into bloginfo_url should be no problem, you just have to make a switch inside the function, and it only applies to e.g. url .

This would be the Code for you:

add_filter('bloginfo_url', 'f711_bloginfo_url_filter', 10, 2 );

It tells you where you hook into, the callback function, the priority in which it is applied compared to other filters, and the number of arguments that can be passed to the function. This is your important part, as 1 is the standard value.

In the Callback Function:

function f711_bloginfo_url_filter( $output, $show ) {

    if ( $show == 'url' ) {
        $output = "this";//whatever you want to do with it
    }

    return $output;

}