php在文件扩展名之前添加文本

I'm trying to add the text "-250x250" before the extension of a linked media file. I am using the following code:

$ext = substr($image, strrpos($image, "."));
$thumb = basename($image, $ext) . "-250x250" . $ext;

The issue I'm having is that this seems to strip away everything BEFORE the file name also, so whilst $image might output as http://www.skizzar.com/template-fox/files/2014/04/fox3.jpg. $thumb only outputs fox3-250x250.jpg

Is there a way to stop my code from stripping away the path leading to the file?

Try this.

$fileName = ' http://www.skizzar.com/template-fox/files/abc.jpg';
$fileArray = pathinfo($fileName);
echo $fileArray['dirname'].'/'.$fileArray['filename'].'-250x250'.'.'.$fileArray['extension'];

Here's a working demo.

Demo

add_image_size( 'my-size', 250, 250, true );
function my_thumb( $size = 'my-size' ){
    global $post;

        $image_id = get_post_thumbnail_id($post->ID);  
        $image_url = wp_get_attachment_image($image_id, $size , false, array( 'alt'   => get_the_title() ,'title' =>  get_the_title()  ));  
        echo $image_url;
    }

then use my_thumb function inside the loop for example :

<img src="<?php echo my_thumb('my-size'); ?>" />

Note: That's will also resize your media files