Remove “%” from strings in serialized arrays in wp_postmeta

Question

In the course of converting a blog from Blogger to WP and running a script to grab hot-linked images for hosting, I ended up with some funky images names like

act%252Bapandas-210x290.png

These image names prevent the image from displaying on a webpage, due the url encoding ending up in the file name itself (don't ask!). I renamed them on the file server, no prob, but the names are also in the attachment metadata for each post.

How can I remove the "%" from all the image references in the wp_postmeta table? *Most of them occur in serialized arrays in meta_values for the meta_keys of _wp_attachment_metadata*. I've had no luck finding a plugin, and am unsure how to institute a pure SQL/PHP solution.

Here is an example of a serialized array entry (further gummed up by the Smush.it plugin, ugh):

a:7:{s:5:"width";s:3:"210";s:6:"height";s:3:"339";s:14:"hwstring_small";s:22:"height='96' width='59'";s:4:"file";s:27:"2011/02/act%252Bapandas.png";s:5:"sizes";a:6:{s:9:"thumbnail";a:4:{s:4:"file";s:27:"act%252Bapandas-210x290.png";s:5:"width";s:3:"210";s:6:"height";s:3:"290";s:10:"wp_smushit";s:271:"Smush.it error: Could not get the image while processing http://new.xxxxx.com/wp-content/uploads/2011/02/act%252Bapandas-210x290.png (/home/xxxxxxxxx/new.xxxxx.com/wp-content/uploads/2011/02/act%252Bapandas-210x290.png)";}s:14:"soft-thumbnail";a:4:{s:4:"file";s:27:"act%252Bapandas-179x290.png";s:5:"width";s:3:"179";s:6:"height";s:3:"290";s:10:"wp_smushit";s:271:"Smush.it error: Could not get the image while processing http://new.xxxxx.com/wp-content/uploads/2011/02/act%252Bapandas-179x290.png (/home/xxxxxxxxx/new.xxxxx.com/wp-content/uploads/2011/02/act%252Bapandas-179x290.png)";}s:14:"mini-thumbnail";a:4:{s:4:"file";s:25:"act%252Bapandas-60x60.png";s:5:"width";s:2:"60";s:6:"height";s:2:"60";s:10:"wp_smushit";s:267:"Smush.it error: Could not get the image while processing http://new.xxxxx.com/wp-content/uploads/2011/02/act%252Bapandas-60x60.png (/home/xxxxxxxxx/new.xxxxx.com/wp-content/uploads/2011/02/act%252Bapandas-60x60.png)";}s:5:"slide";a:4:{s:4:"file";s:27:"act%252Bapandas-210x290.png";s:5:"width";s:3:"210";s:6:"height";s:3:"290";s:10:"wp_smushit";s:271:"Smush.it error: Could not get the image while processing http://new.xxxxx.com/wp-content/uploads/2011/02/act%252Bapandas-210x290.png (/home/xxxxxxxxx/new.xxxxx.com/wp-content/uploads/2011/02/act%252Bapandas-210x290.png)";}s:10:"soft-slide";a:4:{s:4:"file";s:27:"act%252Bapandas-179x290.png";s:5:"width";s:3:"179";s:6:"height";s:3:"290";s:10:"wp_smushit";s:271:"Smush.it error: Could not get the image while processing http://new.xxxxx.com/wp-content/uploads/2011/02/act%252Bapandas-179x290.png (/home/xxxxxxxxx/new.xxxxx.com/wp-content/uploads/2011/02/act%252Bapandas-179x290.png)";}s:10:"mini-slide";a:4:{s:4:"file";s:27:"act%252Bapandas-210x145.png";s:5:"width";s:3:"210";s:6:"height";s:3:"145";s:10:"wp_smushit";s:271:"Smush.it error: Could not get the image while processing http://new.xxxxx.com/wp-content/uploads/2011/02/act%252Bapandas-210x145.png (/home/xxxxxxxxx/new.xxxxx.com/wp-content/uploads/2011/02/act%252Bapandas-210x145.png)";}}s:10:"image_meta";a:10:{s:8:"aperture";s:1:"0";s:6:"credit";s:0:"";s:6:"camera";s:0:"";s:7:"caption";s:0:"";s:17:"created_timestamp";s:1:"0";s:9:"copyright";s:0:"";s:12:"focal_length";s:1:"0";s:3:"iso";s:1:"0";s:13:"shutter_speed";s:1:"0";s:5:"title";s:0:"";}s:10:"wp_smushit";s:255:"Smush.it error: Could not get the image while processing http://new.xxxxx.com/wp-content/uploads/2011/02/act%252Bapandas.png (/home/xxxxxxxxx/new.xxxxx.com/wp-content/uploads/2011/02/act%252Bapandas.png)";}

The issue is changing or removing the "%" character AND updating the array so it reports the correct number of characters (ie the s:13 would indicate yoursite.com is 13 char[]) I'm also open to using a php solution! Whatever can help me fix this mess.

FINAL SOLUTION

See my answer below.

Answer 1

General idea would be to loop through all attachments to retrieve, modify and write back their meta.

Something like this (test thoroughly before using on anything important):

$posts = get_posts(array(
    'post_type' => 'attachment',
    'numberposts' => -1,
));

foreach( $posts as $post ) {

    // retrieve data, unserialized automatically
    $meta = get_post_meta($post->ID,'_wp_attachment_metadata', true);

    // do stuff with $meta array

    // write it back
    update_post_meta($post->ID, '_wp_attachment_metadata', $meta);
}

Answer 2

  $posts = get_posts(array(
                'post_type' => 'attachment',
                'numberposts' => -1,
            ));

    // Recursive String Replace - recursive_array_replace(mixed, mixed, array);
    function recursive_array_replace($find, $replace, $array){
    if (!is_array($array)) {
    return str_replace($find, $replace, $array);
    }
    $newArray = array();
    foreach ($array as $key => $value) {
    $newArray[$key] = recursive_array_replace($find, $replace, $value);
    }
    return $newArray;
    }

    foreach ($posts as $post) {
        // retrieve data, unserialized automatically
        $meta = get_post_meta($post->ID, '_wp_attachment_metadata', true);
        // see if file name has "%" in it
        if (strpos($meta[file], "%")) {
        //recursively scrub "%"
        $meta = recursive_array_replace('%', '', $meta);
        }

        // write it back
        update_post_meta($post->ID, '_wp_attachment_metadata', $meta);
    }