title: How to delete a specific subarray from an array that has been serialized?
body: <p>I'm working in new Wordpress plugin, but I need help with one regular expression.</p>
  
  <p>I have this</p>
  
  <pre><code>a:6:{s:5:"width";s:4:"3000";s:6:"height";s:4:"2100";s:14:"hwstring_small";s:23:"height=\'89\' width=\'128\'";s:4:"file";s:25:"2012/02/sopa_nicearma.jpg";s:5:"sizes";a:3:{s:9:"thumbnail";a:3:{s:4:"file";s:23:"sopa_nicearma-15x10.jpg";s:5:"width";s:2:"15";s:6:"height";s:2:"10";}s:6:"medium";a:3:{s:4:"file";s:25:"sopa_nicearma-300x210.jpg";s:5:"width";s:3:"300";s:6:"height";s:3:"210";}s:5:"large";a:3:{s:4:"file";s:25:"sopa_nicearma-700x490.jpg";s:5:"width";s:3:"700";s:6:"height";s:3:"490";}
  }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:"";}}
  </code></pre>
  
  <p>but I want to delete the thumbnail subarray:</p>
  
  <pre><code>s:9:"thumbnail";a:3:{s:4:"file";s:23:"sopa_nicearma-15x10.jpg";s:5:"width";s:2:"15";s:6:"height";s:2:"10";}
  </code></pre>
  
  <p>to produce this in the end:</p>
  
  <pre><code>'a:6:{s:5:"width";s:4:"3000";s:6:"height";s:4:"2100";s:14:"hwstring_small";s:23:"height=\'89\' width=\'128\'";s:4:"file";s:25:"2012/02/sopa_nicearma.jpg";s:5:"sizes";a:3:{s:6:"medium";a:3:{s:4:"file";s:25:"sopa_nicearma-300x210.jpg";s:5:"width";s:3:"300";s:6:"height";s:3:"210";}s:5:"large";a:3:{s:4:"file";s:25:"sopa_nicearma-700x490.jpg";s:5:"width";s:3:"700";s:6:"height";s:3:"490";}
  }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:"";}}
  </code></pre>
  
  <p>pseudo code:</p>
  
  <pre><code>chain { chain "name image " chain}
  </code></pre>
  
  <p>I have this idea:</p>
  
  <pre><code>$var = preg_replace("(.+)\{(.+)(sopa_nicearma\-15x10\.jpg)(.+)\}/", "", $var);
  </code></pre>
  
  <p>but this doesn't work as desired, I get this:</p>
  
  <pre><code>}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:"";}}
  </code></pre>