Show block on specific pages URL attribute I am looking to show a certain block on a page only when a certain url attribute (using alias)

For example:

I have pages /foo/*

I want to show the The block when viewing /foo/*?showblock

Where * is a wildcard.

I have tried typing this into my "Show block on specific pages" portion of the block settings, but the block never shows. Any ideas? Thanks!
You can use PHP visibility on your block settings to achieve this. Drupal block's visibility does not provide the functionality to display blocks based on parameters after ? (aside from ?q= of course) so you need to do this with custom PHP. 

Set your block visibility to use PHP as the markup and place this in your code:

&lt;?php 
// Show the block if the 'showblock' attribute is available
if (!empty($_GET['showblock'])) {
  return TRUE;
}
return FALSE;

?&gt;


Happy Programming!