PHP Array key search for matching string.

gistfile1.php

<?php

/**
 * Search through an array for a matching key.
 *
 * Examples:
 * <code>
 *      $array = array(
 *          "database.name" => "my_db_name",
 *          "database.host" => "myhost.com",
 *          "database.user" => "admin",
 *          "database.pass" => "a secret."
 *      );
 *
 *      $search = array_contains_key($array, "database");
 *      var_dump($search);
 *
 *      Result:
 *      array (size=4)
 *          'database.name' => string 'my_db_name' (length=10)
 *          'database.host' => string 'myhost.com' (length=10)
 *          'database.user' => string 'admin' (length=5)
 *          'database.pass' => string 'a secret.' (length=9)
 * </code>
 *
 * @param array  $input_array
 * @param string $search_value
 * @param bool   $case_sensitive
 *
 * @return array
 */
function array_contains_key( array $input_array, $search_value, $case_sensitive = false)
{
    if($case_sensitive)
        $preg_match = '/'.$search_value.'/';
    else
        $preg_match = '/'.$search_value.'/i';

    $return_array = array();
    $keys = array_keys( $input_array );
    foreach ( $keys as $k ) {
        if ( preg_match($preg_match, $k) )
            $return_array[$k] = $input_array[$k];
    }
    return $return_array;
}

?>