title: PHP: Copy() producing empty files
body: <p>I am using the following function to <code>copy()</code> a file, The files are typically 1-50KB in size and a file of the correct name is created but it is completely empty.</p>
  
  <pre><code>public function backup() {
      $backup = $this-&gt;_root.'/cfg_'.date('d_m_y').'.backup';
      if (!copy($this-&gt;_file, $backup))
          return false;
      return $backup;
  }
  </code></pre>
  
  <p>I know for certain that <code>$this-&gt;_file</code> correctly points to the file I am attempting to copy. <code>$this-&gt;_file</code> is created by another method of the same class and I perform a <code>chmod()</code> with an octal value of 0755 on it as shown in the following function:</p>
  
  <pre><code>private function createFile($filename) {
      if (!($this-&gt;_pointer = @fopen($filename, 'cb')))
          return false;
      fclose($this-&gt;_pointer);
      chmod($filename, 0755);
      return true;
  }
  </code></pre>
  
  <p>Does anyone know what could be causing this behaviour?</p>