code: public function addFile($strFile, $strName=null)
  	{
  		if (!file_exists($this->strRootDir . '/' . $strFile))
  		{
  			throw new \Exception("File $strFile does not exist");
  		}
  
  		// Remove leading slashes (see #4502)
  		if (strncmp($strName, '/', 1) === 0)
  		{
  			$strName = substr($strName, 1);
  		}
  
  		$this->addString(file_get_contents($this->strRootDir . '/' . $strFile), $strName ?: $strFile, filemtime($this->strRootDir . '/' . $strFile));
  	}
docs: Add a file to the archive
  
  @param string $strFile The file path
  @param string $strName An optional file name
  
  @throws \Exception If $strFile does not exist