I'm writing XLSX2CSV.PHP, a utility which will read an XLSX file and... well, you can guess.
$objReader = new PHPExcel_Reader_Excel2007();
$objPHPExcel = $objReader->load($iFile);
$objWriter = new PHPExcel_Writer_CSV($objPHPExcel);
The input file contains multiple sheets, but the output file shows only the first one. How does this work with a file with multiple sheets?