Fatal error: Class 'ZipArchive' not found in

I have a problem when I install 'Archive_Zip 0.1.1' on the Linux server, but when I try to run the script to create the zip file it gives the fatal error > Fatal error: Class `ZipArchive` not found in ... where I put the code $zip = new ZipArchive; var_dump($zip); $res = $zip->open($filename, ZipArchive::OVERWRITE); if ($res !== TRUE) { echo 'Error: Unable to create zip file'; exit; } if (is_file($src)) { $zip->addFile($src); } else { // echo "<br>" . dirname(__FILE__) . $src;//'/install1'; if (!is_dir($src)) { $zip->close(); @unlink($filename); echo 'Error: File not found'; exit; } recurse_zip($src, $zip, $path_length); } $zip->close(); echo "<br>file name ".$filename; but it doesn't find the class file. Please tell me the solution. What should I do to resolve the problem? I also put the `php.ini` file in the folder where the script is, but it does not work.