Syntax error corrected.

//Example:
define('HOSTNAME', '127.0.0.1');
define('USERNAME', 'root');
define('PASSWORD', 'shames11');
define('DATABASE', 'sdk2');

$mySqlCsv = new downloadCSV();
$mySqlCsv->sql = 'SELECT * FROM `lnk_app_customer`';
$mySqlCsv->csvFilename = 'ramesh.csv';

$mySqlCsv->initDownload();


class downloadCSV
{
/**
* @var string SQL whose output is used to generate a CSV file.
*/
public $sql;

/**
* @var string Name to be used to save CSV file on client machine.
*/
public $csvFilename;

/**
* Initialise download.
*
* @return void
*/
public function initDownload()
{
$tmpFilename = $this->executeSql();
$this->flushTempFile($tmpFilename);
}

/**
* Executes SQL and saves output to a temporary file on server end.
*
* @return string Tempory filename where SQL output is saved.
*/
private function executeSql()
{
// Generate temporary file for storing output of shell command on server side.
$tmpFilename = tempnam(sys_get_temp_dir(), 'CSV');

// Shell command.
$shellCommand = 'mysql \\
--host='.escapeshellarg(HOSTNAME).' \\
--user='.escapeshellarg(USERNAME).' \\
--password='.escapeshellarg(PASSWORD).' \\
--database='.escapeshellarg(DATABASE).' \\
--execute='.escapeshellarg($this->sql).' \\
| sed -e \'s/"/""/g ; s/\t/","/g ; s/^/"/g ; s/$/"/g\' > '.escapeshellarg($tmpFilename);

// Execute shell command
shell_exec($shellCommand);

return $tmpFilename;
}

/**
* Flushes sql output in temp file to client end.
*
* @return void
*/
private function flushTempFile($tmpFilename)
{
// Set CSV headers
header("Content-type: text/csv");
header("Content-Disposition: attachment; filename={$this->csvFilename}");
header("Pragma: no-cache");
header("Expires: 0");

// Stream temp file content to browser.
$src = fopen($tmpFilename, 'r');
$dest = fopen('php://output', 'w');
stream_copy_to_stream($src, $dest);
fclose($src);
fclose($dest);
}
}