export CSV file solved

you can use this as plugin. place this in your wp-content/plugin folder. activate the plugin and you’ll get the link in the menu under the settings with Download Report. Hope it helps some one.

<?php

class CSVExport
{
	/**
	 * Constructor
	 */
	public function __construct()
	{
		if(isset($_GET['download_report']))
		{
			$csv = $this->generate_csv();

			header("Pragma: public");
			header("Expires: 0");
			header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
			header("Cache-Control: private", false);
			header("Content-Type: application/octet-stream");
			header("Content-Disposition: attachment; filename=\"report.csv\";" );
			header("Content-Transfer-Encoding: binary");

			echo $csv;
			exit;
		}

		// Add extra menu items for admins
		add_action('admin_menu', array($this, 'admin_menu'));

		// Create end-points
		add_filter('query_vars', array($this, 'query_vars'));
		add_action('parse_request', array($this, 'parse_request'));
	}

	/**
	 * Add extra menu items for admins
	 */
	public function admin_menu()
	{
		add_menu_page('Download Report', 'Download Report', 'manage_options', 'download_report', array($this, 'download_report'));
	}

	/**
	 * Allow for custom query variables
	 */
	public function query_vars($query_vars)
	{
		$query_vars[] = 'download_report';
		return $query_vars;
	}

	/**
	 * Parse the request
	 */
	public function parse_request(&$wp)
	{
		if(array_key_exists('download_report', $wp->query_vars))
		{
			$this->download_report();
			exit;
		}
	}

	/**
	 * Download report
	 */
	public function download_report()
	{
		echo '<div class="wrap">';
		echo '<div id="icon-tools" class="icon32"></div>';
		echo '<h2>Download Report</h2>';
		//$url = site_url();

		echo '<p><a href="site_url()/wp-admin/admin.php?page=download_report&download_report">Export the Subscribers</a>';
	}

	/**
	 * Converting data to CSV
	 */
	public function generate_csv()
	{
		$csv_output = '';
		$table = 'users';

		$result = mysql_query("SHOW COLUMNS FROM ".$table."");

		$i = 0;
		if (mysql_num_rows($result) > 0) {
			while ($row = mysql_fetch_assoc($result)) {
				$csv_output = $csv_output . $row['Field'].",";
				$i++;
			}
		}
		$csv_output .= "\n";

		$values = mysql_query("SELECT * FROM ".$table."");
		while ($rowr = mysql_fetch_row($values)) {
			for ($j=0;$j<$i;$j++) {
				$csv_output .= $rowr[$j].",";
			}
			$csv_output .= "\n";
		}

		return $csv_output;
	}
}

// Instantiate a singleton of this plugin
$csvExport = new CSVExport();