$this->getResponse()->setHeader('Content-Type', 'text/csv; charset=utf-8')
                            ->setHeader('Content-Disposition', 'attachment; filename="'. $fileName . '"');      

        $contacts = new Contact();
       $fp = fopen('php://output', 'w');        
       foreach ($mongodbCursor as $subscriber) {
           $row = formRow($subscriber);
       fputcsv($fp, $row);
       }      

    ini_set('output_buffering', 0);
    ini_set('zlib.output_compression', 0);
    $this->getResponse()->setHeader('Content-Type', 'text/csv; charset=utf-8')
                            ->setHeader('Content-Disposition', 'attachment; filename="'. $fileName . '"');      

	ob_flush();
	flush();

        $contacts = new Contact();
       $fp = fopen('php://output', 'w');        
       foreach ($mongodbCursor as $subscriber) {
           $row = formRow($subscriber);
       fputcsv($fp, $row);
       }      

		ini_set('output_buffering', 0);
		ini_set('zlib.output_compression', 0);	
		

		ob_start();

		$buffer = str_repeat(" ", 4096);
		$buffer .= "\r\n<span></span>\r\n";

		for ($i=0; $i<5; $i++) {
  			echo $buffer.$i;
  			ob_flush();
  			flush();
  			sleep(1);
		}
		ob_end_flush();		

		ini_set('output_buffering', 0);
		ini_set('zlib.output_compression', 0);	
		

		ob_start();

		for ($i=0; $i<5; $i++) {
  			echo $i;
  			ob_flush();
  			flush();
  			sleep(1);
		}
		ob_end_flush();		

allow_call_time_pass_reference	Off	Off
allow_url_fopen	On	On
allow_url_include	Off	Off
always_populate_raw_post_data	Off	Off
arg_separator.input	&	&
arg_separator.output	&	&
asp_tags	Off	Off
auto_append_file	no value	no value
auto_globals_jit	On	On
auto_prepend_file	no value	no value
browscap	no value	no value
default_charset	UTF-8	no value
default_mimetype	text/html	text/html
define_syslog_variables	Off	Off
disable_classes	no value	no value
disable_functions	no value	no value
display_errors	Off	Off
display_startup_errors	Off	Off
doc_root	no value	no value
docref_ext	no value	no value
docref_root	no value	no value
enable_dl	Off	Off
error_append_string	no value	no value
error_log	no value	no value
error_prepend_string	no value	no value
error_reporting	22527	22527
exit_on_timeout	Off	Off
expose_php	On	On
extension_dir	/usr/lib/php5/20090626	/usr/lib/php5/20090626
file_uploads	On	On
highlight.bg	#FFFFFF	#FFFFFF
highlight.comment	#FF8000	#FF8000
highlight.default	#0000BB	#0000BB
highlight.html	#000000	#000000
highlight.keyword	#007700	#007700
highlight.string	#DD0000	#DD0000
html_errors	Off	Off
ignore_repeated_errors	Off	Off
ignore_repeated_source	Off	Off
ignore_user_abort	Off	Off
implicit_flush	Off	Off
include_path	.:/usr/share/php:/usr/share/pear	.:/usr/share/php:/usr/share/pear
log_errors	On	On
log_errors_max_len	1024	1024
magic_quotes_gpc	Off	Off
magic_quotes_runtime	Off	Off
magic_quotes_sybase	Off	Off
mail.add_x_header	On	On
mail.force_extra_parameters	no value	no value
mail.log	no value	no value
max_execution_time	30	30
max_file_uploads	20	20
max_input_nesting_level	64	64
max_input_time	60	60
max_input_vars	1000	1000
memory_limit	256M	256M
open_basedir	no value	no value
output_buffering	4096	4096
output_handler	no value	no value
post_max_size	64M	64M
precision	14	14
realpath_cache_size	16K	16K
realpath_cache_ttl	120	120
register_argc_argv	Off	Off
register_globals	Off	Off
register_long_arrays	Off	Off
report_memleaks	On	On
report_zend_debug	On	On
request_order	GP	GP
safe_mode	Off	Off
safe_mode_exec_dir	no value	no value
safe_mode_gid	Off	Off
safe_mode_include_dir	no value	no value
sendmail_from	no value	no value
sendmail_path	/usr/sbin/sendmail -t -i 	/usr/sbin/sendmail -t -i 
serialize_precision	100	100
short_open_tag	On	On
SMTP	localhost	localhost
smtp_port	25	25
sql.safe_mode	Off	Off
track_errors	Off	Off
unserialize_callback_func	no value	no value
upload_max_filesize	16M	16M
upload_tmp_dir	no value	no value
user_dir	no value	no value
user_ini.cache_ttl	300	300
user_ini.filename	.user.ini	.user.ini
variables_order	GPCS	GPCS
xmlrpc_error_number	0	0
xmlrpc_errors	Off	Off
y2k_compliance	On	On
zend.enable_gc	On

ini_set('output_buffering', 0);
ini_set('zlib.output_compression', 0);	

	ini_set('output_buffering', 0);
		ini_set('zlib.output_compression', 0);	
		

		ob_start();

		for ($i=0; $i<5; $i++) {
  			echo $i;
  			ob_flush();
  			flush();
  			sleep(1);
		}
		ob_end_flush();		

<?php
ini_set('output_buffering', 0);
ini_set('zlib.output_compression', 0);	
		
ob_start();
for ($i=0; $i<5; $i++) {
	echo $i . '<br/>';;
  	ob_flush();
  	flush();
  	sleep(1);
	}
ob_end_flush();		

<?php
ini_set('output_buffering', false);  
ini_set('zlib.output_compression', false);
for ($i=0; $i<100; $i++) {
    for ($j = 1; $j < 100 ; $j++) print $j."\n";
    print '<br/>';
    flush();
    usleep(1000000*0.1);
}
die();

<?php 
ini_set('output_buffering', 0);
ini_set('zlib.output_compression', 0);	
		
ob_start();
for ($i=0; $i<5; $i++) {
	echo $i . '<br/>';;
  	ob_flush();
  	flush();
  	sleep(1);
	}
ob_end_flush();	

ini_set('output_buffering', 0);
echo ini_get('output_buffering');
exit();
ini_set('zlib.output_compression', 0);	
		
ob_start();
for ($i=0; $i<5; $i++) {
	echo $i . '<br/>';
  	ob_flush();
  	flush();
  	sleep(1);
	}
ob_end_flush();		

ob_start();
for ($i=0; $i<5; $i++) {

	echo $i, '<br/>';
  	ob_flush();
  	flush();
  	sleep(1);
	}
ob_end_flush();		

ob_start();
for ($i=0; $i<5; $i++) {

	echo str_pad('', 4096), $i, '<br/>';
  	ob_flush();
  	flush();
  	sleep(1);
	}
ob_end_flush();		

ob_start();
for ($i=0; $i<5; $i++) {

	echo str_pad('', ini_get('output_buffering')), $i, '<br/>';
  	ob_flush();
  	flush();
  	sleep(1);
	}
ob_end_flush();		

	protected function _initFront()
	/**
	 * hint to the dispatcher that it should not use output buffering to capture output generated by action controllers.
	 *  By default, the dispatcher captures any output and appends it to the response object body content. 
	 */
	{
		$frontController = Zend_Controller_Front::getInstance();
		$frontController->setParam('disableOutputBuffering', 1);		
	}

ob_start();
for ($i=0; $i<5; $i++) {

	echo str_pad('', ini_get('output_buffering')), $i, '<br/>';
  	ob_flush();
  	flush();
  	sleep(1);
	}
ob_end_flush();