PHP buffer output. Put contents in a variable

We all know that PHP is default sending all output to the standard output buffer( the browser in many cases if I can say like that.) That depends off course about your server configurations but that’s how it gets setup into the standard. There is a buffer size set in php.ini; when the output buffer is full, it is automatically flushed and sent to the browser.

Many times in our programming life we wanted to change this standard way and send the contents to a variable instead of printing to the browser .That is very useful if you want to write in a file as a log or if you just need it in a var for future processing or…whatever.

There is a nice workaround here. The solution comes from using the PHP buffering functions.

Let’s have this example:

<?

echo "here is a string";
?>

This would normally print the string under echo. If we want that value stored in a variable we do something like this:

<?
   ob_start();
  echo "here is a string";
  $string=ob_get_contents();
  ob_end_clean();

?>

Now, into the $string variable we would have what the previous echo example displayed.

The idea is simple: The ob_Start() function redirects the output to a buffer. After that all the print, echo are sent to that buffer.

ob_get_contents() returns the content of the buffer and ob_end_clean() kill the buffer, redirecting the output to where it previously was: the standard output.

One useful example of those functions is for example the Wordpress , looked as a CMS. If you ever worked with it, you know about the template function the_content(); That is just echo-ing the content of an article. If you want that in a variable is just simple to use the output buffering functions:

<?
ob_start();
the_content();
$content=ob_get_contents();
ob_end_clean();
?>

Also , it’s very useful to use this functions when you work with template engines such as Smarty or TemplateIT. A tutorial for that will soon come ! Stay posted

Enjoy

One Comment for “PHP buffer output. Put contents in a variable”

1. Joe Says:
   August 14th, 2008 at 10:27 pm

   Thankyou very much for this article! I was racking my brains trying to figure out how to do this… Now I can get the output from my CMS system and do what I want with it!

Post a comment

Name (required)

Mail (will not be published) (required)

Website

Anti-spam text: (Required)*
To prove you're a person (not a spam script), type the security text shown in the picture. Click here to regenerate some new text.